JP2008249760A - Liquid developer and display device manufacturing method using the same - Google Patents

Abstract

A liquid developer capable of forming a toner layer with high resolution and high accuracy is obtained.
A liquid developer comprising toner particles containing a group V metal organic acid salt as a charge control agent on the surface of core particles coated with thermoplastic resin fine particles, wherein the group V metal organic acid is used. The metal component contained in the salt is one selected from the group consisting of vanadium, niobium, and tantalum, and the organic salt component includes octylic acid, naphthenic acid, neodecanoic acid, oleic acid, lauric acid, and stearic acid. It is an organic acid having 6 to 30 carbon atoms, and the thermoplastic resin fine particles have an average particle diameter of 0.1 to 5 μm.
[Selection] Figure 1

Description

  The present invention relates to a method for manufacturing a display device such as a plasma display and a field emission display, and a liquid developer used therefor.

  Conventionally, a photolithography technique has played a central role as a technique for forming a fine pattern on the surface of a substrate. However, while this photolithography technology increases the resolution and performance, it requires huge and expensive manufacturing equipment, and the manufacturing cost is increasing according to the resolution.

  On the other hand, in the manufacturing field of image display devices and the like as well as semiconductor devices, there is an increasing demand for cost reduction as well as performance improvement. However, the above photolithography technique cannot sufficiently satisfy such a requirement.

  Under such circumstances, a pattern forming technique using a digital printing technique has attracted attention. For example, inkjet technology has begun to be put into practical use as a patterning technology that makes use of features such as simplicity of the apparatus and non-contact patterning. However, there has been a limit to high resolution and high productivity.

  On the other hand, the electrophoretic technique including the electrophotographic technique using the liquid toner has an excellent possibility regarding low cost, high resolution, and high productivity. For example, a technique for forming a phosphor layer of a front substrate for a flat panel display using such an electrophoresis technique has been proposed (see, for example, Patent Document 1). In this method, a resin composed of a core portion that is insoluble or swells in an insulating solvent and an outer edge portion that swells or dissolves in the insulating solvent is used as the resin component for the phosphor toner.

However, it is necessary to use a good solvent capable of completely dissolving the resin at the time of toner particle production. For this reason, a volatile organic solvent other than an insulating solvent must be used, and a resin with a controlled SP value must be designed. Chargeability, adhesiveness, and cohesiveness, which are inherent toner characteristics, must be designed. It was difficult to control the materials, and the range of material selection was very limited.
Japanese Patent Laid-Open No. 9-202995

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a liquid developer capable of easily forming a toner layer with high resolution and high accuracy, and an image display apparatus using the liquid developer. It is to provide a manufacturing method.

The liquid developer of the present invention comprises an electrically insulating solvent,
V cores contained in the electrically insulating solvent, a thermoplastic resin particle coating layer provided on the surface of the core particles, and V added as a charge control agent to the surface of the core particles coated with the thermoplastic resin particles And toner particles containing an organic acid salt of a group metal.

Forming a light shielding layer having a plurality of frame-like or stripe-like patterns on a transparent substrate;
The display device manufacturing method of the present invention includes an electrically insulating solvent, a core particle, a thermoplastic resin particle coating layer provided on the surface of the core particle, and the thermoplastic resin. A liquid developer containing toner particles containing a group V metal organic acid salt added as a charge control agent to the surface of the core particle coated with fine particles is supplied to the surface of the image carrier through a supply member, and the supply A development step of forming an electric field between the member and the image carrier to form a dot-shaped or stripe-shaped pattern image on the surface of the image carrier;
A rolling step of rolling the image holding body on which a pattern image is formed with a liquid developer along a transparent substrate having a light shielding layer held at a fixed position;
An electric field is formed between the rolling image carrier and the transparent substrate, and a pattern image on the surface of the image carrier is transferred to the transparent substrate. And a front substrate forming process including a transfer step of forming a phosphor layer and a step of forming a metal back layer on the phosphor layer.

  When the present invention is used, the patterning accuracy is improved, and the toner layer can be formed with high resolution and high accuracy.

  The liquid developer of the present invention contains an electrically insulating solvent and toner particles.

  The toner particles include core particles, a coating layer in which thermoplastic resin fine particles are coated on the core particles, and an organic acid metal salt of a group V metal added on the core particles provided with the coating layer. .

  FIG. 1 is a schematic cross-sectional view showing the configuration of toner particles in a liquid developer according to the present invention.

  As shown in the figure, the toner particle 60 is formed with a coating layer of core particles 61 and resin fine particles 63 attached on the core particles 61.

  Here, the coating layer covers at least a part of the toner particle surface.

  An organic acid metal salt of a V group metal (not shown) is added to the toner particle surface as a charge control agent.

  The charge control agent added to the surface of the toner particles can be adsorbed on the surface, or can take an acid / base coordination with a functional group on the surface.

  Further, in the liquid developer, the charge control agent present in the electrically insulating solvent and at least a part of this organic compound are added to the surface of the thermoplastic resin particle coating layer and adsorbed or coordinated. . The remaining charge control agent and the organic compound may be present in the electrically insulating solvent without acting on the surface of the thermoplastic resin particle coating layer.

  The liquid developer of the present invention has moderate conductivity by including an organic acid metal salt of a group V metal as a charge control agent. As a result, the current value becomes close to 0 in a short time after electrophoresis, and a steady current hardly flows even if voltage is continuously applied. For this reason, the charge control agent remaining in the liquid developer does not move, and convection due to the movement of the charge control agent does not occur in the liquid developer, so that the patterning of the electrodeposited toner layer is disturbed. There is no.

  Thus, the liquid developer of the present invention has good patterning accuracy. Therefore, when the present invention is used, the toner layer can be formed with high resolution and high accuracy.

  When the liquid developer of the present invention is used, the phosphor layer and the color filter layer of the flat image display device can be formed with high resolution and high accuracy. When the phosphor layer is formed, a phosphor can be used as the core particle. Moreover, when forming a color filter, the coloring agent of an inorganic pigment etc. can be used as a core particle.

  The weight ratio of the toner particles to the insulating solvent is preferably 2:98 to 50:50 with respect to 100 parts by weight of the liquid developer.

  If the weight ratio is out of the above range, a large amount of solvent is required to obtain a predetermined film thickness, or toner particles adhere to other than the pattern to be film-formed, which tends to cause contamination. There is.

  Further, the charge control agent is preferably 1 to 50 parts by weight with respect to the toner particles with respect to the core particles.

  The addition amount of the thermoplastic resin fine particles is preferably 5% by volume to 200% by volume with respect to the core particles.

  If the addition amount of the thermoplastic resin fine particles is less than 5% by volume with respect to the core particles, the amount of the thermoplastic resin adhering is too small, so that the probability that the core particles are exposed increases, and the adsorptivity of the charge control agent and This tends to make it difficult to control the chargeability of the toner particles. On the other hand, if it exceeds 200% by volume, the thermoplastic resin cannot adhere to the core particles and tends to be free and aggregated in the solution. In this case, even if a charge control agent or the like is added to give charge to the toner particles, the charge is adsorbed to the released thermoplastic resin and tends to inhibit the charging characteristics of the toner particles. Taking these problems into consideration, the addition amount of the thermoplastic resin fine particles is more preferably 10% by volume or more and 150% by volume or less by volume ratio with respect to the core particles.

  Further, when the Group V metal organic acid salt is less than 1 part by weight based on the toner particles, the toner charge amount is insufficient and the electrodeposited film flows or the toner particles adhere to other portions than the portion where the film should be formed. It tends to cause contamination. On the other hand, when the amount exceeds 50 parts by weight, the amount of ionic components in the developer becomes excessive and the resistance of the entire developer becomes too low, so that the electrophoretic properties of the toner particles tend to be lowered.

  The core particles preferably have an average particle size of 0.01 μm to 10 μm.

  If it is less than 0.01 μm, intermolecular aggregation of the core particles is increased, and uniform dispersion tends to be difficult. Thus, when using core particles with a small average particle size and poor dispersibility (for example, fine pigment particles having an average particle size of several nm), they can be supported on a resin having a larger average particle size. it can. Thereby, dispersibility can be improved and applied. If it exceeds 10 μm, it is difficult to uniformly stir the core particles, and as a result, it tends to be difficult to form a uniform resin layer.

  Examples of the core particles include phosphor particles, colorants such as inorganic pigments, and the like.

Examples of the phosphor that can be used in the present invention include Y ₂ O ₃ : Eu: YVO ₄ : Eu, (Y, Gd) BO ₃ : Eu, Y ₂ O ₂ S: Eu, and γ-Zn ₃ (PO ₄ ) _2. : Mn, (ZnCd) S: Ag + InO ( or _{red), Zn 2 GeO 2: Mn} , BaAl 12 O 19: Mn, Zn 2 SiO 4: Mn, LaPO 4: Tb, ZnS: (Cu, Al), ZnS: _{(Au, Cu, Al),} (ZnCd) S: (Cu, Al), Zn 2 SiO 4: (Mn, As), Y 3 Al 5 O 12: Ce, Gd 2 O 2 S: Tb, Y 3 Al ₅ O ₁₂ : Tb, ZnO: Zn (more green), Sr ₅ (PO ₄ ) ₃ CI: Eu, BaMgAl ₁₄ O ₂₃ : Eu, BaMgAl ₁₆ O ₂₇ : Eu, ZnS: Ag + red pigment, Y ₂ SiO ₃ : Ce (above Color), and the like.

  Examples of inorganic pigments that can be used in the present invention include natural pigments such as ocher, chrome lead, zinc yellow, barium yellow, chromium orange, molybdenum red, chromium green and other ferrocyan compounds such as bitumen, Titanium oxide, titanium yellow, titanium white, bengara, yellow iron oxide, zinc oxide, zinc ferrite, zinc white, iron black, cobalt blue, chromium oxide, spinel green and other oxides, cadmium yellow, cadmium orange, cadmium red, etc. Examples thereof include sulfates such as sulfides and barium sulfate, silicates such as calcium silicate and ultramarine, and metal powders such as bronze and aluminum.

  Examples of organic acid metal salts of Group V metals added as charge control agents of the present invention include vanadium octylate, niobium octylate, tantalum octylate, vanadium naphthenate, niobium naphthenate, tantalum naphthenate, vanadium oleate, Examples include niobium oleate and tantalum oleate.

The electrically insulating solvent used in the liquid developer of the present invention preferably has a boiling point in the temperature range of 70 to 250 ° C. and has a volume resistivity of 10 ⁹ Ω · cm or more, preferably 10 ¹⁰ to 10 ¹⁷ Ω · cm. And a dielectric constant of less than 3.

  Examples of such an electrically insulating solvent include aliphatic hydrocarbons such as n-pentane, hexane and heptane, alicyclic hydrocarbons such as cyclopentane and cyclohexane, chlorinated alkanes, fluorinated alkanes, chlorofluorocarbons and the like. Halogenated hydrocarbon solvents, silicone oils and mixtures thereof can be used. Preferably, components such as Isopar G (registered trademark), Isopar H (registered trademark), Isopar K (registered trademark), Isopar L (registered trademark), Isopar M (registered trademark) and Isopar V (registered trademark) manufactured by Exxon Corporation are used. Branched paraffin solvent mixtures can be used.

  Further, the thermoplastic resin fine particles used in the liquid developer of the present invention can be produced using a polymerization method represented by, for example, a suspension conformation method or an emulsion polymerization method.

  The thermoplastic resin fine particles preferably have an average particle diameter of 0.1 μm to 5 μm.

  As such thermoplastic resin fine particles, for example, acrylic fine particles obtained as a dried powder having a primary average particle diameter of about 0.1 μm to 5 μm can be used. In addition to fine particles, acrylic resin, polyester resin, polyamide resin, nylon resin and other thermoplastic resins that have been granulated or pelletized, or that have been physically pulverized by a fine pulverizer Can be used.

  Further, it can be used after being finely divided in an insulating solvent by a bead mill such as a sand grinder or a ball mill.

  In order to provide the thermoplastic resin fine particles on the core particles, for example, a method in which a dispersion system including the core particles and the thermoplastic resin fine particles is heated and stirred at a temperature equal to or higher than the softening point of the thermoplastic resin fine particles. However, if a hydrophilic phosphor is used as the core particle, it is difficult to adhere even if hydrophobic thermoplastic resin fine particles are applied. In such a case, the core particles are surface-treated with a silane coupling agent in advance, and this silane coupling treatment layer functions as a binder by making the core particles and the thermoplastic resin fine particles have an affinity. The fine resin particles can be deposited on the core particles, or by depositing wax or the like on the core particles together with the thermoplastic resin fine particles, the thermoplastic resin particles can be attached to the surface of the core particles.

  The concentration of an aqueous solution of a silane coupling agent or a water-alcohol solution that performs uniform surface treatment on the core particles, and an aqueous acetic acid solution having a pH of about 4 is preferably 0.01% to 5% by weight.

  When the amount is less than 0.01% by weight, sufficient silane coupling treatment cannot be performed on the surface of the core particles, and the adhesion of the thermoplastic resin fine particles tends to be insufficient. When the amount exceeds 5% by weight, the silane coupling agent. Cannot completely dissolve in the solvent, on the contrary, there is a tendency that unevenness occurs in the silane coupling treatment or aggregation occurs.

  The manufacturing method of the flat image display apparatus according to the present invention includes a process of forming a front substrate.

The process of forming this front substrate is
Forming a light shielding layer having a lattice or stripe pattern on a transparent substrate;
The liquid developer according to the present invention is supplied to the surface of the image carrier through a supply member, and an electric field is formed between the supply member and the image carrier to form a dot or stripe pattern on the surface of the image carrier. A development process for forming an image;
A rolling step of rolling an image carrier on which a pattern image is formed, along a transparent substrate having a light shielding layer held at a fixed position;
An electric field is formed between the rolling image carrier and the transparent substrate, a pattern image on the surface of the image carrier is transferred to the transparent substrate, and a phosphor layer is formed in each region on the transparent substrate partitioned by a light shielding layer. And a transfer step of forming a metal back layer on the phosphor layer.

  In this method, the film thickness of the phosphor layer and the color filter layer of the obtained display device can be controlled by adjusting the composition and concentration of the liquid developer.

  In one embodiment of the present invention, the image carrier may have a patterned electrode layer for forming a pattern image on the surface thereof. By changing the shape of the electrode layer, the phosphor layer and the color filter layer can be patterned into an arbitrary shape easily and at low cost.

  Next, an example of a front substrate forming process used in the present invention will be described with reference to FIGS.

  FIG. 2 is an external view showing an example of a pattern forming apparatus used in the front substrate forming process.

  As shown in FIG. 2, the pattern forming apparatus 10 includes an original plate 1 (image carrier) wound around a peripheral surface of a drum base tube (described later) that rotates in a clockwise direction (arrow R direction) in the figure. A charger 2 that charges a high-resistance layer, which will be described later, of the original 1 with a charge, and a plurality of developing devices that supply the original 1 with liquid developers of each color (r: red, g: green, b: blue) and develop 3r, 3g, 3b (hereinafter also collectively referred to as a developing device 3), a dryer 4 (drying device) that evaporates and drys the solvent component of the liquid developer adhering to the original plate 1 by development by air blow, A stage 6 (holding mechanism) that holds a glass plate 5 as a transparent substrate to be transferred to form a pattern by transferring developer particles attached to the original 1 in a fixed position, and the surface of the glass plate 5 prior to transfer Apply high resistance or insulating solvent to Cloth 7 (wetting apparatus), having a discharger 9 for removing charge of the cleaner 8, and the original plate 1 for cleaning the master 1 having been subjected to transfer.

  The liquid developer accommodated in the developing devices 3r, 3g, and 3b for the respective colors contains toner particles that are charged in an insulating solvent, and development is performed by the electrophoresis of the fine particles in an electric field. The toner particles have core particles, a coating layer in which thermoplastic resin fine particles are coated on the core particles, and a charge control agent added on the coating layer, and the particle size thereof is 1 to 10 μm. Examples of the core particles include phosphor particles of each color having an average particle size of about 4 (μm), a configuration in which pigment fine particles of each color are encapsulated inside the resin particles, or a configuration in which pigment fine particles of each color are supported on the surface of the resin particles. Can be implemented.

  Further, at least one of the liquid developers of r, g, and b is provided on the surface of the core particle, the core particle composed of the ZnS-based phosphor contained in the electrically insulating solvent, and the electrically insulating solvent. A coating layer of thermoplastic resin particles, and toner particles containing a metal compound containing at least one group V metal organic acid salt added as a charge control agent to the surface of the core particles coated with the thermoplastic resin particles.

As shown in the plan view of FIG. 3A, the original plate 1 is formed in a rectangular thin plate shape. As shown in the cross-sectional view of FIG. 3B, the original 1 has a thickness of 0.05 (mm) to 0.4 (mm), more preferably a thickness of 0.1 (mm) to 0.2 ( mm) of a rectangular metal film 12 having a high resistance layer 13 formed thereon. The metal film 12 is flexible and can be composed of materials such as aluminum, stainless steel, titanium, and amber, or may be a metal or other material deposited on a surface such as polyimide or PET, but has a high transfer pattern. In order to form the film with positional accuracy, it is desirable to use a material that hardly causes thermal expansion or elongation due to stress. The high resistance layer 13 is formed of a material (including an insulator) having a volume resistivity of 10 ¹⁰ (Ωcm) or more such as polyimide, acrylic, polyester, urethane, epoxy, Teflon (registered trademark), nylon, or the like. The film thickness is 10 (μm) to 40 (μm), more preferably 20 (μm) ± 5 (μm).

  Further, on the surface 13a of the high resistance layer 13 of the original 1 is formed a dot-like pattern 14 in which a large number of rectangular recesses 14a are arranged in an array as partially enlarged in FIG. In this embodiment, for example, as an intaglio plate for manufacturing a phosphor screen formed on the front substrate of a flat-type image display device, only the recesses 14a corresponding to pixels for one color are recessed from the surface 13a of the high resistance layer 13. In the region 14b for the other two colors which are formed and shown by broken lines in FIG. 4, only a space is secured without forming a recess.

  FIG. 5 shows a cross-sectional view of the original 1 in which one concave portion 14a is enlarged. In the present embodiment, the surface 12a of the metal film 12 is exposed at the bottom of the recess 14a, and the exposed surface 12a of the metal film 12 functions as the patterned electrode layer of the present invention. The depth of the recess 14 a substantially corresponds to the layer thickness of the high resistance layer 13. A surface release layer having a thickness of about 0.5 (μm) to 3 (μm) on the entire surface of the original plate 1 including the surface 12a of the metal film 12 exposed at the bottom of the recess 14a and the surface 13a of the high resistance layer 13. If the coating is applied, transfer characteristics are improved and more preferable characteristics can be obtained.

  FIG. 6 is a schematic cross-sectional view illustrating a state where the film-shaped original plate 1 having the above structure is wound around the drum base tube 31. A notch 31a in the upper part of the drum base tube 31 in the drawing is provided with a clamp 32 for fixing one end of the original plate 1 and a clamp 33 for fixing the other end. When the original 1 is wound on the peripheral surface of the drum base tube 31, first, one end of the original 1 is fixed to the clamp 32, and then the other end 34 is fixed with the clamp 33 while the original 1 is stretched. Thereby, the original 1 can be wound around the prescribed position of the drum base pipe 31 without slack.

  FIG. 7 is a partial configuration diagram for explaining a process of charging the surface 13 a of the high resistance layer 13 of the original 1 wound around the drum base tube 31 by the charger 4 in this manner. The charger 4 is a well-known corona charger, and basically includes a corona wire 42 and a shield case 43. However, the charging uniformity can be improved by providing a mesh-like grid 44. For example, the metal film 12 of the original 1 and the shield case 43 are grounded, a voltage of +5.5 (kV) is applied to the corona wire 42 by a power supply device (not shown), and a voltage of +500 (V) is further applied to the grid 44. When the original 1 is moved in the direction of arrow R in the figure, the surface 13a of the high resistance layer 13 is uniformly charged to about +500 (V).

  The static eliminator 9 shown in the figure has substantially the same structure as the charger 4, but an alternating current (not shown) is applied to the corona wire 46 so as to apply, for example, an alternating voltage having an effective voltage of 6 (kV) and a frequency of 50 (Hz). When the shield case 47 and the grid 48 are connected to the power source, the surface 13a of the high resistance layer 13 of the original plate 1 can be neutralized to approximately 0 (V) prior to charging by the charger 4. The repeated charging characteristics of the resistance layer 13 can be stabilized.

  FIG. 8 is a diagram for explaining the developing operation for the original 1 charged as described above. At the time of development, the developing device 3 of the color to be developed is opposed to the original plate 1, the developing roller 51 (supply member) and the squeeze roller 52 are brought close to the original plate 1, and the liquid developer described above is supplied to the original plate 1. The developing roller 51 is disposed at a position where the peripheral surface thereof is opposed to the surface 13a of the high resistance layer 13 of the original 1 being conveyed with a gap of about 100 to 150 (μm). It rotates at the speed of about 1.5 to 4 times in the same direction (counterclockwise direction in the figure).

  The liquid developer 53 supplied to the peripheral surface of the developing roller 51 by a supply system (not shown) is configured by dispersing charged toner particles 55 as developer particles in a solvent 54 as an insulating liquid. With the rotation of 51, it is supplied to the peripheral surface of the original 1. Here, when a voltage of, for example, +250 (V) is applied to the developing roller 51 by a power supply device (not shown), the positively charged toner particles 55 migrate in the solvent 54 toward the metal film 12 at the ground potential, Collected in the recess 14 a of the original 1. At this time, since the surface 13a of the high resistance layer 13 is charged to about +500 (V), the positively charged toner particles 55 are repelled from the surface 13a and do not adhere.

  After the toner particles 55 are collected in the concave portion 14a of the original 1 in this way, the liquid developer 53 having a reduced concentration of the toner particles 55 subsequently enters a gap where the squeeze roller 52 and the original 1 are opposed. Here, the gap (distance between the surface 13a of the insulating layer 13 and the surface of the squeeze roller 52) is 30 (μm) to 50 (μm), the potential of the squeeze roller is +250 (V). Since it is set to move in the reverse direction at a speed of about 3 to 5 times the speed of the original 1, the development 56 is further promoted and at the same time, a part of the solvent 56 adhering to the original 1 is squeezed out. There is an effect. In this way, a pattern 57 made of toner is formed in the recess 14 a of the original 1.

  By the way, when forming a three-color phosphor pattern on the glass plate 5, first, as shown in FIG. 9, the developing device 3b containing the liquid developer containing the blue phosphor particles moves directly under the original plate 1. Then, the developing device 3b is raised by the lifting mechanism (not shown) and is brought close to the original plate 1. In this state, the original plate 1 is rotated in the direction of arrow R, and the pattern formed by the recesses 14a is developed. When the development of the blue pattern is completed, the developing device 3b is lowered and separated from the original plate 1.

  During this blue developing process, the coating device 7 is moved in the direction of the broken line arrow T1 in the drawing along the surface of the glass plate 5 that has been transported in advance by a transport device (not shown) and is held on the stage 6. It moves and a solvent (insulating liquid) is applied to the surface of the glass plate 5. The role and material composition of this solvent will be described later.

  Thereafter, the original plate 1 carrying the blue pattern on the peripheral surface moves while rotating along the broken line arrow in the figure (this operation is called rolling), and the blue pattern image is transferred to the surface of the glass plate 5. Is done. Details of the transfer will also be described later. The master 1 that has finished transferring the blue pattern is translated to the left in the figure and returned to the initial position during development. At this time, contact with the original plate 1 where the stage 6 holding the glass plate 5 descends and returns to the initial position is avoided.

  Next, the three-color developing devices 3r, 3g, and 3b move to the left in the drawing, and stop when the green developing device 3g is located immediately below the original plate 1. The developing devices are the same as in the blue development. 3g ascending, developing and descending are performed. Subsequently, the green pattern is transferred from the original 1 to the surface of the glass plate 5 by the same operation as described above. At this time, it goes without saying that the transfer position of the green pattern on the surface of the glass plate 5 is shifted by one color from the blue pattern.

  Then, the above operation is repeated for red development, and three-color patterns are arranged and transferred on the surface of the glass plate 5 to form a three-color pattern image on the surface of the glass plate 5. In this way, the glass plate 5 is held and fixed at a fixed position, and the original plate 1 is moved with respect to the glass plate 5, thereby eliminating the need for reciprocating movement of the glass plate 5, securing a large movement space and the apparatus. Increase in size can be suppressed.

  In FIG. 10, the structure of the principal part of the rolling mechanism for rolling the original plate 1 mentioned above along the glass plate 5 is shown. Gears 71 called pinions are attached to both ends in the axial direction of the drum base tube 31 around which the original plate 1 is wound on the peripheral surface. The original 1 is rotated by meshing the gear 71 and the drive gear 73 of the motor 72, and is moved in the right direction in the drawing by meshing the rack 74 and the pinion (gear 71) of the linear track installed at both ends of the stage 6. Translate. At this time, the structure of each part of the rolling mechanism is designed so as not to cause a relative shift between the surface of the glass plate 5 held on the stage 6 and the surface of the original plate 1. In the claims, the movement of moving in parallel along the glass plate 5 while rotating in this way is referred to as rolling.

  According to such a rack and pinion mechanism, since there is no idler for drive transmission, high-accuracy rotation / translation drive without backlash can be realized, and the position on the glass plate 5 is, for example, ± 5 (μm). It becomes possible to transfer a high-precision pattern with high accuracy.

  On the other hand, as shown in FIG. 9, the glass plate 5 (not shown in FIG. 10) is an abbreviation of its back surface 5b (surface on the side away from the original plate 1) with respect to the flat contact surface 6a of the stage 6. It arrange | positions on the stage 6 so that the whole surface may be interviewed. In addition, a vacuum pump (not shown) is connected to the glass plate 5 via a main pipe 77 from a connection pipe 75 to an intake port 76 that extends through the stage 6 to the contact surface 6a. A negative pressure is applied through a suction hole (not shown) opened on the contact surface 6 a of 76, and the suction surface 6 is sucked onto the contact surface 6 a of the stage 6. By this adsorption mechanism, the glass plate 5 is brought into close contact with the contact surface 6a having high flatness by pressing substantially the entire back surface 5b, and is held on the stage 6 with high flatness. By pressing the glass plate 5 against the flat contact surface 6a in this manner, distortion of the glass plate 5 can be corrected, and a transfer gap between the original plate 1 described later can be maintained with high accuracy.

  FIG. 11 is a cross-sectional view of a main part for explaining a state when the toner particles 55 are transferred from the original 1 to the glass plate 5. A conductive layer 81 made of, for example, a conductive polymer is applied to the surface 5a of the glass plate 5 having a light shielding layer (not shown), and the surface 81a of the conductive layer 81 and the high resistance layer 13 of the original 1 are formed. The surface 13a is placed in a non-contact state via the gap d2. For example, d2 is set to a value in the range of 10 (μm) to 40 (μm). When the thickness of the high resistance layer 13 is 20 (μm), for example, the distance between the metal film 12 and the surface 81a of the conductive layer 81 is 30 (μm) to 60 (μm).

  In this state, when a voltage of, for example, −500 (V) is applied to the conductive layer 81 via the power supply device 82 (transfer device), a potential difference of 500 (V) is formed between the metal film 12 at the ground potential, The toner particles 55 are electrophoresed in the solvent 54 by the electric field and transferred to the surface 81 a of the conductive layer 81. As described above, since the toner particles 55 can be transferred even in a non-contact state, it is not necessary to interpose an elastic body such as a blanket or a flexographic plate as in the case of offset printing or flexographic printing, and transfer with high positional accuracy is always realized. It becomes possible to do. After the transfer of the toner particles 55, the conductive layer 81 disappears by putting the glass plate 5 into a baking furnace (not shown) and baking it. Thus, the front substrate of the display device according to the present invention is obtained.

  As described above, in the case where toner particles are transferred to the glass plate 5 using an electric field, it is essential that a solvent exists in the transfer gap to wet between the conductive layer 81 on the glass plate 5 side and the original plate 1. Therefore, it is effective to pre-wet the surface 5a of the glass plate 5 with a solvent prior to transfer. The pre-wet solvent may be insulative or high resistance, but it is more preferable if it is the same solvent as that used for the liquid developer or a charge control agent added thereto. As described with reference to FIG. 9, the pre-wet solvent is applied onto the surface 5 a of the glass plate 5 with an appropriate application amount at an appropriate timing by the application device 7.

  As described above, according to the above-described embodiment, the developed toner particles 55 are transferred to the surface 5a of the glass plate 5 by rolling the original plate 1 with respect to the glass plate 5 arranged at a fixed position. The structure of the rolling mechanism that rolls the original 1 can be reduced in size, and the installation space of the apparatus can be reduced. Further, according to the above-described embodiment, since the toner particles 55 are transferred from the original plate 1 facing each other in a non-contact state to the glass plate 5 using an electric field, a transfer method using a flexographic plate as in the prior art In comparison, the resolution of the transferred image can be increased, and a high-definition pattern can be formed.

  In the above-described embodiment, the toner particles 55 collected (developed) in the concave portion 14a of the original plate 1 are once dried moderately by air blow from the dryer 4, and then the surface 5a of the glass plate 5 is wetted with a solvent. Since the toner particles 55 are transferred (by pre-wetting), the shape of the toner image transferred to the surface 5a of the glass plate 5 can be stabilized, and the pattern outline can be made clear.

  FIG. 12 is a sectional view schematically showing the front substrate thus obtained.

  As shown in FIG. 12, the obtained front substrate 111 includes a transparent substrate 5, a phosphor layer 116 provided in a dot shape thereon, and a light shielding layer 117 provided in a grid around the phosphor layer 116. And have.

  FIG. 13 is a perspective view showing an example of an FED as a display device according to the present invention.

  FIG. 14 is a cross-sectional view taken along the line A-A ′.

  As shown in FIGS. 13 and 14, the FED includes a front substrate 111 and a rear substrate 112 each made of a rectangular glass plate as insulating substrates, and these substrates are arranged to face each other with a gap of 1 to 2 mm. Has been. The front substrate 111 and the back substrate 112 constitute a flat rectangular vacuum envelope 110 whose peripheral portions are bonded to each other via a rectangular frame-shaped side wall 113 and the inside is maintained in a vacuum state. .

  A plurality of spacers 114 are provided inside the vacuum envelope 110 in order to support an atmospheric pressure load applied to the front substrate 111 and the rear substrate 112. As the spacer 114, a plate-like or columnar spacer or the like can be used.

  On the inner surface of the front substrate 111, a phosphor screen 115 having red, green, and blue phosphor layers 116 and a matrix-shaped light shielding layer 117 is formed as an image display surface. These phosphor layers 116 may be formed in stripes or dots. A metal back 120 made of an aluminum film or the like is formed on the phosphor screen 115. Further, a getter film 121 is formed in order to lower the internal pressure of the vacuum envelope 110 to adsorb unnecessary gas inside. The getter powder is mixed with an adhesive material.

  On the inner surface of the rear substrate 112, a number of surface conduction electron-emitting devices 118 that emit electron beams are provided as electron sources that excite the phosphor layer 116 of the phosphor screen 115. These electron-emitting devices 118 are arranged in a plurality of columns and a plurality of rows corresponding to each pixel. Each electron-emitting device 118 includes an electron-emitting unit (not shown) and a pair of device electrodes for applying a voltage to the electron-emitting unit. Further, on the inner surface of the rear substrate 112, a large number of wirings 121 for supplying a potential to the electron-emitting devices 118 are provided in a matrix shape, and the end portions thereof are drawn out of the vacuum envelope 110.

  In such an FED, when an image is displayed, an anode voltage is applied to the phosphor screen 115 and the metal back 120, and the electron beam emitted from the electron-emitting device 118 is accelerated by the anode voltage to collide with the phosphor screen. As a result, the phosphor layer 116 on the phosphor screen 115 is excited to emit light, and a color image is displayed.

EXAMPLE FIG. 15 is a schematic diagram showing an example of an experimental apparatus that can be used in the present invention.

  As shown in the figure, this experimental apparatus includes a three-necked separable flask 30 that can be separated into upper and lower parts, a stirrer 136 having a stirring blade inserted into a central port, a stirrer 136 being driven to rotate, and a central port. An explosion-proof motor 132 for sealing the thermocouple 133 is provided in one of the mouths on both sides of the center mouth, the Dimroth reflux condenser 131, the thermocouple 133 inserted into the separable flask 130 from the other mouth, and the thermocouple 133. The relay temperature control unit 134 is connected, and the mantle heater 135 is connected to the relay temperature control unit 134.

  In this experimental apparatus, while stirring the contents of the separable flask 130 using the stirrer 136, the temperature is always measured by the thermocouple 133, and the mantle heater 35 is operated by the relay temperature control unit 134 based on the measured temperature. The temperature of the contents can be kept constant at all times. The solvent vapor from the contents is cooled and condensed by the Dimroth reflux condenser 131 and returned again into the lower container, thereby preventing an excessive increase in the pressure in the separable flask 130.

Example 1
700 g of a silane coupling agent (KBM-603) solution made by Shin-Etsu Chemical Co., Ltd. was prepared in a 1000 ml beaker, and 50 g of ZnS: Cu, Al-based green light-emitting phosphor particles (average particle size 5.6 μm, specific gravity 4.1) were added. And stirred for 2 hours. Thereafter, the mixture was filtered and dried in a drying oven at 120 ° C. for 3 hours to perform a silane coupling treatment, and then passed through a sieve.

  Next, 180 g of Exxon Chemical's insulating hydrocarbon solvent (Isopar L) having a boiling point range of 191 to 205 ° C. is poured into a 500 ml separable flask, and acrylic fine particles made by Soken Chemical Co., Ltd. having a specific gravity of 1.0 ( MP4009) 2 g and ZnS: Cu, Al-based green light-emitting phosphor particles 18 g subjected to silane coupling treatment were added, a relay temperature control unit was set at 100 ° C. as a temperature controller, and the mixture was heated and stirred with a stirrer. Stirring was continued for 2 hours at a solution temperature of 100 ° C., and then stirred while cooling to room temperature (25 ° C.) over 1.5 hours.

  2 g of niobium octylate manufactured by Nippon Kagaku Sangyo Co., Ltd. was added as a charge control agent to the thus obtained phosphor particle dispersion having a solid content concentration of 10% by weight to obtain a green light emitting phosphor-containing liquid developer. .

  For comparison, a sample was also prepared in which the same molar amount of zirconium naphthenate was added instead of niobium octylate as the charge control agent.

  FIG. 16 shows an outline of an apparatus for measuring the current value of electrophoresis.

  As shown in the figure, the device 90 includes a pair of ITO transparent electrode substrates 91 and 92 installed in a shield 99, and a switch 93 and a switch 93 provided on wiring connected to the one ITO transparent electrode substrate 92. And an oscilloscope 96 connected to the amplifier 97. The power supply 94 and the oscilloscope 96 further include, for example, a personal computer or the like. A CPU 15 is connected to control the power supply 94 and the oscilloscope 96. The two ITO transparent electrode substrates 91 and 92 are arranged to face each other via a Teflon spacer (not shown) to constitute a sandwich cell.

  The Teflon spacer used is, for example, a square with a side of 40 mm, a square hole with a 30 mm square is provided in the center, and one side of the spacer is formed so as to form two paths leading to the hole from one side. Part has been removed. One of the two passes can be used as an air vent and the other as a liquid developer injection path.

  Using the above apparatus, the liquid developer 98 is injected into the sandwich cell, the switch 93 is turned on, a DC voltage of 400 V is applied for 5 seconds, and the toner particles 89 in the liquid developer 98 are electrically supplied to the ITO transparent electrode substrate 91 side. After electrophoresis, the switch was turned off. At this time, the electrophoretic current value was measured with an oscilloscope 96, and the data processing was performed with the CPU 95 based on the obtained measurement data to obtain the electrophoretic current waveform.

  A graph showing an electrophoretic current waveform relating to the obtained liquid developer is shown in FIG.

  In the figure, a graph 161 shows a graph when niobium octylate is used as a charge control agent, and a graph 162 shows a graph when zirconium naphthenate is used as a charge control agent.

  As shown in the graph 161, in the liquid developer using niobium octylate, the current value showed a peak after about 0.01 seconds after the voltage was applied, and decreased sharply to some extent. Here, it can be seen that the toner particles are electrodeposited on the ITO transparent electrode substrate. Thereafter, the current value gradually decreased, and after 0.1 second, the current value decreased to almost 0 μA, and no steady current flowed.

  From this, it was found that all of these developers are positively charged, and none of them is charged with a reverse polarity.

  Thereafter, the sandwich cell was disassembled, and the state of the electrodeposition film obtained on the surface of the ITO transparent electrode substrate 11 was observed. In either case, a uniform phosphor electrodeposition film was formed on the ground-side ITO electrode 91, and nothing adhered to the positive-side ITO electrode 92. At this time, the thickness of the electrodeposited film on the negative electrode side was 11 μm on average, indicating that a sufficiently thick electrodeposited film was formed.

  Further, when the luminance of the phosphor electrodeposition film upon electron beam excitation was measured, it was almost the same as the phosphor film formed by screen printing.

  On the other hand, as shown in the graph 162, in the liquid developer using zirconium naphthenate, the voltage peaked within 0.1 seconds after the voltage was applied, and then suddenly decreased to some extent. Here, it can be seen that the toner particles are electrodeposited on the ITO transparent electrode substrate 11. Thereafter, the current value gradually decreased, and after 0.3 seconds, it decreased to about 0.33 μA and became a steady current.

  From the current waveform shown in FIG. 17, when a liquid developer using each of zirconium naphthenate and niobium octylate as the charge control agent is compared, a steady current flows in the liquid developer using niobium octylate as the charge control agent. Absent.

Pattern accuracy evaluation The green light-emitting phosphor-containing liquid developer obtained in Example 1 is accommodated in 3 g in a developing device having the same configuration as in FIG. 2, and a large number of dots having a width of 147 μm × length of 247 μm are provided. A green light emitting phosphor layer is formed on a transparent substrate having a size of 10 mm × 10 mm by applying an original plate having a size of 10 mm × 100 mm having a pattern in which the arrangement is arranged, and performing development, drying, and transfer. did.

  30 places were selected at random from each of the obtained phosphor layers, the width was measured, and the standard deviation was measured.

  As a result, an average width of 149.87 μm and a standard deviation of 1.43 were obtained.

In a sample in which the charge control agent prepared in the same manner was changed from niobium octylate to zirconium naphthenate, the average width was 151.72 μm and the standard deviation was 1.66.

  Accordingly, it was found that the patterning accuracy was improved by using the liquid developer according to the present invention.

  This is presumably because a liquid developer using niobium octylate as a charge control agent does not flow a steady current and has little fluid movement such as solvent convection. Fluid motion such as solvent convection is thought to contribute to the disturbance of the dot shape after electrodeposition. When niobium octylate, which does not flow a steady current, is used, the average width becomes closer to the desired size. The standard deviation is considered to be small.

Example 2
A green developer containing a green light emitting phosphor was obtained in the same manner as in Example 1 except that the charge control agent was changed to 2 g of tantalum octylate.

  For comparison, a sample in which the same molar amount of naphthenic acid Zr was added instead of niobium octylate as a charge control agent was also produced.

  Using the obtained green light emitting phosphor-containing liquid developer, the current value of electrophoresis was measured.

  From this, it was found that all of these developers are positively charged, and none of them is charged with a reverse polarity.

  Thereafter, the sandwich cell was disassembled, and the state of the electrodeposition film obtained on the surface of the ITO transparent electrode substrate 11 was observed. In either case, a uniform phosphor electrodeposition film was formed on the ground-side ITO electrode 91, and nothing adhered to the positive-side ITO electrode 92. At this time, the thickness of the electrodeposited film on the negative electrode side was 11 μm on average, indicating that a sufficiently thick electrodeposited film was formed.

  When the luminance of the phosphor electrodeposition film upon electron beam excitation was measured, it was almost the same as that of the phosphor film formed by screen printing.

  FIG. 18 shows a current waveform during the electrodeposition experiment.

  In the figure, 171 shows a graph when niobium octylate is used as the charge control agent, and 172 shows a graph when zirconium naphthenate is used.

  From the current waveform shown in FIG. 18, when a liquid developer using each of zirconium naphthenate and niobium octylate as the charge control agent is compared, a steady current flows in the liquid developer using niobium octylate as the charge control agent. Absent. This means that only current with toner particle movement flows and no current flows through the bulk.

  The green light emitting phosphor-containing liquid developer was applied to the developing device in the same manner as in Example 1 to form a green light emitting phosphor layer.

  About each obtained fluorescent substance layer, it carried out similarly to Example 1, the width | variety was measured, and the standard deviation was measured.

  As a result, with respect to the liquid developer using tantalum octylate, results were obtained that the average width was 150.35 μm and the standard deviation was 1.53.

  On the other hand, with respect to the liquid developer using zirconium naphthenate, the average width was 151.72 μm and the standard deviation was 1.66.

  Accordingly, it was found that the patterning accuracy was improved by using the liquid developer according to the present invention.

  In a liquid developer using tantalum octylate as a charge control agent, since a steady current does not flow, it is considered that there is little fluid movement such as solvent convection. Fluid movement such as solvent convection is thought to contribute to the disturbance of the dot shape after electrodeposition. When tantalum octylate, which does not flow a steady current, is used, the average width will approach the desired size. The standard deviation is considered to be small.

Schematic sectional view showing the configuration of toner particles in the liquid developer according to the present invention External view showing an example of a pattern forming apparatus used in a front substrate forming process The top view (a) which shows the original plate used with the pattern formation apparatus of FIG. 2, and sectional drawing (b) FIG. 3 is a partially enlarged plan view partially showing the original plate of FIG. The partial expansion perspective view for demonstrating the structure of one recessed part of the original plate of FIG. Schematic diagram showing a state in which the original plate of FIG. 3 is wound around a drum tube Schematic diagram showing a configuration for charging the surface of the high resistance layer of the original plate of FIG. FIG. 3 is a schematic diagram illustrating a configuration for supplying a liquid developer to the original plate of FIG. 3 to form a pattern of toner particles. Schematic showing a configuration for transferring the pattern formed on the original plate of FIG. 3 to a glass plate Schematic which shows the structure of the principal part of the rolling mechanism for rolling the original plate of FIG. 3 along a glass plate. Operation explanatory diagram for explaining the operation of transferring the toner particles collected in the concave portion of the original plate to the glass plate Sectional drawing which represents typically an example of the front substrate concerning this invention The perspective view showing an example of FED as a display apparatus which concerns on this invention A-A 'sectional view of FIG. Schematic showing an example of an experimental apparatus that can be used in the present invention Schematic showing the outline of the device for measuring the current value of electrophoresis Graph showing electrophoretic current waveform for liquid developer of the present invention Graph showing electrophoretic current waveform for liquid developer of the present invention

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Original plate, 3r, 3g, 3b ... Developing device, 4 ... Dryer, 5 ... Glass plate, 6 ... Stage, 7 ... Coating device, 10 ... Pattern forming device, 12 ... Metal film, 13 ... High resistance layer, 14a Recesses, 61: Nuclear particles, 62: Coating layer, 63 ... Thermoplastic resin fine particles, 60 ... Toner particles, 131 ... Dimroth reflux condenser, 132 ... Explosion-proof motor, 133 ... Thermocouple, 134 ... Relay temperature control unit, 135 ... Mantle heater, 136 ... Stirrer, 110 ... Vacuum envelope, 111 ... Front substrate, 112 ... Back substrate, 113 ... Side wall, 115 ... Phosphor screen, 116 ... Phosphor layer, 117 ... Light shielding layer, 118 ... Electron emitting element 120 ... Metal back 121 ... Getter layer 211, 212 ... ITO electrode 213 ... Spacer 214 ... Injection path 215 ... Air vent hole

Claims (9)

An electrically insulating solvent;
V cores contained in the electrically insulating solvent, a thermoplastic resin particle coating layer provided on the surface of the core particles, and V added as a charge control agent to the surface of the core particles coated with the thermoplastic resin particles A liquid developer comprising toner particles containing a group III metal organic acid salt.   2. The liquid developer according to claim 1, wherein the metal component contained in the group V metal organic acid salt is at least one selected from the group consisting of vanadium, niobium, and tantalum.   The liquid developer according to claim 1, wherein the organic acid component of the group V metal organic acid salt is an organic acid having 6 to 30 carbon atoms.   4. The organic acid according to claim 1, wherein the organic acid is at least one selected from the group consisting of octylic acid, naphthenic acid, neodecanoic acid, oleic acid, lauric acid, and stearic acid. The liquid developer described in 1.   The liquid developer according to claim 1, wherein the thermoplastic resin fine particles have an average particle diameter of 0.1 to 5 μm. Forming a light shielding layer having a plurality of frame-like or stripe-like patterns on a transparent substrate;
The liquid developer according to claim 1 is supplied to a surface of an image carrier through a supply member, and an electric field is formed between the supply member and the image carrier to form the image. A development step of forming a dot-like or stripe-like pattern image on the surface of the holder;
A rolling step of rolling the image holding body on which a pattern image is formed with a liquid developer along a transparent substrate having a light shielding layer held at a fixed position;
An electric field is formed between the rolling image carrier and the transparent substrate, and a pattern image on the surface of the image carrier is transferred to the transparent substrate. And a front substrate forming process including a transfer step of forming a phosphor layer and a step of forming a metal back layer on the phosphor layer.   The method for manufacturing a display device according to claim 6, further comprising a drying step of drying the pattern image formed on the surface of the image carrier before the transfer step.   The display device manufacturing method according to claim 6, further comprising a wetting step of wetting a surface of the transparent substrate with the insulating liquid before the transferring step.   9. The method for manufacturing a display device according to claim 6, wherein the image carrier has a patterned electrode layer for forming the pattern image on a surface thereof.

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