JP2002052670A - White laminated polyester film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a white laminated polyester film excellent in smoothness. SOLUTION: The white laminated polyester film consists of at least a white polyester layer (A) and a polyester layer (B), and the white polyester layer (A) contains titanium dioxide with a mean particle size of 0.01-3 μm and the surface glossiness of the film calculated from the side of the white polyester layer (A) is 60% or more and the number of projections with a height of 200 μm or more on the surface of the white polyester layer (A) is 20 pieces/m2 or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a white laminated polyester film. More specifically, the present invention relates to a white laminated polyester film having excellent smoothness and suitable as a base material of a receiving sheet used for various printing records such as ink jet, thermal transfer, and offset printing.

[0002]

2. Description of the Related Art Conventionally, white polyester films containing inorganic fine particles such as titanium oxide, calcium carbonate, barium sulfate and the like in a polyester and a resin incompatible with the polyester have been used for various applications, particularly for ink jet,
It is applied to the base material of the receiving sheet as a printing record application such as thermal transfer and offset printing. Furthermore, in recent years, with the improvement of printing record accuracy, the smoothness of the film is required, and the white polyester film of high whiteness which enhances the clarity of the printed matter of the inorganic fine particles and gives a more luxurious feeling is required. . In response to such demands, those in which a plurality of the above-mentioned inorganic fine particles are added in combination, those in which inorganic fine particles and an incompatible resin are added in combination, or those in which a fluorescent brightener is further added are known. Has become. Such white polyester films are disclosed in, for example, JP-A-4-153232 and JP-A-6-322153.
No. publication.

[0003]

However, when the above-mentioned white polyester film is used as a base material of a receiving sheet requiring glossiness, the projections due to the aggregation of the inorganic fine particles are formed on the surface layer of the film. If present, printing unevenness and chipping may occur, resulting in poor print quality. Furthermore, there is a problem that the film forming property is reduced and the film is frequently torn, thereby increasing the manufacturing cost.

[0004] The present invention solves the above problems,
It is an object of the present invention to provide a white laminated polyester film having excellent gloss.

[0005]

The white laminated polyester film of the present invention which achieves this object comprises at least a white polyester layer (A) and a polyester layer (B), and the white polyester layer (A) has an average particle size. Diameter 0.01 ~
3 μm of titanium dioxide is contained, and the glossiness of the surface determined from the white polyester layer (A) side is 60% or more;
Further, the white polyester layer (A) is a white laminated polyester film, wherein the number of protrusions of 200 μm or more on the surface is 20 / m ² or less.

[0006]

DETAILED DESCRIPTION OF THE INVENTION In the present invention, a polyester is a polymer obtained by condensation polymerization of a diol and a dicarboxylic acid. Here, dicarboxylic acids are represented by terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, sebacic acid and the like, and diols are ethylene glycol,
Trimethylene glycol, tetramethylene glycol,
This is represented by cyclohexanedimethanol and the like.
Specifically, for example, polyethylene terephthalate, polyethylene-p-oxybenzoate, poly-1,4-cyclohexylene dimethylene terephthalate, polyethylene 2,6-naphthalenedicarboxylate (polyethylene naphthalate) and the like can be used. .

Of course, these polyesters may be either homopolyesters or copolyesters. Examples of copolymerization components include diol components such as diethylene glycol, neopentyl glycol and polyalkylene glycol, adipic acid, Sebacic acid, phthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid,
A dicarboxylic acid component such as 5-sodium sulfoisophthalic acid can be used. In the polyester, if necessary, appropriate additives such as heat stabilizers, oxidation stabilizers, ultraviolet absorbers, weathering stabilizers, and organic easy-to-use additives in amounts not to impair the effects of the present invention. Lubricant, organic fine particles,
A filler, an antistatic agent, a nucleating agent, a dye, a dispersant, a coupling agent and the like may be blended.

As the polyester used in the present invention, polyethylene terephthalate and polyethylene naphthalate are preferred because of their excellent water resistance, durability and chemical resistance.

The white laminated polyester film in the present invention is a white laminated polyester film having two or more layers having at least a white polyester layer (A) and a polyester layer (B), wherein the white polyester layer (A) has an average grain size. It contains titanium dioxide having a diameter of 0.01 to 3 μm, has a surface gloss of 60% or more as determined from the white polyester layer (A) side, and has the white polyester layer (A)
It is necessary that the number of protrusions of 200 μm or more on the surface is 20 / m ² or less. The protrusion of 200 μm or more on the surface of the white polyester layer (A) indicates not the height of the protrusion but the size of the protrusion. Using a laser microscope, observe the protrusions on the surface layer of the white polyester layer (A),
The maximum distance when a straight line is drawn at two points on the outer periphery of the protrusion is measured as the size of the protrusion. The number of protrusions of 200 μm or more on the surface of the white polyester layer (A) is preferably 10 / m ² or less, more preferably 5 / m ² or less, and further preferably 1 / m ² or less. When it is more than 20 / m ² , when used as a base material of the receiving sheet, printing unevenness and chipping occur, and a high-definition image cannot be formed. The lower limit is ideally 0
Pcs / m ² , but usually about 0.1 pcs / m ² .

The average particle size of the titanium dioxide particles in the present invention is preferably 0.05 to 3 μm, and 0.07 to 1 μm.
Are more preferable. If the average particle size is outside the above range, uniform dispersion becomes difficult, the smoothness of the film surface is deteriorated, and further, whiteness, bluishness, glossiness may be reduced due to these. It is not preferable. The amount of the titanium oxide particles is not particularly limited, but is preferably 1 to 35% by weight, more preferably 3 to 20% by weight, and most preferably 3 to 10% by weight. If the addition amount is less than the above range, it is difficult to improve the whiteness characteristics of the film.If the addition amount is more than the above range, film breakage during stretching or inconvenience such as powder generation during post-processing may occur. May occur. The gloss is preferably 70% or more, most preferably 8%.
0% or more. If the glossiness is lower than 60%, the overall resolution during printing is poor and the appearance is not good. On the other hand, when the glossiness is 90% or more, the film transportability in the printing press deteriorates, which is not very preferable.

The white laminated polyester film of the present invention needs to have a laminated structure of at least two layers having at least a white polyester layer (A) and a polyester layer (B). For example, when trying to obtain the effects of the present invention with a single-layer single film, it is very difficult to satisfy all properties such as whiteness, bluishness, glossiness, and concealability (optical density). is there. Further, even if all the characteristics can be satisfied, the raw material cost increases, or the film forming property becomes unstable, resulting in an increase in the manufacturing cost. Therefore, the white polyester layer (A) is made to have a laminated structure of two or more layers, and various characteristics excellent in whiteness, bluishness, glossiness, etc. are expressed in the white polyester layer (A), and the polyester layer (B) is a layer having an excellent optical density. By using a layer having characteristics other than the above-mentioned various characteristics, it becomes possible to satisfy all the necessary characteristics as the whole white laminated polyester film.

In the present invention, at least the white polyester layer (A) contains a fluorescent whitening agent in order to give the white laminated polyester film a clearer and bluish whiteness and to give a high-quality image. It is desirable.

In the present invention, a 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 and bluish color without reducing the lightness of the substance. Examples of the fluorescent whitening agent include trade names "Ubitek" (Ciba-Geigy), "OB-1" (Eastman), "TBO" (Sumitomo Seika Co., Ltd.) and "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. However, in the present invention, the heat brightening agent is particularly excellent in heat resistance and has good compatibility with the polyester described above. It is desirable to select one that can be uniformly dispersed, has little coloring, and does not adversely affect the resin.

The content of the fluorescent whitening agent in the white polyester layer (A) and / or polyester layer (B) is preferably 0.005 to 1% by weight, and 0.01 to 0.1% by weight.
Those in the range of 5% by weight are more preferred. If the content is less than the above range, it is difficult to obtain a sufficient whitening effect, and if the content exceeds the above range, the uniform dispersibility is reduced, the whitening effect is reduced by so-called "density quenching", or the whiteness is reduced by coloring. Is easy to invite.

In order to further improve the bluish whiteness, the white polyester layer (A) and the polyester layer (B) contain a fluorescent whitening agent, and the white polyester layer (A) It is desirable that the content (% by weight) of the fluorescent whitening agent therein is higher than in the polyester layer (B). When the content is lower than that in the polyester layer (B), there is a problem that not only the effect of improving the bluish whiteness is low but also the cost of raw materials tends to increase, which is not preferable. In the above case, the difference in the content of the fluorescent whitening agent between the white polyester layer (A) and the polyester layer (B) is preferably 0.005 to 0.995% by weight, more preferably 0.01 to 0.7%. %, Most preferably 0.02 to 0.5% by weight. When the difference in the content is less than the above range, the effect when the configuration is different from that of the content is small, and as a result, the cost due to the laminated configuration may increase. On the other hand, if the difference in the content is larger than the above range, the content of the fluorescent whitening agent in the white polyester layer (A) increases, which tends to cause a decrease in uniform dispersibility and a decrease in whiteness due to coloring. Is not preferred.

The white laminated polyester film of the present invention has a laminated structure of two or more layers having at least a white polyester layer (A) and a polyester layer (B), and the white polyester layer (A) has titanium oxide particles. When the polyester layer (B) is a layer containing fine bubbles, when used as a base material of a receiving sheet for, for example, ink jet or thermal transfer, printing is performed by imparting flexibility and cushioning properties. This is more preferable for improving the transferability and transferability and for reducing the weight of the substrate. As a method for containing fine bubbles, a method of adding a foaming agent or fine particles and / or adding a thermoplastic resin incompatible with polyester and uniaxially or biaxially stretching the same to generate fine bubbles. Although generally used, it is preferable to use a thermoplastic resin incompatible with polyester in terms of weight reduction effect or film formation stability.

In the present invention, the thermoplastic resin is a thermoplastic resin other than polyester, and is preferably a resin incompatible with polyester. Such a resin is
In a measurement by a known method such as a differential scanning calorimeter (DSC), in a system in which polyester and the thermoplastic resin are melted, in addition to the glass transition temperature (hereinafter abbreviated as Tg) corresponding to the polyester, Is a resin in which Tg corresponding to is observed. Thermoplastic resin incompatible with polyester is dispersed in particles in polyester,
The effect of forming voids in the polyester film by stretching is great. The melting point of such a thermoplastic resin is preferably lower than the melting point of the polyester and higher than the temperature used to orient the film support. From these points, among thermoplastic resins, olefin-based polymers such as polyethylene, polypropylene, polybutene, and polymethylpentene or copolymers thereof (polyolefin) are preferable. Among them, polypropylene having a small critical surface tension, polymethylpentene is preferable,
In particular, polymethylpentene is particularly preferable because it has a large difference in surface tension from polyester and a high melting point, so that it is easy to form fine bubbles at the time of stretching. Further, when a thermoplastic resin having a polar group such as a carboxyl group or an epoxy group or a functional group reactive with a polyester, an olefin-based polymer or copolymer, a polyalkylene glycol, or the like is used in combination as a compatibilizer. This is preferable because the dispersion diameter of the thermoplastic resin becomes small, and the voids formed by stretching can be made finer, whereby the film-forming stability is improved and the whiteness, blue tint and optical density are further improved.

The content of the thermoplastic resin incompatible with the polyester in the polyester layer (B) is not particularly limited.
It is preferably from 35 to 35% by weight, more preferably from 3 to 25% by weight. If the addition amount is less than the above range, the effect of weight reduction is small, and it is difficult to improve the properties of the film such as whiteness and optical density. On the other hand, if it is more than the above range, inconveniences such as tearing of the film may occur during stretching.

In the present invention, each of the white polyester layer (A) and the polyester layer (B) may be the same polyester composition or different polyester compositions. In particular, it is more preferable that different polyester compositions, for example, the polyester (B) be a homopolyester and the white polyester layer (A) be a copolyester, because properties such as easy adhesion can be obtained. Further, it is preferable that the polyester used for the white polyester (A) is polyethylene naphthalate and the polyester used for the polyester layer (B) is polyethylene terephthalate, because the effects of improving weather resistance and rigidity can be obtained.

Further, the white laminated polyester film of the present invention is formed by laminating a white polyester layer (A) on both sides of a polyester layer (B) to form a three-layer laminated structure. This is more desirable in terms of practicality.

In the present invention, the white polyester layer (A) and the polyester layer (B) can be laminated by co-extrusion during melt film formation, or by laminating them separately, Any of the above methods may be used, but the former method is more preferable in terms of cost and the like.

By using a titanium dioxide master chip having a concentration of 35 to 60% by weight as the white polyester layer (A) and diluting the same, coarse projections on the surface of the white polyester layer (A) can be largely reduced. Decrease. The concentration of the titanium dioxide master chip is more preferably 50 to 60% by weight.

The white laminated polyester film of the present invention has a whiteness of 8 determined from the white polyester layer (A) side.
Those having 0% or more, more preferably 85% or more, and most preferably 90% or more are preferable because they exhibit a very beautiful whiteness without dullness. The bluish index (color tone b value) determined from the white polyester layer (A) side is 3.0 or less, more preferably 1.0 or less, and most preferably 0.5.
The following are preferable because they have a bluish color and exhibit excellent whiteness with a luxurious feeling.

The optical density of the white laminated polyester film of the present invention is not more than 0.1 at a thickness of 100 μm.
It is preferably from 6 to 2.0, more preferably from 0.8 to 1.8. When the optical density is less than 0.6, the back side of the film is transparent because the concealability of the film is small, which is not preferable. Further, the optical density is 2.
To exceed 0, a large amount of particles must be contained, and the strength of the film may be weak, which is not preferable.

In the present invention, the thickness of the white laminated polyester film is not particularly limited.
Those having a thickness in the range of about 500 to 500 μm, preferably about 20 to 300 μm are preferred because they have excellent handling properties in practical use as a substrate of the receiving sheet. The thickness of the white polyester layer (A) is preferably 0.5 to 50 μm, more preferably 1 to 25 μm. If the lamination thickness is smaller than the above range, whiteness and bluish color tend to decrease. On the other hand, if it is larger than the above range, the cost is increased and the effect of the laminated structure is reduced, which is not preferable.

In thermal transfer printing or the like, since the print quality is improved as the printing recording sensitivity is increased, the specific gravity of the white laminated polyester film of the present invention is from 0.6 to 1.2 g / cm.
³ is preferable, 0.6 to 0.9 g / cm ³ is more preferable, and 0.6 to 0.8 g / cm ³ is particularly preferable. If the specific gravity is less than 0.6 g / cm ³ , gloss unevenness occurs during printing, which is not preferable. This is considered to be due to the fact that the voids in the film accumulate an excessive amount of heat, resulting in a matte surface. When the specific gravity is 1.2 or more, the printability and transferability may be deteriorated due to poor cushioning property and transportability, and it is not preferable in terms of weight reduction of the base material.

Next, some examples of the method for producing the white laminated polyester film of the present invention will be described.
It is not limited only to such an example.

With respect to the method for producing a white laminated polyester film, in a composite film forming apparatus having an extruder (A) and an extruder (B), a polyester chip and a master chip of titanium dioxide particles are mixed with titanium dioxide particles of 1 to 1.
After mixing to 35% by weight and sufficiently drying in vacuum, the mixture is supplied to an extruder (A) heated to 270 to 300 ° C. In addition, since the polyester layer (B) is laminated, the polyester chips and the titanium dioxide particles and / or the thermoplastic resin incompatible with the polyester are 1 to 35% by weight.
The extruder (A) is mixed with the extruder (B) in the T-die composite die, and the polymer is extruded into the extruder (B). Laminated so as to be on the surface (both sides) and molded into a sheet,
Obtain a molten laminated sheet.

The laminated sheet thus melted was subjected to a surface temperature of 1
On a drum cooled to 0 to 60 ° C., it is tightly cooled and solidified by static electricity to produce an unstretched film. The unstretched film is guided to a group of rolls heated to 80 to 120 ° C., stretched 2 to 5 times in a longitudinal direction (longitudinal direction, that is, a direction in which the film advances), and cooled by a group of rolls of 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 longitudinal and transverse directions, and the area ratio (longitudinal stretching ratio × lateral stretching ratio) is preferably 6 to 20 times. If the area magnification is less than 6 times, the whiteness and mechanical properties of the obtained film become insufficient, and if it exceeds 20 times, the film tends to be easily broken during stretching.

In order to provide the biaxially stretched film thus obtained with flatness and dimensional stability, the biaxially stretched film is placed in a tenter in a tenter.
After heat-setting at ２３０230 ° C., the mixture is gradually cooled, cooled to room temperature, and wound up to obtain the white laminated polyester film of the present invention.

The white laminated polyester film thus obtained is excellent in bluish whiteness and can give a high-quality image when used as a base material of a receiving sheet based on whiteness. It is suitably used as a base material of a receiving sheet used for various printing records such as ink jet, thermal transfer and offset printing.

[0034]

[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 size of inorganic fine particles Transmission electron microscope HU-12 type (manufactured by Hitachi, Ltd.)
The cross section of the white polyester layer (A) or the polyester layer (B) was observed from 3,000 to 200,000-fold magnification using a cross-sectional photograph. That is, the particle portion of the cross-sectional photograph is marked, and the particle portion is subjected to image processing using a high-definition image analysis processing device PIAS-IV (manufactured by Pierce Co., Ltd.). The average diameter when converted to a circle was calculated and defined as the average particle diameter of the inorganic fine particles.

(2) Whiteness According to JIS L-1015, U white manufactured by Shimadzu Corporation
It measured using V-260. Wavelength 450nm and 5
Assuming that the reflectance at 50 nm is B% and G%, respectively.
The whiteness is represented by the following formula: whiteness (%) = 4B-3G.

(3) Blueness index (color tone b value) For a white laminated polyester film, JI was measured using a spectral colorimeter SE-2000 (manufactured by Nippon Denshoku Industries Co., Ltd.).
S Measured under the optical conditions according to Z-8722, JIS
It was determined as a color difference b according to K-7105. The smaller the measured value, the better the blueness.

(4) Opacity The optical density (OD) was determined and measured using an optical densitometer TR927 (manufactured by Macbeth). The greater the measured value, the higher the concealment property.

(5) Gloss Digital gonio-gloss meter UGV-5B (Suga Test Instruments Co., Ltd.)
Was measured according to JISZ-8741. The measurement conditions were an incident angle of 60 ° and a light receiving angle of 60 °.

(6) Size of protrusions The protrusions on the surface layer of the white polyester layer (A) were observed using a laser microscope (Keyence Corporation VF-7500), and straight lines were drawn at two points on the outer periphery of the protrusions. The distance that sometimes became the longest was measured as the size of the protrusion.

(7) Specific Gravity 10 places at equal intervals in the width direction and a constant area (10 cm
× 10 cm), and each is weighed. The specific gravity is determined using the following equation. Specific gravity = (total weight of 10 sheets) / (total volume of 10 sheets) Total volume = thickness × area × sampling number

[0042]

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.

Example 1 A polyethylene terephthalate (hereinafter abbreviated as PET) chip was coated with 50% by weight of an anatase type titanium oxide fine particle master chip having an average particle diameter of 0.3 μm and 7% by weight.
The raw material added so as to be diluted to 180 ° C. is vacuum-dried at 180 ° C. for 3 hours, and then supplied to an extruder (A).
It was melted at 5 ° C. and introduced into a T-die composite die.

On the other hand, 10% by weight of polymethylpentene (hereinafter abbreviated as PMP) and 1% by weight of polyethylene glycol having a molecular weight of 4000 (hereinafter abbreviated as PEG) as a compatibilizer were added to the PET chip. After drying in vacuum at 180 ° C. for 3 hours, the mixture was supplied to an extruder (B) and melted at 285 ° C. by a conventional method to form a white polyester layer (A) in a T-die composite die and a polyester layer (B).
To obtain a laminated melt sheet laminated on both surface layers. The laminated melt sheet was tightly cooled and solidified by an electrostatic charge method on a cooling drum maintained at a surface temperature of 25 ° C. to obtain an unstretched film. Subsequently, the unstretched film was stretched 3.2 times in the longitudinal direction using a group of rolls heated to 98 ° C. according to a conventional method,
It cooled with the roll group of 25 degreeC. Further, the stretched film was guided to a tenter and stretched 3.4 times in a direction perpendicular to the longitudinal direction in an atmosphere heated to 125 ° C. Then in the tenter 2
After heat-setting at 20 ° C., the film was gradually cooled and then wound up. The white polyester layer (A) was 5 μm, and the polyester layer (B) was
A white laminated polyester film having a thickness of 130 μm and a thickness of 20 μm was obtained.

The properties of the thus obtained white laminated polyester film were as shown in Table 1. The printed image was solid printed, and evaluated according to the following criteria according to the printing state at that time. = No printing missing. Very good. The highest image quality. ○ = No printing missing. Good. It is practical. Δ = Printing omission is slightly observed, but practical. × = Many print omissions are observed, making it impractical. From Table 1, the number of protrusions on the surface layer of the white polyester layer (A) was small, and the printed image was also good.

Example 2 Based on Example 1, 0.15% by weight of an optical brightener "OB-1" (manufactured by Eastman) was added to the raw materials supplied to each extruder (A). Otherwise, a white laminated polyester film was obtained in the same manner as in Example 1. As shown in Table 1, the properties of this white laminated polyester film are such that the number of protrusions on the surface layer of the white polyester layer (A) is small, and the properties are excellent, and particularly, bluish whiteness and smoothness (glossiness) are obtained. Excellent, and the printed image was also good.

Example 3 As a raw material supplied to the extruder (A) of Example 2, PET was used.
A white laminated polyester film was produced in the same manner as in Example 2 except that 35 wt% of an anatase-type titanium oxide fine particle master chip having an average particle diameter of 0.3 μm was added to the chip so as to be diluted to 7 wt%. I got As shown in Table 1, the characteristics of this white laminated polyester film were such that slight protrusions on the surface layer of the white polyester layer (A) were confirmed, but the print image was not so affected and was in a practically usable range. .

Example 4 As a raw material supplied to the extruder (A) of Example 2, PET was used.
A white laminated polyester film was produced in the same manner as in Example 2, except that 14 wt% of an anatase type titanium oxide fine particle master chip having an average particle diameter of 0.3 μm was added to the chip so as to be diluted to 7 wt%. I got As shown in Table 1, the properties of this white laminated polyester film were such that the number of projections on the surface layer of the white polyester layer (A) was slightly large, and the printed image had some color omission, but there was no problem in practical use.

Comparative Example 1 As a raw material supplied to the extruder (A) of Example 2, 7% by weight of an anatase type titanium oxide fine particle master chip having an average particle diameter of 0.3 μm was added without being diluted with PET. Except for the above, a white laminated polyester film was obtained in the same manner as in Example 2. As shown in Table 1, the properties of this white laminated polyester film were impractical because the number of projections on the surface layer of the white polyester layer (A) was large and the printed image also had many color omissions.

[0050]

[Table 1]

[0051]

The white laminated polyester film of the present invention is a white laminated polyester film having two or more layers having at least a white polyester layer (A) and a polyester layer (B), wherein the white polyester layer (A) has It contains titanium dioxide having an average particle size of 0.01 to 3 µm, and has a surface gloss of 60 as determined from the white polyester layer (A) side.
% Or more, and the number of protrusions of 200 μm or more on the surface of the white polyester layer (A) is 20 / m ² or less. It can be used as a base material for a required receiving sheet. In addition, by using a fluorescent whitening agent, by exhibiting a bluish whiteness and smoothness to a high degree, when used as a base material of a receiving sheet based on whiteness, it can give a high quality image. it can.

Since the white laminated polyester film of the present invention has the above excellent properties, it is suitably used as a base material of a receiving sheet used for various printing records such as ink jet, thermal transfer and offset printing.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08K 5/00 C08L 67/02 C08L 67/02 (C08L 67/02 // (C08L 67/02 23:02 ) 23:02) B41M 5/26 HF term (reference) 2H086 BA19 BA33 BA41 2H111 CA25 CA31 CA41 4F071 AA15 AA20 AA21 AA44 AA82 AB17 AC00 AE01 AE09 AE22 AF32Y AH16 BB06 BB08 BC01 BC10 BC11 BC14A41A100A AK41C AL05B BA02 BA03 BA06 BA10A BA10C CA13A CA13C CA23A CA23C CA30A CA30B CA30C DD07 DD23B DE01A DE01C GB90 JA13A JA13C JB16B JK15 JL10A JL10C JN21 YY00 YY00A YY00C 4J002 BB031 CF103 CFB011

Claims (9)

[Claims] 1. A white polyester layer (A) comprising at least a white polyester layer (A) and a polyester layer (B), wherein said white polyester layer (A) contains titanium dioxide having an average particle size of 0.01 to 3 μm, A white laminated polyester film, wherein the glossiness of the surface determined from the side A) is 60% or more, and the number of projections of 200 μm or more on the surface of the white polyester layer (A) is 20 / m ² or less. . 2. The white laminated polyester film according to claim 1, wherein a titanium dioxide master chip having a concentration of 35 to 60% by weight is used as the titanium dioxide contained in the white polyester layer (A). 3. The white laminated polyester film according to claim 1, wherein the polyester layer (B) contains fine bubbles. 4. The white laminated polyester film according to claim 3, wherein the polyester layer (B) contains a thermoplastic resin incompatible with the polyester. 5. The white laminated polyester film according to claim 4, wherein the thermoplastic resin is a polyolefin. 6. The white laminated polyester film according to claim 1, wherein at least the white polyester layer (A) contains a fluorescent whitening agent. 7. The white polyester layer (A) and the polyester layer (B) contain a fluorescent whitening agent, and the content of the fluorescent whitening agent in the white polyester layer (A) is in the polyester layer (B). The white laminated polyester film according to claim 6, wherein the content of the whitened polyester film is larger than the content of the fluorescent whitening agent. 8. The white laminated polyester film according to claim 1, which has a three-layer laminated structure, wherein the core layer is a polyester layer (B) and both surface layers are white polyester layers (A). . 9. The white laminated polyester film according to claim 1, having a specific gravity of 0.6 to 1.2 g / cm ³ .