JPH04314583A - Electric discharge recording body - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge recording material used for prepaid cards such as telephone cards and orange cards, and more particularly to a discharge recording material having improved adhesion of a metal vapor deposited layer.

0002

[Prior Art] In recent years, with the spread of cash cards and credit cards, cash vending machines have become even simpler.
The use of prepaid cards such as telephone cards and orange cards that also process information is rapidly increasing.

[0003] However, conventional prepaid cards have a power display that requires a hole to be punched in the card each time the card is used, so there is a drawback that the balance cannot be accurately determined unless the card is inserted into the device used. In order to overcome this drawback, printing type cards have recently been used which have a structure of a base material having a tin vapor deposited layer/a magnetic layer/a tin vapor deposited layer/a protective layer and are capable of displaying the balance. Cards with such a tin vapor-deposited layer print using a thermal method, so it is necessary to melt the tin vapor-deposited film during printing, and since printing is performed at a temperature higher than the melting temperature of tin, the tin and protective layer resin are The dots are heavily contaminated due to melting, etc., and the head wears quickly. There is also a problem that there is a limit to the number of times that printing can be done and the printing speed is slow.

On the other hand, vapor-deposited recording materials that have a colored layer such as carbon black on a base material and a metal vapor-deposited layer such as aluminum on top of the colored layer have a high printing speed, little wear of dots, and a long number of printing times. It is known that there are advantages.

In discharge recording sheets provided with these colored layers, known thermoplastic resins or thermosetting resins can be used as binders for the colored layers, such as acrylic resins, cellulose resins, epoxy resins, and vinyl resins. Resin etc. are mentioned, but odor during discharge printing,
Considering the phenomenon of lees and trailing of images, it is preferable to use cellulose resin, and among them, nitrified cotton is most suitable in terms of dispersibility and strength. However, nitrified cotton has the disadvantage of poor flexibility and may cause cracks in the coating depending on the substrate, and plasticizers have conventionally been used to compensate for this disadvantage.

However, nitrified cotton originally has poor adhesion to metals, and the addition of plasticizer causes it to bleed out to the interface with the vapor-deposited layer, further deteriorating the adhesion and making it impossible to satisfy the preservability required for prepaid cards. There was a problem.

[0007]

[Problem to be solved by the invention]

[0008] An object of the present invention is to provide a discharge recording medium which does not have the above-mentioned problems and has improved adhesion of a metal thin film layer.

[0009]

[Means for Solving the Problems] In the present invention, an aliphatic polyisocyanate, particularly hexamethylene diisocyanate (HMDI) type polyisocyanate, is added to the nitrified cotton instead of the nitrified cotton that has been conventionally used as a binder for the colored layer. This was done based on the knowledge that the above-mentioned problems could be efficiently solved by using nitrified cotton modified by nitrification.

[0010] That is, in the present invention, on a support,
Provided is a discharge recording material provided with a colored layer, a metal thin film layer, and a protective layer, characterized in that the colored layer contains nitrified cotton to which aliphatic polyisocyanate is added.

[0011] Specific examples of aliphatic polyisocyanates include hexamethylene diisocyanate (HMDI),
Chain aliphatic isocyanates such as lysine isocyanate, trimethylhexamethylene diisocyanate and adducts of these isocyanates and active hydrogen compounds, methylcyclohexane-2,4-diisocyanate, 4,4'
-Methylenebiscyclohexyl isocyanate, isophorone diisocyanate, and adducts of active hydrogen compounds thereof, and other alicyclic aliphatic polyisocyanates, such as one or a mixture of two or more thereof. Among these, hexamethylene diisocyanate and hexamethylene diisocyanate-based polyisocyanates, such as bullet type, isocyanurate type, urethane type using trimethylolpropane and polyol, and copolymers with other chain aliphatic and alicyclic isocyanates. This method has excellent plasticization of nitrified cotton, and provides a coating film with excellent physical properties and weather resistance. Therefore, when this modified cotton is used, a colored layer can be formed without adding a plasticizer.

[0012] Regarding the amount of isocyanate added to the nitrified cotton, it is preferable to react the isocyanate in an amount equal to or less than the mole of active hydrogen in the nitrified cotton, and more preferably 0.05 to 0.5 mol to the active hydrogen in the nitrified cotton. be. In other words, if it is less than 0.05 mol, the modification effect by isocyanate will not be sufficient, and if it exceeds 0.5 mol, the viscosity stability will decrease and phenomena such as scum, trailing, and fusion will easily occur during discharge printing. be.

The nitrified cotton to which the isocyanate is added is preferably one with a degree of nitrification of 10 to 13% and a viscosity of 1/8 second to 20 seconds. Further, it is desirable that the nitrified cotton used does not contain water or alcohol that reacts with isocyanate.

Since isocyanate is highly reactive, when preparing the colored layer composition, isocyanate and nitrified cotton may be added and mixed to form isocyanate-added nitrified cotton, or isocyanate and nitrified cotton may be reacted in advance. You may also use

The colored layer contains organic or inorganic pigments and dyes as coloring components, and the isocyanate-added nitrified cotton effectively acts as a binder for the coloring components. Although various colorants known in the art can be used as the colorant, it is preferable to use carbon black. As the carbon black, commonly available commercially available furnace black, contact black, thermal black, lamp black, etc. can be used, and the particle size is 10 mμ.
It is preferable to use a material with a diameter of about 100 mμ.

The colored layer is formed by dissolving the above-mentioned isocyanate-added nitrified cotton in a solvent that is inert to isocyanate, and dissolving or dispersing the coloring agent therein, and coating the solution on the support by a conventional method. do. At this time, a plasticizer (for example, a phthalic acid plasticizer or an adipic acid plasticizer) can be added.The ratio of the colorant to the isocyanate-added nitrified cotton can be set arbitrarily, but it ranges from 1/1 to 1. /20
(weight ratio). The colored layer is preferably formed to have such conductivity that current can be diffused when discharge breakdown occurs in the metal vapor deposited layer. Although the thickness of the colored layer is arbitrary, it is preferably 0.1 to 20μ.

Supports used in the present invention include paper (for example, art paper, coated paper, laminated paper, etc.), natural or synthetic polymeric materials such as plastics and rubber, and rarely metal or nonmetallic inorganic materials. Examples include sheet-like materials, and among these, paper and PET sheets are preferred. In addition to these sheets alone, the support used in the present invention may be a support provided with a magnetic layer on one side.

The metal thin film layer provided on the colored layer is a thin film of metal such as aluminum, zinc, tin, etc.
Examples include those having a thickness of 0 to 2,000 angstroms. Such a thin film can be formed by vacuum evaporation, sputtering, plating, or the like. Among these, an aluminum vapor deposited layer is preferable, and the metal resistance value is 0.1 to 1,000.
It is preferable to form the vapor-deposited thin film so that the resistance is Ω, preferably 1 to 100Ω.

The protective layer provided on the metal thin film layer is provided to physically and chemically protect the metal vapor deposited layer, and conventionally known materials can be used.
The ultraviolet curable resin described in Japanese Patent No. 103493 is preferred. Specifically, examples of the ultraviolet curable resin include those that form an ultraviolet curable film by utilizing, for example, a photoradical polymerization reaction of a vinyl-containing compound. In this type, (1) a monomer or oligomer containing a vinyl group and (2)
It is composed of a photopolymerization initiator. Monomers for (1) include various mono-substituted ethylenes and 1,1-di-substituted ethylenes, and oligomers used include various acrylic oligomers such as unsaturated polyesters, polyol acrylates, oligoester acrylates, and urethane acrylates. be done. Examples of the photopolymerization initiator (2) include benzoin alkyl ether, acetophenone derivatives, benzophenone, benzyl, and alkylamino-substituted benzophenones.

Further, an ultraviolet curing type that utilizes a photo-ring-opening polymerization system of an epoxy group compound can also be used. This is a method in which a substance that generates a Lewis acid upon irradiation with light is mixed with an epoxy resin, causing cationic polymerization by a Lewis acid catalyst to cause curing. As the photoinitiator, aromatic diazonium salts of Lewis acids, aromatic halonium salts of Lewis acids, aromatic sulfonium salts of Lewis acids, etc. are used. By applying these ultraviolet curable resins to the protective layer 4, the heat-sensitive recording medium of the present invention can have excellent properties not only in heat resistance, light resistance, and chemical resistance, but also in abrasion resistance. As such a protective layer, a transparent one is preferable, and the thickness can be set arbitrarily, but 0.3 to 2.0 g/
m2 (solid content) is preferable.

[0021] Since the present invention has the above-mentioned structure, when discharge breakdown is caused in the metal thin film layer by the discharge recording electrode, the thin film layer in the discharge breakdown recording area is scattered, and the colored layer underneath is exposed, thereby forming characters, symbols, and figures. Visible images such as can be freely obtained in the discharge breakdown recording area. In addition, if the colored layer also serves as the magnetic recording layer, or if a magnetic recording layer is separately provided on the support,
At the same time, information can be recorded magnetically. Further, a barcode may be provided on the support opposite to the colored layer to record other information.

[0022]

According to the present invention, the metal thin film layer is firmly fixed to the support via the colored layer and has a protective layer on the surface, so it has excellent durability against repeated use. A discharge recording medium having the following properties is obtained. Therefore, it can be used very suitably as a prepaid card.

[0023] Next, the present invention will be explained with reference to Examples.

[0024]

【Example】

Example 1 Nitrified cotton RS-1 (manufactured by Daicel Chemical Industries, Ltd., IPA Dope 7
5%)) was dried to form I
PA was removed and dissolved in 45 parts of ethyl acetate and 22.5 parts of methyl isobutyl ketone to make a 10% by weight solution. A mixture of 75 parts of the above nitrified cotton and 3 parts of carbon black was dispersed using a sand grinder to obtain a bullet type HMDI polyisocyanate (Duranate 24A manufactured by Asahi Kasei Industries, solid 100%) as an isocyanate. 11.
5 parts were added to make a 15% black paint. The above black paint is coated on a polyester film support with a thickness of 188 μm to form a colored layer at a solid content of 3 g/m2,
Furthermore, a metal film resistance value of 1Ω/c is applied by vacuum evaporation method.
An aluminum vapor-deposited film layer was formed to have a thickness of m2. Next, a UV resin (HO manufactured by Dainippon Ink) was applied on the vapor deposited film layer.
-55) with a gravure coater to reduce the solid content to 0.7 g/m
2 to obtain a discharge recording material.

The adhesion of the obtained sheet was evaluated by the following method. On the other hand, the black paint was formed into a film with a thickness of 10 μm, and its plasticity was evaluated by the following method. Table the results.
Shown in 1.

Adhesion: Adhesion at room temperature: A cellophane adhesive tape (manufactured by Nichiban) was adhered to the obtained sheet, and when peeled off, the adhesion of the vapor deposited layer was visually observed and evaluated according to the following criteria. Acetic acid adhesion: After the obtained sheet was immersed in 5% acetic acid for 24 hours, it was taken out and the adhesion was confirmed in the same manner.

Evaluation Criteria ○...No peeling at all △...Slight peeling ×...Mostly peeled off ××...Full surface peeling

[0028] At the stage of forming the plastic colored layer, the sheet was bent 180 degrees, and the state at that time was judged according to the following criteria. Evaluation criteria ○…No cracks in the colored layer △…
A little crack ×…Cracked

Example 2 A discharge recording material was obtained in exactly the same manner as in Example 1 except that 2 parts of urethane type HMDI polyisocyanate (Asahi Kasei Duranate E-402 solids 90%) was added as the isocyanate in the black paint.

Example 3 In Example 1, the isocyanate in the black paint was bullet type HMDI polyisocyanate, isophorone diisocyanate copolymer (Asahi Kasei Duranate W)
A discharge recording material was obtained in exactly the same manner except that 2 parts (-3330, solids 75%) were added.

Example 4 As the isocyanate-added nitrified cotton, nitrified cotton (BTH-1
/2, manufactured by Asahi Kasei Kogyo, toluene, MIBK dope 70%
) was used and dissolved in 42.9 parts of ethyl acetate and 21.4 parts of methyl isobutyl ketone to obtain a 10% solution, but in the same manner as in Example 1 to obtain a discharge recording material.

Comparative Example 1 In Example 1, 3 parts of carbon black and 1.5 parts of plasticizer SO (epoxidized soybean oil manufactured by Daihachi Chemical Co., Ltd.) were added to 75 parts of 10% nitrified cotton, and then dispersed with a sand grinder to form a black paint. A discharge recording material was obtained in exactly the same manner except for the following.

Comparative Example 2 A discharge recording material was obtained in exactly the same manner as in Comparative Example 1, except that 1.5 parts of BAA (manufactured by Daihachi Chemical Co., Ltd., 1,3-butylene glycol adipic acid polyester) was used as the plasticizer.

Comparative Example 3 Tolylene diisocyanate was used as the isocyanate in Example 1 (Takenate 80 solid 100%, manufactured by Takeda Pharmaceutical Co., Ltd.)
A discharge recording material was obtained in exactly the same manner except that 1.5 parts of the solution was added.

Comparative Example 4 A discharge recording material was obtained in exactly the same manner as in Example 1 except that 1.5 parts of diphenylmethane diisocyanate (Millionate MT solid 100% manufactured by Nippon Polyurethane Co., Ltd.) was added as the isocyanate.

Comparative Example 5 A discharge recording material was obtained in exactly the same manner as in Example 1 except that no isocyanate was added and a black paint was obtained.

The characteristics of the discharge recording materials obtained in Examples 1 to 4 and Comparative Examples 1 to 5 are summarized in Table 1.

[0038]

Claims (2)

[Claims] Claim 1: A discharge recording material comprising a colored layer, a metal thin film layer and a protective layer sequentially provided on a support, wherein the colored layer contains nitrified cotton to which aliphatic polyisocyanate has been added. Characteristic discharge recording material. 2. The discharge recording material according to claim 1, wherein the aliphatic polyisocyanate is a hexamethylene diisocyanate-based polyisocyanate.