JP2000280428A - Base material for card - Google Patents

Abstract

(57) [Abstract] [Problem] Workability and scratch resistance, smoothness, whiteness, color,
To provide a card base material having excellent concealability and the like. A polyester layer mainly containing at least one inorganic fine particle having a Mohs hardness of 5 or more is provided on at least one outermost layer of the polyester layer (A) mainly containing inorganic fine particles having a Mohs hardness of less than 5. (B) is laminated, and the void ratio of the polyester layer (A) is 5 to 5.
30%, and the center line average roughness Ra of the polyester layer (B) is 0.3 μm or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a card base material. More specifically, the present invention relates to a card substrate having a laminated structure and excellent in workability, scratch resistance, whiteness and the like.

[0002]

2. Description of the Related Art Various cards such as telephone cards are on the market, and a white polyester film containing inorganic fine particles has been widely used as a base material for these cards. Above all, as a card substrate having more functionality, the white polyester film itself has a multilayer structure, and a substrate containing specific inorganic fine particles in the surface layer portion has improved scratch resistance and the like as characteristics. It is known that As such a card substrate, for example, JP-A-8-138231 and JP-A-10-95864 are disclosed.

It is also known to use a white polyester film in which a polyester resin contains a thermoplastic resin incompatible with the resin, as a card base material.
As such a card base material, for example, Japanese Unexamined Patent Publication No.
What is disclosed in 168441 and the like is known.

[0004]

However, in the conventional card base material, the blades of these processing machines are damaged in a short time in the processing step of cutting, punching, or punching to the size of the card. There was a problem that the cut property was poor.

[0005] A card base made of a polyester resin and a thermoplastic resin that is incompatible with the resin is capable of whiteness and weight reduction, but has small cavities formed inside the film. Compared to a substrate containing inorganic fine particles, the surface strength of the substrate is reduced and the surface is peeled off, the strength of the substrate itself is reduced and the substrate is easily bent or broken, and furthermore, heat resistance and dimensions Problems such as poor stability were likely to occur.

[0006] The present invention solves the above problems,
An object of the present invention is to provide a card base material which retains excellent workability and has excellent scratch resistance, smoothness, whiteness and the like.

[0007]

According to the present invention, there is provided a card base material comprising a polyester layer (A) mainly containing inorganic fine particles having a Mohs hardness of less than 5 (hereinafter referred to as an "A layer"). A polyester layer (B) (hereinafter, referred to as a B layer) mainly containing at least one inorganic fine particle having a Mohs hardness of 5 or more on at least one outermost layer, and the void ratio of the A layer Is 5 to 30%, and the center line average roughness Ra of the B layer is 0.3 μm or less.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, the voids in the layer A refer to countless fine bubbles formed by the addition of inorganic fine particles or the stretching orientation of the additives. When such fine bubbles are scattered inside the film, the light scattering effect is increased, and the whiteness and the concealing property are improved, and the weight is reduced.

In the present invention, the void ratio in the layer A is 5
It must be ３０30%. Preferably 8 from the viewpoint of film forming property
To 28%, more preferably 10 to 25% from the viewpoint of post-workability and the like. If the void ratio is less than 5, the blades of the processing machine are undesirably damaged during processing such as cutting or punching. On the other hand, if the void ratio exceeds 30%, the film is likely to break, particularly during stretching, which is not preferable.

In the present invention, the polyester is a polymer obtained by condensation polymerization of a diol and a dicarboxylic acid. Examples of the dicarboxylic acid include terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, adipic acid, sebacic acid and the like. And diols are represented by ethylene glycol, trimethylene glycol, tetramethylene glycol, cyclohexanedimethanol and the like. Specifically, for example, polyethylene terephthalate, polyethylene-p-
Oxybenzoate, poly-1,4-cyclohexylene dimethylene terephthalate, polyethylene-2,6-naphthalenedicarboxylate and the like can be used. In the case of the present invention, especially polyethylene terephthalate,
Polyethylene naphthalate is preferred.

Of course, these polyesters may be either homopolyesters or copolyesters.
An appropriate additive such as a heat stabilizer, an oxidation stabilizer, a weather stabilizer, an ultraviolet absorber, an antistatic agent, a dye, a dispersant, a coupling agent, and the like is blended in an amount that does not impair the effects of the present invention. You may.

The polyester used in the present invention is preferably polyethylene terephthalate. The polyethylene terephthalate film is excellent in water resistance, durability, chemical resistance and the like.

In the present invention, the layer B is provided on at least one outermost layer of the layer A. In this case, the polyester of each layer may have the same composition or a different composition. In particular, it is more preferable that each layer has a different composition, for example, the layer A is composed of a homopolyester and the layer B is composed of a copolyester, since characteristics such as easy adhesion can be obtained. Further, it is preferable that the layer A is made of polyethylene terephthalate and the layer B is made of polyethylene naphthalate, because the effects of improving weather resistance and rigidity can be obtained.

In the present invention, the inorganic fine particles constituting the layer A need to have a Mohs hardness of less than 5, preferably less than 4. If the Mohs hardness of the inorganic fine particles is 5 or more, the blades of the processing machine are undesirably damaged during processing such as cutting or punching.

In the present invention, the inorganic fine particles having a Mohs hardness of less than 5 are not particularly limited, but for example, calcium carbonate, barium sulfate, calcium sulfate,
Calcium fluoride, talc, kaolin and the like can be used. One type of inorganic fine particles may be used, or two or more types may be mixed and used. In the present invention, it is particularly preferable to use inorganic fine particles such as calcium carbonate and barium sulfate from the viewpoints of whiteness and void formation. Further, the inorganic fine particles may be in a form such as porous or hollow porous, and further subjected to a surface treatment for further promoting the formation of voids and a surface treatment for improving dispersibility in resin. May be used.

The average particle diameter of the inorganic fine particles is 0.1 to 5
μm is preferred, and those in the range of 0.2 to 3 μm are more preferred. If the average particle diameter is less than 0.1 μm, it is difficult to form voids during stretching, so that the blade of the processing machine is easily damaged. If the average particle diameter exceeds 5 μm, the smoothness of the film surface is liable to deteriorate. The content of the inorganic fine particles is not particularly limited, but is preferably from 5 to 35% by weight, more preferably from 10 to 25% by weight. If the content is less than 5% by weight, the whiteness and concealing properties of the film become insufficient, whereas if it is more than 35% by weight, poor dispersion and tearing of the film at the time of stretching tend to occur.

In the present invention, the layer A mainly containing inorganic fine particles having a Mohs hardness of less than 5 means that the inorganic fine particles are 60% by weight or more based on the total amount of particles contained in the layer.
Preferably 80% by weight or more, more preferably 90% by weight
It refers to the above, and other substances may be added as appropriate.

In the present invention, the inorganic fine particles constituting the layer B must have a Mohs hardness of 5 or more, preferably 6 or more. If the Mohs' hardness of the inorganic fine particles is less than 5, scratch resistance is reduced when used as a processing step or various cards, which is not preferable because scratch resistance is reduced.

In the present invention, the inorganic fine particles having a Moh's hardness of 5 or more are not particularly limited, but for example, titanium oxide, silicon oxide, aluminum oxide, silicon carbide, etc. can be used. One type of inorganic fine particles may be used, or two or more types may be mixed and used. Further, the inorganic fine particles may be in the form of a porous or hollow porous material, or may be those having been subjected to a surface treatment for improving dispersibility in a resin.

In the present invention, it is particularly preferable to use titanium oxide fine particles from the viewpoint of the whiteness of the card base material and its color. As the titanium oxide fine particles, various production methods and the like are disclosed, and in detail, for example, fine particles of rutile type and anatase type described in, for example, Chemical Dictionary (Kyoritsu Shuppan Co., Ltd.) can be used. Above all, it is preferable to use those which are suitable in terms of whiteness, dispersibility, hiding properties, weather resistance and the like.

The average particle diameter of the inorganic fine particles is as follows:
It is preferably from 0.05 to 1 μm, more preferably from 0.1 to 0.7 μm. Average particle size 0.05μ
If it is less than m, uniform dispersion is difficult, and if it exceeds 1 μm, the smoothness of the film surface tends to deteriorate. The content of the titanium oxide fine particles is not particularly limited, but is 5 to 35% by weight.
Are preferable, and those in the range of 10 to 25% by weight are more preferable. If the content is less than 5% by weight, the degree of whiteness and concealing properties of the film are insufficient, and if it is more than 35% by weight, poor dispersion and film breakage during stretching are likely to occur.

In the present invention, the layer B mainly containing at least inorganic fine particles having a Mohs' hardness of 5 or more refers to the above-mentioned inorganic fine particles in an amount of 60% by weight or more based on the total amount of particles contained in the layer, preferably 80% by weight or more, more preferably 90% by weight or more, and other substances may be added as appropriate.

In the present invention, as the card base material,
When a finer shade is required for deeper whiteness and whiteness, the B layer contains the inorganic fine particles of the A layer, or the A layer contains the inorganic fine particles of the B layer in an amount of 3 wt. %, Preferably 1% by weight or less.

In the present invention, in addition to the fine particles added to each layer, fine particles precipitated by the reaction between the catalyst residue and the phosphorus compound in the polyester polycondensation reaction system can be used in combination. As the precipitated fine particles, for example, those composed of calcium, lithium and phosphorus compounds or those composed of calcium, magnesium and phosphorus compounds can be used. The content of these particles is preferably 0.05 to 1 part by weight based on 100 parts by weight of the polyester.

In the card base material of the present invention, the center line average roughness Ra of the layer B must be 0.3 μm or less. The thickness is preferably 0.2 μm or less, and more preferably 0.1 μm or less from the viewpoint of practicality. When the center line average roughness Ra exceeds 0.3 μm, the smoothness of the film surface is deteriorated, so that the scratch resistance, the printability, and the like are easily reduced.

In the present invention, at least one of the layer A and the layer B is provided with a fluorescent whitening agent to give the card base material of the present invention a more vivid whiteness or bluish high-quality image. It is preferable to include an agent.

In the present invention, the fluorescent whitening agent is a polymer that absorbs ultraviolet light in sunlight or artificial light, converts the ultraviolet light into visible light of violet to blue, and radiates it. A compound that promotes whiteness without reducing the lightness of a substance. Examples of such a fluorescent whitening agent include “Ubitek” (Ciba Geigy), “OB-1” (Eastman), and “TBO”.
(Sumitomo Seika Co., Ltd.), "Kay Coal" (Nippon Soda Co., Ltd.), "Kayalite" (Nippon Kayaku Co., Ltd.), "Ryukopua" EGM (Client Japan Co., Ltd.) and the like can be used. The fluorescent whitening agent is not particularly limited, and may be used alone or in combination of two or more in some cases. It is desirable to use one that has good solubility, can be uniformly dispersed, has little coloring, and does not adversely affect the resin.

In the present invention, each layer contains a fluorescent whitening agent. The content of the fluorescent whitening agent is not particularly limited.
It is preferably 0.005 to 1% by weight, more preferably 0.05 to 0.5% by weight. Content 0.0
If it is less than 05% by weight, it is difficult to obtain a sufficient whitening effect, and
If the content exceeds% by weight, uniform dispersibility, whiteness and the like are liable to decrease.

In the present invention, the thickness of the card base material is not particularly limited, but is usually preferably from 50 to 500 μm, more preferably from about 75 to 300 μm in terms of practical handling as the base material. It is preferable because it has excellent properties. The thickness of the layer B to be laminated is 0.5 to 50 μm.
m is preferable, and those having a range of 1 to 30 μm are more preferable in terms of whiteness and hiding power.

In the card base material of the present invention, the whiteness of the layer B is preferably from 80 to 120%, more preferably from 85 to 11 in order to obtain a sharp printability with beautiful whiteness.
The range is 0%. If the whiteness is less than 80%, the whiteness becomes insufficient and the whiteness becomes dull and conspicuous.
When the whiteness exceeds 120%, it is necessary to add a large amount of particles and to form a large amount of voids, and the surface smoothness may be impaired or the film strength may be reduced.

The optical density of the card substrate of the present invention is preferably 0.8 or more. More preferably, it is one or more. When the optical density is 0.8 or more, the back side of the film is difficult to see through and the desired concealing property can be secured, which is preferable.

Further, the card base material of the present invention has a color tone b value of B layer obtained by a color difference meter of 2 to -5, preferably 0.
It is preferable to be within the range of --4, since the whiteness becomes clearer. When the color tone b value is larger than 2 or smaller than -5, the apparent whiteness is insufficient, and when printed, the sharpness of the color tone is likely to be reduced.

The card base material of the present invention is obtained by laminating a B layer on at least one outermost layer of the A layer described above. And a three-layer structure are desirable from the viewpoints of properties such as whiteness, opacity, scratch resistance and practicality.

[0034] The card base material of the present invention may be, if necessary,
The surface of each layer may be subjected to various surface treatments such as a corona discharge treatment, a plasma treatment, an easy-adhesion coating, an antistatic coating, and a surface hardness treatment. Further, a layer for receiving ink, a metal deposition layer, or the like may be provided. Further, it may be used by being bonded to another material such as paper.

Next, some examples of the method for producing a card base material of the present invention will be described, but the present invention is not limited to only these examples.

In a composite film forming apparatus having a main extruder (A) and a sub-extruder (B), a polyester resin chip and inorganic fine particles having a Mohs hardness of less than 5 were mixed as the A layer, and sufficiently vacuum-dried. Later, it is supplied to the main extruder (A) heated to 270 to 300 ° C. In addition, in order to laminate the layer B, separately dried polyester resin chips and inorganic fine particles having a Mohs hardness of 5 or more are mixed, sufficiently vacuum-dried, and then the sub-extruder (B) heated to 270 to 300 ° C.
And the respective melts are laminated in the polymer channel or in the T-die composite die so that the polymer of the extruder (B) comes to the surface layer or both surfaces of the polymer of the extruder (A). The fluorescent brightener is used as a master chip in the main extruder (A) and / or the sub-extruder (B) as necessary.

The melted sheet is subjected to a surface temperature of 10
It is tightly cooled and solidified by static electricity on a drum cooled to 60 ° C. to produce an unstretched composite film. The unstretched composite film is guided to a roll group heated to 80 to 120 ° C, stretched 2 to 5 times in the longitudinal direction, and cooled by a roll group at 20 to 30 ° C.

Subsequently, the film stretched in the longitudinal direction is guided to a tenter while gripping both ends of the film with clips, and 90-140.
The film is horizontally stretched in a direction perpendicular to the longitudinal direction in an atmosphere heated to ° C.

The stretching ratio is 2 to 5 times each in the vertical and horizontal directions, and the area ratio (longitudinal stretching ratio × lateral stretching ratio) is preferably 6 to 20 times. When the area magnification is less than 6 times, the whiteness of the obtained film becomes insufficient, and when it exceeds 20 times, the film tends to be easily broken during stretching.

In order to impart flatness and dimensional stability to the biaxially stretched film obtained in this way, the biaxially stretched film is placed in a tenter for 150 minutes.
After heat-setting at ２３０230 ° C., the mixture is gradually cooled, cooled to room temperature, and wound up to obtain the card base material of the present invention.

[0041]

[Method of measuring and evaluating characteristics] The characteristic value of the present invention is as follows.
According to the following evaluation methods and evaluation criteria. (1) Average particle diameter of particles The particles were dispersed in ethanol and measured using a centrifugal sedimentation type particle size distribution analyzer (CAPA4500, manufactured by Horiba, Ltd.), and the volume average diameter was calculated to be the average particle diameter. (2) Whiteness According to JIS-L-1015, U manufactured by Shimadzu Corporation
When the reflectance of the B layer surface at wavelengths of 450 nm and 550 nm is B% and G% using V-2600, respectively,
Whiteness (%) = 4B-3G. (3) Color Tone The surface color of the film was measured using a color difference meter ND- manufactured by Nippon Denshoku Industries Co., Ltd.
The B layer surface is measured using 6B, and the determination is made based on the obtained b value. (4) Concealing property Obtained by optical density, an optical densitometer (TR92 manufactured by Macbeth)
7), and the hiding power was determined based on the following criteria.
Note that the larger the measured value, the higher the concealing property.

：: Optical density is 0.8 or more Δ: Optical density is 0.5 or more and less than 0.8 ×: Optical density is 0.5 or less (5) Center line average roughness Ra Based on JIS-B-0601 , 3D roughness meter (Co., Ltd.)
The B layer surface was measured using Kosaka Laboratory SE-3AK). Note that the cutoff value was 0.8 mm. (6) Void Ratio A cross section of the film cut in the machine direction (MD) is taken at a magnification of 1000 to 5000 times with a scanning electron microscope to obtain a cross section photograph (Sdm) of the film of the A layer. Further, in the layer A, all voids in the cross section of the film of the photograph were subjected to an image analyzer, and the area corresponding to the voids was defined as a total (Svm). From this, the void cross-sectional integral ratio (Vvm) was determined and defined as the void ratio.

Vvm = Svm / Sdm Similarly, the cross-sectional area ratio of voids (Vvt) was also determined for the cross section of the film cut in the transverse stretching direction (TD), which was defined as the void formation ratio.

The larger value of Vvm and Vvt is defined as the void fraction of the sample. (7) Workability The cutability of the film is poor due to the pain of the blade of the machine using a hole punching machine Telepunch M-20 type manufactured by CSK Corporation (notches or distortions occur in the cut portion by visual observation). Judgment was made on the basis of the following criteria.

○: 400,000 times or more △: 200,000 times or more and less than 400,000 times ×: less than 200,000 times (8) Scratch resistance Using a Gakushin abrasion tester (manufactured by Daiei Kagaku Seiki Seisakusho),
The surface of the layer B was rubbed five times with a cotton cloth under a load of 250 g, and the surface condition was visually observed, and a judgment was made according to the following criteria.

No flaws: 5 points Little flaws: 3 points Many flaws: 1 point Four points between each point, two points, and three or more points are practically acceptable levels. (9) Printability The surface of the film was subjected to corona discharge treatment, and the following coating material was applied using a gravure coater so that the thickness after drying became 0.1 μm, and dried at 120 ° C. for 2 minutes to form an ink receiving layer. Formed.

[Coating Material] Wax composition (A): Aqueous dispersion of acrylic acid-vinyl acetate-ethylene copolymer wax Antistatic agent (B): Acid phosphooxy (polyoxyethylene) previously neutralized with potassium hydroxide Glycol) Monomethacrylate (number of repeating units of oxyethylene glycol n = 5) / butyl acrylate / acrylic acid emulsion-polymerized at a ratio of 70/25/5 (% by weight), phosphoric acid-based conductive polymer having a molecular weight of about 150,000. Aqueous dispersion Additive particles (C): silica having an average particle diameter of 0.3 μm Surfactant (D): fluorinated surfactant (A) / (B) is mixed at a solid content weight ratio of 70/30, and mixed with water. The resulting mixture was diluted to a solid concentration of 1% by weight, and 4% by weight of (C) and 0.05% by weight of (D) based on the total weight of the coating solution were added and mixed.

Next, a color printer (Professional Color P, manufactured by Seiko Denshi Kogyo KK)
oint 2) and a thermal transfer ink ribbon (CH705, manufactured by Seiko Eye Supply Co., Ltd.), a test pattern was printed on the ink receiving layer obtained above. The resulting transferred image was visually evaluated for sharpness and contrast in the following five stages and evaluated.

[0049]

[0050]

The present invention will be described with reference to the following examples and comparative examples, but the present invention is not limited to these examples.

Examples 1 and 2 In order to form the layer A, a raw material obtained by adding 14% by weight of calcium carbonate fine particles having an average particle diameter of 1 μm to a polyethylene terephthalate chip was mixed and dried at 180 ° C. for 3 hours. After that, the mixture is supplied to the extruder (A), and 2
It was melted at 85 ° C. and introduced into a T-die composite die.

On the other hand, in order to form the layer B, the above-mentioned polyethylene terephthalate chip was coated with an average particle diameter of 0.2 μm.
The raw material obtained by adding 13% by weight of anatase type titanium oxide fine particles and 0.15% by weight of a fluorescent whitening agent “OB-1” (manufactured by Eastman) was dried at 180 ° C. for 3 hours, and then extruded (B). , Melted at 285 ° C. by a conventional method, introduced into a T-die composite layer die, laminated on one surface of the A layer (Example 1) and both surface layers (Example 2), and Was tightly cooled and solidified by an electrostatic charge method on a cooling drum maintained at a surface temperature of 25 ° C. Subsequently, the unstretched film was stretched 3.2 times in the longitudinal direction using a roll group heated to 95 ° C. in a longitudinal direction, and cooled by a roll group at 25 ° C. Further, the stretched film was guided to a tenter and stretched 3.2 times in a direction perpendicular to the longitudinal direction in an atmosphere heated to 100 ° C. After that, the film was heat-set at 220 ° C. in a tenter, uniformly cooled, and wound up, and the A layer / B layer was 195/5 μm (Example 1).
A card base material having a layer / layer A / layer B configuration of 5 μm / 190 μm / 5 μm (Example 2) was obtained.

The characteristics of the card base material thus obtained are as follows:
As shown in Table 1, it was excellent in workability, scratch resistance, smoothness, whiteness, concealing property, printability, and the like.

Examples 3 to 5 and Comparative Examples 1 to 3 The types and addition concentrations of the inorganic fine particles and the stretching ratio were changed, and thereafter a card base material was obtained in the same manner as in Example 2. These properties were evaluated and the results are summarized in Table 1. That is, by keeping the Mohs hardness of the inorganic fine particles, the void ratio in the A layer, and the center line average roughness Ra of the B layer within the range of the present invention, a card substrate excellent in various properties can be obtained. Understand.

Example 6 Based on Example 2, silicon oxide having an average secondary particle diameter of 2.5 μm was used as a raw material to be supplied to the extruder (B) of Example 2 and as inorganic fine particles other than titanium oxide fine particles. A card base material was obtained in the same manner as in Example 2 except that 0.4% by weight of Syloid 72 (manufactured by Fuji Serial Co., Ltd.) was used. As shown in Table 2, the properties of the card base material were excellent in each property, and the surface of the base material had a unique color tone and a calm whiteness.

Comparative Example 4 Based on Example 3, calcium carbonate having an average particle diameter of 1.1 μm was used as a raw material to be supplied to the extruder (B) of Example 3.
A card substrate was obtained in the same manner as in Example 3 except that 4% by weight was used. Table 2 shows the characteristics of the card base material.
As shown in the above, the scratch resistance was poor.

[0057]

[Table 1]

[0058]

[Table 2]

[0059]

The card base material of the present invention contains inorganic fine particles of a specific hardness, and further contains inorganic fine particles of a specific hardness in the outermost layer of a layer having a specific void ratio. Since a layer having a surface roughness of 3) is laminated, the weight can be reduced and the punching workability and scratch resistance are excellent.

Further, for the same reason, the card base material of the present invention can provide a high-white material having a bluish tint with a small color tone b value and exhibiting a high quality image. In addition, since it also has excellent light-shielding properties, it can express clear whiteness with less transmitted light, so that a clear printed image can be formed.

Since the card base material of the present invention has the above-mentioned excellent properties, it can be used for credit cards, prepaid cards, various recognition cards, specifically telephone carts, orange cards, transportation cards, pachinko cards, It is optimally used as a base material for magnetic recording cards, IC cards, optical recording cards, and electronic money IC cards typified by medical cards, shopping cards, and the like.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B42D 15/10 501 B42D 15/10 501Z // B29C 55/12 B29C 55/12 B29K 67:00 B29L 9: 00 F term (reference) 2C005 HA09 HA10 HA30 HB05 KA02 KA03 LA02 4F100 AA00A AA00B AA08 AA21B AK41A AK41B AK42 BA02 BA03 BA06 BA10B BA25B BA26 CA13 CA30A CA30B DE01A DE01B GB71 JA13A01 J00 JA12 JK12A00 JK12A00 AG01 AG03 AH38 QA02 QA03 QC06 QD13 QG01 QG18 QM02 QM03 QM11 QM13 QW07

Claims (5)

[Claims] 1. A polyester mainly comprising inorganic fine particles having a Mohs hardness of at least 5 in at least one outermost layer of the polyester layer (A) mainly containing inorganic fine particles having a Mohs hardness of less than 5. The polyester layer (A) has a void ratio of 5 to 5;
30%, and the center line average roughness Ra of the polyester layer (B) is 0.3 μm or less. 2. The card base according to claim 1, wherein the inorganic fine particles having a Mohs hardness of 5 or more are titanium oxide fine particles. 3. The polyester layer (B) having a lamination thickness of 0.
3. The card base according to claim 1, wherein the thickness is in a range of 5 to 50 [mu] m. 4. The card substrate according to claim 1, wherein at least one of the polyester layers (A) and (B) contains a fluorescent whitening agent. 5. An optical density of 0.8 or more and a whiteness of 80 to 1
5. The card base material according to claim 1, wherein the content is 20%.