JP5397137B2 - Overprint card - Google Patents

Description

  The present invention relates to a card such as a magnetic card and an IC card, and more particularly to an overprint card in which an overprint layer as a transparent protective layer is provided on a pattern layer on the surface.

  Magnetic cards and IC cards used for cash cards, credit cards, transportation cards, and the like use cards having various layer configurations based on various standards. Among these, an overprint card having an overprint layer (synonymous with an overcoat layer, hereinafter referred to as an overcoat layer), which is a transparent protective layer, on the surface pattern layer is excellent in design and has a surface pattern. Is not easily worn, and has a good gloss on the surface, so it is widely used for various types of cards.

  The most common method for producing an overprint card is to sandwich the outer side of the core sheet with a transparent oversheet with magnetic stripes, temporarily bond them, and then form a printed layer on the front and back surfaces. A method was used in which a transparent overcoat layer was applied by a roll coater or the like, and the entire surface was hot-pressed with a ferro plate to give a glossy surface.

As described above, the method of forming the overcoat layer by wet coating has the following problems.
1) The lower printing layer may be affected by the solvent of the varnish used when forming the overcoat layer.
2) Drying of the overcoat layer tends to vary, often causing problems due to residual solvent.
3) The thickness of the overcoat layer tends to vary, and as a result, the magnetic output of the card becomes unstable.

Therefore, in order to solve these problems, the applicant has proposed a method for manufacturing an overprint card as described in Patent Document 1. The manufacturing method of the overprint card described in Patent Document 1 is as follows.
1) Temporarily pasting and laminating an oversheet and magnetic tape on the core,
2) A printing layer is provided on the oversheet and the magnetic tape,
3) The adhesive layer surface of the transfer foil in which a protective varnish layer and an adhesive layer are formed on a glossy transfer film on the surface in advance is aligned with the printed layer surface, and bonded by hot pressure.
4) The transfer film is peeled off, the adhesive layer and the protective varnish layer are transferred, and an overprint card having gloss on the surface of the protective varnish layer is produced.

  According to the method described in Patent Document 1, since the overcoat layer is formed by the dried film previously formed on the transfer foil, the quality problem in the overprint card can be improved, and further the overcoat layer can be improved. The manufacturing process of a print card can be shortened.

Japanese Patent Laid-Open No. 2001-162975

  In the method described in Patent Document 1, when the first printing layer having high concealability by the screen printing method and the second printing layer by the offset printing method capable of high-definition printing are used as the printing layer, the overcoat layer It has been found that there may be a problem that the ink film of the second printed layer breaks during the transfer step or when the card is finally embossed.

  This problem is most noticeable when a screen ink using a thermoplastic resin as a binder is used as the first printing layer and an ultraviolet curable offset ink is used as the second printing layer. It was thought that it originated in the difference in the fluidity at the time of the heating of the 2nd printing layer.

  In view of the above problems, the problem to be solved by the present invention is to provide an overprint card in which a pattern ink layer formed using an ultraviolet curable ink is not broken in a transfer process or an embossing process. is there.

As means for solving the above-mentioned problems, the invention according to claim 1 includes a first printed layer printed on a card base material using a screen ink having a thermoplastic resin as a binder, and a first printed layer. An overprint card having a second printed layer printed using an offset ink having an ultraviolet curable resin as a binder and having a transparent overcoat layer formed on the uppermost surface by a transfer method, The screen ink used for the first printing layer is an overprint card comprising a vinyl chloride vinyl acetate copolymer resin and a polyol resin (molecular weight of 15,000 or more and 20,000 or less), and further containing an isocyanate. .

The invention described in Claim 2 is the overprint card according to claim 1, characterized in that floating character embossed.

  In the overprint card according to the present invention, since the uppermost overcoat layer is formed by the transfer method, unlike the overcoat layer by the conventional wet coating method, there is no problem caused by the residual solvent. Further, since the variation in the thickness of the overcoat layer is reduced, in the case of a magnetic card, a card having a stable magnetic strength can be obtained. In addition, since the first printing layer is screen printing, it is possible to ensure a sufficient concealing property to conceal the magnetic stripe, and the second printing layer is UV offset printing. Therefore, a high-definition pattern can be formed efficiently. Further, since isocyanate is added to the screen ink for forming the first printed layer, the ink film of the second printed layer is not broken when the overcoat layer is transferred.

  Moreover, when the screen ink used for a 1st printing layer contains a polyol resin, the effect which prevents the crack of the ink film of a 2nd printing layer increases. In addition, when the polyol resin has a molecular weight of 15,000 or more and 20,000 or less, the compatibility of the ink is good and the stability of the ink is improved, so the quality of the card is stabilized, and this effect is further stabilized. Will be.

The effect of the present invention is also exhibited when the card is embossed with floating characters, and has the effect of preventing the pattern of the second print layer from being broken along with the embossing.

It is the cross-sectional schematic diagram which showed one Embodiment of the overprint card | curd which concerns on this invention.

  Hereinafter, an overprint card according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic sectional view showing an embodiment of an overprint card according to the present invention. An overprint card 1 according to the present invention includes a first printed layer 5 printed on a card base material using a screen ink having a thermoplastic resin as a binder, and an ultraviolet curable resin on the first printed layer. An overprint card having a second printed layer 6 printed using an offset ink as a binder and having a transparent overcoat layer 7 formed on the uppermost surface by a transfer method. It is an overprint card characterized by adding isocyanate to the screen ink used.

  In the embodiment of FIG. 1, after providing the first printed layer 8 and the second printed layer 9 on the back side on the back side of one core sheet 2, an oversheet (table) 3 provided with a magnetic stripe 4 in advance. And the oversheet (back) 10, a card base material is formed by thermocompression bonding.

  There may be one core sheet or a plurality of core sheets. As the core sheet, polyvinyl chloride resin having a thickness of about 0.6 mm or PET-G (polyethylene terephthalate / glycol copolymer resin) is generally used. As the oversheet, a polyvinyl chloride resin or a PET-G transparent sheet having a thickness of about 0.1 mm is used in the same manner as the core sheet.

  In the case of an IC card, a counterbore is made in the card base and an IC chip is fitted. In the case of a non-contact IC card, an inlet incorporating an antenna module is sandwiched. Although the detailed description is omitted, the overprint card of the present invention can be applied to these IC cards.

  Since the first print layer 5 is a layer that conceals the magnetic stripe 4 and becomes the base color of the card pattern, a screen printing method that can provide an ink film with high concealability is suitable. On the other hand, since the card is often embossed with a floating character such as a card number, an ink film having an easiness of elongation that can follow the elongation of the card substrate at this time is required. For this reason, the screen ink used for the first printed layer 5 is often an ink having a thermoplastic resin as a binder that has sufficient elongation.

  On the other hand, since the second printing layer 6 provided on the first printing layer 5 is often a precise printed pattern, the offset printing method is suitable, and in particular, the UV offset printing method using an ultraviolet curable offset ink. Is the most preferred printing method because it requires less heat load on the card substrate.

  Since the binder resin of the ultraviolet curable offset ink is a resin that crosslinks with ultraviolet rays, the ink film is not thermoplastic. Therefore, when heat and pressure are applied to the thermoplastic first printed layer 5 and the second printed layer 6 provided thereon, the second printed layer 6 which is difficult to stretch is cracked due to the difference in elongation between the two. There is. The overcoat layer transfer step, which is the next step, generally corresponds to this.

As a method for providing the overcoat layer 7, a transfer foil in which an overcoat layer and an adhesive layer as necessary are provided in advance on a base film having a mirror surface is prepared, and the first print layer 5 and the second print layer are prepared. The transfer foil is placed on the card base material on which 6 is formed, and the whole is heat-pressed with a flat press to transfer the overcoat layer 7. As hot-pressure conditions at this time, the temperature is 100 to 140 ° C., the pressure is 10 to 15 MPa, and the time is about 5 to 10 minutes.

  The overcoat layer 7 is a resin film obtained by adding a lubricant such as wax to a thermoplastic resin such as an acrylic resin or a vinyl chloride / vinyl acetate copolymer resin, and has a thickness of 2 μm or less, preferably about 1.8 μm. As the base film of the transfer foil, PET, PP (polypropylene resin) or the like is used.

  Although the advantage of providing the overcoat layer 7 by the transfer method has already been described, on the other hand, the second printing layer 6 may be cracked by the heat pressure during the transfer. Therefore, it has been found that a method of adding isocyanate to the screen ink for forming the first printed layer 5 is effective as a method for preventing the second printed layer from cracking. Isocyanate is considered to have a function of cross-linking with a thermoplastic resin, which is a binder of screen ink, to form a urethane bond and to reduce elongation when the ink film is heated.

  At this time, by adding a polyol resin that easily reacts with isocyanate to the screen ink, the effect of preventing cracking is further enhanced. As the polyol resin, commercially available polyol resins such as acrylic polyol resin, polyester polyol resin, and polyether polyol resin can be used. In terms of compatibility with existing binder resins, the molecular weight is 15,000 to 20, About 000 is appropriate. When the molecular weight of the polyol resin is 15,000 or more and 20,000 or less, the ink has high compatibility and stable printing becomes possible.

  Isocyanates such as tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), xylylene diisocyanate (XDI), hexamethylene diisocyanate (HMDI), isophorone diisocyanate (IPDI), or polymers or derivatives thereof, 1 type (s) or 2 or more types can be used.

  By adding isocyanate to the screen ink, cracking of the second printed layer in the transfer process of the overcoat layer can be prevented, but the addition of isocyanate also produces another effect. One of them is an improvement in the adhesion of the screen ink to the card substrate, and the other effect is an effect of preventing the second printed layer from cracking when the card is embossed with a floating character. In the following, the overprint card of the present invention will be described in more detail with reference to examples.

  An overprint card having a cross-sectional configuration as shown in FIG. 1 was produced. As the core sheet, a white amorphous polyester (PET-G) resin sheet having a thickness of 0.6 mm was used. A solid first printing layer (back) was provided on the back surface of the core sheet by screen printing, and a second printing layer (back) was provided by UV offset printing after drying. Next, a transparent PET-G sheet having a thickness of 0.1 mm was set on both surfaces of the printed core sheet as an oversheet, and laminated by a thermal laminating method. A magnetic stripe was previously provided on the surface of the core sheet. The lamination conditions were 140 ° C., 17 MPa, and 7 minutes. On the card substrate thus obtained, a first printing layer (table) was printed by a screen printing method, and further a second printing layer (table) was printed by a UV offset printing method. The binder composition of the screen ink used for the first printed layer (front and back) is 2: 1 (weight ratio) of vinyl chloride vinyl acetate copolymer resin (molecular weight 25,000) and acrylic resin (molecular weight 50,000). The mixed resin was used, and 5 parts of hexamethylene diisocyanate (HMDI) was added as an isocyanate to 100 parts of the ink. The overcoat layer was transferred to the card substrate on which printing was completed. The transfer conditions were 140 ° C., 12 MPa, and 5 minutes.

  Example 1 except that the binder composition of the screen ink was a resin obtained by mixing vinyl chloride vinyl acetate copolymer resin (molecular weight 25,000) and polyol resin (molecular weight 15,000) in 1: 1 (weight ratio). Similarly, an overprint card was produced.

Example 1 except that the binder composition of the screen ink was a resin prepared by mixing vinyl chloride vinyl acetate copolymer resin (molecular weight 25,000) and polyol resin (molecular weight 20,000) in 1: 1 (weight ratio). Similarly, an overprint card was produced.
<Comparative Example 1>

In Example 1, an overprint card was produced in the same manner as in Example 1 except that isocyanate was not added to the screen ink.
<Comparative example 2>

In Example 2, an overprint card was produced in the same manner as in Example 2 except that isocyanate was not added to the screen ink.
<Comparative Example 3>

In Example 3, an overprint card was produced in the same manner as in Example 3 except that isocyanate was not added to the screen ink.
<Comparative Example 4>

Example 1 except that the binder composition of the screen ink was a resin in which vinyl chloride vinyl acetate copolymer resin (molecular weight 25,000) and polyol resin (molecular weight 25,000) were mixed in a 1: 1 (weight ratio). Similarly, an overprint card was produced.
<Comparative Example 5>

In Comparative Example 4, an overprint card was produced in the same manner as in Comparative Example 4 except that isocyanate was not added to the screen ink.
About each above sample, the presence or absence of the crack of the pattern of the 2nd printed layer after transfer was observed. In addition, the compatibility of the screen ink was determined. The results are shown in Table 1. In the table, ◯ indicates good compatibility. Δ indicates a slight problem in compatibility.

Thus, when isocyanate was added to the screen ink, it was possible to prevent the second printed layer from cracking. Further, it was found that when the polyol resin had a molecular weight of 25,000, there was a slight problem in ink compatibility.

1 ... overprint card 2 ... core sheet 3 ... oversheet (table)
4 ... Magnetic stripe 5 ... 1st printing layer (table)
6 ... 2nd printing layer (table)
7 ... Overcoat layer 8 ... 1st printing layer (back)
9 ... Second printing layer (back)
10 ... Oversheet (back)

Claims (2)

A first printed layer printed on a card substrate using a screen ink containing a thermoplastic resin as a binder, and an offset ink on the first printed layer printed using an ultraviolet curable resin as a binder. An overprint card having a second printed layer and having a transparent overcoat layer formed on the uppermost surface by a transfer method, wherein the screen ink used for the first printed layer is made of vinyl chloride / vinyl acetate copolymer resin and polyol An overprint card comprising a resin (molecular weight of 15,000 or more and 20,000 or less), and further containing an isocyanate. The overprint card according to claim 1, wherein a floating character embossing is performed.

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