JPS58157872A - Ink medium - Google Patents

Abstract

PURPOSE:An ink medium, having an electrically conductive hot-melt ink layer on an electrically anisotropic support containing a specific electrically conductive material in holes of a porous sheetlike substrate having independent holes, and capable of recording printings at a high energy efficiency and high printing speed. CONSTITUTION:An ink medium obtained by forming an electrically conductive hot-melt ink layer 14, preferably prepared by dispersing a pigment having a low resistance, etc., in a hot-melt resin having 60-150 deg.C melting point, on the rear of an electrically anisotropic support 13 prepared by filling an electrically conductive material 12, e.g. a thermosetting resin containing a dispersed electrically conductive agent, e.g. carbon black, having a volume electrical resistivity of <=1X10<-1> of that of a porous sheetlike substrate 11, e.g. a polyester, etc. having preferably 10mum-1mm. thickness, in the porous sheetlike substrate 11 having independent holes, preferably having 40-100mu opening diameter. When a signal voltage is applied to the ink medium, the part just under a signal electrode 15 is selectively molten through a part (12a) filled with the electrically conductive material 12 under heating, and the ink is stuck to the surface of a transfer paper 21 to carry out the recording.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ink medium, and more particularly to a transfer ink medium used in a non-injected printer.

Fax plotter, word processor, CP
Various non-impact methods are currently known as recording methods for U terminal printers, kanji printers, etc. Among them, the inkjet recording method is a method that directly converts electrical signals into images without going through processes such as development and fixing.
There are heat sensitive recording methods, discharge breakdown recording methods, etc.

However, plain paper copying is not possible except for the inkjet method. The inkjet recording method also has (1) poor reliability due to the use of ink liquid, such as instability of liquid properties due to thermal fluctuations and nozzle clogging due to drying, etc.; (2)
There is a limit to the miniaturization of the print head, making it difficult to print in multiples, making solid-state scanning difficult; (3) Since the image is a dot image made of ink droplets, there is a viscosity limit, making it impossible to achieve ultra-high speed; (
4) Since the pigment in the ink is a dye, it has drawbacks such as being light and easily fading when exposed to light.

As an alternative to the above-mentioned method and a non-impact method capable of transferring to plain paper, a method that uses a low melting point color i and thermally transfers this coloring material using an electric signal is attracting attention. As this method, Japanese Patent Publication No. 84-1049Ii describes
A thermal recording medium in which a coloring material with a melting point or softening point of 70 to 150°C is formed in the form of scales on a support using a binder that is easily soluble in heat, or a thermal head transfer method using this has been reported. ing. However, this method (1) uses a thermal head, which causes sticking between the transfer material and the transfer material;
(2) The printing speed is very slow at 10ml to 1ff1l, and (3) the dot density is low and high resolution cannot be obtained. Previously, Japanese Patent Application Laid-Open No. 55-86793 has reported a current-carrying recording material having a multilayer structure having different resistance values and a current-carrying transfer method using the same. However, this method also has the following problems: 11) The layer structure of the recording material is complicated; (2) it is difficult to control each layer, making it difficult to reproduce the ink medium (recording material); and (3) the running cost is extremely high. (4) There are drawbacks such as a narrow material allowance for the ink layer and poor manufacturing reliability.

The cane of the present invention was developed with the aim of solving the above-mentioned drawbacks of the prior art, and has a high mechanical strength, a simple structure, and easy ink layer formation for reuse.
Another object of the present invention is to provide an ink medium capable of recording with high energy efficiency, high printing speed, and high resolution.

That is, the ink medium of the present invention is an electrically anisotropic material in which the pores of a porous sheet-like substrate having independent through-holes are filled with a conductive material whose 1-volume electric resistance is 1×lθ times or less that of the substrate. It is characterized by having a conductive hot-melt ink layer on one side of the support.

FIG. 1 shows a partial plan view of the ink medium of the present invention, and FIG. 2 shows a cross-sectional view thereof. A conductive heat-melting ink layer 14 is provided on the back surface of the support 13 .

Figures B-a and 3-b are diagrams for explaining the principle of non-impact recording using the ink medium of the present invention. In FIG. 3-a, when a signal voltage is applied to the signal electrode 15, the current flows from the conductive material filled part 12a directly below the signal electrode to the signal electrode surface of the conductive heat-melting ink layer 14 → to the conductive material. Return path electrode 16@ of hot melt ink layer 14
The flow forms a circuit from the lower part to the return path electrode 16.

In this way, a conductive path is secured and maintained by the conductive heat-melting ink M14, and by setting a large difference in area between the signal electrode (stylus electrode) 15 and the return electrode (segment [camellia]) 16, the signal The current density is dense directly below the electrode 15, while the current flows from the signal electrode to the return electrode in a diffused manner, so the current density is sparse in this portion. Generation of Joule heat (=I"R), so in the case of uniform resistance, the amount of heat generated is determined by the square of the current. Then, the area ratio of the signal electrode and the return electrode is For example, 1
If the difference is on the order of 0'' to 101, the calorific value, that is, the temperature of the ink, will appear as a difference on the order of 10' to 10. The ink is thermally melted and adhered to the surface of the transfer paper 21, and non-impact recording is completed.

In order to perform clear recording in response to the image signal, it is necessary to selectively increase the current density in the ink area directly below the recording electrode, but for this to occur, the current must have an electrical difference. It is necessary to flow selectively in the vertical direction through the electrically anisotropic support, in other words, the resistance in the length direction of the electrically anisotropic support is required to be greater than the resistance in the thickness direction. In order to achieve this, (1) the structural property is that the conductive material is supported by sheet materials in the length direction, and (2) the sheet material has a higher resistance than the conductive material. Both electrical and material properties are required.

Figures 4-a to 7-b show various structural examples of the electrically anisotropic support of the present invention.

Figures 4-a and 4-b are a sectional view and a plan view, respectively, showing the case where a mesh-like porous sheet-like substrate of 1.1 m is used. Figures 3-a and 5-
Similarly, a punched porous sheet-like substrate 11b
FIG. 2 is a cross-sectional view and a plan view showing an electrically anisotropic support when using the electrically anisotropic support. Figures 6-a and 6-b are cross-sectional views showing an electrically anisotropic support using a porous sheet-like substrate lie formed by joining circular or polygonal tubular objects in the lateral direction. and a plan view. Although this figure shows a case in which tubular objects having a hexagonal cross section are joined together at the side surfaces to form a honeycomb shape, the shape of the tubular objects is not particularly limited. Figures 7-a and 7-b show the case where a lattice-type porous support (lid) is used. The various methods of forming the electrically anisotropic support (knitting, punching, joining of tubular bodies, etc.) and the shape of the holes have been exemplified above, but the examples are not limited to these. Any can be used as long as it is filled with. From the viewpoint of resolution, it is preferable that the pore diameter is small, the pore density is high, and the geometric surface area is small.
Generally, the opening diameter is 10 μm to 2 m, preferably 40 to 1
It is about 00P. Further, the thickness of the porous sheet-like substrate is generally about 5 μm to 5 fi, preferably 10 μm.
m to 1 m.

In order to ensure electrical anisotropy, the porous sheet-like substrate must have not only the shape but also its electrical properties. FIG. 8 is a diagram schematically showing the flow of current directly under the pole 15 when an electric signal is applied. At this time, most of the current (preferably most of it) flows as shown by the solid line, and as shown by the broken line. It is necessary to avoid short-circuiting. For this purpose, the volume electrical resistance value of the porous sheet-like substrate 11 needs to be at least 10 times larger than the volume electrical resistivity value of the conductive material 120, preferably at least I x 10" times, more preferably I x It is 10" or more. In this way, by creating a difference in conductivity, the stain current flows as shown by the solid arrow, ensuring electrical anisotropy, but in reality, the porous sheet-like substrate is made of a so-called insulating material. Preferably, 1 G
It is preferable to have a volume electrical resistance value of 'Ω・- or more,
More preferably, it is 10"Ω.100 or more. It is not necessarily necessary that the entire porous sheet-like substrate be made of a material having the above-mentioned electrical properties, and the porous support sheet is made of a good conductor. The inner surface of the hole of this sheet is
Furthermore, the entire surface may be coated with a material having the above-mentioned electrical characteristics. That is, if a high resistance portion is provided so that the current selectively flows in the direction of the solid line in FIG. For example, gold wires are knitted to form the porous sheet-like substrate shown in Figures 4-& and 4-b, and then this is covered with an insulating material (electrode material, resin, etc.) described later. By coating, a porous sheet-like substrate with excellent mechanical strength can be obtained. The insulating material may be coated by a thin film forming method such as a PVD method (vacuum deposition), or by a coating film forming method such as a solvent coating method.

Porous sheet-like substrates can be made of metals such as aluminum, stainless steel, nickel, copper, and iron, synthetic resins such as polyester, polyamide, fluororesin, polyimide, polycarbonate, silicone resin, and various metal oxides and nitrides. thing,
Can be formed from ceramics such as carbides,
For conductive materials, it is necessary to use them with an insulating coating. The insulating coating is made of the above-mentioned synthetic resin or ceramic material (specifically, The, , B・0°All0@,
ZrO2, 8101, Tl01. BrZr0@,
CaZr01.

81Zr04, BN, AIN, 818N4
, TIN, Ta1N, HfN.

N'! of 81C, ThN, VN, CrN, MgO and their alloys. t or more than 2 seconds). Note that when punching holes are to be created, laser processing, photo-etching processing, electronic processing, mechanical processing, etc. are used.

As already explained, the conductive material 12 needs to have a volume resistivity value in a predetermined relationship with the porous sheet-like substrate 11, but it is preferable that the conductive material 12 is a so-called good conductor.
Preferably less than 1 G'Ω, more preferably 10
"Has a volume electrical resistance value of Q*cm or less. Specific examples of conductive materials include hard-to-melt resins such as thermosetting resins in which conductive agents such as carzen black, metal powder, and quaternary ammonium salts are dispersed, and conductive materials. Examples include plastic resin and metal.

To produce the electrically anisotropic support of the present invention, the pores of a porous sheet-like substrate may be filled with a conductive material, and if necessary, one or both surfaces may be polished to ensure flatness.

The conductive heat-melting ink layer (1) forms a current path when an image signal is generated, and (2) melts due to Joule heat to perform surface recording on the transfer paper. Therefore, (l) electrical conductivity and (2) image forming properties (thermofusibility).

The conductive heat-melting ink layer of the present invention is required to have both properties (coloring property), but the conductive heat-melting ink layer of the present invention has a single layer structure that has both of these properties, and a multilayer structure that separates each property functionally. It includes both.

#1, #9 and #10rAIJ are schematic cross-sectional views showing embodiments of the ink medium of the present invention, respectively.
In the figure, a single-layer conductive hot-melt ink layer 14 is provided on one surface of the electrically anisotropic support 13, and in FIG. A conductive hot melt ink layer 14' is provided. From the viewpoint of ensuring electrical anisotropy, that is, from the viewpoint of energy efficiency and resolution, a single layer type is preferable.
From the viewpoint of freedom in material selection, the laminated type 4 is preferable.

To explain the type shown in FIG. 9, the conductive heat-melting ink layer 14 preferably has a volume electrical resistance value of 10 eg, more preferably 1 G"Ω.- or less. Ink layer 144 Regarding the relationship between the electrical resistance value of the electrically conductive material 12 and the electrical resistance value of the electrically conductive material 12, when the electrical resistance value of the electrically conductive material 12 is large, the ink layer 1
The melted portion of 4 mainly melts according to the diameter of the signal electrode, and when the electrical resistance value of the ink layer 14 is equal or larger, it melts according to the diameter of the through hole, that is, the conductive material.

The ink layer 14 also needs to be heat-fusible, preferably at 200°C or lower, more preferably at 60°C.
It has a melting point of ~150°C. It is also required to have an image forming ability, generally a coloring ability, that is, it is required to contain a coloring material.

Examples of the conductive hot-melt ink layer material having a function similar to a resin include (1) a low-resistance pigment or an auxiliary coloring pigment dispersed in a hot-melt resin; Dispersed conductive material and coloring material, (
3) There are heat-melting resins that have been given conductivity or coloring ability, but the type shown in (1) is the most practical.

Low-resistance pigments such as black, iron black, iron oxide, graphite, and metal powders are used, and as coloring auxiliary pigments, common pigments or dyes are used.

As the heat-melting resin, those having fluidity of preferably 200 tl or less and more preferably 40 to 150°C are used, such as canalpa wax, auriculie wax, No99 fin wax, beeswax, ceresin wax, and whale wax. Natural waxes such as P2, synthetic waxes such as low molecular weight polyethylene, oxidized waxes, and ester waxes, and surfactants that are solid at room temperature such as sorbitan stearate, prozelene gelicol monostearate, glycerin stearate, and polyoxyethylene stearate. Examples include higher fatty acids that are solid at room temperature such as lauric acid, palmitic acid, rhistic acid, stearic acid, and behenic acid, and higher aliphatic alcohols such as cetyl alcohol and lauryl alcohol, as well as mineral oil, vegetable oil, and animal oil. You may also use oily substances such as, lanolin, castor oil, etc.

The thickness of the conductive heat-melting ink layer 14 is suitably 1 to 100 μm, preferably! I~30 μm.

To explain the type shown in FIG. 10, the conductive layer 17 is preferably 10 Ω, more preferably FiI
D'Ωam or less. Further, the film thickness is preferably 1 to 40 μm, preferably 8 to 2 G71111. Specific examples of the constituent material of the conductive layer 17 include the same materials as the conductive material 12. The heat-melt ink layer 18 is no different from the conductive heat-melt ink layer 14 shown in FIG. 9, except that it is not required to be electrically conductive. That is, this ink layer 18 has a thermal aM
! Contains type II resins and pigments (irrespective of electrical properties).

FIG. 11 is a schematic diagram of an apparatus that performs continuous recording on transfer paper using the ink medium of the present invention.

The ink medium 19 responds to the signal from the recording electrode section 20,
An image 22 is transferred onto a transfer paper 21.

This transfer mechanism has already been explained in Figures 11-1 and s.
The explanation was given according to figure -b. Then, the ink medium 19
Heater 23 heats the ink tank containing the melted ink! ! 4, the ink medium 19 is regenerated by cooling the ink medium 77 by a roller 25, controlling the layer thickness by a blade 26, and smoothing the surface by a roller 27 which may be heated if necessary. .

As explained above, the ink medium of the present invention secures the electrical anisotropy of the ink support and also forms a conductive path with the ink layer, thereby (1) suppressing heat generation in the ink support and increasing the It has excellent properties such as energy efficiency, (2) internal heating with fewer input restrictions and faster printing speed, and (3) less spread of dots. Furthermore, the interface between the ink support and the ink layer is the interface between the ink support and the ink layer, where there is a resistance gap where the contact resistance may increase, and contact loss is small because the contact is static. Thus, according to the ink medium of the present invention, high energy efficiency,
High-density, high-speed non-inject printing on plain paper is possible, but the ink medium is simple in structure, easy to manufacture and reproduce, and the printing unit can also be used with recording electrodes such as multi-stylus electrodes. Since image recording is done in a very simple manner, stability and reliability are high.

Example 1 Carne black (Columbia Carzen Co., Conductex BC) was added to alkyd-modified silicone resin (thermosetting type: Toshi Silicone Co., Ltd.; sRgxto) at a weight ratio of 0.76 and dispersed for 1 hour. The resulting dispersion was coated with a polyester mesh (
÷3sO9 (opening diameter approx. 45μ) and fill the openings, dry and harden at 100℃ for 20 minutes, then polish the surface to the same thickness as the mmesh. , an electrically anisotropic support was obtained.

The volume resistivity of this electrically anisotropic support in the thickness direction was measured to be 830 Ω·F. Further, when measured by attaching electrodes in the length direction, it was found to be SSOΩ steel.

Next, the streamer/styrene (Nick Company; ♂Co2 Stick A-
75) A toluene solution containing a dispersion of conductive carbon (same as above)* (solid content: 2!IVT$) was applied to a thickness of 10 μm on the electrically anisotropic support described above to prepare an ink medium. did.

Using this ink medium, a printing device consisting of a stylus electrode with a diameter of 80 ps and a return electrode with an area of 10 m x 3 G- was used.
When applying 100 #s of lupus, a solid image with a density of 1.4 could be transferred onto plain paper.

Example 2 A stainless steel mesh (◆150) was placed in a vacuum system,
The degree of vacuum was set to 6 x 10''-'Terr. Next, Ar
4 x 10 Torr gas, 6 x 1 horse gas
0-"Torr" 1, and 99% as sputtering material.
．． Targeting a 99% Al plate, a stainless steel mesh was heated to 250°C, and oRF snorting was performed for 6 hours at 100 KM, resulting in an A film with a thickness of about 1 pus.
An IN film was formed.

Next, a conductive carbon (same as above), part by weight of SO and a polycarbonate resin solution (-1% in pansuite manufactured by Kinjinsha) were added.
800% tetrahydrofuray I S vt% solution) w
0 weight parts/-, py i k were dispersed, and this dispersion was applied to the openings of the mesh coated with Ceramic Z, filling the openings to obtain an electrically anisotropic support. The electrical resistance of this support was measured and the thickness resistance was 80 Q/a''
, the surface resistance was 10-Ω10.

Next, solid cedar ink with a melting point of 110°C in which Carne was dispersed (
Apply a volume resistivity of 50 Ω cm) to one side of the support 1
An ink layer of 0 pfi was formed to obtain an ink medium.

When this ink medium was used and a 50V, 5OtaA, 50μ3 square wave and e-lus were applied to a stylus electrode with a shoulder diameter of 100μ, a solid image with a reflection opening of 1.3 could be printed on plain paper.

Example 3 Stainless steel mesh film (15o) tcM curable silicone resin (KP-80, manufactured by Shin-Etsu Chemical Co., Ltd.) was sprayed and coated using an air gun to insulate the stainless steel wire. Then, it was cured and dried in 100'0.30 minutes, completing the insulation treatment of the mesh core material.

Next, conductive carzene (same as above) was added to alkyd-modified silicone resin (thermosetting type: Toray Silicone 8R2110) at a K weight ratio of 1=1, and dispersed in Lumil for 1 hour. Apply the liquid to the blade coating method.
Fill in the opening of the insulation treated mesh and heat at 100°C for 1
Let it harden and dry for 5 minutes, and then dry the coated surface. 7. When a small amount of the insulated surface was observed during polishing, the product was polished to the ζ angle to obtain an electrically anisotropic support. The electrical resistance of the support in the thickness direction is 15
Ω, and the electric resistance in the longitudinal direction was 10·Ω/crIl (point contact with a pin electrode).

Next, a conductive heat-melting ink containing carzene dispersion having a melting point of 106° C. was coated on this support to a thickness of 20 μm, and dried to form an ink layer to obtain an ink medium.

Using this ink medium, input an electric signal at 150V and 70V with a 50μ pulse from the stylus electrode, and set a current path by installing return electrodes with an area 200 times the area of the stylus on both sides of the stylus electrode. When transferred to plain paper, a dot density of 1150 was obtained.

Example 4 Conductive carin (Columbia Carn, Conductex SC) was applied to one side of the electrically anisotropic support prepared in Example 3.
) with a solid content of 65 wt 4 g (thermosetting type: Toray Silicone Co., Ltd. 5R211)
The 2-hole dispersion of G) was applied by a blade coating method and cured and dried at 120° C. for 30 minutes to form a conductive layer with a thickness of about 4 μm.

Next, hot-melt M! polyethylene wax with a melting point of 105° C. and copper 7 talocyanine pigment (manufactured by Sumitomo Chemical Co., Ltd.) were mixed in a weight ratio of 3:1 onto the above support. Colored ink cloth and 6
An ink layer of PrIL thickness was provided.

When printing was performed on this current transfer ink medium under the conditions of Example 3, a blue print was obtained.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 and 2 are a plan view and a sectional view showing an example of the structure of an ink medium according to the present invention. Figures 3-a and 3-b are diagrams showing a transfer mechanism using the ink medium of the present invention. Figures 4-a to 7-b are a cross-sectional view and a plan view, respectively, showing a configuration example of the electrically anisotropic support of the present invention. Figure 48 is a perspective view of the electrical anisotropy of the ink medium of the present invention. FIG. 9 and FIG. 10 are cross-sectional views showing an example of the structure of the conductive heat-melting ink layer of the present invention. FIG. 911 is a diagram illustrating the sorces when images are continuously recorded using the ink medium of the present invention. 11... Porous sheet-like substrate 12... Conductive material 13... Electrically anisotropic support 14, 14'... Conductive hot melt ink layer 15...
Signal electrode 16...Return electrode 19...Ink medium 20...Recording electrode section 21...Transfer paper 7-b diagram

Claims (1)

[Claims] 1. In the pores of a porous sheet-like substrate having independent through-holes, a conductor having a volume electrical resistance of I x 10-' times or less of the substrate! 1. An ink medium comprising a conductive heat-melting ink layer on one surface of an electrically anisotropic support filled with a conductive material.