JP2001026087A - Laminated white polyester film for ic card - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated white polyester film for an IC card available for the core sheet of the IC card, in which adhesion properties for ink, matt properties, curl resistance, carrying properties are excellent and especially masking properties are excellent. SOLUTION: In the laminated white polyester film for the IC card, the laminated film is formed by laminating a layer A consisting of polyester A on one side of a layer B consisting of polyester B. Polyester A contains 5-35 wt.% white pigment having 0.1-1.0 μm mean particle diameter and intrinsic viscosity is 0.45-0.80 dl/g. Polyester B is polyester containing 2-35 wt.% at least one kind of black pigment selected from carbon black and artificial graphite. Whiteness of the face of the layer A in the laminated film is >=85 and the optical density of the laminated film is 1.5-6.0.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated white polyester film for an IC card, which is excellent in adhesiveness to ink, matting property, curl resistance, and transportability, particularly excellent in high concealment property, and suitable for a core sheet of an IC card. The present invention relates to a useful laminated white polyester film for an IC card.

[0002]

2. Description of the Related Art Since an IC card is superior to a conventional magnetic card such as a credit card and a cash card in terms of large recording capacity and multifunctionality, its practical use is being advanced as a substitute for them. The IC card has a configuration in which a built-in module including an integrated circuit (IC chip) and an antenna coil is embedded in the same plastic card as a conventional magnetic card. Although there are several types of this configuration, it is basically a three-layer configuration, in which a built-in module is sandwiched between core sheets, and oversheets are provided as protective layers on both sides of the core sheet. At that time, a pattern is printed on one or both sides of the core sheet like a prepaid card or a credit card,
In some cases, a magnetic recording layer or the like is provided. As the core sheet, a metal, an epoxy resin, and a hard vinyl chloride resin have conventionally been generally used, and recently, a polyimide resin has been particularly used. However, when these are used for the core sheet, the structure in which the built-in module is sandwiched between the core sheets requires a high concealing property and whiteness such that the internal IC chip, circuit and the like cannot be seen through.

Conventionally, as a laminated polyester film for a magnetic card, for example, concealing films disclosed in JP-A-8-108458 and JP-A-8-138231 have been known. Even when used as a core sheet, the built-in module cannot be completely hidden. As a remedy, a method of further increasing the white pigment concentration of the core layer of the laminated film is considered. Increasing the white pigment concentration to about 50% by weight results in a film that satisfies such concealing properties, but on the other hand has the problem that the film-forming properties are remarkably reduced, making production difficult.

On the other hand, in the mass production process of IC cards, there is a case where an IC card sheet having a built-in module sandwiched between long core sheets is conveyed in a state of being wound in a roll shape. Transportability is also required.

[0005]

DISCLOSURE OF THE INVENTION The present invention provides an ink which is excellent in adhesiveness to ink, matting property, curling resistance, and transportability, particularly excellent in high concealing property, and useful for a core sheet of an IC card.
An object of the present invention is to provide a laminated white polyester film for a C card.

[0006]

According to the present invention, a layer A made of polyester A is provided on one side of a layer B made of polyester B.
Wherein the polyester A
Is a white pigment having an average particle size of 0.1 to 1.0 μm,
% By weight and an intrinsic viscosity of 0.45 to 0.80 dl
/ G of polyester, wherein the polyester B is
A polyester containing 2 to 35% by weight of at least one black pigment selected from carbon black and artificial graphite, and having a whiteness of 85 or more on the layer A side of the laminated film and an optical density of the laminated film 1.5-
6.0 is a laminated white polyester film for an IC card, which is 6.0. The present invention also includes a laminated film in which a layer A is further laminated on the layer B side surface of the laminated white polyester film for an IC card. Hereinafter, the present invention will be described in detail.

<Substrate Composition> Both polyesters A and B constituting the laminated film of the present invention are polyesters obtained by condensation polymerization of a diol and a dicarboxylic acid. Examples of the dicarboxylic acids include terephthalic acid and Isophthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4′-diphenyldicarboxylic acid, adipic acid,
Sebacic acid and the like, and as the diol, for example, ethylene glycol, 1,4-butanediol,
4-cyclohexanedimethanol, 1,6-hexanediol, and the like. Particularly, polyethylene terephthalate and polyethylene-2,6-naphthalenedicarboxylate are preferred. The polyester may be a homopolymer or a copolymer.Examples of the copolymer component include diol components such as diethylene glycol, neopentyl glycol, and polyalkylene glycol.
Adipic acid, sebacic acid, phthalic acid, isophthalic acid,
And dicarboxylic acid components such as 2,6-naphthalenedicarboxylic acid and 5-sodium sulfoisophthalic acid.
Various additives can be blended with the polyester to such an extent that the properties are not impaired. For example, antistatic agents,
Examples include a heat-resistant agent, an antioxidant, a whitening agent, an ultraviolet absorber, organic particles, and inorganic particles.

[0008] Polyesters A and B in the present invention
May be different or the same for the polymerization component, the copolymerization component, the intrinsic viscosity, or the composition components other than the pigment described below. However, the polyester A constituting the layer A has an intrinsic viscosity of 0.45 to 0.80 d.
It must be 1 / g. 0.45 dl / g intrinsic viscosity
If it is less than 1, the film-forming property is deteriorated, while 0.80 dl / g
Exceeding the limit results in excessive quality and lowers the productivity of the raw material polymer, which is uneconomical.

<White Pigment> In the present invention, the polyester A constituting the layer A contains a white pigment. Examples of the white pigment include anatase-type titanium oxide, rutile-type titanium oxide, and barium sulfate. Of these, anatase-type titanium oxide is preferable. Such a white pigment has an average particle size of 0.1 to 1.0 μm and an addition amount of 5 to 35 μm.
% By weight. If the average particle size is less than 0.1 μm, the concealability of the film is poor, and if it exceeds 1.0 μm, the film formation stability is poor. If the amount is less than 5% by weight, the whiteness and hiding properties of the film are poor, while if it exceeds 35% by weight, the film-forming stability is poor.

The layer A of the laminated film of the present invention must have a whiteness of 85 or more. In order to make the whiteness 85 or more, the average particle size and the amount of the white pigment are adjusted. In particular, the whiteness tends to increase as the amount of addition increases, so it is preferable to adjust the amount of addition within the above range. The whiteness is a value represented by lightness (L ^* ) in the L ^* / a ^* / b ^* color system.

<Black Pigment> In the present invention, the polyester B constituting the layer B contains 2 to 35% by weight of at least one black pigment selected from carbon black and artificial graphite. Such a black pigment preferably has an average primary particle size of 0.01 to 0.2 μm. When the average particle size of the primary particles is less than 0.01 μm, as a result, the specific surface area tends to be large and it is difficult to be added at a high concentration. Since the size of the aggregated particles tends to be large, breakage tends to occur during film stretching, and the productivity tends to decrease. When the addition amount is less than 2% by weight, the concealing property of the film decreases, and when it exceeds 35% by weight, the film formation stability decreases.

The optical density of the laminated film of the present invention is 1.5
It needs to be ~ 6.0. When the optical density is less than 1.5, when an IC card is produced, the concealing property is reduced, the internal IC chip is seen through, and the appearance of pattern printing on the surface of the card is deteriorated. On the other hand, if it exceeds 6.0, it is excessive quality and uneconomical. To keep the optical density within the above range,
This can be achieved by providing the layer B containing the above-mentioned black pigment. Further, by providing the layer B, in addition to the improvement of the concealing property, the effect of imparting conductivity for preventing an electric failure of an IC chip or the like is exhibited.

<Lubricant> Polyester A in the present invention
Is from 0.01 to 1.0 μm of silica having an average particle size of 0.1 to 1.0 μm.
It is preferable to further contain 1.0% by weight. If the average particle size is less than 0.1 μm or the addition amount is less than 0.01% by weight, the film transportability is poor, while the average particle size is 1.0%.
If the thickness exceeds μm or the amount exceeds 1.0% by weight, the film will not only have low film formation stability, but will also have excessive quality.

The 60 ° gloss of the laminated film of the present invention is as follows:
It is preferably in the range of 50 or less. If the glossiness exceeds 50, the IC card becomes glossy when formed into an IC card, which is not preferable in terms of design as an IC card. The 60 ° glossiness of 50 or less can be achieved by adjusting the average particle size and the amount of the white pigment to be contained in the polyester A, and by further adding the above silica.

The white pigment and the black pigment to be contained in the laminated film of the present invention, and the above-mentioned silica and other particles to be contained as necessary, are added to the polyester before being added to the polyester and subjected to particle size adjustment and coarsening using a purification process. Preferably, particle removal is performed. In addition, as industrial means of the production process, for example, a jet mill, a ball mill or the like can be mentioned as a pulverizing means, and for example, a dry or wet centrifuge can be used as a classifying means. Of course, these means may be used in combination of two or more kinds and may be purified stepwise. In addition, various methods can be used as a method for containing the compound. A typical method is as follows.

(A) A method of adding before the end of the transesterification or esterification reaction during the synthesis of the polyester, or before the start of the polycondensation reaction. (A) A method of adding to a polyester and melt-kneading. (C) A method in which master pellets containing a large amount of titanium oxide or other lubricant added in the above methods (A) and (B) are kneaded with a polyester containing no such additives, and a predetermined amount of additives is contained. .

In the case of using the method (a) of adding at the time of polyester synthesis, it is preferable to add titanium oxide or another lubricant to the reaction system as a slurry dispersed in glycol.

<Coating Layer> Furthermore, in the present invention,
Copolyester, acrylic on at least one layer A surface
-Based copolymer, substance having sulfonate group and fine particles
It is preferable to laminate a coating film containing as a main component. This
The copolyester of the component forming the coating film of
Has a sulfonate group for all dicarboxylic acid components
Having a dicarboxylic acid component ratio of 1 to 16 mol%
It is a synthetic polyester. Such copolyesters are
Phthalic acid, isophthalic acid, 2,6-naphthalenedicarbo
Acid, hexahydroterephthalic acid, 4,4'-diphenyl
Rudicarboxylic acid, phenylindanedicarboxylic acid,
Pinic acid, sebacic acid, 5-sulfoisophthalic acid, trime
Carboxylic acid compounds such as ritic acid and dimethylolpropionic acid
Min, and 5-Na sulfoisophthalic acid, 5-K sulfo
Sulfones such as isophthalic acid and 5-K sulfoterephthalic acid
A dicarboxylic acid component having an acid base and ethylene glycol
, Diethylene glycol, neopentyl glycol,
1,4-butanediol, 1,6-hexanediol,
1,4-cyclohexanedimethanol, glycerin,
Limethylolpropane, alkylene of bisphenol A
Consists of hydroxy compound components such as oxide adducts
Polyester, an aqueous solution, an aqueous dispersion or
Used as an emulsion. As a component to form the above coating film
Acrylic copolymer used as the acrylic copolymer
Copolymerization of unsaturated monomer mainly composed of ter monomer
Body. Acrylic ester monomer used as the main component
Examples of-include methyl methacrylate, methacrylic acid
Ethyl, butyl methacrylate, methyl acrylate,
Ethyl acrylate, butyl acrylate, ethyl crotonate,
Glycidyl methacrylate, 2-hydroxyacrylate
Ethyl, 2-ethylhexyl acrylate, acrylic acid
Mid, methacrylamide, acrylic acid, methacrylic acid,
Sodium acrylate, potassium methacrylate, acrylate
Monium, N-methylolacrylamide, N-methoxy
Cimethylacrylamide and the like can be mentioned. Ma
Further, as the unsaturated monomer used as a copolymer component,
For example, vinyl chloride, vinyl acetate, styrene, vinyl acetate
Ter, butadiene, isoprene, vinyl vinyl sulphonate
And the like for copolymerization. The acrylic copolymer is water
To improve the solubility and dispersibility of the functional coating liquid
Acrylate, methacrylate, acrylic acid, acrylic
Amide, 2-hydroxyethyl acrylate, N-methyl
Copolymer component of hydrophilic monomer such as roll acrylamide
It is preferable to include as. With the components forming the coating film
As the substance having a sulfonate group used as the
Sulfonate metal salt or having the above sulfonate group
Copolyesters obtained by copolymerizing dicarboxylic acid components
No. As organic sulfonic acid metal salts, RSO _Three
X (wherein R is an aliphatic group, an alicyclic group, or an aromatic group;
X is a metal such as Na, K, and Li)
And specifically, metal alkyl sulfonate
Salts, metal salts of alkyl benzene sulfonic acids, etc.
You. This alkyl group includes octyl, decyl, dode
Sill (lauryl), tetradecyl (myristyl), hex
Examples include sadesyl and octadecyl (stearyl)
You. More specific compounds include lauryl sulfone
Acid Na, lauryl sulfonic acid K, lauryl sulfonic acid L
i, Na stearyl sulfonic acid, stearyl sulfonic acid
K, Li stearylsulfonate, dodecylbenzenesulfur
Sodium phosphate, dodecylbenzenesulfonic acid K, dodecyl
Li benzenesulfonate can be exemplified. Further above
As the fine particles used as components for forming a coating film, organic
Or inorganic fine particles, specifically calcium carbonate
, Calcium oxide, aluminum oxide, kaolin, acid
Silicon oxide, zinc oxide, crosslinked acrylic resin particles, crosslinked poly
Styrene resin particles, melamine resin particles, cross-linked silicone
Examples include resin particles. The average particle size of the fine particles is 20 to
A range of 80 nm is preferable, and a film of less than 20 nm
Is easy to block, while if it exceeds 80 nm, it is easy to cut
Decrease. Further, in the present invention, a coating film is formed.
In addition to the above components, other trees such as melamine resin
Fats, antistatic agents, coloring agents, surfactants, ultraviolet absorbers, etc.
Can be used.

In the present invention, at least one layer A
The coating film composed of the above components is laminated on the surface.For example, after applying an aqueous solution containing the component that forms the coating film to a stretchable polyester film, the film can be laminated by drying, stretching and heat-treating as necessary. it can. The solid concentration of this aqueous solution is usually 30% by weight or less, and 10% by weight.
The following are more preferred. The stretchable polyester film is an unstretched polyester film, a uniaxially stretched polyester film, or a biaxially stretched polyester film. Among these, a vertically stretched polyester film uniaxially stretched in the extrusion direction (longitudinal direction) of the film is particularly preferable. In addition, when the aqueous solution is applied to the polyester film, it is not preferable to perform the normal application step, that is, the step of separating the film from the manufacturing process of the biaxially stretched and heat-set polyester film because dust and dirt are easily involved. From such a viewpoint, application in a clean atmosphere, that is, application in a film manufacturing process is preferable. And
According to this coating, the adhesion of the coating film to the polyester film is further improved. As a coating method, any known coating method can be applied. For example, a roll coating method, a gravure coating method, a roll brushing method, a spray coating method, an air knife coating method, an impregnation method, a curtain coating method, or the like can be used alone or in combination. The coating amount is running film 1 m ² per 0.5
-20 g, more preferably 1-10 g. The aqueous liquid is preferably used as an aqueous dispersion or an emulsion.

<Production Method> The laminated film of the present invention can be produced by a known production method. For example, the resin constituting each layer is separately melted and co-extruded, and after lamination and fusion before solidification, biaxial stretching, a method of heat setting, the resin constituting each layer is separately melted, It can be manufactured by extruding into a film, laminating the both in an unstretched state or after stretching, or the like. Examples of the stretching method include a sequential biaxial stretching method and a simultaneous biaxial stretching method.

The sequential biaxial stretching method will be described more specifically. First, the polyester constituting each layer is melted, co-extruded, and laminated and fused, then heated by a roll,
It is heated by infrared heating or the like and stretched in the machine direction to obtain a machined film. This stretching is preferably performed by utilizing the peripheral speed difference between two or more rolls. The stretching temperature is a temperature higher than the glass transition point (Tg) of the polyester, and furthermore, 20 degrees above the Tg.
It is preferable to set the temperature to 40 ° C. higher. The stretching ratio is
It is preferable to set it to 2.5 times or more and 4.0 times or less. More preferably, it is 2.8 times or more and 3.9 times or less. 2.5
When the ratio is less than 2 times, unevenness of the thickness of the film becomes worse, and a good film cannot be obtained. The longitudinally stretched film is then
A biaxially oriented film is formed by sequentially performing transverse stretching, heat setting, and thermal relaxation treatments, and these treatments are performed while the film is running. The transverse stretching process is started at a temperature 20 ° C. higher than the glass transition point (Tg) of the polyester. Then, the heating is performed while the temperature is raised to a temperature (120 to 30) C lower than the melting point (Tm) of the polyester. The stretching start temperature is (Tg + 4
0) It is preferable that the temperature is not higher than 0 ° C. The maximum stretching temperature is preferably a temperature (100 to 40) C lower than Tm. The temperature rise in the transverse stretching process may be continuous or stepwise (sequential). Usually the temperature is raised sequentially. For example, the transverse stretching zone of the stenter is divided into a plurality of sections along the film running direction, and the temperature is raised by flowing a heating medium at a predetermined temperature in each zone. If the transverse stretching start temperature is too low, the film breaks, which is not preferable. The maximum stretching temperature is (Tm-1
20) If the temperature is lower than 20 ° C., the heat yield of the film increases, and the uniformity of the physical properties in the width direction decreases, which is not preferable. On the other hand, if the maximum stretching temperature is higher than (Tm−30) ° C., the film becomes soft and breaks due to disturbance or the like, which is not preferable. The magnification of the transverse stretching is preferably 2.5 times or more and 4.0 times or less. More preferably, it is 2.8 times or more and 3.9 times or less. If the ratio is less than 2.5 times, the thickness unevenness of the film becomes worse and a good film cannot be obtained.
If it exceeds twice, breakage tends to occur during film formation, which is problematic.

The thickness of the laminated film of the present invention is preferably 25 to 300 μm, more preferably 50 to 250 μm.
m, especially 75 to 188 μm. If the thickness is less than 25 μm, the card will not be rigid and the concealment property cannot be secured. On the other hand, those having a thickness exceeding 300 μm are not economical. The ratio of the layer A to which the white pigment is added and the layer B to which the black pigment is added (layer B / layer A) is preferably 0.01%.
To 0.5, more preferably 0.02 to 0.4, and particularly preferably 0.03 to 0.2. If it is less than 0.01, the effect of improving the concealing property is reduced. On the other hand, if it exceeds 0.5, the whiteness of the layer A may be reduced.

The layer structure of the laminated film of the present invention may be A / B / A in addition to A / B. Further, as long as the object of the present invention can be achieved, an A or B layer or another layer can be further laminated.

An IC card sheet can be manufactured by sandwiching and laminating an IC card built-in module composed of an IC chip, an antenna coil and the like on the laminated film of the present invention. When sandwiching and laminating the built-in module in the laminated film, it is preferable to laminate so that the layer A is on the outside. As a method of laminating, a known method can be employed, and for example, a method of thermocompression bonding can be mentioned. In addition, a long IC card sheet can be manufactured by arranging a plurality of built-in modules at an appropriate interval on a long laminated film, covering the laminated module on the laminated module, and laminating the laminated modules.

[0025]

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples.
In addition, each characteristic value was measured by the following method.

1. Whiteness (L ^* / a ^* / b ^* value) Y = 9 by SZ- # 90 type color difference meter manufactured by Nippon Denshoku Industries Co., Ltd.
The L ^* , a ^* , and b ^* values are measured with the film placed on a white standard plate having tristimulus values of 4.95, X = 93.63, and Z = 112.32. The value of lightness (L ^* ) was expressed as whiteness. The L ^* value, a ^* value, and b ^* value are based on the L ^* / a ^* / b ^* color system defined by CIE1976.

2. Optical density V (Visual) in three primary colors of a film sample using an optical densitometer (TR-310) manufactured by X-Rite Co.
The optical density was measured.

3. Glossiness A glossiness of 60 ° was determined according to JIS-Z8741 (2). The average of n = 5 was defined as the average glossiness.

4. Intrinsic viscosity After dissolving in O-chlorophenol, the pigment and particles were removed by centrifugation and filtration, and the measurement was performed at a temperature of 35 ° C.

[Examples 1 to 7, Comparative Examples 1 to 5 and Reference Example 1] An anatase type titanium oxide particle as a white pigment and silica (spherical or massive) as a lubricant were added to the polyester A constituting the layer A. And polyethylene terephthalate to which the amounts shown in Tables 2 and 3 were added, and to the polyester B constituting the layer B, carbon black was added as a black pigment in the amounts shown in Tables 1 and 2 and supplied to separate extruders to give 280 ° C. Melt extrusion with
The sheets were laminated, co-extruded from a die onto a sheet, and cast at 25 ° C. At that time, the ejection amount was adjusted so that the layer configuration and the layer thickness shown in Tables 1 and 2 were obtained. This unstretched sheet was longitudinally stretched at a temperature of 110 ° C. and a magnification of 3.0 times, and then transversely stretched at a temperature of 125 ° C. and a magnification of 3.3 times with a tenter, heat-treated, and biaxially having a thickness shown in Tables 1 and 2. A stretched laminated white polyester film was obtained. In each of the films, a 10% by weight aqueous solution having the following solid composition was applied between the longitudinal stretching and the transverse stretching in an amount of 4 g / m ² (wet) to the layer A surface of the film by a microgravure coating method. Dried. Tables 1 and 2 show the properties of these laminated films. <Solid content composition of coating liquid> (1) 75% by weight of copolyester [Terephthalic acid (22 mol%) and isophthalic acid (1 mol as acid components)
%), 2,6-naphthalenedicarboxylic acid (65 mol
%) And 4,4′-diphenyldicarboxylic acid (12 m
ol%), as a glycol component, a copolymerized polyester obtained by copolymerizing ethylene glycol (75 mol%), 1,4-cyclohexanedimethanol (10 mol%), and a propylene oxide adduct of bisphenol A (15 mol%). Tg: 80 ° C., average molecular weight:
21500) (2) 20% by weight of a polymer antistatic agent represented by the following formula

[0031]

Embedded image

(3) 5% by weight of polyoxyethylene nonyl phenyl ether

[0033]

[Table 1]

[0034]

[Table 2]

[0035]

According to the present invention, a laminated white polyester for an IC card which is excellent in adhesiveness to ink, matting property, curl resistance, and transportability, particularly excellent in high concealment property, and useful for a core sheet of an IC card. A film can be obtained.

 ──────────────────────────────────────────────────の Continuing on the front page F term (reference) 2C005 MA10 MA11 NA09 NB01 NB13 PA01 RA04 4F100 AA20B AA20C AA37A AK25D AK25J AK41A AK41B AK41C AK41D AK41J AK42 AL01 AL01D BA03 BA04 BA06 BA07 BA10BBAC BAE BAC JA06B JA06C JA20B JA20C JL04 JL10A JL10B JL10C JN21 JN26 JN30 YY00 YY00A YY00B YY00C 5B035 AA07 AA11 AA13 BA05 BB09 CA01 CA02 CA23 CA35

Claims (5)

[Claims] 1. One side of a layer B made of polyester B,
A laminated film in which a layer A made of polyester A is laminated, wherein the polyester A has an average particle size of 0.1 to 1.0.
a polyester having a white pigment of 5 to 35% by weight and an intrinsic viscosity of 0.45 to 0.80 dl / g, wherein the polyester B is at least one kind of black selected from carbon black and artificial graphite 2 to 35 pigments
% By weight, wherein the whiteness of the layer A surface of the laminated film is 85 or more, and the optical density of the laminated film is 1.5 to 6.0.
Laminated white polyester film for C card. 2. A laminated white polyester film for an IC card, wherein a layer A is further laminated on the layer B side surface of the laminated film according to claim 1. 3. Polyester A has an average particle size of 0.1 to
3. The laminated white polyester film for an IC card according to claim 1, further comprising 0.01 to 1.0% by weight of 1.0 μm silica. 4. The method according to claim 1, wherein the 60 ° gloss is 50 or less.
Or the laminated white polyester film for an IC card according to 2. 5. The IC card according to claim 1, wherein a coating mainly composed of a substance having a copolyester, an acrylic copolymer, a sulfonate group and fine particles is laminated on at least one layer A surface. For laminated white polyester film.