JPH04361085A - Discharge destruction record - Google Patents

Abstract

PURPOSE:To provide a discharge breakdown recording body having excellent environment resistant property and printing property. CONSTITUTION:As a constituting metal of a metallic thin film layer 4, aluminum to which at least 1 kind selected from a group consisting of manganese, copper, and magnesium is added is used. A base layer 3 includes high-molecular particles and the surface thereof is made to have a roughness of 250 sec or less in Bekk smoothness.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is an electrical discharge destruction recording material that prints by destroying a part of a metal thin film layer provided on a base layer by electrical discharge and making holes, and which has excellent environmental resistance and printing properties. This invention relates to a discharge breakdown recording material with good characteristics.

0002

BACKGROUND OF THE INVENTION Conventionally, as a printing method with good environmental resistance, a thermal printing method has been adopted in which printing is performed by heating a part of a thin film layer of a low-melting point metal to form holes in the melt.

[0003] Printing using this thermal printing method is virtually impossible to rewrite and has excellent stability over time, so it can be used for the purpose of printing and displaying amounts, counts, dates, etc. has been used extensively.

As a specific example of a recording medium using this thermal printing method, for example, as shown in Japanese Patent Laid-Open No. 59-199284, a magnetic recording layer is provided on a substrate, and a non-magnetic metal or A thin film of an alloy is provided as a heat-sensitive recording layer, and a colored layer is provided between the heat-sensitive recording layer and the magnetic recording layer.
Alternatively, various methods have been proposed, such as providing a colored layer and a protective layer on the heat-sensitive recording layer, and further providing an adhesive layer between each layer.

However, with this thermal printing method, printing is performed while heating and cooling the thermal head, so there is a limit to the printing speed, and the usable range is significantly limited in fields that require high-speed processing such as stations and supermarkets. It has the disadvantage of being restricted.

As another printing method that utilizes melting of a thin metal film, a printing method using discharge destruction has been proposed, as shown in Japanese Patent Publication No. 30157/1983, for example.

[0007] Items printed using this discharge destruction printing method are
Like the thermal printing method described above, it is not rewritable and has the excellent feature of being capable of high-speed printing.

[0008] However, the recording material based on this discharge destruction printing method, ie, the discharge destruction recording material, has a problem in that it has poor environmental resistance compared to the recording material using the thermal printing method.

This is because the principle of this discharge destruction printing method is
Printing is done by applying electricity to the metal thin film layer to melt and scatter it to create holes, so the protective layer formed on the metal thin film layer cannot be thickened, and therefore it is difficult to provide sufficient protection. This is because they cannot perform to their full potential.

[0010] Furthermore, this discharge destruction printing method is not necessarily sufficient in terms of print density, and is inferior to the thermal printing method in terms of obtaining clear prints.

[0011] This is because, in this discharge destruction printing method, discharge destruction of the metal thin film layer occurs microscopically only in the energized portion of the print dots, so it is normally difficult to form complete print dots. . Another reason is that the state of current flow from the electrode needle is susceptible to subtle changes in the thickness of the protective layer formed on the metal thin film layer.

[0012] That is, since the protective layer is thin, about 1 μm at most, when it is formed by a normal coating method such as a gravure coater, the film thickness generally varies by about ±20%. By the way, the high electrical resistance makes it difficult to conduct electricity, resulting in lower print density, etc.
This tends to cause variations in print density.

However, by reducing the thickness of the protective layer, the variation in print density can be reduced;
As a result, environmental resistance deteriorates, making it unsuitable for practical use.

[0014]

As described above, the conventional discharge destruction recording material based on the discharge destruction printing method has the problems of poor environmental resistance of the printing layer and low print density.

As mentioned above, if the environmental resistance of the discharge breakdown recording medium is poor, the metal thin film layer will be corroded when exposed to a high humidity environment, causing changes in appearance or falling off, resulting in the printed portion being damaged. If it disappears or becomes unclear and cannot be recorded, and if the print density of the discharge breakdown recording medium is low, visibility becomes poor, leading to a decline in print quality and reliability.

Therefore, the present invention aims to eliminate the poor environmental resistance and low print density of the printing layer of the discharge rupture recording material, and to provide a discharge rupture recording material with good environmental resistance and printing characteristics. purpose.

[0017]

[Means for Solving the Problems] The present inventors have conducted various studies to find means for improving the environmental resistance and printing characteristics of the printing layer of the discharge breakdown recording material, and have found the following environmental resistance and printing characteristics. We have developed various means to improve printing characteristics.

First, to explain the means for improving the environmental resistance of the printing layer, the present inventors used a metal selected from the group consisting of aluminum, manganese, magnesium, and copper as the metal constituting the metal thin film layer. at least 1
It has been found that the environmental resistance of the printing layer can be improved by using a material to which seeds are added. This will be explained in detail as follows.

Aluminum is generally used as the metal constituting the metal thin film layer of the discharge breakdown recording material.

[0020] This is because aluminum has good conductivity,
Moreover, when made into a thin film, it has high whiteness and good appearance,
This is based on the fact that it is easy to form a thin film and has good mass productivity.

The reason why the environmental resistance of the printing layer of this discharge destruction recording material is poorer than that of thermal printing is that, as mentioned above, the thickness of the protective layer is usually limited to about 1 μm or less, so moisture etc. This is because the metal thin film layer is corroded in a corrosive atmosphere such as a high humidity atmosphere.

However, if the thickness of the protective layer is increased, the corrosion resistance will be improved, but the electrical resistance will increase accordingly, making it difficult to conduct electricity to the metal thin film layer and deteriorating the printing quality.

Therefore, the present inventors considered improving the corrosion resistance of the metal itself constituting the metal thin film layer, and conducted studies on improving the corrosion resistance by adding alloying elements to aluminum.

[0024] As a result, by adding at least one member selected from the group consisting of manganese, magnesium and copper to aluminum, practically sufficient corrosion resistance can be obtained even when the thickness of the protective layer is thin. I found out.

This is considered to be because the addition of the above-mentioned metal elements strengthens the bonding of the oxide film formed on the surface of aluminum and makes it passivated.

[0026] The amount of manganese, magnesium, copper, etc. added to this aluminum is 0.0% relative to aluminum.
A range of 0.05 to 20% by weight is preferred. Addition amount of manganese, magnesium, copper, etc. to aluminum is 0.0
If it is less than 5% by weight, the effect of increasing corrosion resistance will not be sufficiently obtained, and if the amount of these metals added is less than 20% by weight.
If the amount increases, it becomes difficult to form a stable solid solution, and in some cases, inclusions may precipitate at grain boundaries.
This is because corrosion resistance decreases.

Next, we discovered that electrochemical reactions between the metal thin film layer and other layers are involved as a cause of corrosion, and we investigated means to prevent this. It has been found that corrosion of a metal thin film layer can be prevented by providing a layer containing a metal whose standard electrode potential is more base than that of the constituent metals of the layer.

This will be explained in detail as follows. In the electrochemical reaction, the partner layer of the metal thin film layer is a colored layer.

[0029] In other words, carbon black, magnetic powder, etc. are added as colored pigments to this colored layer.
In an aqueous solution, these act as counter electrodes for the metal thin film layer, and the disappearance of the print occurs when the metal thin film layer side becomes the anode in this electrochemical reaction, and the constituent metals dissolve out.

Therefore, this can be prevented by intentionally making the metal thin film layer side a cathode by some means. Therefore, as a means for achieving this, a layer containing a metal whose standard electrode potential is more base than that of the constituent metals of the metal thin film layer is provided so that the metal thin film layer always becomes a cathode.

In the above, an anode is an electrode that emits electrons in an electrochemical reaction, and a cathode is an electrode that takes in electrons. For example, when aluminum is used as the constituent metal of the metal thin film layer,
Magnesium and the like are metals whose standard electrode potential is more base than aluminum, and by forming a layer containing magnesium and the like, the metal thin film layer can be used as a cathode.

The layer containing a metal whose standard electrode potential is more base than the constituent metals of the metal thin film layer may be a thin film formed by vapor deposition, sputtering, etc. of the metal whose standard electrode potential is more base. Alternatively, it may be formed as a layer by coating a resin with the metal having a base electrode potential dispersed therein.

Note that when the discharge breakdown recording material is immersed in a solution that acts as an electrolyte solution, such as saline solution (sodium chloride aqueous solution), metals whose standard electrode potential is less noble will be eluted; Since it does not cause the disappearance of , there is no practical problem.

[0034] Furthermore, if structural improvements are made to the formation site of the layer containing the metal having a base electrode potential, it is possible to make almost no change in appearance.

Furthermore, in a discharge breakdown recording material having a structure in which a base layer is formed of a transparent resin on a colored layer and a metal thin film layer is formed on the base layer, a barrier layer is provided between the base layer and the colored layer. It has also been found that by forming a relatively thick resin with high insulating properties, the electrochemical reaction between the metal thin film layer and the colored layer can be reduced.

[0036] This is because the above electrochemical reaction, that is, the movement of ions between the electrodes, is less likely to occur as the distance between the electrodes is longer and the insulation resistance is higher, and as a result, the electrochemical reaction becomes more difficult to proceed. This is an application of

[0037] If the thickness of the base layer is increased, the distance between the electrodes becomes longer, but the base layer must have good adhesion with the metal thin film layer, so it is not necessary to use a highly insulating resin. Therefore, it is preferable to form the barrier layer with a resin different from that of the base layer.

[0038] The thicker the barrier layer is, the higher the corrosion-preventing effect will be, but the effect will be exhibited if it is 1 μm or more. Although there is no particular restriction on the upper limit of the thickness, in reality there is a restriction due to the necessity of making the color of the underlying colored layer appear clearly, and generally 5 μm or less is appropriate.

In particular, when magnetic powder is used as the colored pigment in the colored layer to also serve as magnetic recording, if this barrier layer is too thick, the magnetic output will decrease, so the thickness of the barrier layer should be 5.
It needs to be less than μm.

Further, the insulating property of this barrier layer has a clear effect when the resistivity is 10 9 Ω·cm or more. Furthermore, in order to improve the environmental resistance of the discharge rupture recording material, it is preferable that the barrier layer has higher heat resistance and moisture resistance.

[0041] Examples of the resin for forming such a barrier layer include polyurethane resin, acrylic resin, polyimide resin, vinyl chloride-vinyl acetate copolymer, silicone resin, acrylic-silicon resin, polyester resin, epoxy resin, and phenoxy resin. Synthetic resins such as resins and mixtures thereof can be used. Further, these may be crosslinked with an isocyanate compound or the like, if necessary.

Furthermore, the present inventors have discovered that corrosion of the metal thin film layer can also be prevented by using a resin containing a functional group that chemically bonds with the metal as the material for the protective layer formed on the metal thin film layer. Ta.

[0043] This is because the resin of the protective layer chemically bonds with the metal of the metal thin film layer, resulting in strong adhesion between the metal and the resin, reducing moisture penetration as much as possible, and improving corrosion resistance. It is based on In particular, when the discharge breakdown recording medium takes the form of a card or sheet, corrosion due to moisture infiltration into the metal/resin interface, that is, crevice corrosion, which tends to occur at the edges of these, is significantly less likely to occur.

As the resin containing a functional group that chemically bonds with the metal used in such a protective layer, a silicone polymer such as acrylic-silicon is suitable, but other polymers can also be used.

Next, the results of studies conducted to improve printing characteristics will be described.

As a result of various studies on means for improving printing characteristics, the present inventors have found that the printing characteristics can be improved by roughening the surface of the discharge breakdown recording material to a Bekk smoothness of 250 seconds or less. It was found that an improvement could be obtained.

[0047] This will be explained in detail as follows. The present inventors first observed the printed part in detail using a microscope and elucidated the mechanism of electricity passing from the electrode needle to the metal thin film layer, which is the basis of printing.

As a result, it was found that microscopically there is an electric field concentration area within one dot, which is the starting point of current flow, and that discharge breakdown occurs selectively in this area.

Based on this knowledge, if the surface roughness of the discharge destruction recording material is intentionally made rougher and fine convex portions are provided, discharge will occur more easily, and some variation in the thickness of the protective layer will be reduced. We thought that stable and smooth printing would be possible even if there was a problem.

Based on this idea, we investigated the relationship between the surface roughness of the discharge destruction recording material and the printing characteristics, and determined that the Bekk smoothness of the surface roughness of the discharge destruction recording material was roughened to 250 seconds or less. It has been found that if it is planarized, discharge occurs more easily and higher print density can be stably obtained.

In this case, strictly speaking, it is the roughness of the surface of the metal thin film layer that affects the printing, but in reality, by checking the roughness on the surface of the discharge breakdown recording medium, the roughness of the metal thin film layer can be checked. The roughness of the surface can be determined.

[0052] This is because the thickness of the metal thin film layer and protective layer on the underlayer is usually about 1 μm in total, so the surface of the discharge breakdown recording material maintains the uneven shape of the underlayer almost faithfully. It is from.

[0053] As a means of intentionally obtaining such a rough surface, a method of roughening the surface by including fine particles of an appropriate particle size in the base layer or the colored layer is adopted. be able to.

According to such a method, it is possible to adjust the surface roughness by appropriately selecting the particle diameter of the fine particles to be contained.

In particular, in the colored layer, it is possible to use colored pigments to simultaneously perform coloring for obtaining contrast in printing and the above-mentioned surface roughening.

However, carbon black and the like used as colored pigments tend to act as electrodes in an aqueous solution, and their addition tends to promote the electrochemical reaction between the metal thin film layer and the colored layer, so it is not suitable for practical use.

Therefore, the present inventors have discovered the following two means to stably roughen the surface without causing a decrease in corrosion resistance.

One of them is to use electrochemically inactive organic polymer fine particles.

[0059] Organic polymer fine particles have high insulating properties, so unlike inorganic pigments such as carbon black, they do not act as electrodes in an aqueous solution and do not cause an electrochemical reaction with a metal thin film layer.

[0060] Such organic polymer fine particles include:
Various synthetic resins such as acrylic resin, melamine resin, vinyl chloride resin, polyurethane resin, polyester resin, polyethylene, polypropylene, epoxy resin, polyvinylidene chloride, and polyamide, and fine particles of mixtures thereof can be used.

[0061] Such organic polymer fine particles are preferably contained in a barrier layer provided on the colored layer or in an underlayer.

Another method is to roughen the surface of the underlayer or barrier layer by chemical or mechanical treatment.

[0063] As a specific means of chemical treatment, a typical method is to immerse the surface of the base layer or barrier layer in a soluble chemical such as an organic solvent for a short time to dissolve and swell a part of the surface layer. be. At this time, it is possible to adjust the surface roughness by adjusting the type of chemical and the immersion time.

[0064] Further, as specific means for mechanical treatment,
There is sandblasting and calendaring.

Even in such mechanical treatment, the surface roughness can be adjusted by adjusting the type of sand and blasting conditions in sandblasting, and by selecting the type of roll in calendering.

[0066] As a matter of course, the surface roughening caused by these treatments does not cause corrosion of the metal thin film layer due to electrochemical reactions. As a result of roughening the surface in this manner, the print density was improved and the variation in density was reduced.

Next, in order to improve printing characteristics, we investigated the material of the underlayer, and by using a resin with a low glass transition temperature and low elastic modulus at high temperatures as the material of the underlayer, we improved the printing density. I discovered that it is possible to

This is because when a metal thin film layer melts and scatters due to Joule heat, the smaller the adhesive force with the base layer, the more advantageous it is for scattering, and the softer it melts at a high temperature, the stronger the adhesive force is. This is because the

The effect is effective when the glass transition temperature is 100°C or lower, and the effect is particularly remarkable when the glass transition temperature is 80°C or lower. However, if the glass transition temperature is lower than 30° C., it is not preferable because the storage stability of the print will be impaired.

[0070] Examples of resins with a low glass transition temperature used as materials for such an underlayer include acrylic resins, polyvinyl butyral, vinyl chloride-vinyl acetate copolymers, polyacetals, polyimides, acrylic-silicon resins, and mixtures thereof. Can be used.

[0071] The thickness of the underlayer varies depending on the type of material and the formation method, but it is usually suitable to be 5 μm or less. However, in general, when the thickness is less than 0.2 μm, it becomes difficult to perform the function as an underlayer.

As the substrate, films of plastics such as nylon, cellulose diacetate, cellulose triacetate, polystyrene, polyethylene, polypropylene, polyester, polyimide, polycarbonate, polyethylene terephthalate, and polyethylene naphthalate can be used.

As the protective layer, it is suitable to use a silicone polymer such as acrylic-silicon as described above, but it is also possible to form a multi-layered layer by forming a layer of an ultraviolet curable acrylic modified resin on top of the protective layer. is also possible.

However, the overall thickness of the protective layer needs to be 1 μm or less in order to conduct electricity through the metal thin film layer as described above, and normally about 0.5 μm is appropriate. However, in general, when the thickness is less than 0.1 μm, it becomes difficult to function as a protective layer.

[0075] Resins used as binders for colored pigments in the colored layer include vinyl chloride-vinyl acetate copolymers, cellulose resins, vinyl chloride resins, polyvinyl butyral resins, polyurethane resins, polyester resins, and acrylic resins. type resins, phenolic resins, isocyanate compounds, etc. can be used. Among these, it is preferable to use polyurethane resins, vinyl chloride-vinyl acetate copolymers, vinyl chloride resins having acrylic hydroxyl groups, and the like.

The colored pigment used in the colored layer must have a color that can be visually recognized in contrast with the metal thin film layer, but from the viewpoint of contrast, black is preferable, and coloring for display and the like are preferable. When attempting to perform magnetic recording at the same time, magnetic powder is used.

[0077] By using this magnetic powder, the above-mentioned surface roughening can be performed at the same time, and by selecting the particle size of the magnetic powder, irregularities of arbitrary roughness can be obtained. Also,
Carbon black is a typical colored pigment other than magnetic powder, but inorganic pigments and organic pigments of various other colors can also be used.

The metal thin film layer can be formed on the base layer by vacuum evaporation, plating, sputtering, or the like. As mentioned above, aluminum to which at least one metal selected from the group consisting of manganese, copper, and magnesium is added is suitable as a material for forming this metal thin film layer, but corrosion resistance can be improved by other means. In some cases, for example, aluminum, silver, tin, etc. can also be used.

[0079] In the discharge destruction recording medium thus produced, the earth electrode and the printing electrode are brought into contact with the protective layer, and electricity is applied to melt and scatter part of the metal thin film layer, thereby creating holes in the metal thin film layer. It is printed by opening the . The printing speed of this discharge destruction recording material is very fast, and it can print at a speed about three times that of a normal thermal printing method.

[0080]

[Examples] Next, the present invention will be explained in more detail with reference to Examples.

Example 1 Various discharge breakdown records were prepared and evaluated.

I. Preparation of discharge breakdown recording bodies In this Example 1, all discharge breakdown recording bodies had the structure shown in FIG.

First, the outline of the discharge breakdown recording material shown in FIG. 1 will be explained. In the figure, 1 is a substrate, 2 is a colored layer, 3 is a base layer, 4 is a metal thin film layer, and 5 is a protective layer. .

The substrate 1 is made of a polyethylene terephthalate film with a thickness of 188 μm, and includes a colored layer 2, a base layer 3,
The metal thin film layer 4 and the protective layer 5 are formed as shown in the following A to D, respectively.

A. Formation of colored layer 2 80 parts by weight of barium ferrite magnetic powder (average particle size 0.8 μm), 10 parts by weight of acrylic hydroxyl group-containing vinyl chloride-vinyl acetate-vinyl alcohol copolymer [U. C
．． VAGF (trade name) manufactured by Company C], 7 parts by weight of polyurethane resin [Pandex T52 manufactured by Dainippon Ink & Chemicals Co., Ltd.
01 (trade name)], 1 part by weight of a trifunctional polyisocyanate compound [Coronate (trade name) manufactured by Nippon Polyurethane Industries, Ltd.], 4 parts by weight of carbon black, 260 parts by weight of toluene and 260 parts by weight of cyclohexanone. The mixture was mixed and dispersed in a ball mill for 100 hours to prepare a magnetic paint.

[0086] This magnetic coating material was applied onto a substrate 1 made of a polyethylene terephthalate film with a thickness of 188 μm by a gravure method to form a black colored layer 2 with a thickness of 15 μm.

B. Formation of Base Layer 3 On top of the colored layer 2, an acrylic-silicon resin made by copolymerizing an acrylic resin with a silane compound [Silacoat SCT6101 (trade name) manufactured by Chisso Corporation] is applied to a thickness of 2.5 μm using a gravure method. Then, a base layer 3 was formed.

C. Formation of metal thin film layer 4 Using the following six types of Al-based alloys and Al, a vacuum of 1
Underlayer 3 was formed at 0-5 Torr and at a deposition rate of 50 Å/sec.
50% by vacuum deposition on the base layer 3 without heating.
A metal thin film layer 4 was formed by forming a film to a thickness of 0 Å.

[0089] The types of metals are expressed by element symbols: Al is aluminum, Mn is manganese, Cu is copper,
Mg is magnesium. The percentages indicating the amounts of alloying elements are percentages by weight.

A, Al-1%Mn B, Al-0.1%Cu-1%Mn C, Al-
2.5%Cu, Al-0.3%Cu-1%Mg, Al-
5%Mg, Al-10%Mg, Al

D. Formation of protective layer 5 The following a
, b were coated to form a protective layer 5 with a thickness of 0.4 μm, and samples A-a, E-b, Ro-a, Ro-b, Ha-a, Ha-b, Knee-a, Knee-b, Ho-a, Ho-b, He-
Fourteen types of discharge breakdown recording bodies were prepared: a, h-b, to-a, and to-b.

a. Acrylic-silicone resin made by copolymerizing acrylic resin with a silane compound [Silacoat SCT6101 (trade name) manufactured by Chisso Corporation]. Note that the acrylic-silicone resin of a. has strong chemical bonds with metals through siloxane bonds. have characteristics.

b. acrylic resin

II. Evaluation of discharge destruction recording materials The printing characteristics and environmental resistance of the 14 types of discharge destruction recording materials obtained as described above were investigated. Those test methods and evaluation methods are as shown in E to G below.

E. Printing test A dot density of 8 lines/print was applied to the 14 types of discharge destruction recording materials mentioned above.
Printing speed is 150 mm/mm using a discharge breakdown printer head with dot dimensions of 120 μm x 120 μm.
Printed in sec.

F. Evaluation of Printing Print density was evaluated by measuring so-called reflection density. The reflection density was measured using an RD915 type densitometer manufactured by Macbeth. The measurement was performed on a 5 mm square printed area, and the average density including the unfused area between each dot was determined. Also,
The shape of the font was observed using a 100x optical microscope.

[0097] As a result of the above test, there was no difference in print density or font shape between the discharge breakdown recording materials, and the printing characteristics were the same.

G. Environmental resistance The above 14 types of discharge breakdown recording materials were stored at 60°C and relative humidity 9.
After being left in a 0% atmosphere for 10 days, changes in appearance and fading of the printed area were observed. Also, in 5% saline solution, 2
After soaking for 4 hours, changes in appearance were examined.

The test results are shown in Table 1. For comparison, Sn
A thermal printing type recording material (sample 1) using tin (tin) was also tested at the same time.

The evaluation criteria shown in Table 1 are as follows. ◎: There is no change in appearance at all ○: There is some change, but it does not affect the printing □:
Corrosion occurs, but the print is legible ×: Severe corrosion makes the print illegible

[0101]

[Table 1]

As shown in Table 1, samples A, B, C, D, E, and F in which Cu, Mn, or Mg was added to Al were
(Those with a are compared with each other, and those with b are compared with each other.) All of them had improved corrosion resistance.

In particular, sample row a and knee sample were prepared using the acrylic silicone resin of a for the protective layer 5 and adding three types of metals.
Sample a and Mg-rich sample H-a were heated at 60°C-90°C.
%, no corrosion was observed at all even in a high temperature and high humidity atmosphere and in saline water.

[0104] These results show that by adding Cu, Mn or Mg to Al, the corrosion resistance of the metal thin film layer is improved, and a discharge breakdown recording material comparable to that of a thermal printing type recording material can be obtained. I understand.

[0105] Furthermore, in a comparison of two types of protective layers, the sample using acrylic-silicon resin (a), which has the property of chemically bonding with metal, had generally higher resistance than the sample using acrylic resin (b). It showed environmental friendliness, and the effect of improved adhesion to the metal thin film layer was confirmed.

Example 2 In Example 2, the effect of improving environmental resistance by forming a layer containing a metal whose standard electrode potential is less noble than that of the metal constituting the metal thin film layer was confirmed.

a. A thin Mg film was formed on the first base layer with a thickness of 2 μm, and a second base layer with a thickness of 0.5 μm was formed thereon.

Next, a thin Al film is formed as a metal thin film layer 4 on the second underlayer by vapor deposition, and a protective layer 5 is formed on the metal thin film layer using the same acrylic-silicon resin as in Example 1 a. A sample a was prepared, which is a discharge breakdown recording material having the same structure as in Example 1 except for the above.

The above Mg thin film was formed by resistance heating vapor deposition.
It was formed to a thickness of 0 Å. In addition, the material of the base layer includes
Acrylic-silicon resin was used for both the base layer and the second base layer.

The structure of the discharge breakdown recording material of sample a is shown in FIG.
As shown.

In the discharge breakdown recording material shown in FIG. 2, the underlayer consists of two layers, a first underlayer 3a and a second underlayer 3b. 3b, an Mg thin film is formed as a layer 6 containing a metal whose standard electrode potential is more base than that of the metal constituting the metal thin film layer 4.

b. An Al thin film is formed as the metal thin film layer 4, and 3 Mg powders having an average particle size of 0.5 μm are added to the same acrylic-silicon resin as in Example 1 a on the metal thin film layer 4.
Sample b consisting of a discharge breakdown recording material having the same structure as in Example 1 was prepared except that the protective layer 5 containing 0% was formed.

The structure of the discharge breakdown recording material of sample b is shown in FIG.
As shown in FIG. 2, in the discharge breakdown recording material of sample b, the protective layer 5 also functions as a layer 6 containing a metal whose standard electrode potential is less noble than the metal constituting the metal thin film layer 4.

[0114] The environmental resistance of these two types of samples was tested in the same manner as in Example 1. For comparison, a discharge breakdown recording material similar to sample a was prepared, except that a thin film of Al was formed between the first base layer 3a and the second base layer 3b instead of the thin film of Mg, and this was used as the sample. A similar test was conducted as c.

Table 2 shows the results of the environmental resistance test. The evaluation criteria are also the same as in Example 1.

[0116]

[Table 2]

As shown in Table 2, sample a in which a thin film of Mg, which is a metal whose standard electrode potential is less noble than that of Al, was formed and sample b in which Mg powder was contained in the protective layer 5 had a lower standard electrode potential than that of sample c. It has improved environmental resistance, and print disturbances due to corrosion did not occur even in high-temperature, high-humidity environments or in saline water.

[0118] Furthermore, the printing characteristics of these three types of discharge breakdown recording materials, Samples a, b, and c, were investigated in the same manner as in Example 1, and no difference was found between the three.

From the above results, by forming the layer 6 containing a metal whose standard electrode potential is less noble than the metal used as the constituent metal of the metal thin film layer 4, a discharge breakdown recording material with good environmental resistance can be obtained. This was confirmed.

Example 3 A layer of the following four types of resin was formed to a thickness of 2 μm as a barrier layer between the colored layer 2 and the base layer 3, and a thin aluminum film was formed by vapor deposition as the metal thin film layer 4. Discharge breakdown recording bodies a, b, c, and d having the same structure as in Example 1 were prepared, except that a protective layer 5 was formed on the metal thin film layer 4 using the same acrylic-silicon resin as in Example 1 a. did. a. Polyimide resin with resistivity of 1015 Ω·cm b. Urethane resin with resistivity of 1011Ω・cm c. Resistivity is 1
09 Ω・cm acrylic resin d. Resistivity is 103 Ω
・cm of butyral resin

The structure of the discharge breakdown recording material of Example 3 is as shown in FIG.

[0122] In the discharge breakdown recording material of Example 3, barrier layers 7 are provided between the colored layer 2 and the base layer 3 using the resins a, b, c, and d, respectively. It has the same structure as the discharge breakdown recording body shown in FIG.

[0123] The same environmental resistance test as in Example 1 was conducted on the above four types of discharge breakdown recording bodies. The results are shown in Table 3. The evaluation criteria are the same as in Example 1.

[0124]

[Table 3]

As shown in Table 3, the environmental resistance is improved by providing the barrier layer 7 between the colored layer 2 and the base layer 3, which is a resin layer with high resistivity. Resin resistivity is 109
When the resistance becomes Ω·cm or more, a clear effect can be obtained.

[0126] When the printing characteristics of the above four types of discharge breakdown recording media were examined in the same manner as in Example 1, the results were the same for all of them.

Example 4 In this Example 4, the particle size of the barium ferrite magnetic powder contained in the colored layer 2 was changed, the underlayer contained organic polymer fine particles, and the underlayer had a rough surface. The effects of chemical treatment on printing characteristics and environmental resistance were investigated.

[0128] Preparation of samples ① to ① A. Formation of Colored Layer 2 Colored layer 2 was formed in the same manner as in Example 1, except that the average particle size of the barium ferrite magnetic powder was changed to the following four types.

[0129] ■ 0.7μm ■　1μm ■　1.5μm ■　4μm

B. Formation of base layer 3 An acrylic-silicon resin [Silacoat SCT6101 (trade name) manufactured by Chisso Corporation] is coated to a thickness of 2.5 μm on the above four types of colored layers 2 by a gravure method to form a base layer 3.
was formed.

[0131] Four types of discharge breakdown samples (■, ■, ■, and ■) having the structure shown in FIG. A recording body was produced.

[0132] The protective layer 5 is made of acrylic-silicon resin [Cylacoat SCT6101 (trade name) manufactured by Chisso Corporation].
It was formed with

Sample (2) uses barium ferrite magnetic powder with an average particle size of 0.7 μm in the colored layer 2, and Sample (2) uses barium ferrite magnetic powder with an average particle size of 1 μm in the colored layer 2. Sample ■ has an average particle size of 1.5
Sample 2 uses barium ferrite magnetic powder with an average particle diameter of 4 μm for the colored layer 2.

[0134] When the Bekk smoothness of the surface of the four types of discharge breakdown recording bodies obtained in this way was measured, it was found that sample
The test time was 280 seconds for sample (2), 250 seconds for sample (2), 150 seconds for sample (2), and 80 seconds for sample (2).

[0135] Preparation of samples ① to ②A. Formation of Colored Layer 2 Colored layer 2 was formed in the same manner as in Example 1, except that barium ferrite magnetic powder having an average particle diameter of 0.7 μm was used.

B. Formation of base layer 3 ■ Prepare a coating material by adding 30% by weight of melamine resin powder with an average particle size of 1 μm to acrylic-silicon resin [Silacoat SCT6101 (trade name) manufactured by Chisso Corporation], and apply this coating material to the above-mentioned colored layer. 2 by gravure coating method on 2
．． The base layer 3 was formed by coating to a thickness of 5 μm.

■~■ Underlayer 3 was formed by applying only the same acrylic-silicon resin as in (1) above to a thickness of 2.5 μm using the gravure method.

[0138] The surface of the base layer 3 formed in steps ① to ① above was subjected to surface roughening treatment by the following three types of means (a), (b), and (c).

A. The surface of the base layer 3 has a center line average roughness of 1.
Roughening is carried out using a 0 μm calender roll.

B. Methyl ethyl ketone, which is an organic solvent with a fast drying speed, is coated on the surface of the base layer 3 using a gravure coater to roughen the surface.

C. The surface of the underlayer 3 is roughened by sandblasting.

[0142] A metal thin film layer 4 was formed by vapor deposition of Al on each of the substrates on which the base layer 3 was formed in step (1) above and the surface roughened in steps A to C after forming the base layer 3 in steps (1) to (3) above. , and further a of Example 1 on the metal thin film layer 4.
A protective layer 5 was formed using the same acrylic-silicon resin as shown in FIG.

[0143] Sample (2) has a base layer 3 formed in the above process (2), and the base layer 3 of sample (2) contains particles with an average diameter of 1 μm.
It contains 30% by weight of melamine resin powder.

[0144] Sample (2) is obtained by forming the base layer 3 in steps (1) to (3) above, and then roughening the surface of the base layer 3 in step (A) above.
Sample (2) is obtained by forming the base layer 3 in steps (1) to (3) above, and then roughening the surface of the base layer 3 in step (2) above. Sample (2) is obtained by forming the base layer 3 in steps (1) to Base layer 3
The surface has been roughened.

[0145] Samples ① to ② prepared in this manner
When the Bekk smoothness of the surface of the discharge breakdown recording material of different types was measured, sample
The time was 5 seconds, and the time for sample ① was 70 seconds.

C. Evaluation of Printing Print density was evaluated by measuring reflection density. The reflection density was measured using an RD915 type densitometer manufactured by Macbeth.

[0147] The measurement was carried out on a 5 mm square printed area, and the average density including the unfused area between each dot was determined. The results are shown in Table 4. In addition, in order to investigate the variation in density, measurements were taken at 10 locations in the 100mm2 printed area.
The maximum and minimum values at that time are shown in Table 4 as the fluctuation range of print density.

[0148] The evaluation criteria for print density and the evaluation criteria for the variation width of print density shown in Table 4 are as follows.

[0149] Evaluation criteria for print density ○: Reflection density ≧1 □: 0.7≦Reflection density<1 ×: Reflection density <0.7

[0150] Evaluation criteria for print density variation range ○: Print density variation range ≦0.2 □: 0.2<Print density variation range≦0.6×: Print density variation range>0.6

[0151]

[Table 4]

As can be seen from the results shown in Table 4, the print density was low and the variation range of print density was large for sample ① with Beck smoothness of 280 seconds;
Samples ■ to ■ of seconds or less had high print densities, and the range of variation in print density was small.

[0153] In particular, samples with Bekk smoothness of 100 seconds or less ■
- ■ had a high print density, and especially samples ■, ■, ■, and ■ whose Beck smoothness was 80 seconds or less had a small variation in print density and had excellent print characteristics.

D. Evaluation of Environmental Resistance Next, the environmental resistance was evaluated in the same manner as in Example 1 for the discharge breakdown recording materials of Samples ① to ②, which had good printing characteristics in the printing evaluation of C above. The results are shown in Table 6. The evaluation criteria are the same as in Example 1.

[0155]

[Table 5]

As shown in Table 5, sample (2) in which the surface of the underlayer 3 was roughened by roughening the particle size of the barium ferrite magnetic powder that also served as a colored pigment was severely corroded and the printed characters were difficult to read. Environmental resistance was poor.

On the other hand, sample (2) in which fine particles of organic polymer were contained in the underlayer 3, and samples (2) and (2) in which the surface of the underlayer 3 was roughened by mechanical or chemical treatment.
and ■ had little corrosion, and it was confirmed that these treatments could improve printing characteristics without reducing environmental resistance.

Example 5 In Example 5, the influence of the material forming the underlayer 3 on printing characteristics was investigated.

A. Formation of Underlayer 3 The following four types of resins were applied to a thickness of 2.5 μm using a gravure method to form the underlayer 3, but discharge breakdown recording bodies A, B, I created C and D.

A. Polyvinyl butyral resin with a glass transition temperature of 50°C, B. Polymethyl methacrylate with a glass transition temperature of 110°C. C. Thermosetting polyurethane resin with a glass transition temperature of 70°C. D. Acrylic resin with a glass transition temperature of 90°C.

[0161]
These four types of discharge breakdown recording materials A, B, C, and D have a dot density of 8 lines/mm and the size of one dot is 120 μm x 1.
Using a 20 μm discharge rupture printer head, a voltage of 5
Printing was performed under the conditions of 0 V and a printing speed of 150 mm/sec.

[0162] The results are shown in Table 6. The evaluation criteria for printing are the same as in Example 4.

[0163]

[Table 6]

As is clear from the results shown in Table 6, sample B in which a resin with a glass transition temperature of 110° C. was used for the base layer 3 had a low print density, but the lower the glass transition temperature, the higher the print density. Sample A, which uses a resin with a glass transition temperature of 50°C, and Sample C, which uses a resin with a glass transition temperature of 70°C, have high print density, and especially sample A, which has a low glass transition temperature of 50°C, has a high print density. The print was clear.

[0165] In addition, these four types of discharge destruction recording materials were
Leave it in an atmosphere of 0°C and 90% relative humidity for 10 days.
After observing changes in appearance and fading of printed parts, we found that
In all cases, the appearance was only slightly discolored, the printed characters were sufficiently legible, and there was no difference between the four types of discharge breakdown recording materials.

From the above results, it is considered that good printing characteristics can be obtained if the glass transition temperature of the resin used for the underlayer 3 is about 80° C. or lower.

[0167]

[Effects of the Invention] As explained above, in the present invention, it was possible to improve the environmental resistance and printing characteristics of the discharge breakdown recording material.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view schematically showing a main part of a discharge breakdown recording medium according to the present invention.

FIG. 2 is a cross-sectional view schematically showing a main part of the discharge breakdown recording medium according to the present invention.

FIG. 3 is a cross-sectional view schematically showing a main part of the discharge breakdown recording medium according to the present invention.

[Explanation of symbols]

1 Substrate 2 Colored layer 3 Base layer 4 Metal thin film layer 5 Protective layer 6 Layer containing a metal whose standard electrode potential is more base than the metal constituting the metal thin film layer 7 Barrier layer

Claims (13)

[Claims] [Claim 1] Metal thin film layer 4 provided on base layer 3
In the discharge destruction recording material that is printed by destroying a part of the metal layer by electric discharge and making holes, at least one metal selected from the group consisting of manganese, copper, and magnesium is added as the metal constituting the metal thin film layer 4. A discharge breakdown recorder characterized by using aluminum. [Claim 2] Metal thin film layer 4 provided on base layer 3
A layer 6 containing a metal whose standard electrode potential is more base than that of the metal constituting the layer 6.
A discharge destruction recording body characterized by forming. 3. The discharge breakdown recording material according to claim 2, wherein the layer 6 containing a metal whose standard electrode potential is more base than the metal constituting the metal thin film layer 4 is a thin film made of the base metal. . 4. The layer 6 containing a metal whose standard electrode potential is more base than the metal constituting the metal thin film layer 4 is made of a resin in which the base metal is dispersed.
Discharge destruction record as described. 5. The discharge breakdown recording material according to claim 1, wherein the underlayer 3 contains a colored pigment. 6. The discharge breakdown recording material according to claim 1, wherein the base layer 3 is a transparent layer formed on the colored layer 2 containing a colored pigment. 7. The discharge breakdown recording material according to claim 5 or 6, wherein the colored pigment is a magnetic powder. 8. The discharge according to claim 6 or 7, characterized in that a barrier layer 7 having a resistivity of 109 Ω·cm or more and a thickness of 1 μm or more is formed between the base layer 3 and the colored layer 2. Destructive record. 9. The method of claim 1, 2, 3, 4, 5, 6, or 7, wherein the protective layer 5 in contact with the metal thin film layer 4 is made of a resin containing a functional group that chemically bonds with the metal. 8. The discharge breakdown recording material according to 8. Claim 10: Surface roughness is 250 in Bekk smoothness.
A discharge destruction recorder characterized by having a surface roughness of less than 2 seconds. 11. The discharge breakdown recording material according to claim 10, wherein the surface is roughened by incorporating fine particles of organic polymer into the underlayer 3 or the barrier layer 7 . 12. The surface of the base layer 3 or the barrier layer 7 is roughened by dissolving or swelling by chemical treatment, or by mechanical treatment such as calendering or sandblasting. Discharge destruction record. [Claim 13] The base layer 3 has a glass transition temperature of 80°C.
A discharge breakdown recording material characterized by using the following resin.