JP2008003240A - Fixing device, image forming apparatus and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fixing device, an image forming apparatus and an image forming method for efficiently forming an image with low fixing energy. <P>SOLUTION: The fixing device includes a light source and a heat source, has a transparent optical path for the light from the light source, and a toner for forming a toner image is controlled to maintain a color developing state or non-color developing state by imparting color developing information by light. The image forming apparatus includes the above fixing device. The image forming method includes a toner image forming step, a color developing information imparting step of imparting the color developing information by light to the toner image, a transfer step, and a fixing step of fixing the toner image transferred to a recording medium surface. The toner for forming the toner image is controlled to maintain a color developing state or non-color developing state by imparting the color developing information by light. Fixing in the fixing step accompanies with simultaneous processes of color development to develop a color in the toner image to which the color developing information is imparted and of light irradiation to fix the developed color of the toner image. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fixing device, an image forming apparatus, and an image forming method that can be applied to toner that develops different colors by exposing light of different wavelengths.

  A recording technique using toner that develops different colors by exposing light of different wavelengths has been proposed (for example, see Patent Document 1). In this technique, as shown in FIG. 6, first, the photosensitive member 121 is uniformly charged using a charger 122. Next, an electrostatic latent image is formed on the photoreceptor 121 by the electrostatic latent image forming head 126. Then, the electrostatic latent image on the photoconductor 121 is developed using the full color particles FMCT charged in the developing device 123 to obtain a toner image.

  Next, from the three colored light writing heads 127a, 127b, and 127c that are the first light sources, the first lights R1a, R1b, and R1c including the component lights of wavelengths ν1a, ν1b, and ν1c that can be photoisomerized are obtained. The toner image is irradiated according to the full-color recording data to cause a color development reaction.

  After the irradiation, the toner image is transferred onto the recording medium 129 by the transfer device 124. Thereafter, the toner image is fixed on the recording medium by the fixing roller 125. In this full-color image forming apparatus, a light fixing head 128 having a built-in lamp for irradiating visible light is disposed on the downstream side of the fixing roller 125 as a heat developing means. This optical fixing head 128 performs optical fixing. The paper (recording medium) on which the image has been formed after the light fixing is thereafter discharged out of the apparatus.

However, in this apparatus, if the toner fixing roller 125 and the light fixing head 128 for fixing and fixing the color are separately provided, not only will the space be taken up, but both of them will generate heat, so that energy is wasted and the surroundings There was a problem of raising the temperature.
JP 2003-330228 A

  The object of the present invention is to solve the above-described conventional problems. That is, an object of the present invention is to provide a fixing device, an image forming apparatus, and an image forming method capable of efficiently forming an image with low fixing energy.

  As a result of intensive studies to solve the above problems, the present inventors have arrived at the following present invention and found that the problems can be solved.

  That is, the present invention is a fixing device for fixing a toner image on a recording medium, which includes a light source and a heat source, at least a light path of light from the light source is transparent, and a toner that forms the toner image The fixing device is a toner that is controlled so as to maintain a colored state or a non-colored state by applying coloring information by light.

  When the toner as described above is used, the color development of the toner must be finally stopped by light irradiation. If the light source for performing this light irradiation is provided separately from the fixing device, not only the device configuration becomes complicated, but also the energy becomes inefficient. Therefore, by providing the light source together with the heat source in one fixing device and making the optical path of the light transparent, it is possible to efficiently form an image with low fixing energy.

  It is preferable that at least a part of the members constituting the optical path is in contact with the toner image. By bringing them into contact with each other, the distance between the light source and heat source and the toner image is reduced, and an image can be efficiently formed with lower fixing energy.

  The toner is present in a state of being isolated from each other, and a first component and a second component that develop color when they react with each other, and a photocurable composition containing either the first component or the second component It is preferable that the toner is such that the photocurable composition is maintained in a cured or uncured state by providing color development information by light, and the reaction for color development is controlled.

  As the toner used in the present invention, it is possible to develop one specific color (or maintain a non-colored state) when the above-described binder resin is provided with color development information by light called a color development part. If a structure having one or more continuous regions (possible) is used, the light-receiving portion receives light, so that the light receiving efficiency of one toner particle can be increased. In addition, since the coloring information imparting mechanism is not a reversible reaction, it has the advantage that there is no time restriction until coloring by heating, so printing up to a low speed range is possible, that is, it can correspond to a wide speed range, Also, there is a merit that the degree of freedom is high with respect to the arrangement place of the fixing device or the like where coloring is performed by heating.

  Further, the present invention is an image forming apparatus including the fixing device of the present invention described above. Since the image forming apparatus is provided with the fixing device of the present invention, it is possible to efficiently form an image with low fixing energy.

  Furthermore, the present invention provides a toner image forming step for forming a toner image on the surface of an image carrier (also referred to as an image carrier), a color information providing step for providing color information by light to the formed toner image, A transfer step for transferring the toner image to which the color development information is applied to the surface of the recording medium; and a fixing step for fixing the toner image transferred to the surface of the recording medium. A toner that is controlled to maintain a colored state or a non-colored state by providing coloring information, and fixing in the fixing step is a coloring process for coloring the toner image to which the coloring information is given, and the toner image An image forming method characterized by being accompanied by a light irradiation process for fixing the color development of

  According to the fixing device, the image forming apparatus, and the image forming method of the present invention, an image can be efficiently formed with low fixing energy.

  In the present invention, known toners can be used, but the following toners are preferably used in view of the effects of the present invention. That is, when each particle of toner is exposed to light having a different wavelength, the toner has a function of developing a color corresponding to the wavelength or maintaining a non-colored (non-colored) state (hereinafter referred to as “color development”). It may be referred to as “the toner according to the present invention”). In other words, the toner has a color developing substance (and a coloring portion including this) that can develop color by providing color information by light inside, and the toner can develop color or non-color by the color information by the light. In other words, the toner is controlled to maintain this state.

  Here, the “applying color development information” refers to a desired region of the toner image in order to control the color development / non-color development state and the color tone when color is developed in units of individual toner particles constituting the toner image. This means that one or more kinds of light having a specific wavelength is selectively given, or no light is given. The toner will be described later.

  In the image forming apparatus (image forming method) using the toner, such a toner is mounted on one developing device, and four types of cyan (C), magenta (M), yellow (Y), and black (K) are used. An electrostatic latent image is formed on the image carrier by the logical sum of the color image formation information, and the electrostatic latent image is developed with the toner to form a toner image. Thereafter, light having a wavelength corresponding to the color information is obtained. Then, the toner image is exposed to give color development information to the toner image. Thereafter, the toner image to which the coloring information is given is transferred to a recording medium, and then fixed to the recording medium by heat and pressure. At this time, the color reaction of the toner is performed by the heat, and a color image is obtained.

  Accordingly, since a full color image can be obtained with one image carrier and one developing device, the size of the main body of the image forming apparatus is as close as possible to that of a monochrome printer, and the apparatus can be miniaturized. Become. In addition, since it is not necessary to layer toner for each color when forming a toner image, unevenness of the image surface can be suppressed, the gloss of the image surface can be made uniform, and the toner can be colored with a pigment or the like. Since no agent is used, it is possible to obtain a silver salt-like image.

  The image forming process to which the present invention is applied is not particularly limited, such as a so-called electrophotographic process or a process (ionography) for forming an electrical latent image with ions or the like on a dielectric. First, an image forming apparatus (image forming method) for forming a color image by an electrophotographic process using a toner that can control color development or non-color development according to color development information by light, to which the present invention is applied. A brief explanation. The image forming apparatus using the ionography will be described as appropriate since only the toner image forming process described later is different and the other processes are the same.

  FIG. 1 shows a schematic configuration of an image forming apparatus provided with the fixing device of the present invention. The image forming apparatus shown in FIG. 1 supplies a photosensitive member (image carrier) 10 used in a normal electrophotographic process, a charging device (charging means) 12, an exposure device (exposure means) 14, and a toner to the surface of the image carrier. A developing device (toner image forming means) 16 for forming a toner image T, an optional charge removing means 18, a transfer device (transfer means) 20 for transferring a toner image to which color development information described later is applied onto a recording medium, A fixing device (fixing means) 22 for fixing the toner image transferred onto the recording medium and an optional cleaner 24 are provided.

Further, in this apparatus, there is provided a color information providing device 30 for applying color information to the developed toner image T from the surface side of the photoconductor 10 by light, and the fixing device 22 is a color development means for coloring the toner image. Also, it serves as a light irradiation means for irradiating the recording medium 26 with light for fixing the color development of the toner.
Hereinafter, an image forming method using the first image forming apparatus of the present invention will be described along each step in image formation.

<Toner image forming step>
When the image carrier as shown in FIG. 1 is a photoreceptor 10, the toner image forming means includes a charging device 12 for charging the surface of the photoreceptor and an electrostatic latent image on the surface of the photoreceptor by exposure. An exposure device 14 to be formed, and a developing device 16 that converts the electrostatic latent image into a toner image with a developer containing the toner are included.

  First, the entire surface of the photoreceptor 10 is charged by the charging device 12. As the photosensitive member 10, any known one can be used, but as will be described later, when the coloring information providing device 30 is inside the photosensitive member 10, a transparent photosensitive member that can transmit exposure light is used. preferable. Here, “transparent” in the present specification means that the transmittance of the emitted light (emitted light / incident light) with respect to the incident light is 50% or more in the wavelength range to be used.

  The photoconductor 10 has a transparent material such as glass or plastic as a base, and its thickness is determined from required mechanical strength, and is about 0.1 mm to 5 mm. As the plastic, polycarbonate, polyester, polymethacrylic acid ester, polyimide (PI), polyamideimide (PAI) and the like are preferable.

  The PI or PAI resin is generally colored yellowish brown, but is preferably used as a transparent one in the present invention. PI or PAI resin is transparent because it is less likely to cause charge transfer in the molecule, fluorinated acid or diamine component, or diaminodiphenyl sulfone, or alicyclic structure in acid or diamine component , Etc.

  The substrate may be a belt as well as a cylindrical body. When the substrate is a belt, the thickness is determined by design matters such as the diameter and tension of a roll for stretching the belt, and is about 30 μm to 200 μm. Further, an endless belt having no seam is preferable to one having a seam.

The substrate needs to be electrically conductive in order to allow electric charge to flow, and there is a method of forming a transparent electrode on the substrate in addition to a method of dispersing a transparent conductive material. To do this, vapor deposition or or sputtering a thin film of transparent metal oxide such as ITO and SnO _2, the metal solution fine particles are dispersed in a binder resin of the oxide or solution thin be produced by applying a conductive polymer such as polypyrrole, And a thin layer obtained by applying and baking a solution in which ultrafine particles such as silver and gold are dispersed in a medium. The thickness is determined from required conductivity and permeability, and is about 0.01 μm to 10 μm.

  The ultrafine metal particles refer to metal particles having a particle size of 1 nm to 100 nm, preferably 3 nm to 50 nm. When the metal has such a fine size, the melting point is lowered to about 100 to 300 ° C. This is because as the particle size decreases, the surface energy increases dramatically and attempts to bond (sinter) each other. The melting point varies depending on the particle size, but also varies depending on the dispersion concentration in the dispersion medium, the type and concentration of the dispersant, and the like. Examples of metals that are preferably used include gold, silver, copper, nickel, palladium, indium, platinum, zinc, and tin. The shape of the ultrafine particles is preferably spherical or an ellipsoid similar to a sphere.

  In order to produce ultrafine metal particles, atomizer method that vaporizes metal in the form of mist, method of heating silver particles by agglomeration in aqueous solution, method of reducing silver oxide thin film in vacuum hydrogen atmosphere, laser melting method, gas There are a phase growth method and a sol-gel method.

  In addition to ultrafine particles, fine particles having a particle size of 0.1 μm or more and 10 μm or less may be used in combination. Although the fine particles do not have a low melting point, when the ultrafine particles are dissolved and sintered, the fine particles are also sintered at the same time, so that the fine particles can be used as an extender. It is also effective for reducing the material cost. The mixing ratio of the ultrafine particles and the fine particles is arbitrary, but the ultrafine particles are preferably required to be 5% by mass or more of the fine particles. The ultrafine particles and the fine particles may be the same metal or different metals, but in the case of different metals, those that are easily fused to each other are preferable.

  The surface of the ultrafine particles may be coated with a resin or an additive. Examples of such resins include acrylic resins, urethane resins, epoxy resins, and butyral resins. Examples of such additives include amine compounds, silicone compounds, coupling agents, and organic acids.

  The ultrafine metal particles are applied after being dispersed in a dispersion medium. Examples of the dispersion medium include water and organic solvents such as alcohols, ketones, esters, and hydrocarbon compounds, and a plurality of types may be mixed. . A surfactant or a thickener may be used for dispersion or dispersion stability.

  A small amount of binder resin may be used. The binder resin is preferably one that is separated or decomposed when the ultrafine metal particles melt and hardly remains in the metal layer. For example, acrylic resin, urethane resin, epoxy resin, butyral resin, polyethersulfone, polysulfone, Etc.

  The solid concentration of the ultrafine metal particle dispersion is preferably 10 to 60%, more preferably 12 to 55%. The viscosity of the metal ultrafine particle dispersion is preferably 1 to 1000 mPa · s, more preferably 2 to 900 mPa · s or less. The thickness of the molten metal layer formed by applying ultrafine metal particles is more preferably 0.05 to 6 μm. However, in order to ensure transparency, a thinner one is preferable. The coating method on the substrate is arbitrary, but when importance is attached to the uniformity of the film thickness, a dip coating method or an annular coating method is preferable.

  After the application, heating is performed at a temperature equal to or higher than the melting point, so that the ultrafine particles are sintered and a metal molten layer is formed. The melting temperature of the sintered metal layer becomes the original melting point of the metal and does not dissolve at the above temperature. In the case of using a polyimide resin (PI) as a base during sintering, it is preferable to perform sintering of metal ultrafine particles and imidization of the PI precursor layer at the same time because the adhesion between the two becomes strong. That is, during imidization, a part of the metal constituting the metal layer formed on the surface of the PI precursor layer enters the PI precursor layer, and the PI precursor reacts in a state where the metal is taken in. It is considered that the adhesion between the layer and the PI resin layer is increased. In addition, imidization and formation of the metal layer are completed by one heating, and not only the adhesion between the two becomes high, but also energy and time required for production can be efficiently reduced. When the metal constituting the metal melting layer is easily oxidized or denatured, such as copper or nickel, during heating, it is preferable to heat in an inert gas such as nitrogen or argon.

Another method for imparting conductivity to the substrate is to disperse a transparent metal oxide such as ITO or SnO ₂ as the conductive powder. In that case, the conductivity is not high, but a volume resistivity of about 10 ⁵ to 10 ¹² Ωcm is sufficient for flowing an electrostatic charge.

  As the photosensitive layer formed on the transparent electrode, a known laminated or single layer organic photoconductor (OPC), inorganic a-Si, or the like can be used. A thing with high is good. The thickness of the photosensitive layer is determined in particular from the transparency and the insulating property that can withstand the charged potential considering the reduction in the film thickness due to repeated use, and is preferably about 10 to 50 μm. An undercoat layer may be provided between the photosensitive layer and the substrate as necessary. Further, a layer for protecting the photosensitive layer may be provided on the photosensitive layer.

  The undercoat layer is made of a transparent resin (eg, vinyl acetate resin, urethane resin, polyvinyl acetal resin, alcohol-soluble nylon resin, etc.) and a copolymer thereof, or a curable metal organic compound (eg, zirconium alkoxide compound, titanium alkoxide). A compound, a silane coupling agent, and the like) are applied alone or in combination.

  The charge generation layer (CGL) in the laminated organic photoreceptor is formed by coating a charge generation agent (CGM) in a binder resin (for example, polyvinyl butyral).

  In the present invention, in order to improve transparency, it is better to use CGM as light as possible (for example, cyanine, azulenium, squalium, gallium phthalocyanine, hydroxygallium phthalocyanine). In order to prevent deterioration, it is preferable that the photosensitive wavelength of CGM is insensitive to the wavelength of color exposure described later.

  The thickness of the CGL is usually about 0.1 to 1 μm, but in the present invention, it is better that the film thickness is thin to prevent deterioration, and about 0.01 to 0.2 μm is preferable. When the film thickness of CGL is reduced, the sensitivity to image exposure is reduced. However, in the present invention, a relatively strong light source is used for color development exposure of toner, so that the amount of light may be increased correspondingly in image exposure.

  The charge transfer layer (CTL) formed on or under the CGL is formed by coating a charge transport agent (CTM) with a binder resin (for example, polycarbonate, polyarylate, polymethyl methacrylate, polyester, etc.).

  CTM is often yellow, but in the present invention, transparent ones such as benzidine compounds and triphenylamine compounds are preferred. The thickness of the CTL is preferably about 10 to 50 μm.

  Examples of the photosensitive layer include inorganic photosensitive layers such as Se and a-Si, and single-layer or multilayer (charge generation layer, charge transport layer, etc.) organic photosensitive layers. In order to further scatter the incident light, it is preferable to disperse organic particles such as metal oxide and fluororesin particles having a particle size of several tens of nanometers to several microns in the photosensitive layer. However, as described above, since light passes through the photosensitive layer and it is necessary to expose even the toner, a material having good light transmittance is preferable. As a measure of transparency, the transmittance of the photosensitive layer itself is preferably 50% or more, and more preferably 70% or more.

Further, since the exposure for providing color information, which will be described later, is performed with a considerably stronger intensity than the exposure for forming a normal latent image (the amount of light energy used for providing color information is used in a normal electrophotographic process) The exposure amount of the photoconductor (about 1000 times the ² mJ / m ² ) is necessary, and the photoconductor 10 may be damaged. For example, the photosensitivity of the charge generation layer of the photoconductor 10 is 1/1000 that of the conventional photoconductor. If so, it will not be a problem because it is balanced. In addition, the thickness of the photosensitive layer is determined from an insulating property that can withstand a charged potential in consideration of the transparency and film thickness reduction with time, and is preferably in a range of approximately 5 to 50 μm.

  In the case of a belt-shaped photoconductor, a transparent resin such as PET or PC can be used as a transparent substrate, and the thickness is determined by design matters such as the diameter and tension of a roll on which the belt-shaped photoconductor is stretched. It is the range of about 10-500 micrometers. Other layer configurations are the same as in the drum.

  On the other hand, when forming a toner image by ionography, a dielectric is used instead of the photoreceptor 10. As the dielectric, it is preferable to use a transparent dielectric for the same reason. As the transparent dielectric, a transparent dielectric layer, for example, a transparent plastic such as PET or PC can be used instead of the photosensitive layer in the transparent photoreceptor.

  A known charging means 12 can be used to charge the photoreceptor 10. In the case of the contact method, a roll, a brush, a magnetic brush, a blade, or the like can be used. In the case of non-contact, a corotron, a scorotron, or the like can be used. The charging means is not limited to these.

  Among these, a contact-type charger is preferably used because of its excellent charge compensation capability. In the contact charging method, the surface of the photosensitive member is charged by applying a voltage to a conductive member brought into contact with the surface of the photosensitive member. The shape of the conductive member may be any of a brush shape, a blade shape, a pin electrode shape, a roll shape, and the like, but a roll-like member is particularly preferable. Usually, a roll-shaped member is comprised from the resistance layer, the elastic layer which supports them, and a core material from the outside. Furthermore, a protective layer can be provided outside the resistance layer as necessary.

  As a method of charging the photosensitive member 10 using these conductive members, a voltage is applied to the conductive member, and the applied voltage is preferably a DC voltage or a DC voltage superimposed with an AC voltage. As the voltage range, the DC voltage is preferably positive or negative 50 to 2000 V, more preferably 100 to 1500 V, further preferably 100 to 600 V, depending on the required charging potential of the photoreceptor. When the AC voltage is superimposed, the peak-to-peak voltage (Vpp) is 400 to 1800 V, preferably 800 to 1600 V, the frequency of the AC voltage is 50 to 20000 Hz, preferably 100 to 5000 Hz, and sine waves, square waves, and triangular waves are generated. Either can be used. The charging potential is preferably set in the range of 100 to 600 V in terms of the absolute value of the potential.

  A known exposure device 14 can be used for forming the electrostatic latent image. As the exposure device 14, for example, a laser scanning system, an LED image bar system, analog exposure means, an ion flow control head, or the like can be used, and the surface of the photoconductor 10 is exposed as indicated by an arrow A in FIG. It is possible. In addition to this, new exposure means developed in the future can be used as long as the effects of the present invention are achieved.

  The wavelength of the light source is in the spectral sensitivity region of the photoconductor 10. Until now, the near-infrared having an oscillation wavelength near 780 nm as the wavelength of the semiconductor laser has been mainstream, but an oscillation wavelength laser in the 600 nm range and a laser having an oscillation wavelength near 400 to 450 nm can be used as a blue laser. . A surface-emitting laser light source capable of multi-beam output is also effective for color image formation.

  Exposure to the photoconductor 10 is performed as a logical sum of the image formation information of the four colors at a position where toner described later is developed in the case of reversal development, and at a position other than developing toner in the case of regular development. The exposure spot diameter is preferably in the range of 10 to 50 μm. As the exposure amount, it is preferable that the post-exposure potential is in the range of about 5 to 20% of the charging potential. However, when changing the toner development amount according to the gradation of the image, the exposure position The exposure amount may be changed according to the development amount every time.

  On the other hand, in the case of the ionography, a latent image is formed on the image carrier by an ion writing head. As an ion writing head, for example, an ion flow On / Off control using an image signal (Japanese Patent Laid-Open No. 4-122654), or an ion flow itself is controlled On / Off (Japanese Patent Laid-Open No. 6-99610). Publication) can be used. In this method, not only a dielectric but also a photosensitive member can be used as the image carrier.

  A known developing device 16 can be used for developing the electrostatic latent image. As a development method, a two-component development method composed of fine particles and toner for carrying a toner called a carrier, or a one-component development method composed of only a toner, and further improvement of other characteristics in these development methods Any developing method in which other constituents may be added can be used.

  Further, depending on the developing method, any one of the developer that develops in contact or non-contact with the photoreceptor 10 or a combination thereof can be used. Furthermore, a hybrid development method combining the one-component development method and the two-component development method can also be used. In addition to this, a new developing means developed in the future can be used as long as the effect of the present invention is achieved.

In the case of using the toner according to the present invention, examples of the toner contained in the developer include a color developing portion capable of developing Y color (Y color developing portion) and a color developing portion capable of developing M color (M color developing portion). And a color developing portion capable of developing C color (C color developing portion) may be included in one toner particle, and the Y color developing portion, the M color developing portion, and the C color developing portion are included separately for each toner. It may be a thing. The toner development amount (the amount of toner attached to the photoreceptor) varies depending on the image to be formed, but is preferably in the range of 5 to 50 g / m ² in a solid image, and in the range of 10 to 40 g / m ² . More preferably.

  In addition, in the formed toner image T, the light for providing coloring information to be described later must spread over the entire irradiated portion, and therefore it is preferable to keep the toner layer thickness below a certain level. Specifically, in the solid image, the toner layer is preferably 3 layers or less, more preferably 2 layers or less. The toner layer thickness is a value obtained by measuring the thickness of the toner layer actually formed on the surface of the photoconductor 10 and dividing this by the number average particle diameter of the toner.

<Coloring information application process>
Next, as shown in FIG. 1, color information by light is imparted to the surface of the photoconductor 10 by the color information imparting device 30 to the toner image T thus obtained.

  Any device can be used as the coloring information providing device 30 as long as the toner particles to be colored at that time can irradiate light having a wavelength for developing a specific color with a predetermined resolution and intensity. For example, an LED image bar, a laser ROS, or the like can be used. Note that the irradiation spot diameter of the light applied to the toner image T is preferably adjusted to be in the range of 10 to 80 μm, and more preferably in the range of 15 to 60 μm.

The wavelength of light used to maintain the colored or non-colored state is determined by the material design of the toner used. For example, when using a toner that develops color when irradiated with light of a specific wavelength (photochromic toner), yellow 405 nm light (referred to as λ _A light) for color development (Y color), 535 nm light (referred to as λ _B light) for cyan (C color) color development for magenta (M color) When irradiating, light of 657 nm (referred to as λ _C light) is irradiated to each desired position for color development.

When the secondary color is developed, the light is combined. When the red (R color) is developed, λ _A light and λ _B light are used. When the green (G color) is developed, λ _A light and When the λ _C light is colored blue (B color), the λ _B light and the λ _C light are respectively applied to the desired positions for color development. Further, when the black color (K color), which is the tertiary color, is developed, the λ _A light, λ _B light, and λ _C light are applied to the desired positions for color development.

On the other hand, in the case of a toner that maintains a non-colored state by irradiation with light of a specific wavelength (light non-colorable type toner), for example, to prevent yellow (Y color) from being colored, 405 nm light (λ _A light) , 535 nm light (λ _B light) to prevent magenta (M color) color development, and 657 nm light (λ _C light) color development to prevent cyan (C color) color development. Irradiate each desired position. Accordingly, λ _B light and λ _C light are generated when Y color is generated, λ _A light and λ _C light are generated when M color is generated, and λ _A light and λ _B light are generated when C color is generated. Each of the desired positions for color development is irradiated.

When the secondary color is developed, the light is combined. When the red (R color) is developed, λ _C light is emitted. When the green (G color) is developed, λ _B light is transformed into blue (B When a color is developed, λ _A light is irradiated to each desired position for the color development. Further, when black (K color) which is a tertiary color is developed, exposure is not performed at a desired position where the color is developed.

For the light from the coloring information applying device 30, a known image modulation method such as pulse width modulation, intensity modulation, or a combination of the two described above can be used as necessary. The exposure amount of light in each preferably in the range of 0.05~0.8mJ / cm ^2, and more preferably in the range of 0.1~0.6mJ / cm ^2. Particularly with respect to the exposure amount, exposure required amount is correlated with the amount of toner developed, for example, 0.2～0.4MJ the toner developing amount (solid) of about 5.5g / ^{m 2} / ^{m 2} It is preferable to perform exposure within the above range.

  In the present invention, when exposure for providing color information (hereinafter sometimes referred to as “color information providing light”) is performed from the back side of the image carrier, the light transmitted through the image carrier is irradiated to the toner. When light passes through the image carrier, scattering occurs due to the interface of each layer constituting the image carrier, the incident angle, internal impurities, etc., and the light spreads when emitted from the surface of the image carrier to It is possible to shine light at more angles. As a result, reflection on the toner surface is promoted, and it is possible to irradiate light uniformly over the gaps between the toner images developed in multiple layers, so that the color of the toner is improved and the color reproduction range in the image is widened. Therefore, the exposure may be performed from the back surface of the image carrier.

  Further, exposure from the back surface (back surface) of the image carrier is performed when an exposure device for providing color development information is arranged in the vicinity of the developed toner image (particularly in the vicinity of the image carrier such as an LED image bar). This is advantageous because it can provide an anti-smudge effect due to scattering of the toner image on the exposure apparatus.

  By being performed from the back side, for example, when light is transmitted through the transparent photosensitive layer, scattering occurs due to an interface of each layer, an incident angle, impurities in the photosensitive body, and the like, and the light spreads when emitted from the surface of the transparent photosensitive body. The light is irradiated at a larger angle with respect to the toner surface as compared with the case where it does not spread. For this reason, absorption and reflection on the toner surface are promoted, and it becomes possible to evenly irradiate the gaps between the multi-layer developed toners.

  In the present invention, when a transparent photoconductor is used as the image carrier, the sensitivity wavelength range of the transparent photoconductor, the relationship between latent image formation and development, the arrangement of the color information providing device, and exposure light is irradiated by the color information providing device. Various configurations can be adopted depending on the position of exposure and the arrangement of exposure means for forming a latent image.

  On the other hand, in the case of image formation by ionography, there is specifically a configuration using a transparent dielectric as an image carrier and an ion writing head for forming a latent image on the transparent dielectric. In this case, since the image carrier is a transparent dielectric, the coloring information imparting light can pass through the transparent dielectric both on the upstream side and the downstream side of the charging device, and transparent even if the coloring information imparting light is strong. This is advantageous because the dielectric does not degrade optically.

  In the image formation by ionography, it is also possible to use a transparent photoreceptor as the image carrier as described above, and in this case, the above configuration is a preferable configuration as it is, but if a transparent dielectric is used, As described above, the degree of freedom in design and the durability of the image carrier can be further improved.

  Hereinafter, it will be briefly described at what timing and for what position control the exposure for giving the coloring information is performed.

  FIG. 2 is a specific circuit block diagram of the print control unit in the image forming apparatus of the present invention. In the figure, a logical sum circuit 40, an oscillation circuit 42, a magenta color control circuit 44M, a cyan color control circuit 44C, a yellow color control circuit 44Y, and a black color control circuit 44K constitute a printer controller. On the other hand, the optical writing head 62 and the coloring information imparting exposure head 64 constitute an exposure unit.

  Image data obtained by converting input RGB signals into CMYK values by an interface (I / F) (not shown) is further transmitted from the interface (I / F) to magenta (M), cyan (C), yellow (Y), and black. The pixel data (K) is output to the OR circuit 40. Here, the logical sum circuit 40 calculates the logical sum of CMYK and outputs it to the optical writing head 62.

  That is, logical sum data including all CMYK pixel data is output to the optical writing head 62, and optical writing is performed on the photosensitive member 10 as described above. Therefore, an electrostatic latent image based on logical sum data including all CMYK pixel data is formed on the peripheral surface of the photoreceptor 10.

  The CMYK pixel data is also supplied to the corresponding magenta color control circuit 44M to black color control circuit 44K, and the color information providing exposure head is synchronized with the oscillation signals fm, fc, fy, and fk output from the oscillation circuit 42. 64. That is, color data corresponding to each of magenta (M), cyan (C), yellow (Y), and black (K) is supplied to the color information imparting exposure head 64, and the toner image T developed on the photoreceptor 10 is developed. Corresponding to the above, light of a specific wavelength for maintaining a colored or non-colored state is irradiated. In this way, a photo-curing reaction, which will be described later, occurs in the toner that has received the irradiated light, and color development information is imparted.

For example, color signal fm outputted from the magenta coloring control circuit 44M irradiates the lambda _B light in the color of the toner to the toner in a state capable of color development of magenta (M) color. In addition, the color development signal fc output from the cyan color development control circuit 44C irradiates the color development portion in the toner with the λ _C light, and makes the toner capable of developing cyan (C) color. Further, the same applies to yellow (Y) and black (K), and the color signals fy and fk output from the yellow color control circuit 44Y and the black color control circuit 44K are transmitted to the color development portion in the toner by the λ _A light or Irradiation with λ _A light, λ _B light, and λ _C light enables a yellow (Y) or black (K) color.

  As described above, the mechanism for forming a full color image has been described with respect to the color information providing step (means) in the present invention. However, the color information providing step in the present invention is a monochromatic color that produces one of yellow, magenta, and cyan. It may be a color information providing step for forming a color image. In this case, only the light of a specific wavelength corresponding to the desired color development among the yellow, magenta, and cyan is emitted from the color development information imparting exposure head 54. Other preferable conditions and the like are the same as those at the time of full-color image formation.

<Transfer process>
The toner to which the color development information is given is then transferred to the recording medium 26 at a time. A known transfer device 18 can be used for transfer. For example, rolls, brushes, blades, and the like can be used for the contact method, and corotron, scorotron, pin corotron, and the like can be used for the non-contact method. Also, transfer by pressure or pressure and heat is possible.

  The transfer bias is preferably in the range of 300 to 1000 V (absolute value), and alternating current (Vpp: 400 V to 4 kV, 400 to 3 kHz) may be superimposed.

<Fixing process>
The toner image T, which is in a state capable of color development (or maintaining a non-color development state) after the transfer process, is colored as described above when the recording medium 26 is heated by the fixing device 22. Here, the fixing device 22 includes a light source and a heat source, and at least an optical path of light from the light source is transparent.

  The heat source is used for color development as described above (color development process), and the light source is used for fixing the color development of the toner image (light irradiation process). At least the light path of the light from the light source is transparent so that the light from the light source is applied to the toner image. For example, when the fixing member 35 that directly contributes to fixing by contacting the toner image is a belt-like body, at least the contact surface of the belt with the toner image T is transparent. In the case of a roll-shaped body, at least the contact surface with the toner image T of the roll is transparent.

  The fixing device 22 that exposes the toner T has a developer function in the toner by applying heat to the toner in addition to a normal electrophotographic fixing function that melts the color toner and fixes the toner particles on the paper. It is necessary to have a function of causing the toner to develop color by diffusing and moving the toner and reacting with the color former in the microcapsule.

  Color fixation by light irradiation (light irradiation treatment) is an exposure in which the color development of the toner is not further advanced. For example, in the apparatus described in Japanese Patent Laid-Open No. 2003-330228, the toner is fixed on the paper. In the present invention, a transparent fixing member 35 including a light emitting light source 37 and a heater 36 is used to perform fixing at the same time as fixing.

  The transparent fixing member 35 has a transparent material made of glass, plastic or the like as a base material, and a transparent non-adhesive release resin or rubber layer is provided on the surface thereof in order to improve the release property to the toner. Is. As a form of the substrate, there are a cylindrical roll having no flexibility or a belt having flexibility, and FIG. 1 shows an example of the belt. If it is desired to lengthen the nip, a belt is more advantageous.

  In the case of plastic, polyimide (PI) and polyamideimide (PAI) are preferable from the viewpoint of heat resistance. A general PI or PAI resin is colored yellowish brown, but a transparent material is preferably used in the present invention. PI or PAI resin is transparent because it is less likely to cause charge transfer in the molecule, fluorinated acid or diamine component, or diaminodiphenyl sulfone, or alicyclic structure in acid or diamine component , Etc.

  In the case where the fixing member 35 is a belt, the thickness is determined by design matters such as the diameter and tension of the roll 38 that stretches the belt, and is about 50 μm to 200 μm. Further, an endless belt having no seam is preferable to one having a seam.

  As the releasable resin to be formed on the surface of the fixing member 35, among the releasable resins used for the surface layer of the conventionally known fixing member, those having high transparency can be applied, such as fluororesin and silicone. Preferred examples include rubber and fluororubber.

  Examples of fluororesins include polytetrafluoroethylene (PTFE, melting point 327 ° C.), tetrafluoroethylene / perfluoroalkyl ether copolymer (PFA, melting point 310 ° C.), tetrafluoroethylene / hexafluoropropylene copolymer (FEP, melting point 275). ° C), ethylene-tetrafluoroethylene copolymer (ETFE, melting point 270 ° C), ethylene-monochlorotrifluoroethylene copolymer (ECTFE, melting point 245 ° C), etc., but in terms of transparency, PFA and FEP are preferable. The fluororesin can be formed into a layer by applying a paint in which fine particles are dispersed in water and baking it at a temperature equal to or higher than the melting point.

  When a fluororesin layer is formed on PI, after the PI precursor solution is applied onto the core body, the solvent is dried to such an extent that a film can be formed, and then a fluororesin-dispersed paint is applied and heated to form an PI imide. There is a method of improving the adhesion between the two by simultaneously performing the heat treatment and melt baking of the fluororesin. In addition, energy and time required for production can be efficiently reduced.

  Inside the transparent fixing device 22, a color light source (light source) 37 and a heater (heat source) 36 are included. As the heater, a halogen lamp with a large amount of light is suitable. A known lamp, fluorescent lamp, LED or the like can be used for the light emission source 37. The wavelength and illuminance depend on the toner design, but should be set taking into account the amount of light from the halogen lamp. If the light amount of the halogen lamp is sufficient to fix the color, it can also serve as a color light source, but if only the short wavelength component is insufficient, for example, the light source only needs to be able to color only the short wavelength component. In this way, the energy required for the light source can be reduced.

  As specific conditions, the illuminance is preferably in the range of 1000 to 10000 lux, and the exposure time is preferably in the range of 1 to 10 sec.

  As the pressure member 25 on the opposite side of the transparent fixing member 35, a known pressure fixing roll or a belt device as described in Japanese Patent No. 3298354 can be used.

<Other processes>
In this invention, it is preferable to include the light irradiation process which irradiates light to the image obtained through the fixing and coloring process. This makes it possible to decompose or deactivate the reactive substances remaining in the color-development part that has been controlled to be incapable of color development. Can be removed and bleached.
In this embodiment, the light irradiation step is provided after the fixing step. However, in the case of a fixing method that does not heat and melt, for example, pressure fixing in which fixing is performed using pressure, the fixing step is performed after the light irradiation step. Can also be done.

  In addition to these, the above-described image forming method may include a known process used in an electrophotographic process performed using a colorant such as a conventional pigment, for example, after transferring a toner image. A cleaning step for cleaning the surface of the image carrier may be included. As the cleaner 20, a known one can be used, and a blade, a brush, or the like can be used. A so-called cleaner-less process in which the cleaner 20 is removed is also applicable.

  In addition, the transfer process includes a first transfer process in which a toner image is transferred from an image carrier to an intermediate transfer body such as an intermediate transfer belt, and the toner image transferred onto the intermediate transfer body is used as a recording medium. An intermediate transfer method including a second transfer step for transferring may be used.

<Toner to be used>
Next, the toner preferably used in the present invention will be described.
As described above, the toner used in the present invention is a toner that is controlled so as to be able to maintain a colored state or a non-colored state by applying coloring information by light. “Maintaining a colored or non-colored state” is also as described above.

  There are various types of toner having the above functions. For example, the toner disclosed in Patent Document 2 is a plurality of microcapsules having a capsule wall whose substance permeability is changed by an external stimulus. Are dispersed and mixed in a toner resin, and one of two kinds of reactive substances (color dye precursors) mixed with each other to cause a color reaction is contained in the microcapsule and the other. (Developer) is contained in the toner resin outside the microcapsule.

  This toner uses a photoisomerized substance that increases the substance permeability when irradiated with light of a specific wavelength as the capsule wall, and when applying light irradiation or ultrasonic waves using this cis-trans transition, Two kinds of reactive substances existing inside and outside the capsule react to develop color.

  Therefore, in such a toner, a large amount of the microcapsules cannot be present in the toner, and these may be unevenly distributed. Therefore, the microcapsules may not receive sufficient light when used in the present invention. is there.

  For this reason, in the present invention, a photocurable composition comprising a first component and a second component that exist in a state of being separated from each other and that develop color when reacted with each other, and any one of the first component and the second component And the photocurable composition is maintained in a cured or uncured state by the application of color development information by light, and the reaction for color development is controlled (hereinafter referred to as “F toner”). In some cases). The color development mechanism and simple configuration of the toner will be described below.

  As will be described later, the F toner can be colored in one specific color (or can maintain a non-colored state) when color development information by light called a color development portion is imparted to the binder resin. ) It has one or more continuous areas.

  FIG. 3 is a schematic view showing an example of the color developing portion in the F toner. FIG. 3A is a cross-sectional view of one color developing portion, and FIG. 3B is an enlarged view of the color developing portion.

  As shown in FIG. 3 (A), the color developing section 60 is composed of color-forming microcapsules 50 containing color formers of the respective colors and a composition 58 surrounding the color-forming microcapsules 50, as shown in FIG. 3 (B). The composition 58 is photopolymerized with a developer monomer (second component) 54 having a polymerizable functional group that develops color by being close to or in contact with the color former (first component) 52 contained in the microcapsule 50. And an initiator 56.

  As the color former 52 encapsulated in the color developable microcapsules 50 in the color development portion 60 constituting the toner particles, a triaryl leuco compound having excellent color hue is suitable. As the developer monomer 54 for coloring the leuco compound (electron donating property), an electron accepting compound is preferable. In particular, phenolic compounds are common, and can be appropriately selected from color developers used for heat-sensitive and pressure-sensitive paper. The color former develops color by an acid-base reaction between the electron donating color former 52 and the electron acceptor developer monomer 54.

As the photopolymerization initiator 56, a spectral sensitizing dye that generates a polymerizable radical that is exposed to visible light and serves as a trigger for polymerizing the developer monomer 54 is used. For example, a reaction accelerator of the photopolymerization initiator 56 is used so that the color-developing monomer 54 can cause a sufficient polymerization reaction for the three primary color exposures such as R color, G color, and B color. For example, by using an ion complex composed of a spectral sensitizing dye (cation) that absorbs exposure light and a boron compound (anion), the spectral sensitizing dye is photoexcited by exposure and electron transfer to the boron compound causes a polymerizable radical to be generated. To initiate polymerization. By combining these materials, a color recording sensitivity of about 0.1 to 0.2 mJ / cm ² can be obtained as the photosensitive color developing portion 60.

  Depending on the presence / absence of light irradiation for color forming information on the color forming part 60 having the above-described configuration, some of the color forming part 60 has a polymer developer compound that has been polymerized and a developer monomer 54 that has not been polymerized. . In the color development unit 60 having the developer monomer 54 that has not been polymerized by a subsequent color development device such as heating, the color developer monomer 54 migrates due to heat or the like, and migrates through the pores of the partition walls of the color developer microcapsule 50. Passes through and diffuses into the color former microcapsules. The developer monomer 54 and the color former 52 diffused in the microcapsule 50 are, as described above, the color former 52 is basic and the developer monomer 54 is acidic, so that the color developer 52 is acid-base. The reaction will cause color development.

  On the other hand, the developer compound that has undergone the polymerization reaction cannot pass through the pores of the partition walls of the microcapsule 50 due to the bulk due to the polymerization in the subsequent color development step by heating or the like, and the color former 52 in the color development microcapsule. Color cannot be developed because it cannot react. Therefore, the chromogenic microcapsule 50 remains colorless. That is, the color developing portion 60 irradiated with the specific wavelength light is colored and exists.

  After color development, the entire surface is exposed again with a white light source at an appropriate stage to polymerize all remaining undeveloped color developing monomer 54 to achieve stable image fixing, and residual spectral sensitizing dye. The ground color is erased by disassembling. Note that the spectral sensitizing dye of the photopolymerization initiator 56 corresponding to the visible light region remains as a ground color until the end. Color phenomenon can be used. In other words, a polymerizable radical is generated by electron transfer from a photoexcited spectral sensitizing dye to a boron compound. This radical causes polymerization of the monomer, while reacting with the excited dye radical to cause color separation of the dye. As a result, the pigment can be decolored.

  In the F toner, the color developing portions 60 (for example, coloring in Y color, M color, and C color) that perform such different color development are used as color developing agents other than the color developing agent 52 intended by the respective developer monomers 54. And can be used as one microcapsule in a state where they do not interfere with each other (in a state where they are isolated from each other). In this F toner, the space other than the microcapsules containing the electron-donating color former is filled with the electron-accepting developer and the photocurable composition, and the color-developing portion constituted thereby receives the light. The light receiving efficiency of the toner particles is overwhelmingly higher than that of the toner disclosed in Patent Document 2. Therefore, the effect of the back exposure can be fully utilized as compared with other toners.

  In addition, as described above, the coloring information imparting mechanism is not a reversible reaction, and as a result, there is no time restriction until color development by heating. As a result, printing up to a low speed range is possible, that is, it is compatible with a wide speed range. In addition, there is also a merit that the degree of freedom is high with respect to the arrangement place of the fixing device or the like where coloring is performed by heating.

The configuration of the F toner will be further described in detail.
The F toner includes a first component and a second component that exist in a state of being separated from each other as colorable substances (coloring substances) and that develop colors when they react with each other. As described above, color development is facilitated by color development utilizing the reaction of two types of reactive components. The first component and the second component may be pre-colored in a state before color development, but are particularly preferably substantially colorless substances.

  In order to facilitate the color development control, two types of reactive components that develop color when reacting with each other are used as the color developing materials. However, these reactive components do not diffuse the substance even when the color development information by light is not given. If they exist in the same easy matrix, spontaneous color development may progress during storage or manufacture of the toner. For this reason, it is necessary that the reactive component be contained in different matrices (separated from each other) that are difficult to diffuse into each other region unless coloring information is given. is there.

  Thus, in order to inhibit the material diffusion in the state where the color development information by light is not given and prevent spontaneous color development at the time of storage or production of the toner, the first component of the two types of reactive components is Contained in the first matrix, the second component is contained outside the first matrix (second matrix), and between the first matrix and the second matrix, there is diffusion of the substance between the two matrices. When an external stimulus such as heat is applied, a partition wall having a function that enables diffusion of substances between both matrices according to the kind, strength, and combination of the stimulus is provided. Is preferred.

  In order to arrange two types of reactive components in the toner using such a partition wall, it is preferable to use microcapsules. In this case, the F toner preferably includes, for example, the first component of the two types of reactive components inside the microcapsule and the second component outside the microcapsule. In this case, the inside of the microcapsule corresponds to the first matrix and the outside of the microcapsule corresponds to the second matrix.

  This microcapsule has a core part and an outer shell covering the core part, and inhibits diffusion of substances inside and outside the microcapsule and external stimulus as long as external stimulus such as heat is not given. In this case, there is no particular limitation as long as it has a function that enables diffusion of substances inside and outside the microcapsule according to the type, strength, and combination of the stimulus. The core part contains at least one of the reactive components.

  In addition, the microcapsule may be capable of diffusing substances inside and outside the microcapsule by applying light irradiation or a stimulus such as pressure, but the substance can be diffused inside and outside the microcapsule by heat treatment (outer shell substance). Particularly preferred are thermoresponsive microcapsules (which increase permeability).

  In addition, the substance diffusion inside and outside the microcapsule when a stimulus is applied, from the viewpoint of suppressing a decrease in color density during image formation or suppressing a change in color balance of an image left in a high temperature environment, It is preferably irreversible. Therefore, the outer shell of the microcapsule irreversibly increases its substance permeability due to softening, decomposition, dissolution (compatibility with surrounding members), deformation, etc. by applying heat treatment, light irradiation and other stimuli. It is preferable to have the function of

Next, a preferable configuration when the F toner includes microcapsules will be described.
Such a toner preferably includes a first component and a second component that develop color when they react with each other, a microcapsule, and a photocurable composition in which the second component is dispersed. Examples of the toner include the following three modes.

  That is, the F toner includes a first component and a second component that develop color when they react with each other, a photocurable composition, and microcapsules dispersed in the photocurable composition, and the first component is A mode (first mode) in which the second component is contained in the microcapsule and contained in the photocurable composition, a first component and a second component that develop color when reacted with each other, and a photocurable composition A mode in which the first component is included outside the microcapsule and the second component is included in the photocurable composition (second mode), or the first component that develops color when reacted with each other And a second component, one microcapsule containing the first component, and another microcapsule containing a photocurable composition in which the second component is dispersed (third embodiment). It is preferable.

  Among these three modes, the first mode is particularly preferable from the viewpoints of stability before giving color development information by light, control of color development, and the like. In the following description of the toner, the toner will be described in more detail on the premise of the toner of the first aspect. However, the configuration, material, manufacturing method, etc. of the toner of the first aspect described below are the same as those of the second aspect. Of course, the toner of the third aspect and the third aspect can also be used / reused.

In addition, it is particularly preferable that the F toner using a combination of the above-described thermoresponsive microcapsule and the photocurable composition is one of the following two types.
(1) Even if the photocurable composition is heat-treated in an uncured state, the material diffusion of the second component contained in the uncured photocurable composition is suppressed, and light is emitted by irradiation with the color forming information providing light. When the heat treatment is performed after the curable composition is cured, a toner of a type that promotes material diffusion of the second component contained in the cured photocurable composition (hereinafter, referred to as “photochromic toner”). is there).
(2) When the photocurable composition is heat-treated in an uncured state (a state where the second component is not polymerized), the material diffusion of the second component contained in the uncured photocurable composition is promoted. When the photocurable composition is cured by irradiation with the color forming information imparting light (after the second component is polymerized), the material diffusion of the second component contained in the cured photocurable composition is caused. The type of toner to be suppressed (hereinafter sometimes referred to as “light non-color developing toner”).

  The main difference between the photochromic toner and the non-photochromic toner is in the material constituting the photocurable composition. In the photochromic toner, the photocurable toner has no photopolymerizability. ) Whereas the second component and the photopolymerizable compound are at least included, the photo-non-colorable toner includes at least the second component having a photopolymerizable group in the molecule in the photocurable composition. .

  The photocurable composition used in the photochromic toner and the non-photochromic toner preferably contains a photopolymerization initiator, and various other materials are contained as necessary. May be.

  As the photopolymerizable compound and the second component used in the photochromic toner, the interaction between the photocurable composition and the second component in the photocurable composition works in an uncured state. In the photocurable composition, the substance diffusion is suppressed, and the interaction between the two decreases in the state after curing of the photocurable composition (polymerization of the photopolymerizable compound) by irradiation with the color forming information imparting light. A material that facilitates diffusion of the second component is used.

  Therefore, in the photochromic toner, before the heat treatment (coloring step), the coloration information imparting light having a wavelength for curing the photocurable composition is irradiated in advance, so that the first color contained in the photocurable composition. The two-component material diffusion becomes easy. Therefore, when the heat treatment is performed, a reaction (coloring reaction) between the first component in the microcapsule and the second component in the photocurable composition occurs due to dissolution of the outer shell of the microcapsule or the like.

  On the contrary, the second component is trapped in the photopolymerizable compound even if it is heat-treated without irradiating the color-forming information imparting light having a wavelength for curing the photocurable composition, and comes into contact with the first component in the microcapsule. The reaction between the first component and the second component (coloring reaction) does not occur.

  As described above, in the photochromic toner, the first component and the second component are applied by combining the presence / absence of irradiation with color forming information providing light having a wavelength for curing the photocurable composition and the heat treatment. Can control the color development of the toner.

  Further, in the non-photochromic toner, since the second component itself has photopolymerization property, even when irradiated with the color forming information imparting light, the wavelength of this light is not the wavelength that cures the photocurable composition, Since the second component contained in the photocurable composition can be easily diffused, if the heat treatment is performed in this state, the first component in the microcapsule and the photocurable composition are dissolved by dissolution of the outer shell of the microcapsule. Reaction (coloring reaction) with the second component in the composition occurs.

  On the contrary, when the coloring information imparting light having a wavelength for curing the photocurable composition is irradiated before the heat treatment, the second components contained in the photocurable composition are polymerized with each other. The material diffusion of the second component contained in the composition becomes difficult. Therefore, the second component cannot be brought into contact with the first component in the microcapsule even when the heat treatment is performed, and the reaction (coloring reaction) between the first component and the second component does not occur.

  As described above, in the non-photochromic toner, the first component and the second component can be applied by combining the heat treatment with the presence / absence of irradiation with color forming information providing light having a wavelength for curing the photocurable composition. Since the reaction (coloring reaction) with the components can be controlled, the color development of the toner can be controlled.

  Next, a preferable structure of the F toner will be described in more detail when the toner includes the photocurable composition and microcapsules dispersed in the photocurable composition. In this case, the toner may have only one color developing portion including a photocurable composition and microcapsules dispersed in the photocurable composition, but preferably has two or more. Here, the “coloring part” means a continuous region that can develop a specific color when an external stimulus is applied as described above.

  When the toner includes two or more coloring portions, only one type of coloring portion that can develop the same color may be included in the toner, but two or more types of coloring that can develop colors different from each other may be included. It is particularly preferable that the part is contained in the toner. This is because the color that can be developed by one toner particle is limited to only one type in the former case, but can be two or more in the latter case.

  For example, as two or more types of color developing portions capable of developing colors different from each other, a yellow coloring portion capable of developing yellow, a magenta coloring portion capable of developing magenta, and a cyan coloring portion capable of developing cyan Combinations including these are mentioned.

  In this case, for example, when only one type of coloring portion is colored by the application of an external stimulus, the toner can be colored in one of yellow, magenta, or cyan, and any two When various types of coloring portions develop color, the colors developed by these two types of coloring portions can be combined, and various colors can be expressed with a single toner particle.

  The control of the color to be developed when the toner includes two or more types of coloring portions that can develop colors different from each other depends on the types and combinations of the first component and the second component contained in each type of coloring portion. In addition to making the wavelength different, it can be realized by making the wavelength of light used for curing the photocurable composition contained in each type of color developing portion different.

  That is, in this case, since the wavelength of light necessary for curing the photocurable composition contained in the color developing portion differs for each type of color developing portion, a plurality of types having different wavelengths according to the type of color developing portion are used as control stimuli. Coloring information imparting light may be used. In order to make the wavelength of light necessary for curing the photocurable composition contained in the color developing part different, a photopolymerization initiator sensitive to light of a different wavelength is used for each type of color developing part. It is suitable for inclusion in the product.

  For example, when the toner includes three types of color-developing parts capable of coloring yellow, magenta, and cyan, the photocurable composition contained in each type of color-forming part has a light wavelength of 405 nm, 532 nm, and If a material that cures in response to any of 657 nm is used, the toner can be colored to a desired color by properly using these three color-developing information-giving lights (lights having specific wavelengths). The wavelength of the coloring information imparting light can be selected from the visible wavelength, but may be selected from the ultraviolet wavelength.

  The toner used in the present invention may include a base material mainly composed of a binder resin similar to that used in a toner using a colorant such as a conventional pigment. In this case, it is preferable that each of the two or more coloring portions is dispersed as a particulate capsule in the base material (hereinafter, one capsule-like coloring portion may be referred to as a “photosensitive / thermosensitive capsule”). is there). Further, in the base material, a release agent and various additives may be contained in the same manner as a toner using a colorant such as a conventional pigment.

  The photosensitive / thermosensitive capsule has a core portion containing a microcapsule or a photocurable composition, and an outer shell covering the core portion, and this outer shell is used in the toner production process and toner storage described later. In the above, there is no particular limitation as long as the microcapsules and the photocurable composition in the photosensitive / thermosensitive capsule can be stably held so as not to leak out of the photosensitive / thermal capsule.

  However, in the present invention, in the toner production process described later, the second component passes through the outer shell and flows out to the matrix outside the photosensitive / thermosensitive capsule, or in the photosensitive / thermosensitive capsule capable of developing other colors. In order to prevent the second component from flowing through the outer shell, it is preferable that the second component contains a water-insoluble material such as a binder resin made of a water-insoluble resin or a release material as a main component.

  Next, the toner constituent materials used for the F toner and the materials and methods used for adjusting the toner constituent materials will be described in more detail below.

  In this case, at least a first component, a second component, a microcapsule containing the first component, and a photocurable composition containing the second component are used for the toner, and a photopolymerization initiator is contained in the photocurable composition. Is particularly preferable, and various auxiliary agents and the like may be included. Further, the first component may be present in a solid state in the microcapsule (core portion), but may be present together with a solvent.

  In the light non-color-forming toner, an electron-donating colorless dye or a diazonium salt compound is used as the first component, and an electron-accepting compound having a photopolymerizable group or a photopolymerizable group is used as the second component. A coupler compound or the like is used. In the photochromic toner, an electron-donating colorless dye is used as the first component, and an electron-accepting compound (“electron-accepting developer” or “developer”) is used as the second component. And a polymerizable compound having an ethylenically unsaturated bond is used as the photopolymerizable compound.

  In addition to the above-listed materials, various materials similar to those constituting conventional toners using colorants; binder resins, mold release agents, internal additives, external additives, etc., as necessary It can be used as appropriate. Hereinafter, each material etc. are demonstrated in detail.

-1st component and 2nd component-
As the combination of the first component and the second component, the following combinations (a) to (tu) can be preferably mentioned (in the following examples, the former represents the first component and the latter represents the second component, respectively). .

(A) A combination of an electron-donating colorless dye and an electron-accepting compound.
(A) A combination of a diazonium salt compound and a coupling component (hereinafter appropriately referred to as “coupler compound”).
(C) A combination of an organic acid metal salt such as silver behenate or silver stearate and a reducing agent such as protocatechinic acid, spiroindane or hydroquinone.
(D) A combination of a long-chain fatty acid iron salt such as ferric stearate or ferric myristate and a phenol such as tannic acid, gallic acid or ammonium salicylate.
(E) Organic acid heavy metal salts such as nickel, cobalt, lead, copper, iron, mercury and silver salts such as acetic acid, stearic acid and palmitic acid, and alkali metals or alkaline earth such as calcium sulfide, strontium sulfide and potassium sulfide A combination of a metal sulfide or a combination of the organic acid heavy metal salt and an organic chelating agent such as s-diphenylcarbazide or diphenylcarbazone.

(F) A combination of a heavy metal sulfate such as a sulfate such as silver, lead, mercury or sodium and a sulfur compound such as sodium tetrathionate, sodium thiosulfate or thiourea.
(G) A combination of an aliphatic ferric salt such as ferric stearate and an aromatic polyhydroxy compound such as 3,4-hydroxytetraphenylmethane.
(H) A combination of an organic acid metal salt such as silver oxalate or mercury oxalate and an organic polyhydroxy compound such as polyhydroxy alcohol, glycerin or glycol.
(G) A combination of a ferric salt of a fatty acid such as ferric pelargonate or ferric laurate and a thiocesylcarbamide or isothiocecilcarbamide derivative.
(Co) A combination of a lead salt of an organic acid such as lead caproate, lead pelargonate or lead behenate and a thiourea derivative such as ethylenethiourea or N-dodecylthiourea.

(Sa) A combination of a higher aliphatic heavy metal salt such as ferric stearate or copper stearate and zinc dialkyldithiocarbamate.
(B) Those that form an oxazine dye such as a combination of resorcin and a nitroso compound.
(Su) A combination of a formazan compound and a reducing agent and / or a metal salt.
(C) A combination of a protected dye (or leuco dye) precursor and a deprotecting agent.
(So) A combination of an oxidizing color former and an oxidizing agent.

(Ta) A combination of phthalonitriles and diiminoisoindolines. (A combination that produces phthalocyanine.)
(H) A combination of isocyanates and diiminoisoindolines (a combination that produces a colored pigment).
(Iv) A combination of a pigment precursor and an acid or a base (a combination formed by a pigment).

  The first component listed above is preferably a substantially colorless electron-donating colorless dye or a diazonium salt compound. As the electron-donating colorless dye, conventionally known dyes can be used, and any dye that reacts with the second component and develops color can be used.

  Specifically, phthalide compounds, fluoran compounds, phenothiazine compounds, indolylphthalide compounds, leucooramine compounds, rhodamine lactam compounds, triphenylmethane compounds, triazene compounds, spiropyran compounds, pyridine Examples thereof include various compounds such as phosphines, pyrazine compounds, and fluorene compounds.

  In the case of the non-photochromic toner, the second component is a substantially colorless compound having a photopolymerizable group and a site that develops color by reacting with the first component in the same molecule. Any compound that has both functions of reacting with the first component such as an electron-accepting compound having a photopolymer or a coupler compound having a photopolymerizable group to develop a color and reacting with light to be cured and cured. be able to.

  The electron-accepting compound having a photopolymerizable group, that is, a compound having an electron-accepting group and a photopolymerizable group in the same molecule has a photopolymerizable group and is one of the first components. Any colorant can be used as long as it reacts with an electron-donating colorless dye and develops color and can be cured by photopolymerization.

  The electron-accepting developer as the second component in the case of the photochromic toner includes phenol derivatives, sulfur-containing phenol derivatives, organic carboxylic acid derivatives (for example, salicylic acid, stearic acid, resorcinic acid, etc.), and Examples thereof include metal salts thereof, sulfonic acid derivatives, urea or thiourea derivatives, acidic clay, bentonite, novolac resins, metal-treated novolac resins, metal complexes, and the like.

  Further, in the photochromic toner, a polymerizable compound having an ethylenically unsaturated bond is used as a photopolymerizable compound, and this is at least in a molecule such as acrylic acid and a salt thereof, an acrylic ester, and an acrylamide. It is a polymerizable compound having one ethylenically unsaturated double bond.

  Next, the photopolymerization initiator will be described. The photopolymerization initiator can generate radicals by irradiating with color forming information imparting light to cause a polymerization reaction in the photocurable composition, and can accelerate the reaction. The photocurable composition is cured by this polymerization reaction.

The photopolymerization initiator can be appropriately selected from known ones, and includes, among others, a spectral sensitizing compound having a maximum absorption wavelength at 300 to 1000 nm and a compound that interacts with the spectral sensitizing compound. It is preferable that
However, if the compound that interacts with the spectral sensitizing compound is a compound having both a dye part and a borate part having a maximum absorption wavelength at 300 to 1000 nm in the structure, the spectral sensitizing dye is used. It does not have to be.

  As the compound that interacts with the spectral sensitizing compound, one or more compounds are appropriately selected from known compounds capable of initiating a photopolymerization reaction with the photopolymerizable group in the second component. Can be used.

  By making this compound coexist with the above-mentioned spectral sensitizing compound, it is sensitive to the irradiation light in the spectral absorption wavelength region and can generate radicals with high efficiency. Generation of radicals can be controlled using an arbitrary light source in the outer region.

  The “compound interacting with the spectral sensitizing compound” is preferably an organic borate salt compound, a benzoin ether, an S-triazine derivative having a trihalogen-substituted methyl group, an organic peroxide or an azinium salt compound. Borate salt compounds are more preferred. By using this “compound that interacts with the spectral sensitizing compound” in combination with the spectral sensitizing compound, radicals can be generated locally and effectively in the exposed exposed portion, thereby increasing the sensitivity. Can be achieved.

  In addition, the photo-curable composition further promotes the polymerization by a transfer agent such as an oxygen scavenger or a chain transfer agent of an active hydrogen donor as an auxiliary agent for the purpose of promoting the polymerization reaction. Other compounds can also be added.

  Examples of the oxygen scavenger include phosphine, phosphonate, phosphite, first silver salt, and other compounds that are easily oxidized by oxygen. Specific examples include N-phenylglycine, trimethyl parbituric acid, N, N-dimethyl-2,6-diisopropylaniline, and N, N, N-2,4,6-pentamethylanilic acid. Furthermore, thiols, thioketones, trihalomethyl compounds, lophine dimer compounds, iodonium salts, sulfonium salts, azinium salts, organic peroxides, azides and the like are also useful as polymerization accelerators.

  In the F toner, a first component such as an electron-donating colorless dye or a diazonium salt compound is encapsulated in a microcapsule.

  A conventionally known method can be used as a microencapsulation method. For example, a method using coacervation of hydrophilic wall forming materials described in U.S. Pat. Nos. 2,800,547 and 2,800,458, U.S. Pat. No. 3,287,154, British Patent No. 990443, Japanese Patent Publication No. 38-19574, No. 42. No. -446, No. 42-771, etc., an interfacial polymerization method described in US Pat. Nos. 3,418,250 and 3,660,304, and an isocyanate polyol wall material described in US Pat. No. 3,796,669 are used. A method using an isocyanate wall material described in US Pat. No. 3,914,511, a method using a urea-formaldehyde system, a urea formaldehyde-resorcinol-based wall forming material described in US Pat. Nos. 4001140, 4087376, and 4089802, US 402 No. 455, a method using a wall forming material such as melamine-formaldehyde resin, hydroxybrovir cellulose, etc., Japanese Patent Publication No. 36-9168, Japanese Patent Application Laid-Open No. 51-9079, in situ method by polymerization of monomers, British Patent No. 952807, No. 965074, electrolytic dispersion cooling method, U.S. Pat. No. 3,111,407, British patent No. 930422, spray drying method, JP-B-7-73069, JP-A-4-101858, Examples include the method described in Kaihei 9-263057.

  The microcapsule wall material that can be used is added inside and / or outside the oil droplets. Examples of the material for the microcapsule wall include polyurethane, polyurea, polyamide, polyester, polycarbonate, urea-formaldehyde resin, melamine resin, polystyrene, styrene methacrylate copolymer, styrene-acrylate copolymer, and the like. Among these, polyurethane, polyurea, polyamide, polyester, and polycarbonate are preferable, and polyurethane and polyurea are more preferable. Two or more kinds of the polymer substances can be used in combination.

  The volume average particle size of the microcapsules is preferably adjusted to be in the range of 0.1 to 3.0 μm, and more preferably adjusted to be in the range of 0.3 to 1.0 μm.

  The photosensitive / thermosensitive capsule may contain a binder, and this is the same for a toner having one color developing portion.

  Examples of the binder include those similar to the binder used for emulsifying and dispersing the photocurable composition, a water-soluble polymer used for encapsulating the first reactive substance, polystyrene, polyvinyl formal, polyvinyl butyral, poly Acrylic resins such as methyl acrylate, polybutyl acrylate, polymethyl methacrylate, polybutyl methacrylate and copolymers thereof, solvent-soluble polymers such as phenol resin, styrene-butadiene resin, ethyl cellulose, epoxy resin, urethane resin, or these It is also possible to use a polymer latex. Of these, gelatin and polyvinyl alcohol are preferred. Moreover, you may use the binder resin mentioned later as a binder.

  For the F toner, a binder resin used in conventional toners can be used. For example, in a toner having a structure in which photosensitive / thermal capsules are dispersed in a base material, the binder resin can be used as a main component constituting the base material and a material constituting the outer shell of the photosensitive / thermal capsule. It is not limited to this.

  The binder resin is not particularly limited, and a known crystalline or amorphous resin material can be used. In particular, a crystalline polyester resin having sharp melt properties is useful for imparting low-temperature fixability. As the amorphous polymer (amorphous resin), a known resin material such as a styrene acrylic resin or a polyester resin can be used, but an amorphous polyester resin is particularly preferable.

  In addition, the F toner may contain other components other than those listed above. Other components are not particularly limited and may be appropriately selected depending on the purpose. For example, various known additives used in conventional toners such as release agents, inorganic fine particles, organic fine particles, and charge control agents. Can be mentioned

Next, a method for manufacturing F toner will be briefly described.
The F toner is preferably prepared using a known wet manufacturing method such as an aggregation coalescence method. In particular, a first component and a second component that develop color when they react with each other, a photocurable composition, and a microcapsule dispersed in the photocurable composition, wherein the first component is contained in the microcapsule. The wet manufacturing method is suitable for producing a toner having a structure in which the second component is contained in the photocurable composition.

  The microcapsule used for the toner having the above structure is particularly preferably a thermoresponsive microcapsule, but may be a microcapsule that responds to other stimuli such as light.

  For the production of toner, a known wet manufacturing method can be used. Among the wet manufacturing methods, the maximum process temperature can be kept low, and the toner having various structures can be easily produced. It is particularly preferable to do this.

  Compared to conventional toners mainly composed of pigments and binder resins, toners having the above structure contain more photocurable compositions containing low-molecular components as the main component. Although the strength of the particles obtained by the above method tends to be insufficient, the aggregation and coalescence method does not require a high shearing force, and it is preferable to use the aggregation and coalescence method in this respect as well.

  In general, the aggregation and coalescence method includes an aggregation step in which a dispersion of various materials constituting a toner is prepared, and then aggregated particles are formed in a raw material dispersion obtained by mixing two or more types of dispersions. And a coalescing step for fusing the agglomerated particles formed on the surface of the agglomerated particles to form a coating layer between the agglomeration step and the fusing step. The adhesion process (coating layer formation process) to form is implemented.

  Also in the production of the F toner, although the types and combinations of the various dispersions used as raw materials are different, the toner can be prepared by appropriately combining the adhering step in addition to the aggregation step and the fusion step.

  For example, in the case of a toner having a photosensitive / thermosensitive capsule dispersion structure in a resin, first, (a1) a microcapsule dispersion in which microcapsules containing a first component are dispersed and a photocurable composition containing a second component A first aggregating step for forming first agglomerated particles in a raw material dispersion containing a photocurable composition dispersion in which a product is dispersed; and (b1) a raw material on which the first agglomerated particles are formed. An adhesion step of adding a first resin particle dispersion in which resin particles are dispersed to the dispersion and attaching the resin particles to the surface of the aggregated particles; and (c1) attaching the resin particles to the surface. One or more types of photosensitive materials that can develop colors different from each other through a first fusion step in which a raw material dispersion containing aggregated particles is heated and fused to obtain first fused particles (photosensitive / heat-sensitive capsules).・ Prepare heat-sensitive capsule dispersion .

  Subsequently, (d1) second aggregated particles are formed in a mixed solution obtained by mixing the one or more types of photosensitive / thermosensitive capsule dispersion and the second resin particle dispersion in which the resin particles are dispersed. By passing through a second aggregating step and (e1) a second fusing step of heating the mixed solution containing the second agglomerated particles to obtain second fused particles, a photosensitive / thermosensitive capsule dispersion structure is obtained. A toner having the same can be obtained.

  Two or more kinds of photosensitive / thermosensitive capsule dispersions are preferably used in the second aggregation step. Further, the photosensitive / heat-sensitive capsules obtained through the steps (a1) to (c1) may be used as they are as toner (that is, toner including only one color developing portion).

  In the case of producing a toner including only one color developing portion, a release agent dispersion liquid in which a release agent is dispersed in the raw material dispersion liquid in which the first aggregated particles are formed instead of the above-described adhesion step. And adding a first resin particle dispersion liquid in which resin particles are dispersed in a raw material dispersion liquid after passing through the first adhesion process. A second adhesion step of adding resin particles to the surface of the aggregated particles to which the release agent has been added may be carried out.

The volume average particle size of the F toner that can be used in the present invention is not particularly limited, and can be appropriately adjusted according to the structure of the toner and the type and number of color developing portions contained in the toner.
However, there are about 2 to 4 types of coloring portions that can be developed in different colors contained in the toner (for example, when the toner includes three types of coloring portions that can develop colors of yellow, cyan, and magenta) ), The volume average particle diameter corresponding to each toner structure is preferably within the following range.

  That is, for example, when the toner structure is a photosensitive / thermosensitive capsule dispersion structure in a resin, the volume average particle diameter of the toner is preferably in the range of 5 to 40 μm, and more preferably in the range of 10 to 20 μm. The volume average particle size of the photosensitive / thermosensitive capsule contained in the photosensitive / thermosensitive capsule dispersed structure toner having such a particle size is preferably in the range of 1 to 5 μm, preferably in the range of 1 to 3 μm. It is preferable that

  The volume average particle diameter of the photosensitive / heat-sensitive capsule is directly the size of the color development portion in the toner. For this reason, when the volume average particle diameter is less than 5 μm, the amount of color developing components contained in the toner decreases, so that color reproducibility may deteriorate and image density may decrease. On the other hand, if the volume average particle size exceeds 40 μm, unevenness on the image surface becomes large, and gloss unevenness on the image surface may occur.

  In addition, the photosensitive / thermosensitive capsule dispersion type toner in which a plurality of photosensitive / thermosensitive capsules are dispersed therein has a particle diameter as compared with a small-diameter toner (volume average particle diameter of about 5 to 10 μm) using a conventional colorant. However, since the resolution of the image is determined not by the particle size of the toner but by the particle size of the photosensitive / heat-sensitive capsule, a higher-definition image can be obtained. In addition, since the powder fluidity is also excellent, sufficient fluidity can be ensured even if the amount of the external additive is small, and the developability and cleaning properties can be improved.

  On the other hand, in the case of a toner having only one color developing portion, it is easier to reduce the diameter as compared with the case described above, and the volume average particle diameter is preferably in the range of 3 to 8 μm, and in the range of 4 to 7 μm. Is preferred. When the volume average particle size is less than 3 μm, the particle size is too small, so that sufficient powder fluidity may not be obtained or sufficient durability may not be obtained. If the volume average particle size exceeds 8 μm, a high-definition image may not be obtained.

  In the present invention, in addition to the F toner described above, any toner can be used as long as it is controlled so as to maintain a colored or non-colored state by light irradiation (or by no light irradiation). It can be used regardless of the structure, coloring mechanism, etc.

  The volume average particle size distribution index GSDv is preferably 1.30 or less, and the ratio (GSDv / GSDp) of the volume average particle size distribution index GSDv and the number average particle size distribution index GSDp is preferably 0.95 or more. .

  More preferably, the volume average particle size distribution index GSDv is 1.25 or less, and the ratio (GSDv / GSDp) of the volume average particle size distribution index GSDv and the number average particle size distribution index GSDp is 0.97 or more. Is more preferable.

  When the volume distribution index GSDv exceeds 1.30, the resolution of the image may decrease, and the ratio of the volume average particle size distribution index GSDv to the number average particle size distribution index GSDp (GSDv / GSDp) is If it is less than 0.95, the toner chargeability may be reduced, the toner may be scattered, fogging, etc. may occur, leading to image defects.

  In the present invention, the volume average particle diameter of the toner and the values of the volume average particle size distribution index GSDv and the number average particle size distribution index GSDp are measured and calculated as follows.

First, with respect to the divided particle size range (channel) of the toner particle size distribution measured using a measuring device such as Coulter Multisizer II (manufactured by Beckman-Coulter), the smaller diameter side of the volume and number of individual toner particles A cumulative distribution is drawn from the particle size, and the particle size that is 16% cumulative is defined as the volume average particle size D16v and the number average particle size D16p. The particle size that is 50% cumulative is the volume average particle size D50v and the number The average particle size is defined as D50p. Similarly, particle diameters that are 84% cumulative are defined as volume average particle diameter D84v and number average particle diameter D84p. In this case, the volume average particle size distribution index (GSDv) is defined as (D84v / D16v) ^1/2 and the number average particle size index (GSDp) is defined as (D84p / D16p) ^1/2. Can be used to calculate the volume average particle size distribution index (GSDv) and the number average particle size index (GSDp).

  The volume average particle size of the microcapsules or the photosensitive / thermosensitive capsules can be measured using, for example, a laser diffraction particle size distribution measuring device (LA-700, manufactured by Horiba, Ltd.).

  The toner of the present invention preferably has a shape factor SF1 represented by the following formula (1) in the range of 110 to 130.

SF1 = (ML ² / A) × (π / 4) × 100 (1)
[In the above formula (1), ML represents the maximum length (μm) of toner, and A represents the projected area (μm ² ) of toner. ]

  When the shape factor SF1 is less than 110, the toner tends to remain on the surface of the image carrier in the transfer process during image formation. Therefore, it is necessary to remove the residual toner. The cleaning property at the time of cleaning tends to be impaired, and as a result, an image defect may occur.

  On the other hand, when the shape factor SF1 exceeds 130, when the toner is used as a developer, the toner may be destroyed due to collision with a carrier in the developing device. At this time, as a result, the fine powder increases or the release agent component exposed on the toner surface may contaminate the image carrier surface and the like to impair the charging characteristics, and the occurrence of fog caused by the fine powder, etc. May cause problems.

The shape factor SF1 was measured as follows using a Luzex image analyzer (manufactured by Nireco Corporation, FT). First, an optical microscope image of the toner dispersed on the slide glass is taken into a Luzex image analyzer through a video camera, and the maximum length (ML) and projected area (A) of 50 or more toners are measured. (ML ² / A) × (π / 4) × 100 was calculated, and a value obtained by averaging the values was determined as the shape factor SF1.

<Developer>
The toner used in the present invention may be used as it is as a one-component developer, but in the present invention, it is preferably used as a toner in a two-component developer comprising a carrier and a toner.

  Here, from the viewpoint that a color image can be formed with one type of developer, the developer is (1) a color development including the photocurable composition and microcapsules dispersed in the photocurable composition. One type of toner having two or more types of parts, and two or more types of coloring parts contained in the toner can develop colors different from each other, or (2) the photo-curing property Two or more kinds of toners having one coloring part including a composition and microcapsules dispersed in the photocurable composition, and the coloring parts of the two or more kinds of toners are mixed with each other. It is preferable that the developer be of a type that can develop different colors.

  For example, in the former type of developer, the toner includes three types of color developing portions, and the three types of color developing portions include a yellow color developing portion capable of developing a yellow color and a magenta color forming portion capable of developing a magenta color. In the latter type of developer, a yellow color developing toner that can develop a yellow color, and a magenta color that can develop a magenta color. The toner is preferably contained in the developer in a state where the color developing portion and the cyan color developing toner capable of developing a cyan color are mixed.

  The carrier that can be used for the two-component developer is preferably formed by coating the surface of the core material with a resin. The core material of the carrier is not particularly defined as long as the above conditions are satisfied, for example, magnetic metals such as iron, steel, nickel, cobalt, alloys of these with manganese, chromium, rare earth, ferrite, magnetite, etc. From the viewpoint of the surface property of the core material and the resistance of the core material, ferrite, particularly an alloy with manganese, lithium, strontium, magnesium or the like is preferable. Further, the resin covering the surface of the core material is not particularly limited as long as it can be used as a matrix resin, and can be appropriately selected according to the purpose.

  The mixing ratio (mass ratio) of the toner of the present invention and the carrier in the two-component developer is preferably in the range of toner: carrier = 1: 100 to 30: 100, and about 3: 100 to 20: 100. The range of is more preferable.

(toner)
In the following manner, the light non-color-forming F toner in which the light emitting portion (photosensitive / heat-sensitive capsule) was dispersed in the binder resin was obtained.

-Preparation of microcapsule dispersion (1)-
In 16.9 parts by mass of ethyl acetate, 8.9 parts of an electron-donating colorless dye (1) capable of developing a yellow color is dissolved, and capsule wall material (trade name: Takenate D-110N, Takeda Pharmaceutical Co., Ltd.) 20 parts by mass and 2 parts by mass of capsule wall material (trade name: Millionate MR200, manufactured by Nippon Polyurethane Industry Co., Ltd.) were added.
The resulting solution was added to a mixed solution of 42 parts by mass of 8% by mass phthalated gelatin, 14 parts by mass of water, and 1.4 parts by mass of a 10% by mass sodium dodecylbenzene sulfonate solution. Emulsified and dispersed at 0 ° C. to obtain an emulsion. Next, 72 parts by mass of a 2.9% tetraethylenepentamine aqueous solution was added to the obtained emulsion and heated to 60 ° C. with stirring. After 2 hours, the electron-donating colorless dye (1) was added to the core. To obtain a microcapsule dispersion (1) having an average particle size of 0.5 μm.
The glass transition temperature of the material constituting the outer shell of the microcapsule contained in this microcapsule dispersion (1) (the material obtained by reacting Takenate D-110N and Millionate MR200 under the same conditions as above). Was 100 ° C.

-Preparation of microcapsule dispersion (2)-
A microcapsule dispersion (2) was obtained in the same manner as in the preparation of the microcapsule dispersion (1) except that the electron-donating colorless dye (1) was changed to the electron-donating colorless dye (2). The average particle size of the microcapsules in this dispersion was 0.5 μm.

-Preparation of microcapsule dispersion (3)-
A microcapsule dispersion (3) was obtained in the same manner as in the preparation of the microcapsule dispersion (1) except that the electron-donating colorless dye (1) was changed to the electron-donating colorless dye (3). The average particle size of the microcapsules in this dispersion was 0.5 μm.
The chemical structural formulas of the electron donating colorless dyes (1) to (3) used for the preparation of the microcapsule dispersion are shown below.

—Preparation of Photocurable Composition Dispersion (1) —
100.0 parts by mass (mixing ratio 50:50) of a mixture of electron-accepting compounds (1) and (2) having a polymerizable group and 0.1 part by mass of a thermal polymerization inhibitor (ALI) were added to isopropyl acetate (to water). (Solubility of about 4.3%) was dissolved in 125.0 parts by mass at 42 ° C. to obtain a mixed solution I.
In this mixed solution I, hexaarylbiimidazole (1) [2,2′-bis (2-chlorophenyl) -4,4 ′, 5,5′tetraphenyl-1,2′-biimidazole] 18.0 Part by mass, 0.5 part by mass of a nonionic organic dye, and 6.0 parts by mass of an organic boron compound were added and dissolved at 42 ° C. to obtain a mixed solution II.
The above mixed solution II was added to a mixed solution of 300.1 parts by mass of an 8% by mass gelatin aqueous solution and 17.4 parts by mass of a 10% by mass surfactant (1) aqueous solution, and a homogenizer (manufactured by Nippon Seiki Co., Ltd.). ) For 5 minutes at a rotational speed of 10,000, followed by desolvation treatment at 40 ° C. for 3 hours to obtain a photocurable composition dispersion (1) having a solid content of 30% by mass.
In addition, the electron-accepting compound (1) which has a polymeric group used for preparation of a photocurable composition dispersion liquid (1), the electron-accepting compound (2) which has a polymeric group, and thermal polymerization inhibitor (ALI) Structural formulas of hexaarylbiimidazole (1), surfactant (1), nonionic organic dye, and organoboron compound are shown below.

-Preparation of photocurable composition dispersion (2)-
0.6 parts by mass of the following organic borate compound (I), 0.1 part by mass of the spectral sensitizing dye-based borate compound (I) shown below, and the following auxiliary agent (1) for the purpose of increasing sensitivity: 5 parts by mass of the following electron-accepting compound (3) having a polymerizable group was added to a mixed solution of 1 part by mass and 3 parts by mass of isopropyl acetate (solubility of about 4.3% in water).

The obtained solution was mixed with 13 parts by weight of a 13% by weight aqueous gelatin solution, 0.8 part by weight of the following 2% by weight surfactant (2) aqueous solution, and 0.8 part by weight of the following 2% by weight surfactant (3) aqueous solution. And emulsified with a homogenizer (manufactured by Nippon Seiki Co., Ltd.) for 5 minutes at a rotational speed of 10,000 rotations to obtain a photocurable composition dispersion (2).
In addition, the electron-accepting compound (3), auxiliary agent (1), surfactant (2) and surfactant (3) having a polymerizable group used for the preparation of the photocurable composition dispersion (2). The structural formula is shown below.

-Preparation of photocurable composition dispersion (3)-
In place of the spectral sensitizing dye-based borate compound (I), the photocurable composition dispersion liquid (2) was used except that 0.1 part by mass of the spectral sensitizing dye-based borate compound (II) shown above was used. A photocurable composition dispersion (3) was obtained in the same manner as in the preparation.

-Preparation of resin particle dispersion-
Styrene: 460 parts by mass nbutyl acrylate: 140 parts by mass Acrylic acid: 12 parts by mass Dodecanethiol: 9 parts by mass The above components were mixed and dissolved to prepare a solution. Subsequently, an emulsion (monomer) in which 12 parts by weight of an anionic surfactant (manufactured by Rhodia, Dowfax) was dissolved in 250 parts by weight of ion-exchanged water, and the above solution was added and dispersed and emulsified in a flask. Emulsion A) was prepared.
In addition, 1 part of an anionic surfactant (Dowfax, manufactured by Rhodia Co., Ltd.) was dissolved in 555 parts by mass of ion-exchanged water and charged into a polymerization flask. The polymerization flask was sealed, a reflux tube was installed, and the polymerization flask was heated to 75 ° C. with a water bath while being slowly stirred while injecting nitrogen.

Next, a solution obtained by dissolving 9 parts of ammonium persulfate in 43 parts by mass of ion-exchanged water was added dropwise to the polymerization flask through a metering pump over 20 minutes, and then the monomer emulsion A was also added to the metering pump. Over 200 minutes.
Thereafter, the polymerization flask was kept at 75 ° C. for 3 hours while stirring slowly, to complete the polymerization.
As a result, a resin particle dispersion having a median particle diameter of 210 nm, a glass transition point of 51.5 ° C., a weight average molecular weight of 31,000, and a solid content of 42% by mass was obtained.

-Preparation of photosensitive / thermosensitive capsule dispersion (1)-
-Microcapsule dispersion (1): 150 parts by mass-Photocurable composition dispersion (1): 300 parts by mass-Polyaluminum chloride: 0.20 parts by mass-Ion exchange water: 300 parts by mass The above ingredients are mixed. Nitric acid is added to the prepared raw material solution to adjust the pH to 3.5, and after thoroughly mixing and dispersing with a homogenizer (IQA, Ultra Tarrax T50), it is transferred to a flask and stirred with a three-one motor in a heating oil bath. While heating to 40 ° C. and holding at 40 ° C. for 60 minutes, 300 parts by mass of the resin particle dispersion was further added and gently stirred at 60 ° C. for 2 hours. Thus, a photosensitive / thermosensitive capsule dispersion (1) was obtained.
The volume average particle size of the photosensitive / thermosensitive capsules dispersed in this dispersion was 3.53 μm. Further, spontaneous color development of the dispersion was not confirmed during the preparation of the dispersion.

-Preparation of photosensitive / thermosensitive capsule dispersion (2)-
-Microcapsule dispersion (2): 150 parts by mass-Photocurable composition dispersion (2): 300 parts by mass-Polyaluminum chloride: 0.20 parts by mass-Ion exchange water: 300 parts by mass A photosensitive / thermosensitive capsule dispersion (2) was obtained in the same manner as in the preparation of the photosensitive / thermosensitive capsule dispersion (1) except that the components were used.
The volume average particle size of the photosensitive / thermosensitive capsules dispersed in this dispersion was 3.52 μm. Further, spontaneous color development of the dispersion was not confirmed during the preparation of this dispersion.

-Preparation of photosensitive / thermosensitive capsule dispersion (3)-
-Microcapsule dispersion (3): 150 parts by mass-Photocurable composition dispersion (3): 300 parts by mass-Polyaluminum chloride: 0.20 parts by mass-Ion exchange water: 300 parts by mass A photosensitive / thermosensitive capsule dispersion (3) was obtained in the same manner as in the preparation of the photosensitive / thermosensitive capsule dispersion (1) except that the components were used.
The volume average particle size of the photosensitive / thermosensitive capsules dispersed in this dispersion was 3.47 μm. Further, spontaneous color development of the dispersion was not confirmed during the preparation of this dispersion.

-Preparation of toner-
Photosensitive / thermosensitive capsule dispersion (1): 750 parts by mass Sensitive / thermosensitive capsule dispersion (2): 750 parts by mass Photosensitive / thermosensitive capsule dispersion (3): 750 parts by mass The flask was transferred to a flask, heated to 42 ° C. while heating in the flask, and maintained at 42 ° C. for 60 minutes, and then 100 parts by mass of the resin particle dispersion was further added and gently stirred.

  Thereafter, the pH in the flask was adjusted to 5.0 with a 0.5 mol / liter sodium hydroxide aqueous solution, and then heated to 55 ° C. while stirring was continued. During the temperature rise to 55 ° C, the pH in the flask usually drops to 5.0 or lower, but here, an aqueous sodium hydroxide solution is added dropwise to keep the pH from dropping to 4.5 or lower. did. This state was maintained at 55 ° C. for 3 hours.

  After completion of the reaction, the mixture was cooled, filtered, sufficiently washed with ion exchange water, and then solid-liquid separated by Nutsche suction filtration. Then, it was redispersed in 3 liters of ion exchange water at 40 ° C. in a 5 liter beaker, and stirred and washed at 300 rpm for 15 minutes. This washing operation was repeated 5 times, followed by solid-liquid separation by Nutsche suction filtration, followed by freeze-drying for 12 hours to obtain toner particles in which photosensitive / thermosensitive capsules were dispersed in a styrene resin. When the particle diameter of the toner particles was measured with a Coulter counter, the volume average particle diameter D50v was 15.2 μm.

  Subsequently, 1.0 part by mass of hydrophobic silica (manufactured by Cabot, TS720) was added to 50 parts by mass of the toner particles, and mixed with a sample mill to obtain an externally added toner.

(Developer)
As a carrier, 30% by mass of styrene / acrylic copolymer (number average molecular weight: 23000, weight average molecular weight: 98000, Tg: 78 ° C.) and granular magnetite (maximum magnetization: 80 emu / g, average particle size: 0.5 μm) 70% by mass is kneaded, pulverized, and classified to a volume average particle size of 100 μm. The toner and the carrier are weighed so that the toner concentration is 5% by mass and mixed for 5 minutes by a ball mill. Thus, developer 1 was obtained.

(Image forming apparatus and image forming)
Image formation was performed using the image forming apparatus shown in FIG. Specifically, a scorotron was used as the charging device 12. As the exposure device 14, an LED image bar having a wavelength of 780 nm capable of forming a latent image with a resolution of 600 dpi was used. The developing device 16 includes a metal sleeve for developing a two-component magnetic brush and can perform reversal development. The toner charge amount when the developer was loaded in the developing unit was about −5 to −30 μC / g.

The color-generation information providing device 30, the peak wavelength 405 nm (exposure ^{amount: 0.2mJ / cm 2), 532nm} ( exposure ^{amount: 0.2mJ / cm 2), 657nm} ( exposure amount: 0.4mJ / cm ²⁾ light An LED image bar with a resolution of 600 dpi capable of irradiating the image was placed outside the photoconductor 10, and the point of coloring information was placed 2 mm away from the development point on the photoconductor surface.

The transfer device 20 includes a semiconductive roll formed by coating a conductive elastic body on the outer periphery of a conductive core material as a transfer roll. The conductive elastic body is made by dispersing two types of carbon black consisting of ketjen black and thermal black in an incompatible blend formed by mixing NBR and EPDM, and has a roll resistance of 10 ^8.5 Ωcm, The Asker C hardness is 35 degrees.

  A fixing belt in the fixing device 22 was produced as follows. An aluminum cylinder having an outer diameter of 84 mm and a length of 450 mm was prepared, and the surface was roughened to Ra 1.0 μm by blasting with spherical alumina particles (manufactured by Fuji Seisakusho Co., Ltd., particle size 105 to 125 μm). A silicone-based mold release agent (Sepa Co., Ltd., manufactured by Shin-Etsu Chemical Co., Ltd.) was applied to the substrate, and baked at 300 ° C. for 1 hour to obtain a core.

  FIG. 4 shows an annular coating device 80. A sealing material 74 having a hole with an inner diameter of 82 mm was attached to the bottom of an annular coating tank 77 having an inner diameter of 140 mm, a height of 80 mm, and an opening at the bottom of 100 mm, and the solution 73 was placed inside. Further, an aluminum annular body 75 having an outer diameter of 96 mm, a minimum inner diameter of 85.2 mm, a maximum inner diameter of 90 mm, and a height of 30 mm was placed in a floating state on the solution.

  Another other core body 72 is stacked under the core body 71, the core body 71 is passed through the sealing material 74, the solution 73 and the annular body 75 are passed through, and pulled up at a speed of 0.6 m / min. . As a result, a coating film 76 having a wet film thickness of 0.6 mm was formed.

  The core was taken out, leveled, and heated and dried at 150 ° C. for 30 minutes while rotating at 15 rpm to form a PI precursor layer. After taking out, the core body is made vertical, a conical lid is attached to one end of the core body, an adhesive tape having a width of 20 mm is wound once, and a coating treatment (coating 85 in FIG. 5) is applied to the end of the PI precursor film. gave.

  Next, in addition to water as a solvent, a PFA aqueous paint (fluorine resin dispersion, concentration 60%, viscosity 300 mPa · s) containing ethanol and t-butanol is applied. The solid content is 55% by mass of PFA powder (large particles) having a particle size of about 17 μm, 40% by mass of PFA powder (small particles) having a particle size of about 1 μm, and barium sulfate powder having a particle size of about 2 μm. Is 5% by mass.

  As shown in FIG. 5, this was put in a coating tank 87 having an inner diameter of 140 mm and a height of 500 mm. In addition, this liquid was previously subjected to a defoaming treatment under a reduced pressure of 20 hPa for 12 hours. At the upper part of the coating tank 87, an annular blower 88 for attaching an airflow of 5 m / min in an annular direction toward the upper 45 ° was attached. The core body 71 was made vertical with the coating 85 on the bottom, and was immersed in the paint 86 leaving 5 mm from the top. Next, while applying an air stream, the core 71 was pulled up at a speed of 0.2 m / min to form a PFA coating film.

  After completion of the pulling, the coating was removed, the lower lid was removed, and the coating was dried in a drying furnace at 80 ° C. for 10 minutes. As the heating and baking step, the core was heated at 150 ° C. for 20 minutes, 220 ° C. for 20 minutes, and 380 ° C. for 30 minutes to form a PI resin film, and the PFA coating film was baked. After the core had cooled to room temperature, the film was removed to obtain an endless belt having a PFA layer of 25 μm thickness on a PI resin of 70 μm thickness. Both ends were cut to obtain a fixing belt (fixing member 35) having a length of 334 mm. The white light transmittance of this fixing belt was measured with an illuminometer T10 (Konica Minolta) under a xenon lamp standard light source and found to be 70%.

  The fixing device uses the fixing belt, is stretched on four rolls including a roll 38, has a 1 kW halogen lamp 36 (length 350 mm, color temperature 2500 K), and has a fixing temperature of It controlled so that it might become 180 degreeC. The pressure roll 25 has a 7 mm thick silicone rubber layer on the surface of an aluminum tube having an outer diameter of 40 mm and a thickness of 1.5 mm. The nip length is 22 mm.

  The photoreceptor 10 is formed by forming a 20 μm layer of polyvinyl butyral resin in which zinc oxide is dispersed as an undercoat layer on an aluminum pipe of 60φ × 340 L (outer diameter: 60 mm, length: 340 mm), and CGL is CGM. Bragg angles (2θ ± 0.2 °) of the X-ray diffraction spectrum using Cukα rays are 7.5 °, 9.9 °, 12.5 °, 16.3 °, 18.6 °, 25.1. 15 parts of hydroxygallium phthalocyanine represented by a crystal form having a diffraction peak at a position of °, 28.1 °, 10 parts of vinyl chloride-vinyl acetate copolymer resin (VMCH, manufactured by Nihon Unicar) as a binder resin And a solution comprising 300 parts of n-butyl acetate solvent, dispersed in a sand mill for 4 hours, dip-coated on the undercoat layer and dried at 100 ° C. for 10 minutes to form a layer having a thickness of about 0.05 μm CTL is composed of 40 parts of N, N′-diphenyl-N, N ′-(m-tolyl) benzidine and 60 parts of polycarbonate Z resin (Iupilon Z600, manufactured by Mitsubishi Gas Chemical Company) having a weight average molecular weight of 60,000 parts of monochlorobenzene. It is a 25 μm thick layer formed by dissolving in a mixed solvent consisting of 150 parts of tetrahydrofuran and dip-coating on CGL and drying at 135 ° C. for 40 minutes. Since this photoreceptor has a CGL film thickness thinner than usual (0.2 μm), the sensitivity is low, but deterioration due to strong exposure is reduced.

The printing conditions were set as follows by the image forming apparatus having the above configuration.
Photoconductor linear velocity: 10 mm / sec.
-Charging conditions: -400V applied to scorotron screen and -6kV DC applied to wire. At this time, the surface potential of the photosensitive member was −400V.
-Exposure: Exposure was performed with a logical sum of image information for four colors of Y, M, C, and black, and the potential after the exposure was about -50V.
Development bias: A rectangular wave of alternating current Vpp 1.2 kV (3 kHz) is superimposed on direct current −330V.
Developer contact conditions: peripheral speed ratio (development roll / photoreceptor) 2.0, development gap 0.5 mm, developer weight on the development roll 400 g / m ² , toner development amount on the photoreceptor was solid The image was 5 g / m ² .
Transfer bias: DC + 800V applied.
Fixing temperature: The fixing roll surface temperature is set to 180 ° C.

  Under the above conditions, a chart having a gradation image portion was printed for each color of Y, M, C, R, G, B, and K. The coloring information was given to the toner in the combinations shown in Table 1 below (indicating that the toner is colored in a desired color when the LED marked with a circle emits light). In addition, in order to control the color density by the light emission intensity or the light emission time, time width modulation in which the time of one dot is divided into eight is adopted.

(Image evaluation)
The following evaluation was performed about the print sample obtained on the said conditions.
-Color density-
When the image density of the solid image part for each of the colors Y, M, and C was examined with a density measuring device X-Rite 938 (manufactured by X-Rite), the image density was 1.5 or more and sufficient color development was obtained for any color. confirmed.

-Color reproducibility-
For each color of R, G, B, Y, M, and C, the color reproducibility was examined using a 5% to 100% gradation chart in 5% increments. It was excellent.

  The color fixing by the fixing device 22 was performed in the nip length with the halogen lamp 36 and the fluorescent lamp 37 including the three wavelengths, and the illuminance was 5000 lux.

  From the above, in an image forming apparatus that can obtain a color image with a single image exposure, the exposure to fix the color of the toner is performed at the time of fixing. It was confirmed that the rise can be suppressed.

It is a schematic block diagram of the 1st embodiment of this invention. It is a circuit block diagram of a printing control unit. 2A and 2B are schematic diagrams for explaining a toner color development mechanism, in which FIG. 1A shows a color development portion and FIG. 2B shows an enlarged state thereof. It is a schematic explanatory drawing of a cyclic | annular coating apparatus. It is a schematic explanatory drawing of a dip coating apparatus. It is a schematic block diagram which shows an example of the conventional image forming apparatus.

Explanation of symbols

10: Photoconductor (image carrier)
12 ... Charging device (charging means)
14 ... Exposure apparatus (exposure means)
16... Developing device (toner image forming means)
18: Charge removing means 20: Transfer device (transfer means)
22: Fixing device (fixing means)
24 ... Cleaner 25 ... Pressure member 26 ... Recording medium 30 ... Coloring information applying device 35 ... Fixing member 36 ... Heating heater 37 ... Coloring light source 38 ... Roll T ... Toner image

Claims (5)

A fixing device for fixing a toner image on a recording medium,
Including a light source and a heat source, at least a light path of light from the light source is transparent,
A fixing device, wherein the toner forming the toner image is a toner that is controlled to maintain a colored state or a non-colored state by applying coloring information by light.   The fixing device according to claim 1, wherein at least a part of a member constituting the optical path is in contact with the toner image.   A first component and a second component that are present in a state where the toners are isolated from each other and react with each other; and a photocurable composition containing any one of the first component and the second component. 2. The toner according to claim 1, wherein the photocurable composition maintains a cured or uncured state by applying color development information by light, and the reaction for color development is controlled. 3. The fixing device according to 2.   An image forming apparatus comprising the fixing device according to claim 1. A toner image forming step for forming a toner image on the surface of the image carrier, a color information providing step for applying color information by light to the formed toner image, and a toner image to which the color information is added on the surface of the recording medium A transfer step of transferring, and a fixing step of fixing the toner image transferred to the surface of the recording medium,
The toner that forms the toner image is a toner that is controlled to maintain a colored state or a non-colored state by applying coloring information by light,
The image forming method characterized in that the fixing in the fixing step is accompanied by a color development process for developing the color of the toner image to which the color development information is applied and a light irradiation process for fixing the color development of the toner image.

Images