JPH0987557A - Ion ink - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the detection and reading of data codes with a high accuracy even under bad conditions, such as in a dark place or at high humidity and temp., by using a specific ink in a recording method wherein information is recorded with an ion-conductive ink contg. an ion-conductive electrolyte and is read by a predetermined method. SOLUTION: Information is recorded with an ion-conductive ink contg. an ion-conductive electrolyte and is read by forming a cell circuit by bringing a sensor terminal having an anode and a cathode as respective terminals into contact with the ink to detect the resultant voltage as an information signal. The ink used is an ion ink comprising a colloidal silica as the base material and an electrolyte (e.g. LiClO4 ) contained therein. Pref. the ink further contains a substance capable of absorbing water in air and/or a humectant (e.g. ZnCl2 ) in order that the ink after printing always may contain at least 1wt.% free water.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an information card, an information retrieval card, a game device charge card, a POS system, and an F card.
A system, luggage tag, printed matter, address, various tariffs, securities, admission tickets, publications, cryptographic information, exhibition fee cards,
It belongs to the field of publications in combination with CDs, CD-ROMs, DVDs, etc.

[0002]

2. Description of the Related Art As is well known, today's society is largely supported by the development of advanced science and technology, and has a social structure that cannot be realized without information, distribution and automation centered on multimedia. .

Various automatic recognition technologies that support these have been put into practical use, such as bar code, data carrier, machine vision, OCR, magnetic stripe, and voice recognition. However, although they technically satisfy social needs to some extent, they lack the information capacity, are expensive, and are inferior in operability and portability.

The most important key technology for solving these problems is a data recording method and a data detecting method. The conditions required for these recording and detection technologies are extremely severe,
It is said that it must operate stably in all environments. For example, there should be no mistakes even in extremely cold regions, hot regions such as deserts, or hot and humid regions directly below the equator. In addition, it is practically necessary that it can be used in a dark place, a dusty place, or a narrow place. Furthermore, it is necessary that precautionary measures be taken to prevent counterfeiting or falsification of cash vouchers. Reference number = MP07-10
3

[0005]

In order to solve these problems, JP-A-48-101836 "Optical reading device using optical fiber" and JP-A-47-455 are used.
37, "Card reading method and reader having relief", JP-A-54-54049 "Electrical resistance printing apparatus", JP-A-3-278987 "Recording agent, recording material, recording read-out method and apparatus". JP-A-4-338598 "Recording body and recording method of recording body", JP-A-60-83184
Many ideas and inventions such as "bar code reading method" were made.

In order to solve the above problems, the present invention can detect and read a data code accurately and accurately even in a bad environment of small size, low cost, dark place, high humidity and high temperature. An object is to provide an ion ink most suitable for a contact type reading method and a recording method.

[0007]

To achieve the above object, a data code was recorded with an ink containing an electrolyte, and this was recorded with an electrolyte with a sensor consisting of a cathode and an anode of a battery. Contact the data code. The electromotive force generated by this is detected and the data is read.

The data of the present invention is recorded by diluting a water-soluble or oily electrolyte with an appropriate binder, and then paper, synthetic paper, synthetic resin, ceramics, leather, cloth, wood, glass, living things. Data coded according to a certain rule.
It is made by applying, printing, affixing or marking.

Writing / reading of the data code which has been practically used in the past is performed by magnetic recording, electric energy, thermal energy, light energy, sound energy, far infrared energy, electromagnetic energy, Various energy such as ultraviolet energy and radiation energy is applied from the outside, and reflection, reaction, change in magnetic force, etc., against the energy are recorded to record record number = MP07-10.
Although the read information was detected and read, the present invention contains an ion conductive material applied to an energy-embedded sensor capable of reading an information signal without applying any energy from the outside. The present invention provides a ionic ink that does.

Conventionally, it was largely affected by dirt, scratches, and external environment such as light and dark, high temperature, humidity and other external environment. Most of the cause was that the output signal energy was small.

It is possible for the present inventors to solve these various problems by increasing the output signal energy. The present inventors reverse the principle of a battery, which has been well known as a can of energy since ancient times, to write / write information. The present invention provides a method for applying to scraping (Japanese Patent Laid-Open No. 7-175877), and the present invention provides an ionic ink most suitable for the writing / cleaning.

Most of the recording and reading of information is performed by tapes and cards based on extremely thin paper or plastic. Therefore, the recording of information is required to be very thin.

According to the present invention, if there is an ink having ion conductivity even in a dry condition of the normal living environment (at least 10%), this ink is used to print information in various shapes and connect it to a potentiometer. It is thought that it is possible to measure the potential difference caused by the ionization tendency of the anode and the cathode when the anode electrode and the cathode electrode are pressed against this information.

Dry (at least 10%) to complete the invention
It was essential to develop an ion-conducting ink that has ion-conducting properties even in the above state. As a result of trying a large number of compositions, the inks shown in Examples 1 and 2 have ionic conductivity. Reference number = MP07-10
It was found that No. 5 was a large and practical colorless ink.

[0015] Further, although various measures have been devised as a preventive measure against forgery, alteration, etc. in cash vouchers such as securities, the ultimate solution has not yet been established and is an eternal problem.
Nevertheless, transparency is a great advantage when implementing preventive measures.

If a transparent material is used, the
This is an effective and practical method from the viewpoint of security because it is impossible to decipher the rule of the code.
Further, when it is desired to record a colored information mark, it is sufficient to mix a colorant with the ink.

The ion-conducting inks described in Examples 1 to 14 of the present invention were colorless and transparent, which was invisible when printed. Various colors can be colored by adding a pigment to this. Therefore, it can be used for various applications such as recording colorful information or recording colorless and transparent information mark.

The necessary conditions and problems to be provided for the ionic ink of the present invention will be described below. Information is recorded by an ion-conducting ink containing an ion-conducting electrolyte, and the sensor terminal having the anode electrode and the cathode electrode as terminals thereof is brought into contact with the ion-conducting ink to form a battery circuit. The ionic ink of the present invention used in a method of detecting an electric potential generated by the information signal as an information signal can be used for any printed matter currently in circulation, for example, CD, CD-R.
Contents, indexes and explanations that can be combined with OM and DVD,
It can be applied to cards, books, tickets, newspapers, weekly magazines, slips, and other uses. ,

It must be able to withstand various environments and various usage forms, sufficiently exhibit its function, and have no failure to read information. The ionic ink after printing is transparent and has a free water content of 0.1 to 15% by weight. Reference number = MP06-10
It is required to hold 6.

The conditions required for this ink are described below.
You. 1. The base of ion ink is binder, vehicle,
Stabilizer, soluble in ionic ink, having water retention capacity
To be. Binder effect and water retention effect of ionic ink
Commonly known as colloidal silica, that is, water-based silica
Kasol is used as a base for ion inks. This
− Li + , Ca ++ , Na + , Mg ++ Such as metal io
Cl- , OH- , SO4^-Anion and water retention (sucking
Gelation of colloidal silica for substances with strong wetness
If these salts do not crystallize, the
It can be used as a tank.

When an organic binder (PVA, polyethylene oxide, etc.) is used as the ink binder, after printing on paper, a polymer film containing no ions or an extremely thin ion concentration is formed on the printed surface. A problem was found that ion detection was disturbed and electromotive force detection was hindered. Even in the step of drying the printed matter, free ions must be uniformly dispersed (diffused) even on the surface of the ink.

2. As cations, Li ⁺ , Ca ⁺⁺ ,
Salts that are harmless and have a small molecular weight cation such as Na ⁺ and Mg ⁺⁺ .

3. As anions, Cl ⁻ , OH ⁻ , B
Salts having anions such as F ₄ ⁻ , ClO ₃ ⁻ , ClO ₄ ⁻ , SO ₄ ⁻ .

4. In order for the ions of the ink to be ionically conductive, at least 0.1% should be present in the printed dry ink.
It is necessary to always keep more than weight, preferably more than 1% by weight of free water. However, the dried ink after printing has a reference number of 15% by weight or more and a reference number = MP07-10.
7 If water is present, it becomes too damp to be suitable as a printed matter.
Further, solid electrolytes and polymer electrolytes developed by various companies for batteries have a strong hygroscopic property when printed, so that the paper becomes sticky in the air and is not practical.

In order for the printed ion ink to always retain free water (0.1 to 10% by weight), a water-supplying substance that absorbs water from the air is necessary. Water absorbing substances that meet this purpose include zinc chloride (ZnCl ₂ ), magnesium chloride, and magnesium perchlorate (Mg (Cl
O ₄ ) ₂ ), calcium chloride, etc. can be used, but magnesium chloride, calcium chloride, etc. release free water when the humidity is 30% or less, and there is a case of only crystal water, so it is suitable for applications It is necessary to properly select.

When the terminals (anode, cathode) of the information signal reading sensor are brought into contact with the printed ionic ink, the amount of water in the ionic ink required to generate an electric potential is relative to the ink. 1-5% by weight was sufficient.

However, if the sensitivity of the sensor is increased, it is 0.1
% Water can be detected, but signal to noise ratio (S / N)
Becomes smaller. However, since it is said that the relative humidity in the natural world in which humans live does not fall below 10%, it is maintained at 1% or more in the normal use state.

In order to keep the free water of 0.1 to 15% based on the weight of the ink in the ion ink after printing, it is necessary to absorb the water in the air.
A moisturizer that holds a certain amount of absorbed water is required. However, if the amount is too large, the code pattern written with ionic ink may be blurred and misread the information.

When used in combination with the diffusion inhibitor, the effect of preventing this is enhanced. Moisture absorbent (Maintenance reference number = MP07-10
8 can also be a liquid medicine), specifically, ZnCl ₂ , M
g (ClO ₄ ) ₂ , LiClO ₄ , MgCl ₂ , CaC
l ₂ , etc. Instead of zinc chloride (ZnCl ₂ ) (which can also be used as an ionic substance), Mg without using heavy metals
(ClO ₄ ) ₂ (magnesium perchlorate) may be used. Furthermore, polyacrylic acid, sodium polyacrylate, urea, polypropylene glycol, polyethylene glycol, hyaluronic acid, sodium hyaluronate, etc. can be used.

5. When printed with this ink, the ink should dry so that it can be printed with the normal printing speed currently in practical use.

6. The operating temperature must be -50 ℃ as it must be usable in the desert from the Arctic and Antarctic where humans live.
It must be able to normally conduct ions and be used in the range of + 50 ° C.

7. By increasing the potential of the information signal, S /
Increase the N ratio. To increase the potential, it is possible to reduce the internal impedance. In order to reduce the internal impedance, it is necessary to increase the limit equivalent ion conductivity. In order to increase the ultimate equivalent ion conductivity, it is necessary to select an ionic substance having a high limit equivalent ion conductivity and increase the addition amount of the ionic substance.

Further, as conditions for the ionic substance, the ions become ions in the presence of water, the ion transport number is as large as possible, the ion radius is small, and the smaller the ion radius, the easier the ion migration. .

Furthermore, conditions such as that ions easily move among polymer substances such as vehicles, that they are difficult to crystallize in the presence of water or polymer substances, and that they are uniformly dissolved or dispersed in the vehicle, etc. To satisfy
There are lithium chloride, magnesium perchlorate, lithium perchlorate, sodium chloride, calcium chloride, potassium chloride, reference number = MP07-109 rubidium chloride, and the like.

8. When the printed matter is splashed with water and the ions are easily washed away, the water is splashed and then the ions are diffused, the cords are blurred and come into contact with each other, and the information is deviated. It is necessary to include an inhibitor. As a bleeding prevention and ion diffusion inhibitor,
SB latex, 2M-515A, 2M-45A (Takeda Pharmaceutical Co., Ltd.), melamine formaldehyde resin, etc. could be used.

9. Since it is used in various environments for a long period of time, it is necessary to add an antifungal agent and a preservative to prevent the generation of mold, which include formalin, sodium propionate and sodium dehydroacetate.

10. It is also necessary to add a gel preventive agent and a viscosity stabilizer in order to prevent the ionic substance from gelling during storage. Specifically, there are ammonium thiocyanate, sodium thiocyanate, phenol and butyl alcohol.

11. As a dispersant, trimethylol melamine, tetrasodium pyrophosphate, tributyl phosphate, as an antifoaming agent, octyl alcohol.
It is necessary to add thiol, tributyl phosphite, senka antiform (Nippon Yakuhin Chemical Co., Ltd.).

Therefore, it is a technically difficult point that the free water necessary for the ion conduction of the ions is required, although it feels dry to the touch.

Furthermore, what is necessary for this ink is to contain as much ionic substance as possible. Reference number = MP07-10
10 However, the ionic substance is difficult to dissolve in the vehicle of commonly used printing ink, and it is also difficult to uniformly disperse and mix them.

Even if they seem to be uniformly dispersed even if they are mixed for a long time, if they are left for several days, they will be sedimented or become non-uniform. Therefore, a new vehicle was needed to dissolve the required amount of ionic material.

In general, the vehicle is an oil-based or water-based basic ink base for printing, but the vehicle of the ionic ink of the present invention may be any water-based resin. The role of this vehicle is important for dissolving ionic substances, retaining water, adhering to paper, and dispersing, fixing and retaining additives such as ionic substances and water absorbing substances.

An example of the composition of this vehicle will be described. Colloidal silica, polyvinyl alcohol, polyvinylpyrrolidone, polyacrylic acid, sodium polyacrylate, polyacetic acid emulsion, acrylic emulsion,
Examples include glue, gum arabic, starch, dextrin, carboxymethyl cellulose, sodium hyaluronate and the like.

Furthermore, the solid electrolytes and polymer electrolytes for batteries cannot be used as the ink of the present invention.
Since these solid electrolytes and polymer electrolytes for batteries are supposed to be used in a sealed battery container, when exposed to air, oxygen in the air oxidizes the components and ionic substances crystallize. This is not suitable for the purpose of the present invention because it does not show ionic conduction.

Specific compositions of ion conductive inks for recording information of the present invention are shown in Examples 1 to 14.

[0046]

【Example】

Reference number = MP07-10
11

Example 1 Ionic ink composition (weight ratio) 1.10% by weight polyvinyl alcohol (PVA), degree of polymerization 1200 ... 8% 2. Propylene glycol (CH ₃ CH (OH) CH ₂ OH) ... 0.5% 3. 3. Lithium perchlorate (LiClO ₄ ) ... 22% 4. Zinc chloride (ZnCl ₂ ) ... 4% 5. Urea _{(H 2 NCONH 2) ··· 1.5} % 6.95% ethyl alcohol - Le _{(C 2 H 5 OH) ···} 30% 7. Water: 32%

[0047]

[Example 2] Ion ink composition (weight ratio) 1.10% by weight polyvinyl alcohol (trade name PVA), degree of polymerization 1200 ... 8% 2. Propylene glycol (CH ₃ CH (OH) CH ₂ OH) ... 0.5% 3. _3. Mg (ClO ₄ ) ₂ (magnesium perchlorate) 22% Zinc chloride (ZnCl ₂ ) ... 7% 5. Urea _{(H 2 NCONH 2) ··· 1.5} % 6.95% ethyl alcohol - Le _{(C 2 H 5 OH) ···} 30% 7. Water: 32%

[0048]

[Example 3] Ion ink composition (weight ratio) 1.10% by weight polyvinyl alcohol (trade name PVA), degree of polymerization 1200 ... 8% 2. Propylene glycol (CH ₃ CH (OH) CH ₂ OH) ... 0.5% Reference number = MP07-10
12 3. _3. Mg (ClO ₄ ) ₂ (magnesium perchlorate) 22% Zinc chloride (ZnCl ₂ ) ... 4% 5. Urea _{(H 2 NCONH 2) ··· 1.5} % 6.95% ethyl alcohol - Le _{(C 2 H 5 OH) ···} 30% 7. Water: 32% 8. Sodium dehydroacetate (preservative) ・ ・ ・ 0.05%

[0049]

[Example 4] Ion ink composition (weight ratio) 1.10% by weight polyvinyl alcohol (trade name PVA), degree of polymerization 1200 ... 8% 2. Propylene glycol (CH ₃ CH (OH) CH ₂ OH) ... 0.5% 3. _3. Mg (ClO ₄ ) ₂ (magnesium perchlorate) 22% Magnesium chloride (MgCl ₂ ) ... 4% 5. Urea _{(H 2 NCONH 2) ··· 1.5} % 6.95% ethyl alcohol - Le _{(C 2 H 5 OH) ···} 30% 7. Water: 32%

[0050]

[Example 5] Ion ink composition (volume ratio) Colloidal Silica Co., Ltd. Nissan Kagaku Co., Ltd .: Product name “SNO-TEX No. 20” with pH adjusted to 3 to 4 with HCl ... 100 ml 2. Lithium perchlorate (LiClO ₄ ) 10% aqueous solution ・ ・ ・ 50 ml 3. Mg (ClO ₄ ) ₂ Magnesium perchlorate 10% aqueous solution ・ ・ ・ 50 ml Reference number = MP07-10
Thirteen

[0051]

[Example 6] Ion ink composition (volume ratio) Colloidal Silica Co., Ltd. Nissan Kagaku Co., Ltd .: Product name “SNO-TEX No. 20” with pH adjusted to 3 to 4 with HCl ... 100 ml 2. Lithium perchlorate (LiClO ₄ ) 10% aqueous solution ・ ・ ・ 50 ml 3. Mg (ClO ₄ ) ₂ Magnesium perchlorate 10% aqueous solution ・ ・ ・ 50 ml 4. Sodium dehydroacetate (preservative) ・ ・ ・ 1 ml

[0052]

[Example 7] Ion ink composition (volume ratio) Colloidal Silica Co., Ltd. Nissan Kagaku Co., Ltd .: Product name “SNO-TEX No. 20” with pH adjusted to 3 to 4 with HCl ... 100 ml 2. Lithium borofluoride (LiBF ₄ ) 15% aqueous solution ... 50 ml 3. Polyethylene oxide (Polymerization degree 10,000) 5% aqueous solution ... 50 ml 4. Sodium dehydroacetate (preservative) ・ ・ ・ 1 ml

[0053]

[Example 8] Ion ink composition (volume ratio) Colloidal Silica Co., Ltd. Nissan Kagaku Co., Ltd .: Product name “SNO-TEX No. 20” with pH adjusted to 3 to 4 with HCl ... 100 ml 2. Lithium borofluoride (LiBF ₄ ) 15% aqueous solution ・ ・ ・ 50 ml Reference number = MP07-10
14 3. Mg (ClO ₄ ) ₂ Magnesium perchlorate 10% aqueous solution ・ ・ ・ 50 ml 4. Polyethylene oxide (degree of polymerization 10,000) 5% aqueous solution ... 50 ml 5. Sodium dehydroacetate (preservative) ・ ・ ・ 1 ml

[0054]

[Example 9] Ion ink composition (volume ratio) Colloidal Silica Co., Ltd., manufactured by DuPont, USA: Product name “Cataloid SN” with pH adjusted to 2 to 4 with HCl ... 100 ml 2. Lithium perchlorate (LiClO ₄ ) 20% aqueous solution ... 50 ml 3. Mg (ClO ₄ ) ₂ (Magnesium perchlorate 10% aqueous solution) ··· 50 ml 4. Sodium dehydroacetate (preservative) ・ ・ ・ 1 ml

[0055]

[Example 10] Ion ink composition (volume ratio) Colloidal Silica Co., Ltd., manufactured by DuPont, USA: Product name “Cataloid SN” with pH adjusted to 2 to 4 with HCl ... 100 ml 2. Lithium perchlorate (LiClO ₄ ) 20% aqueous solution ... 50 ml 3. Mg (ClO ₄ ) ₂ (Magnesium perchlorate 10% aqueous solution) ··· 50ml

[0056]

[Example 11] Ion ink composition (volume ratio) Colloidal Silica Co., Ltd., manufactured by DuPont, USA: Product name “Cataloid SN”, reference number = MP07-10
15 pH adjusted to 2-4 with HCl ... 100 ml 2. CaCl ₂ , 20% aqueous solution ... 50 ml 3. Mg (ClO ₄ ) ₂ (Magnesium perchlorate 10% aqueous solution) ··· 50ml

[0057]

Example 12 Ion ink composition (volume ratio) Colloidal Silica Co., Ltd., manufactured by DuPont, USA: Product name “Cataloid SN” with pH adjusted to 2 to 4 with HCl ... 100 ml 2. CaCl ₂ , 20% aqueous solution ... 50 ml 3. Lithium perchlorate (LiClO ₄ ) 20% aqueous solution ・ ・ ・ 50 ml

[0058]

[Example 13] Ion ink composition (volume ratio) Colloidal Silica Co., Ltd., manufactured by DuPont, USA: Product name “Cataloid SN” with pH adjusted to 2 to 4 with HCl ... 100 ml 2. Urea ... 5g 3. Mg (ClO ₄ ) ₂ (Magnesium perchlorate 10% aqueous solution) ··· 50 ml 4. Sodium dehydroacetate (preservative) ・ ・ ・ 1 ml

[0059]

[Example 14] Ion ink composition (volume ratio) Colloidal Silica Co., Ltd., manufactured by DuPont, USA: Product name “Cataloid SN” with pH adjusted to 2 to 4 with HCl ... 100 ml 2. Urea, ... 5 g, reference number = MP07-10
16 3. Mg (ClO ₄ ) ₂ (Magnesium perchlorate 10% aqueous solution) ··· 50 ml 4. CaCl ₂ , 20% aqueous solution ... 50 ml 5. Sodium dehydroacetate (preservative) ・ ・ ・ 1 ml

The evaluation of the ionic inks of Examples 1 to 14 described above was carried out by naturally drying the samples printed on the high-quality paper with the ionic inks of Examples 1 to 14 in a room and then
g / Al electrode sensor- (sensor-terminal cross-sectional area: silver 1.5
(mmφ) is applied to the ink coated surface, and the results of measuring the potential (measured with an input impedance of 10 MΩ) and the ionic conductivity are shown below. The ionic conductivity σ is a value obtained by applying this ink to a high-quality paper and drying it at room temperature (23 ° C., Rh = 50%) for one day.

Sample electromotive force (mv) Ionic conductivity σ (S · Cm ⁻¹ ) Example 1 80 to 150 mv 4.53 × 10 ⁻⁴ Example 2 65 to 100 mv 4.53 × 10 ⁻⁶ Example 3 70 ˜120 mv 4.37 × 10 ⁻⁶ Example 4 100 to 200 mv 7.30 × 10 ⁻⁶ Example 5 150 to 300 mv 8.95 × 10 ⁻⁵ Example 6 150 to 300 mv 2.50 × 10 ⁻⁵ Example 7 200 to 400 mv 4.23 × 10 ⁻⁵ Example 8 200 to 350 mv 6.74 × 10 ⁻⁴ Example 9 150 to 250 mv 5.53 × 10 ⁻⁴ Example 10 200 to 300 mv 6.55 × 10 ⁻⁵ Example 11 150 to 200 mv 2.34 × 10 ⁻⁵ Example 12 150 to 250 mv 3.05 × 10 ⁻⁵ Example 13 100 to 200 mv 1.89 × 10 ⁻⁵ Example 14 100 to 250 mv 4.12 × 10 ^-5 adjustment Physical number = MP07-10
17

According to the above results, the silica gel type has one to two orders of magnitude higher ionic conductivity and electromotive force than the polyvinyl alcohol type of Examples 1 to 4. The colloidal silica changes into a silica sol when dried, but the aqueous silica sol has the following properties. (1) It is semi-permanently stable and shows fluidity even at high concentration (50%). (2) The particles are amorphous and do not crystallize even when dried or baked at 800 ° C. Since the particles are colorless and transparent, the characteristics of the coating are not impaired. (3) Since the particles are very fine (several to several mμ), the surface area per unit weight is large. (4) Since the sol having a concentration up to about 30% has a viscosity of about several cp, it almost penetrates where water can penetrate.
Therefore, the dispersibility with other substances is very good. (5) By evaporating the water content from the sol, the colloidal particles firmly adhere to the concave portions of the substance, and the particles also form a strong bond with the siloxane bond, and thus become a very good binder. For this reason, when printed on paper with ink that uses this as a base material, it does not become greasy and stabilizes at a constant humidity (10% to
Since it is maintained at 30%), the electromotive force can be detected stably.

NISSAN CHEMICAL CO., LTD .: Trade name "SNO-TEX No. 20" and Catalog-SN (commercial item: trademark of DuPont) were particularly good results. Catalo
id-SNSiO ₂ is a variety having a concentration of 20% and stabilized in an acidic region, and is particularly suitable for use in an acidic region and for mixing with an organic solvent and an electrolyte. Thus, it is not easy to develop an ionic ink that meets many conditions, but this ink is applied to all fields and is extremely industrially effective.

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical display location G11B 5/80 G11B 5/80

Claims (9)

[Claims] 1. Information is recorded by an ion conductive ink containing an ion conductive electrolyte, and a sensor terminal having an anode electrode and a cathode electrode as respective terminals is brought into contact with this to form a battery circuit. In a method of recording and reading out information by detecting the electric potential generated by the information as an information signal, the ionic ink used in the method is characterized in that an electrolyte is contained in a colloidal silica as a base material. 2. The ionic ink according to claim 1, which absorbs water in the air so as to always retain 1% or more of free water based on the weight of the ionic ink after printing, and /
Or an ionic ink containing a moisturizer. 3. The ionic ink according to claim 1, wherein the ionic ink after printing is a transparent ionic conductive ink. 4. An ionic ink, wherein the ionic substance contained in the ionic ink of claim 1 is uniformly dispersed or dissolved in water or a vehicle. 5. The ionic ink according to claim 1, further comprising an ionic diffusion inhibitor which prevents the ionic substance in the ionic ink from being washed away by the contact between the ionic ink after printing and the external water. A characteristic ion ink. 6. An ionic ink comprising the ionic ink of claim 1 containing a preservative, a viscosity stabilizer, an antigelling agent, a dispersant and a defoaming agent. 7. The ionic ink according to claim 1, which is particularly transparent. 8. When dissolving an electrolyte in colloidal silica,
A method for producing an ionic ink, which comprises adjusting and dissolving PH. 9. A publication printed with the ionic ink of claim 1. Reference number = MP07-10
Two