JPH0825792A - Image forming method and manufacturing method of decorative aluminum plate - Google Patents

Abstract

(57) [Summary] [Object] To provide a decorative aluminum plate provided with an image having sufficient color density without color mixing, scanning unevenness, and image blurring. [Structure] For an anodized film formed on the surface of a plate or foil made of aluminum or an aluminum alloy,
A method of manufacturing a decorative aluminum plate for forming an image by an ink jet recording method, comprising dehydrating and activating the anodized film, causing ink droplets to fly to a predetermined position of the anodized film, and performing a plurality of recording head A step of recording a thinned image a plurality of times by scanning, and dyeing the dye contained in the attached ink into the anodized film from the anodized film, and removing the excess component contained in the ink droplet. And a method for producing a decorative aluminum plate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording material having a plate or foil of aluminum or aluminum alloy, such as name plate, display plate, wall material for construction, vehicle panel and various parts, tableware, aluminum can, interior decoration. The present invention relates to an image forming method for recording characters, graphic patterns, pictures, etc. on a display panel and a method for manufacturing a decorative aluminum plate.

[0002]

2. Description of the Related Art Paper is mainly used as a material to be recorded by ink jet recording, and other than paper, it is limited to a plastic film having at least one surface provided with a layer having an ink absorbability by a special treatment. Was there. This is because the ink jet recording apparatus is mainly used for office work, so that it is often recorded on paper as an information medium, and further, ink droplets are ejected and adhered to a recording material. Due to the nature of the inkjet recording method, it is considered that the recording material is required to have ink absorbability and fixability.

Under these circumstances, the application of inkjet recording to recording materials made of materials other than paper and plastic films is attracting attention as the speed and functionality of inkjet recording apparatuses increase. Among them, inkjet recording on a metal material such as aluminum or its alloy can not only provide a simpler recording method on a metal material as an alternative to printing etc., but can also provide characters, patterns, pictures, etc. made of a metal material. It is also expected to promote the expansion of uses of recorded materials.

Aluminum or its alloy is mentioned as a metal material used in various fields and applications. Among them, anodized film, so-called alumite film, formed on the surface of aluminum to improve the corrosion resistance, surface strength and decorativeness of aluminum is suitable for building materials, tableware, electronic equipment panels, etc. It has been used for a long time as a heat dissipation plate that utilizes its excellent heat dissipation. In particular, since the alumite coating has a good dyeing property, the member having the alumite coating is also used as a decorated wall plate material, a member for a door, or an artistic ornament itself. Furthermore, it has a wide range of uses such as various personal name plates.

As a method for coloring or recording an alumite coating (anodic oxide coating), a photographic printing method is the mainstream. This method forms a color image with a multicolor recording liquid by repeating a series of steps of applying a resist, exposing, developing, dipping in a recording liquid (dye) of a predetermined color, and peeling the resist for each color. is there.

The photo-printing method conventionally used for recording on a material made of aluminum or an alloy thereof having an anodic oxide coating has many steps, is complicated, and takes a lot of time. If the number is increased, the number of processes and the processing time are greatly increased. Therefore, there is a limit in processing a large amount of material.

Therefore, if an ink jet recording method capable of high-speed color recording is applied to this, the processing time can be greatly shortened and the productivity can be further improved, and it is necessary for the photo printing method. A resist, a developing solution, a cleaning solution, etc. are not required, and the cost can be significantly reduced. Further, it is possible to solve the problems of environmental pollution due to waste liquid such as developer and cleaning liquid after use and its treatment.

Application of ink jet recording to an alumite coating is disclosed in, for example, Japanese Patent Application Laid-Open No. 62-115074 and Japanese Patent Application Laid-Open No. 3-147883. In the methods described in these publications, the conventional inkjet recording method is merely applied directly to the plate material having the alumite coating.

[0009]

In ink jet recording, the ink absorbency and fixability of a recording material are particularly important. When the fixability is poor, the ink droplets applied first and the ink droplets applied later are applied. Color mixing with ink droplets makes it impossible to obtain desired color reproducibility and sharpness. If the surface of the recording material is not wet, the ink will be repelled on the surface, so that a good image cannot be obtained.

However, the alumite coating as described above is not always sufficient in terms of ink wettability, ink absorbability and ink fixability, and even if ink jet recording is directly applied to the alumite coating, the following result is obtained. However, it is not always practical.

Most of the ink applied to the alumite coating is not absorbed by the anodic oxide coating, and the ink droplets are mixed on the surface, resulting in a blurred image. Further, the ink fixing property is poor with the alumite coating, and various rollers involved in the conveyance of the recording material and the control of the recording position in the ink jet recording apparatus come into contact with the unfixed portion of the ink, so that a trace of the roller is recorded on the recording surface. It appears and damages the recorded image.

On the other hand, even when ink-jet recording is carried out using a conventionally well-known dye for alumite as an ink component, the surface of the alumite coating cannot be sufficiently colored, and a particularly dark color and a sufficient color can be obtained. It has the drawback of not having it.

Further, in normal ink jet recording, in order to increase the printing speed, recording is simultaneously performed by a recording head having a large number of nozzles. However, when recording is performed in an unfixed state, the ink of the previously written line is generated. There is also a drawback that uneven stripes are generated in which a portion having a high density is generated for each line by being pulled by the ink of a line to be written later.

Therefore, it is practically practical to directly apply the high-speed color recording by the ink jet recording method to a recording material made of a material other than the conventionally used materials such as paper, such as a metal such as an alumite coating. I can't say.

On the other hand, ink jet recording apparatuses for can manufacturing and printing of lot numbers have been put into practical use, but many of them use oil-based inks or pigment-based inks,
If the small-diameter ink droplets necessary for forming a high-definition image cannot be ejected or if the nozzles are arranged at a high density, clogging easily occurs and the applicable fields are limited, and a higher-definition image is recorded. It is not practical to use. Further, in the ink jet recording apparatus for these applications, the processing accuracy of the nozzles is not sufficient, the nozzle density can be increased only up to about several nozzles / mm, and it is difficult to improve the accuracy of the image.
There is a problem in image quality when it is applied to decoration. Therefore, it is not practical to apply the ink jet recording method in this field to the recording of the alumite film.

As described above, if the conventional ink jet recording method is simply applied to the alumite coating film of aluminum or its alloy, there are the following problems.

1) Color mixing (bleeding) between the colors occurs and the image is blurred.

2) Line unevenness in the print scan of each print head occurs.

3) Unfixed ink is transferred to a transport roller or the like in the apparatus, and a ghost image and an image collapse occur.

4) The dyeing property of the color ink on the alumite coating is poor, and the image density is lowered by washing with water after printing, and the image becomes thin.

Therefore, the present invention has been made in view of these problems, and an object thereof is to adopt an ink jet recording system for an aluminum anodic oxide coating (alumite coating) to mix colors, scan unevenness, image blurring, etc. Without
An object of the present invention is to provide an image forming method and a method for manufacturing a decorative aluminum plate, which are necessary for a technique for forming a recorded image having an excellent image performance such as having a sufficient color density.

[0022]

The above object can be achieved by the present invention described below.

According to the present invention, at least one or more color ink droplets are ejected from a recording head having an ink ejection port to an anodized film formed on the surface of a plate or foil made of aluminum or an aluminum alloy by an ink jet recording method. An image forming method of forming an image by applying
(1) First of dehydrating and activating the anodized film
(2) Ink droplets are ejected from a discharge port of the recording head in accordance with an image signal to a predetermined position of the dehydrated and activated anodized film, and thinning is performed by a plurality of scans of the recording head. The second step of forming a desired image by recording the image a plurality of times, and (3) dyeing the dye contained in the ink adhering to the anodic oxide film, on which the recorded image is formed, into the anodic oxide film. The image forming method is characterized in that the image forming method comprises a third step of depositing and removing an excessive component contained in the ink droplets. In the second step, the thinned image is printed by each scan of the print head. Dots are recorded so as not to be continuous on the anodized film, and when the next ink droplet is applied adjacent to the ink droplet applied previously in the second step, the evaporation in the previous ink droplet is performed. Component evaporates After that, the next ink droplet is applied, and in the second step, when the next ink droplet is applied over the previously applied ink droplet, the evaporation component in the previous ink droplet is evaporated. Then, the next ink droplet is applied, an image is formed using a multicolor ink, and the treatment for the anodized film in at least one of the first step and the third step includes a heat treatment, The treatment for the anodized film in at least one of the step 3 and the third step,
A treatment for the anodized film in at least one of the first step and the third step, including an electromagnetic induction treatment,
It includes a process of blowing a dry gas, the third step includes a washing process, and the inkjet recording method is a bubble jet recording method.

Further, according to the present invention, at least one or more colors of ink are discharged from a recording head having an ink discharge port to an anodized film formed on the surface of a plate or foil made of aluminum or an aluminum alloy by an ink jet recording system. A method of manufacturing a decorative aluminum plate for forming an image by applying droplets, comprising: (1) a first step of dehydrating and activating the anodized film; and (2) the dehydrated and activated anode. Forming a desired image by ejecting ink droplets from a discharge port of the recording head according to an image signal to a predetermined position of an oxide film and recording a thinned image a plurality of times by a plurality of scans of the recording head. 2 steps,
(3) A third step of dyeing the dye contained in the ink adhering to the anodic oxide coating on which the recorded image has been formed to the anodic oxide coating to remove excess components contained in the ink droplets. It is a method of manufacturing a decorative aluminum plate having.

According to the image forming method and the method for producing a decorative aluminum plate of the present invention, the above dehydration and activity are applied to the anodized film formed on the surface of the plate or foil of aluminum or its alloy before application of ink droplets. The dyeing property of the ink is improved by performing the chemical treatment, and the ink is applied as a thinned image so that dots are not continuously formed between the scans of the recording head, and the ink droplets previously applied when recording a plurality of times. When applying the ink droplets adjacent to, the area at least overlapping the previously applied ink droplets is almost completely fixed,
When the dye in the ink is dyed and then the ink droplets are applied to adjacent areas, and when the ink droplets are applied on top of the previously applied ink droplets, the dots previously formed are almost completely fixed and An image without ink bleeding is formed by dyeing the above dye and then the next ink droplet is overlapped, and finally a recorded image having excellent image performance on the anodized film can be formed.

[0026]

EXAMPLE The recording material in the present invention has an anodized film formed on the surface of a plate or foil of aluminum or its alloy. The recording material may have a structure in which a foil of aluminum or its alloy is laminated on a portion made of a material other than aluminum or its alloy, for example, various materials (base material) such as clard material.

The aluminum or its alloy used in the present invention can be used without any particular limitation as long as it has a good ability to form an anodized film. For example, a pure aluminum-based plate or foil such as JIS-1050 or Mg is contained. It is possible to use a plate material, a foil or the like made of an aluminum alloy for alumite, such as the above alloy.

An anodic oxide film of aluminum or its alloy plate or foil of a material having a predetermined shape and size is formed by a press or the like so as to prevent undesired deformation such as warpage and burrs. It is preferable that the surface is subjected to a treatment for adjusting its surface property by a mechanical method, chemical polishing, or the like, if necessary, for good image formation during recording.

By adjusting the surface roughness,
It is possible to select those having various surface states from glossy to white, and by selecting these, it is possible to enhance the metal-likeness and to make the image closer to the recording on paper or the like.

As the treatment method used for this surface treatment,
Mechanical processing methods such as short blasting in which a beaded abrasive is sprayed on the surface or a chemical method using an etching solution can be used, but gas generation when the recording material is immersed in the etching solution, grain boundaries A chemical polishing method is preferable because it can effectively form an uneven portion with a ridge on the outer circumference.

If necessary, the surface of the material on which the anodic oxide coating is formed is further subjected to degreasing treatment and acid cleaning treatment which are generally carried out, and then electrolysis in, for example, a sulfuric acid bath. An anodic oxide coating is formed by an anodic oxidation method and washed with water. The film thickness of the anodized film is, for example, 5 to 25 μm.

FIG. 1 schematically shows the structure of an anodized film of aluminum or its alloy. The anodic oxide coating 1 formed on the surface of the base 4 made of aluminum or its alloy is composed of a large number of cells 3, and pores (micropores) 2 are formed substantially at the center of each cell. The bottom of this pore 2 is constituted by a barrier layer 5 of an oxide film at the boundary with the base 4.

Therefore, the larger the diameter of the pore 2, the higher the dyeing property and the ink receptivity, and the deeper the pore 2, the higher the ink receptivity. It is preferable to select and use conditions that can form pores in such a state.

The diameter and depth of the pores 2 can be increased by treatment at a higher temperature or with a higher concentration electrolyte, but the thinner the barrier layer 5, the lower the corrosion resistance of the material itself. It is preferable to set the electrolysis conditions in consideration of these requirements.

For example, the electrolytic solution composition may be 10 to 10% of sulfuric acid.
A 30% weight ratio solution was prepared, an SUS plate was used as a cathode, the above-mentioned pretreatment was applied to the anode, and an aluminum plate that had been degreased, washed with water and smut-removed before the anodizing treatment was set, and the bath temperature was set to about 25. The current temperature is controlled to 60 to 300 mA / m ² in an electrolytic cell which is controlled at ℃ and well stirred.
Then, anodization is performed for a predetermined time until the required film thickness is obtained. Then, it is taken out from the electrolytic cell, washed thoroughly with water, dried and stored.

Further, the electrolytic treatment is divided into two steps,
It is also effective to adopt the condition that large pores are formed in the first step and the condition that small pores are formed in the second step, and grow the barrier layer on the base side to improve the corrosion resistance. . In this case, the treatment of the second stage may be carried out in the same bath as the first stage, or in a bath different from the first stage. In order to grow the barrier layer, it is also effective to use a boric acid-based electrolytic solution.

A recording material obtained by forming an image forming surface made of an anodic oxide film on the surface of a portion made of a plate or foil of aluminum or its alloy as described above is stored, if necessary, and then It is processed in the first step in the image forming method of the invention.

When the recording material is stored, it is preferable to manage the storage state so as to meet the initial purpose because the storage state has a great influence on the image forming scan. As described with reference to FIG. 1, the anodic oxide coating is composed of a large number of cells having pores, and the presence of the pores allows the ink to be absorbed in the coating to enable recording. However, if the anodic oxide coating is left in an atmosphere containing water (water vapor) and oxygen such as in the atmosphere,
Hydroxide is formed by the reaction with water and oxygen, and if this is formed in the pores, the pores become narrowed or blocked, and when the reaction proceeds, most of the pores in the film are blocked. The decrease in the pore volume and the blockage reduce the ink receptivity (ink absorbability), which causes a problem that the image quality is likely to deteriorate due to the occurrence of blurring and color mixing.
Therefore, it is preferable to block moisture and oxygen when storing the recording material. As a method of storing the recording material,
It can be stored in a container that can form a nitrogen gas atmosphere by flowing nitrogen gas, can be stored in a container that can form a dry air atmosphere by containing a moisture-proofing agent such as silica gel or an oxygen scavenger, and can block the outside air. preferable.

An example of the storage method is shown in FIGS. Figure 2
Is a storage box 32 in which a tube (N ₂ blow tube) 33 for blowing nitrogen gas is set, and the inside of the box is replaced with nitrogen to store the recording material 31. In the case of FIG. 3, the oxygen absorber 35 is enclosed and sealed together with the recording material in a resin bag 34 for storage. The storage method shown in FIG. 4 is an adhesive tape 36 composed of a film 36-1 such as a polyethylene terephthalate film that is impermeable to oxygen and water vapor, and an adhesive layer 36-2 formed on the surface of the film 36-1. 2 is a method of covering the surface of the anodic oxide coating 31-1 formed on 2 and sealing it, and blocking the contact with the atmosphere and storing.

In the first step of the image forming method of the present invention, the anodic oxide coating forming the image forming surface of the recording material is dried and activated.

By this treatment, the aluminum anodic oxide coating forms a boehmite (AIO (OH)) and γ-AI which are formed on the outer surface portion during the formation of the coating.
_The water adsorbed on ₂ O ₃ is dehydrated and condensed to form activation points. Since this activation point reacts with moisture in the air and tries to return to the original state immediately, it is important to perform it immediately before the recording process. When this activation point is formed, the reactive group of the dye contained in the ink is bonded at this point, and the dyeing property is enhanced. In addition, the water in the ink is absorbed, and the ink receiving amount is increased, which is an excellent effect.

In the first step, heat treatment, electromagnetic induction treatment, dry air blowing treatment, or the like can be used. An active gas such as H ₂ or O ₃ may be mixed in the dry air. Also, a method of charging by corona discharge can be used.

Specifically, for example, dry air heated to 60 ° C. is about 20 liters / min at 20 cm × 5 cm.
Spray on the aluminum anodized film through the openings in. The aluminum plate on which the aluminum anodic oxide coating is formed is passed through the opening at a speed of about 30 cm / min and conveyed to the inkjet recording unit. Further, since the effect cannot be sufficiently exhibited when the outside air temperature and the aluminum plate are low, it is preferable to preliminarily heat up to about 60 ° C. by providing a heating heater for plate heating on the transport tray.

At the end of the processing in the first step,
Inkjet recording (second step) is performed on the recording material. For the inkjet recording in the second step, a recording device or recording method applied to a recording material such as ordinary paper can be used.

The ink contains a volatile solvent and a non-volatile solvent in addition to water and dye for the purpose of effectively operating the ink jet device.

Further, in order to increase the recording density, it is necessary to reduce the area where the dye is not dyed on the recording surface. For example, as shown in FIGS. 6A and 6B, 360 dpi
Under the recording conditions of, the diameter of the ink droplets is appropriately about 100 μm, and when the distance between the ink droplets is 70.5 μm, dots are formed so that the ink droplets 21 overlap each other on the anodized film 22 formed on the aluminum 23. To do.

On the other hand, for example, as shown in FIGS. 7A and 7B, the diameter of the ink droplet is 70.5 μ at 360 dpi.
If it is set to m, an undyed area remains on the surface.

If the undyed area remains in this way, the density as an image will be insufficient no matter how high the dye density of each dot is increased.

Therefore, the dots are formed so as to have the relationship as shown in FIGS. 6 (a) and 6 (b).

When a plurality of dots are formed in the ink droplet state as shown in FIGS. 6 (a) and 6 (b), the anodic oxide film 22 is covered with paper, cloth, or a substrate having an absorptive structure. Unlike a recording material, since it does not have ink permeability, the ink that has landed on the surface has a force that causes the ink droplets to coalesce due to the surface tension of the ink.

That is, from the state of FIG. 8A to that of FIG.
It becomes the state of.

When the volatile solvent is volatilized from this state, the ink in a state where the dye concentration is increased is left, but this also aggregates in the center portion due to the surface tension (FIG. 8).
(C)). When this progresses further, an image with a large amount of dye in the central portion and a smaller amount of the dye toward the outside becomes as shown in FIG. 8D, and the non-volatile solvent may remain in the central portion due to aggregation.

This means that in the case of a single color, the density becomes uneven and the image quality is degraded, and in the case of a color, the inks of different colors formed adjacently cause bleeding.

When ink droplets are repeatedly ejected, the ink droplet volume increases as shown in FIG. 9, and even the undyed area is dyed as shown in FIG. 9B. Overflow will occur.

Therefore, in the present invention, FIG.
(F), as shown in FIGS. 11 (a) to 11 (f), after the volatile solvent of the ink droplet that has landed first has almost volatilized (FIG. 10).
(A) to (c)) By landing the next ink droplet (FIGS. 10D to 10F), the density unevenness and bleeding described above do not occur.

This can be achieved by recording a thinned image as shown in FIG. 12 a plurality of times.

That is, in the first pass, the nozzles N1 and N3 in each block are simultaneously driven to print odd-numbered columns, and 2
Nozzles, N2 and N4 are simultaneously driven in the pass to print even rows, nozzles N2 and N4 are simultaneously driven to print in odd rows in the third pass, and nozzles N1 and N3 are printed in the fourth pass.
Are driven simultaneously to print even columns.

As a result, the dot interval in the same pass is 2
Since dots are separated (DB in the figure), blurring due to dots within the same pass and between passes can be prevented.

In the case of color, this can be achieved by fixing one color and then repeating the other colors in the same manner.

In this case, in order to prevent color misregistration, multicolor registration is a known means. It may be performed by a mechanical or electrical method.

Next, the ink will be described.

The ink is not particularly limited as long as the intended purpose can be achieved, but an ink using a coloring material (dye) having a good anodized film dyeing property is more preferable. That is, in the anodized film of aluminum or its alloy,
The aluminum or its alloy side is used as an anode for electrolytic treatment in an electrolytic solution such as sulfuric acid at a direct current or an alternating current to form an oxide film, so that the film is formed of aluminum or its alloy in the dehydration condensation process in the electrolytic oxidation reaction. Is still contained in the various intermediate products generated when the oxide is converted into its oxide. This intermediate product is highly reactive (for example, boehmite), and the dyeing property can be improved by using a dye having high reactivity with such an intermediate product. Examples of such dyes include dyes having at least one anionic group, and dyes having a carboxyl group and / or a sulfone group are particularly preferable.

The pH of the ink is preferably on the alkaline side rather than the acidic side. It is considered that this is because the coating is formed on the anode side and is easily dissolved on the alkali side.

Further, the solvent component of the ink is not limited as long as the initial purpose can be achieved, but glycerin and glycols having a high molecular weight which are used in conventional inks for ink jet recording used for paper and the like are used. The non-volatile solvent remains on the image forming surface after the volatile solvent evaporates as shown in FIG. 5, for example.

FIG. 5 is a diagram showing the amount of evaporation of the ink containing the non-volatile solvent over time. FIG. 5 shows the evaporation amount of the ink put in the petri dish under the drying condition of 60 ° C., the vertical axis shows the evaporation amount, and the horizontal axis shows the time. First, when ink is added at 60 ° C., the volatile component evaporates, and the evaporation amount increases according to the evaporation rate. However, when the volatile component is completely evaporated and only the non-volatile component remains, the ink amount remains constant. If this is more than the amount that can be received by the cell, the surrounding ink drops will mix with each other and bleed,
Image quality may deteriorate.

In the case of paper or cloth, or a recording material having a structure in which the base of the image forming surface has a solvent absorbing property, these non-volatile solvents permeate into the base, so that the dye forming the image of the surface layer may be absorbed. No impact or negligible. On the other hand, in the anodized film formed on the surface of aluminum or its alloy, since the penetration of the non-volatile solvent in the direction of the base does not occur when using paper or the like,
These may remain in the coating and cause color mixing, blurring, bleeding, and the like. For inks prepared only with water and dye, it is not possible to use these non-volatile solvents in ink jet ink recording devices, because bubbles are not generated in the device and the ink does not have a viscosity suitable for recording. Essential for effective operation. Therefore, in order to prevent the above-mentioned problem due to the non-volatile solvent, the content of the non-volatile solvent in the ink should be smaller than the total volume of the pores existing in the area where the ink droplets land and spread on the image forming surface. Is preferably set so that the non-volatile solvent occupies.

Since the ink absorbency of the anodized film is defined by the volume of the pores, the amount of the dye dyed in the ink during ink jet recording in the present invention is
It is preferably set according to the structure of the anodic oxide coating forming the image forming surface, particularly the volume of the pores. For example, the cell diameter of the anodized film having the structure shown in FIG. 1 is about 400 angstroms, and the pore diameter is about 100 angstroms.
The depth of the pores is about 10 μm, and when recording under the condition of 400 dpi, one side of each pixel is about 63 μm.
Among the present approximately 2.4 million cells, the internal volume per one pore of about 0.0008Myuemu ^3, the total volume of pores per pixel is about 1900μm ^3. The value obtained by dividing the total capacity of the pores by the area of one pixel is the receiving height, which is 0.46 μm. The dye concentration in the ink in this case is defined by the receiving height. When the volume per unit ink drop (ejection amount) is 30 ng, the receiving height of 0.23 μm gives a dye concentration of about 3%. In addition, the degree of coloring and the reflection O.D. D. From the viewpoint, in order to obtain a clear image, the receiving height is preferably 0.2 μm or more, and in forming the anodized film, the film thickness, cell density, and pore size satisfying this receiving height are It is desirable to set the electrolysis conditions so that they can be obtained.

Under the above-mentioned condition settings, when the ink droplet ejection amount is 30 ng and the aluminum anodic oxide film acceptance amount is 0.46 μm, the permissible amount of the non-volatile component contained in the ink is less than or equal to the above-mentioned film acceptance amount. Is important. Therefore, it was revealed that the image bleeding can be suppressed by controlling the content to be 6% by weight or less.

This is determined by the shapes of the cells and pores and the film thickness of the anodized (alumite) film. That is, if the film thickness is about 20 μm, the compounding ratio can be doubled, and if the cell density is high and the pore size is large, the compounding ratio can be further increased. However, about 10% is the upper limit for general alumite, and 5%
It is desirable to set it as follows.

When the non-volatile solvent is completely removed,
There is a case where the clogging of the ink-jet head and the reproducibility are deteriorated, and the image quality is rather deteriorated. Therefore, it is important to set the optimum mixing ratio within the above range.

The non-volatile component is composed of diethylene glycol, triethanolamine, polyethylene glycol, glycerin, urea and the like in addition to the dye.
Any solvent and additives may be used as long as they are excellent in J (inkjet) suitability and do not adversely affect printing on alumite.

Further, in the bubble jet recording, the volatile component is a solvent which is foamed by heating, and may be water, isopropyl alcohol, acetone or alcohols, and has excellent I / J suitability and printing of alumite. Any solvent may be used as long as it does not adversely affect.

The evaporation rate of this volatile component is 1.0 × 10 ⁻⁵ g / mm in a mixed state of each solvent and in a dry environment at 60 ° C.
It is preferably in the range of ^{2 · sec~1.0 × 10 -7 g /} mm 2 · sec. At this time, the speed of complete evaporation of the ink droplets hit on the alumite surface is several seconds to several tens of seconds, which means that the ink droplets will dry within one scan to several scans. By repeating a plurality of times to form a desired image, high-quality image recording can be performed without bleeding or bleeding.

At the end of ink jet recording,
The third step, that is, the step of evaporating the solvent component of the ink in the anodized film on which the image is formed and fixing the dye component of the ink, is performed on the image formed on the image forming surface.

In the third step, the coloring component contained in the ink is a dye, the other components are necessary components for ink jet recording, and are unnecessary components after the alumite coloring. Therefore, after the dye in the ink has settled in the cell after recording and the dyeing reaction with the coating is completed, it is necessary to quickly remove the unnecessary components.

First, in order to efficiently dye the dye and the film, it is important to heat the film itself to promote the reaction. Then, in order to deposit the dye in the pores of the cell,
It is important to evaporate the volatile components in the ink as quickly as possible and to keep the dye in the cell in order to form a high quality image.

Further, since the discharge amount is usually designed to maximize the recording density, the dye is set to the maximum value of the film reception amount as much as possible, but the head discharge amount varies so much that the film reception amount is large. The phenomenon of being driven over the capacity occurs. Further, in forming an image, multi-colored ink may be ejected at the same place, and the dye itself may become an unnecessary component, so that it may remain on the film. If the dye remains in the film in this way, it will ooze out by a subsequent sealing treatment to improve the corrosion resistance of anodized aluminum, deteriorating the image quality, and even if it is used as it is, it will be resistant to water, condensation, etc. The same bleeding occurs in the environment where the image quality is required, and the image quality is not durable.

An example of a specific method for removing the above unnecessary components after recording will be described below.

First, an aluminum plate on which an alumite coating has been formed after ink jet recording is heated to 1000 W from the bottom.
While passing over the heat sheet of No. 1, heat from the upper part with an infrared lamp, 500 W × 3, and pass at a moving speed of about 30 cm / min. Also, in this example, Y, M,
Since four colors of C and Bk were overprinted, as a post-treatment, the recording surface was washed with pure water to remove excess dye and dried to obtain a recorded material. Then, the recorded material is subjected to alumite sealing treatment for 10 minutes in pure water boiled to about 100 ° C., and then dried to obtain a finished product.

The relationship between the cell composition of alumite and the amount of ejected ink will be described in more detail below.

In the alumite cell structure shown in FIG.
The cell size diameter is A μm, and the diameter a of the pore formed in the cell
The thickness of the alumite coating is L μm.
Here, since the alumite cells are arranged in a substantially regular hexagonal shape, the cell surface area Sc is

[0082]

[Outside 1] And the surface area Sp of the pore is

[0083]

[Outside 2] Becomes

Therefore, the area ratio Cp occupied by the pores is

[0085]

[Outside 3] Becomes

Therefore, if the barrier layer 5 in the drawing is ignored, the ink receiving amount height Ra (μm) per unit area is

[0087]

[Outside 4] Becomes

At this time, the volume of the ink droplet to be shot is set to Vd
(Μm ³ ) and the implantation area is Sd (μm ² ),
Ink drop height h (μ
m) is h = Vd / Sd.

At this time, when the volume ratio of the non-volatile component in the ink is X, the height t (μm) of the non-volatile component after drying is t = XVd / Sd (μm). It is important that this height t does not exceed the above-mentioned ink reception amount height Ra. If t ≦ Ra is not satisfied, the ink overflows and the image quality deteriorates as described above. Therefore,

[0090]

[Outside 5] That is,

[0091]

[Outside 6] It is important to select the mixture ratio X and the film thickness L so that In general, in inkjet, Vd / Sd = 10 μm, a / A of alumite coating =
Since it is 0.25, usually X ≦ 0.0076L ^* (L ^* is dimensionless).

Next, an example of a recording apparatus that can be used in the image forming method of the present invention will be described.

FIG. 13 is a schematic diagram showing the entire recording apparatus. In the figure, 710 is a recording head, which is 400 dp.
i, an inkjet recording head with 128 nozzles,
The ejection amount is 25 ng per dot. Furthermore, four heads for four colors of Y (yellow), M (magenta), C (cyan), and Bk (black) are provided. Here, the registration of each head is mechanically aligned. The recording timings of the four colors are provided with a time difference depending on the set position of the head, the feed speed of the recording material, etc., and the four-color scanning is set so that a full-color image can be recorded. A recording material 701 is an image forming surface by forming an anodic oxide coating on the surface made of the above-mentioned aluminum or its alloy plate or foil. Stocker 71
A plurality of recording materials 701 are set in No. 1 and sent to a belt conveyor by a conveyor 712 and sent to a printing tray 715. Reference numeral 714 is an auxiliary roller for feeding.

Recording material 7 sent to printing tray 715
01 is firmly adsorbed and fixed on the tray by suction with the pump 716. The recording material 701 on 715 is the first
Of the anodic oxide film of the recording material 701 is removed by being sent to an area where the processing step (dehydration, activation step) is performed and heated by irradiation of infrared rays from the infrared lamp 704. Since the dehydration reaction is performed, the film is activated. Further, by rotating the fan 704 to blow air, the effect of the treatment in the first step can be further promoted.

When the recording material is carried out from the area of the first processing step by the feed motor 717, the recording head 71 is immediately discharged.
Inkjet recording by 0 is performed. Various ink jet recording methods such as a piezo method and an electrostatic method can be used for the ink jet recording which is the second step, but a bubble jet method which can stably perform high speed recording is preferable.

As the image forming method, the above-described method of forming a desired image by performing the thinned image a plurality of times is adopted. As the ink used here, those having various compositions can be used, and as described above, the kind of dye or the content of the non-volatile solvent suitable for the anodized film is selected and used. Is preferred. The recording material on which the image is recorded is immediately conveyed to the area where the processing of the third step is performed. Here, the volatile solvent of the ink present in the anodic oxide coating on which the image is formed is evaporated and scattered, and the dye of the ink is reacted with the coating to promote dyeing and ensure fixation. Is done to In this apparatus, the third step is performed by the heating means 703 including a fan and an infrared lamp as a set. In the third step, the purpose is to dye the dye in the ink, and the water and oxygen in the air react with the anodized film to form hydroxides to block the pores in the film. Since it is also a preferable process for dyeing the dye, unlike the first step, it is not always necessary to operate the fan.

The recording material (recorded material having a recorded image) that has undergone the above three processing steps is conveyed to the stocker 719 via the belt conveyor 20 and the feed roller 721.
It is stored at a predetermined position by the handler 718.

In the illustrated example, the recording material 701 has a plate-like shape, but a tray 715 that conveys it.
Is appropriately adjusted so as to correspond to the shape of the recording material.
For example, by using a spacer 811 or the like as shown in FIG. 14, it becomes possible to cope with recording on a disc-shaped recording material. Further, it is desirable that this apparatus has means for adjusting the distance between the recording head and the image forming surface of the recording material according to the thickness of the recording material.

In order to accelerate the heating effect in the first step and the third step, the tray is additionally provided with a heating means such as a heater to heat the recording material before each processing. By setting it, heating efficiency can be improved and effective processing can be performed even for processing a relatively large recording material having a large heat capacity.

When the heat treatment is carried out, the dimensions are deformed due to thermal expansion, the width and feed directions of the recording are deviated, and there are problems such as occurrence of white stripes in the recorded image and deviation of the print size. 15 occurs, the surface temperature of the image forming surface of the recording material 901 is detected by the temperature sensor 902 and is amplified by the amplifier (Amp), and this is amplified by the A / D converter (A). / D) to digitize and then compare with a preset value with a comparator, and print head 910 with the optimum delay signal for the clock signal.
It is preferable to use a system that sends a signal to the motor 903 and adjusts so that the recording material can be set in the correct position.

As described above, in the case of the anodic oxide coating of aluminum or its alloy, the sealing rate of the pores constituting the coating, the film thickness, the pore size, the cell density, etc. have a great influence on the ink receiving amount. However, the characteristics of these coatings also vary among a plurality of recording materials formed under the same conditions, and when recording is performed under the same conditions in the second step, image quality variations, especially among lots, occur. It may occur. In such a case, print on the part of the anodic oxide film where no recording is performed in advance, pre-examine the print density, the balance of shades between colors, and feed back the results to determine the pulse width of the recording head. Such a problem can be solved by further adding a control means for controlling the head temperature, the time between full pulses, etc. to adjust the ejection amount.

Further, in order to convey the recording material with high accuracy, a mark is marked on the non-printed area of the recording material by etching or pressing, and the position is read by an appropriate reading means to always keep the position of the recording material. It is also possible to check and check the position and control the transfer means to carry out more accurate transfer. Further, when the recording material has warp or the like, it is also effective to add a function of correcting the warp to the roller or the like in order to correct the warp or the like. Further, if the above-mentioned mark impairs the product value, it may be removed by means such as a shirring press after printing.

The member having a portion made of aluminum or its alloy on which an image is formed in this manner may be used without being sealed in the entire pore as it is, for example, for indoor interior use, or for outdoor use. If reliability is required, it is preferable to perform a sealing treatment of pores separately to obtain a product.

[0104]

According to the present invention, an ink is formed by subjecting the anodized film formed on the surface of a plate or foil of aluminum or its alloy to the above-mentioned dehydration and activation treatment before application of ink droplets. When the ink is applied multiple times as a thinned image and the next ink droplet is applied adjacent to the previously applied ink droplet, at least the previously applied ink droplet overlaps. When the area is almost fixed and the dye in the ink is dyed, the next ink droplet is applied to the adjacent portion, and when the next ink droplet is formed by superimposing it on the ink droplet applied previously, it is applied first. The ink droplet is almost fixed, the dye in the ink is dyed, and then the next ink droplet is overlapped, whereby an image without ink bleeding is formed, and finally a recorded image having excellent image performance on the anodic oxide film and Equipped with it It is possible to form a decorative aluminum plate.

[Brief description of drawings]

FIG. 1 is a schematic view showing the structure of an anodized film of aluminum or its alloy.

FIG. 2 is a diagram showing a storage example of a recording material on which an anodized film is formed.

FIG. 3 is a diagram showing a storage example of a recording material on which an anodized film is formed.

FIG. 4 is a diagram showing a storage example of a recording material on which an anodized film is formed.

FIG. 5 is a diagram showing a state of evaporation of a solvent in the inkjet ink.

FIG. 6 is a diagram showing an ideal image processing state on a recording material.

FIG. 7 is a diagram showing an inappropriate image processing state on a recording material.

FIG. 8 is a diagram showing how dots landed on a recording material aggregate.

FIG. 9 is a diagram showing how dots landed on a recording material overflow.

FIG. 10 is a diagram showing an image forming method of the present invention on a recording material.

FIG. 11 is a diagram showing an image forming method of the present invention on a recording material.

FIG. 12 is a diagram showing thinning driving of the present invention.

FIG. 13 is a schematic diagram of an apparatus for performing the image forming method of the present invention.

FIG. 14 is a diagram showing a configuration of a tray used in an apparatus for performing the image forming method of the present invention.

FIG. 15 is a diagram showing an example of a position correction system according to the temperature of the image forming surface of the recording material when aligning the recording material and the recording head in the apparatus for performing the image forming method of the present invention.

[Explanation of symbols]

1 anodized film (anodized film) 2 pores 3 cells 4 base 5 made of aluminum or its alloy 5 barrier layer 21 ink drops 22 anodized film 23 base made of aluminum or its alloy 31, 901 image forming surface made of anodized film Recording material having 31-1 Anodized film 31-2 Base made of aluminum or its alloy 32 Storage box 33 N ₂ blow tube 34 Resin bag 35 Deoxidizer 36 Adhesive tape 36-1 Plastic film 36-2 Adhesive layer 701 , 910 Recording head 702 Area where first step is performed 703 Area where third step is performed 704 Infrared lamp 705 Fan 711, 719 Stocker 712, 718 Handler 713, 720 Belt conveyor 714, 721 Feed roller 715 Carry tray 7 16 Suction pump 717, 903 Feed motor 811 Auxiliary seat 902 Temperature sensor

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location B41J 2/485 29/00 B44C 1/14 B41J 3/12 M 29/00 GH

Claims (11)

[Claims] 1. An ink droplet of at least one color is applied to an anodized film formed on the surface of a plate or foil made of aluminum or an aluminum alloy by an ink jet recording method from a recording head having an ink ejection port. An image forming method for forming an image by: (1) a first dehydration and activation treatment of the anodized film;
(2) Ink droplets are ejected from a discharge port of the recording head according to an image signal to a predetermined position of the dehydrated and activated anodized film, and thinning is performed by a plurality of scans of the recording head. A second step of forming a desired image by recording an image a plurality of times, and (3) dyeing the dye contained in the ink adhering to the anodized film from the anodized film on which the recorded image is formed, into the anodized film. An image forming method comprising a third step of depositing and removing an excessive component contained in the ink droplet. 2. The image forming method according to claim 1, wherein in the second step, the thinned image is recorded such that dots printed by each scan of the print head are not continuous on the anodized film. 3. In the second step, when the next ink drop is applied adjacent to the previously applied ink drop, after the evaporation component in the previous ink drop has evaporated, the next ink drop The image forming method according to claim 1, wherein: 4. In the second step, when the next ink drop is applied by superimposing it on the previously applied ink drop, the next ink drop is removed after the evaporation component in the previous ink drop is evaporated. The image forming method according to claim 1, wherein the image forming method is provided. 5. The image forming method according to claim 1, wherein an image is formed using multicolor ink. 6. The image forming method according to claim 1, wherein the treatment for the anodized film in at least one of the first step and the third step includes heat treatment. 7. The image forming method according to claim 1, wherein the treatment on the anodized film in at least one of the first step and the third step includes an electromagnetic induction treatment. 8. The image forming method according to claim 1, wherein the treatment on the anodized film in at least one of the first step and the third step includes a blowing treatment with a dry gas. 9. The image forming method according to claim 1, wherein the third step includes washing with water. 10. The image forming method according to claim 1, wherein the inkjet recording method is a bubble jet recording method. 11. An ink droplet of at least one color is applied to an anodized film formed on the surface of a plate or foil made of aluminum or an aluminum alloy by an inkjet recording method from a recording head having an ink ejection port. A method of manufacturing a decorative aluminum plate for forming an image by: (1) A first dehydration and activation treatment of the anodized film.
(2) Ink droplets are ejected from a discharge port of the recording head according to an image signal to a predetermined position of the dehydrated and activated anodized film, and thinning is performed by a plurality of scans of the recording head. The second step of forming a desired image by recording the image a plurality of times, and (3) dyeing the dye contained in the ink adhering thereto from the anodized film on which the recorded image is formed, into the anodized film. A method for manufacturing a decorative aluminum plate, comprising a third step of depositing and removing an excessive component contained in the ink droplet.