JP2002036765A - Oversheet for card - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oversheet for a card that does not exceed a curve standard value of card even if the card is embossed under a condition of a card made of polyvinyl chloride resin when the sheet is formed into the card. SOLUTION: The oversheet is a sheet used as a top layer of a plastic card. The main ingredient is substantially an amorphous polyester resin and the rest consists of a polycarbonate resin or a polyallylate resin or a composite to which a mixture of them is added by 20-70 mass percent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet used as a material of a surface layer of a plastic card such as a magnetic stripe card and an IC card.

[0002]

2. Description of the Related Art As a material for a plastic card such as a magnetic stripe card, a polyvinyl chloride resin (hereinafter, referred to as "PVC") has been conventionally used. In general, a magnetic stripe card is formed by superimposing a transparent oversheet on which a magnetic tape is temporarily attached on a printed white core sheet, and heat-sealing the sheets with a hot press (hereinafter, referred to as a “strip”).
It is called "laminate". ), Cut it into a card shape with a punching blade, and finally engraved with an embosser (hereinafter,
"Emboss". ). The PVC sheet can be mass-produced by a calender method, and is a material suitable for cards, which is excellent in printability, lamination suitability, and embossability. Recently, with the ecology boom in the world, there is a growing need for a card sheet made of a material other than PVC. There has been proposed a sheet made of a conductive polyester resin. This material has processing suitability for cards close to PVC sheets and can be made into cards using the same equipment as PVC sheets, so it is said to be the favorite sheet material to replace PVC. However, there is a problem that the warpage of the card after embossing (hereinafter referred to as "embossed curl") becomes large.

[0003] If the emboss curl is large, not only the appearance of the card is poor, but also it may be difficult to insert the card into a reader / writer. Therefore, a sheet that has a small emboss curl even when embossed under the same conditions as PVC is desired. Was rare.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a PVC.
An object of the present invention is to provide an oversheet made of a non-crystalline polyester resin for cards in which the emboss curl does not increase even when embossing under the same conditions.

[0005]

As a result of various studies, the present inventors have found that the contribution of the oversheet to the embossed curl is large, and that the use of an oversheet of a certain composition can reduce the embossed curl. Was.

The above object is achieved by the following means.

That is, the present invention provides a sheet used as a surface layer of a plastic card, which comprises a substantially non-crystalline polyester-based resin as a main component, a polycarbonate resin or a polyarylate resin, or a mixture thereof at 20 mass%. % Or more and not more than 70% by mass. The present invention proposes an oversheet for a card, characterized in that terephthalic acid, ethylene glycol and 1,4-cyclohexane are substantially non-crystalline polyesters. It includes a dehydration condensate of dimethanol.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The polyester referred to in the present invention is
Refers to a dehydrated condensate of an aromatic dicarboxylic acid and a diol, and is referred to as "substantially non-crystalline polyester" used in the present invention.
The term “copolymerized polyester” refers to a polyester having particularly low crystallinity, which does not cause clouding or poor fusion due to crystallization even when subjected to practically frequently performed thermal processing such as press fusion. Specifically, a polyester resin (trade name: PETG, manufactured by Eastman Chemical Co., Ltd.), which is a dehydrated condensate of terephthalic acid, ethylene glycol, and cyclohexanedimethanol, may be mentioned as a commercially available product. This material is excellent in processability and physical properties and is a suitable material for a card sheet.

In the present invention, a coloring agent, a lubricant, or a material for improving physical properties such as heat resistance may be added to the sheet as necessary. A polycarbonate resin, a polyarylate resin, or a mixture thereof is uniformly added to the sheet by melt-kneading in an amount of 20% by mass or more and 70% by mass or less. When these concentrations are 20% by mass
If the concentration is less than 70%, the effect of improving the embossed curl will be insufficient, and if the concentration exceeds 70% by mass, the height of the embossed characters will be difficult to be obtained, and may fall below the standard.

[0010]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples.

(Examples 1 to 6) (Comparative Examples 1 to 5) As a substantially non-crystalline polyester resin, PE was used.
Using TG6763 (manufactured by Eastman Chemical Company),
Using a blend of 90% by mass of PETG6763 and 10% by mass of titanium oxide, a thickness of 0.5% was obtained by a T-die extrusion method.
A 6 mm core sheet was obtained.

Subsequently, the materials shown in Table 1 were added to PETG6763, and a thickness of 0.1 g was extruded by a T-die extrusion method.
mm oversheet was obtained. Characters are printed on one surface of the obtained core sheet (hereinafter, this surface is referred to as “back surface”), and register marks for positioning the magnetic stripe are printed on the opposite surface (hereinafter, this surface is referred to as “main surface”). The over-sheet is overlaid on the back side, the over-sheet on which the magnetic stripe is temporarily attached is overlaid on the back side, sandwiched between two chromium-plated steel sheets, a press temperature of 110 ° C., and a sample pressure of 98 N / cm. ^Under pressure of ² , the sheets were fused and integrated.

Subsequently, concealment printing is performed on the front surface of the obtained sheet by screen printing, a pattern is printed thereon by offset printing, and an OP varnish is further applied thereon,
After drying, press temperature 90 ° C, sample pressure 49N / c again
Under a pressure of m ² , a sheet was obtained in which the mirror surface of the chrome-plated plate was transferred to the printing surface. After punching the obtained sheet into a card shape, Nippon Data Card's embosser “DC90
00 ”and keep the card at 0 ° C with PVC card conditions
Then, the characters of the 7B font were embossed into 16 characters × 3 lines, and the results of evaluation of emboss whitening, emboss cracking and emboss curl are summarized in Table 1. The emboss curl was measured using a height cage, and the maximum curl amount including the thickness of the card other than the embossed characters was Jis x 6
2.5m as specified in 301 (1998)
m or less was rated as ○, and those exceeding 2.5 mm were rated as x. The height of the embossed character is also measured using a height cage, and the height from the non-embossed portion of the card to the top of the embossed character in the range of 0.4 to 0.48 mm as specified in Jisx6302 is represented by .4mm
The following were evaluated as x.

[0014]

[Table 1]

As shown in Table 1, Examples 1 to 4 in which polycarbonate or polyarylate was added to the polyester resin in an amount of 20 to 70% by mass had little emboss curl and the warp did not exceed the standard value. 10% by mass of each of polycarbonate and polyarylate (total amount 2
Examples 5 and 6 in which 0% by mass) and 25% by mass (total amount of 50% by mass) were added also have small emboss curls, and the warpage does not exceed the standard value.

Comparative Example 1 in which neither polycarbonate nor polyarylate was added, and 20% in polycarbonate
Comparative Example 2 having less than 20% by mass has a large emboss curl, and Comparative Example 4 having less than 20% by mass of polyarylate also has an unfavorable emboss curl exceeding a specified value.

In Comparative Examples 3 and 5 in which the content of polycarbonate or polyarylate exceeds 70% by mass, the emboss height is lower than the standard value, which is not preferable.

[0018]

According to the present invention, when the sheet of the present invention is processed into a card, even if it is embossed under the conditions of a PVC card, the warpage of the card does not exceed the standard value.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) // C08L 67:00 C08L 67:00

Claims (2)

[Claims] 1. A sheet used as a surface layer of a plastic card, comprising a substantially non-crystalline polyester resin as a main component, and a polycarbonate resin, a polyarylate resin, or a mixture thereof at 20% by mass.
An oversheet for a card, comprising a composition to which at least 70% by mass or less is added. 2. The card oversheet according to claim 1, wherein the substantially non-crystalline polyester is a dehydrated condensate of terephthalic acid, ethylene glycol and 1,4-cyclohexanedimethanol.