JPH081887A - Laminated polyester film - Google Patents

Abstract

PURPOSE:To obtain a base material film suitable for a thermal transfer material excellent in hot stickiness resistance by providing a laminating film based on a wax compsn. and a metal salt of higher fatty acid having a specific m.p. on at least one surface of a polyester film. CONSTITUTION:A laminated polyester film is obtained by providing a laminating film based on a wax compsn. and a metal salt of higher fatty acid with an m.p. of 105 deg.C or higher on at least one surface of a polyester film. As a wax compd., various commercial waxes, for example, petroleum wax, vegetable wax, animal wax or low mol.wt. polyolefins can be used. When a mixture prepared by further adding an oily substance showing fluidity or pasty properties at the normal temp. to the laminating film compsn. is used, printing running properties in a high pulse width region are made further excellent.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated polyester film, and more particularly to a base film suitable for a thermal transfer material.

[0002]

2. Description of the Related Art In recent years, various recording systems have been developed with the development of office automation. Among them, a thermal recording system which produces less noise during printing and is easy to operate is noted. Has been done. In the thermal recording method, a thermal recording device such as a thermal printer is used, and the recording paper and the thermal ink layer of the thermal transfer material are brought into contact with each other to selectively heat the film by a pulse signal from a heating head on the opposite side of the ink layer. As a result, the ink heated through the film is melted or sublimated and transferred to the recording paper. As the heat-sensitive transfer material, a thin plastic film is generally used in order to improve thermal efficiency.

However, in general, when a plastic film is used as a base film for a heat-sensitive transfer material, a phenomenon in which the film partially fuses to the thermal head due to the amount of heat given by the thermal head appears. This phenomenon is called a stick phenomenon, and when this phenomenon occurs, not only the thermal transfer material does not smoothly run, but there is a problem that the thermal head is significantly contaminated and the sharpness of printing is impaired.

In order to prevent this sticking, it has been proposed to provide a heat resistant protective layer on the surface of the base film opposite to the ink layer. In the thermal transfer method, a melted ink layer mainly composed of a low-melting wax and a pigment or dye is provided on one side of the substrate film, but the ink layer and the heat-resistant protective layer may be blocked and the ink layer may be peeled off depending on storage conditions. There may be a problem. recent years,
For the purpose of high-speed printing, the ink layer tends to have a lower melting point, and this phenomenon is becoming more and more prominent.

Conventionally, in order to avoid the above-mentioned sticking, various heat-resistant protective layers have been proposed on the surface of the plastic film which comes into contact with the thermal head. For example, one provided with a heat-resistant protective layer of silicon, melamine, phenol, epoxy, polyimide or the like (Japanese Patent Laid-Open No. 55-7467), and an anti-stick layer composed of an inorganic pigment having high lubricity and a resin having high heat resistance. Some are provided (JP-A-56-1).
55794). In addition, a layer comprising a water-soluble or water-dispersible silicone and a resin is provided (JP-A-60-
No. 192628), a layer comprising a water-dispersible fluorine-based resin and an aqueous polymer is provided (JP-A-60-19263).
No. 0), a wax and / or a liquid or paste-like substance applied or transferred at room temperature (JP-A-59-148697 and JP-A-60-56583).
There is.

[0006]

However, since the one provided with the heat-resistant protective layer such as silicon or melamine does not sufficiently slide with the head, the thermal transfer ribbon of the printer having a low pulse width or the platen drive type printer is not used. It has poor running properties and has the drawback of stopping running in the case of printing spots or extreme cases. Further, the one to which an inorganic pigment is added has a problem that the head life is shortened due to friction with the thermal head and the surface is roughened so that the thermal conductivity is poor and clear printing cannot be obtained. In the case of laminates of silicone resin and fluorine resin, it is easy to transfer these resins to the surface to which ink is applied after winding on a roll, which causes repellency during ink application and peeling due to poor ink adhesion. There was such a problem. A laminated film obtained by applying wax or the like to a plastic film and drying it is a sub-film.
Although it has an excellent lubrication action with Mullhead, it has a drawback that the heat-resistant protective layer has a low melting point, and since it is a composition similar to the ink layer, blocking easily occurs. In particular, in recent years, the thermal transfer printer is in the direction of increasing the printing speed, and development of a thermal transfer material capable of coping with this is desired. The object of the present invention is one which does not have the above-mentioned drawbacks, that is, a word processor, a facsimile, a bar code printer provided with a heat-resistant protective layer which does not cause sticking and does not block with a low melting point ink layer. Another object of the present invention is to provide a laminated polyester film suitable as a base film for a heat-sensitive transfer material, which can be preferably used in a wide range of regions from a low pulse width region to a high pulse width region such as a video printer.

[0007]

According to the present invention, a polyester film is provided with a wax-based composition and a laminated film mainly composed of a higher fatty acid metal salt having a melting point of 105 ° C. or more on at least one surface of the polyester film. The main point is a polyester film.

The polyester film referred to in the present invention is a general term for a polymer film having an ester bond as a main bonding chain of its main chain, and polyethylene terephthalate is particularly preferable as a base film for a thermal transfer material, Films such as polyethylene-2,6-naphthalate, polyethylene α, β-bis (2-chlorophenoxy) ethane 4,4, -dicarboxylate, polybutylene terephthalate, etc., among them, quality and economy In consideration of properties, etc., polyethylene terephthalate film, (hereinafter polyethylene terephthalate is abbreviated as PET),
Polyethylene-2,6-naphthalate film (hereinafter polyethylene-2,6-naphthalate is abbreviated as PEN) is particularly preferable. In particular, when a PEN film is used as the base film for the heat-sensitive transfer material which is the object of the present invention, wrinkling of the base film is less likely to occur even when high energy is applied for high-speed printing, and thus the printing accuracy is high. Good and good. Of course, PEN / PET, PEN / PET / P
A base film having a two-layer or three-layer structure such as EN is also an example of a preferable structure. Here, polyethylene terephthalate means that 80 mol% or more, preferably 90 mol% or more, and more preferably 95 mol% or more has ethylene terephthalate as a repeating unit. You may replace a part of component with the following 3rd components.

-Acid component-Isophthalic acid, 2,6-naphthalenedicarboxylic acid, 1,
5-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 4,4-diphenyldicarboxylic acid, 4,
4, -diphenyl sulfone dicarboxylic acid, 4,4, -diphenyl ether dicarboxylic acid, p-β-hydroxyethoxybenzoic acid, adipic acid, azelaic acid, sebacic acid, hexahydroterephthalic acid, hexahydroisophthalic acid, ε- Oxycaproic acid, trimellitic acid, trimesic acid, pyromellitic acid, α, β-bisphenoxyethane-4,4, -dicarboxylic acid, α, β-bis (2-chlorophenoxy) ethane-4,4, -dicarboxylic acid Acid, 5-
Sodium sulfoisophthalic acid etc.

-Glycol component-Propylene glycol, butylene glycol, hexamethylene glycol, decamethylene glycol, neopentylene glycol, 1,1-cyclohexane dimethanoe
1,4-socrohexane dimethanol, 2,2-bis (4-β-hydroxyethoxyphenyl) propane,
Bis (4-β-hydroxyethoxyphenyl) sulfone, diethylene glycol, triethylene glycol,
Pentaerythritol, trimethylolpropane, polyethylene glycol, polytetramethylene glycol and the like.

Known additives such as heat stabilizers, oxidation stabilizers, weathering stabilizers, ultraviolet absorbers, organic lubricants, pigments, dyes, organic or inorganic fine particles are added to the base polyester film. You may mix a filler, an antistatic agent, a nucleating agent, etc. Particularly, inorganic and / or organic fine particles are added, and the average surface roughness of the polyester film after biaxial orientation is 0.03 to 0.4 μm, preferably 0.0.
When the thickness is 5 to 0.2 μm, the running property of the present invention can be further improved.

The intrinsic viscosity of the above polyester (measured in orthochlorophenol at 25 ° C.) is 0.40 to 1.2.
0 dl / g, preferably 0.50 to 0.80 dl / g,
The range of 0.5 to 0.75 dl / g is more preferable for the present invention.

The polyester film is preferably biaxially oriented from the viewpoint of mechanical strength and dimensional stability. The biaxially oriented polyester film is obtained by stretching a PET sheet in a non-stretched state in the longitudinal direction and the width direction, so-called biaxial directions by about 2.5 to 5.0 times each and further thermally fixing it to complete the crystal orientation. It is produced and exhibits a biaxially oriented pattern by wide-angle X-ray diffraction.

The thickness of the polyester film is not particularly limited, but when the laminated polyester film of the present invention is used as a base film for a heat-sensitive transfer material, it is 0.5 μm or more 3
It is preferably 0 μm or less, preferably 1 μm or more and 10 μm or less from the viewpoint of heat transfer property and mechanical strength.

In the present invention, the above-mentioned polyester film has a wax composition and a melting point of 105 on at least one side.
It has a laminated film mainly composed of a higher fatty acid metal salt having a temperature of ℃ or higher. The main component as used herein means that the weight ratio in the laminated film composition is 50% or more, preferably 60% or more. As the wax-based compound, various commercially available waxes, for example, petroleum-based wax, plant-based wax, mineral-based wax, animal-based wax, low molecular weight polyolefins and the like can be used, but are not particularly limited.
In the present invention, the use of petroleum wax and plant wax is preferable from the viewpoint of stick resistance. Examples of petroleum waxes include paraffin wax, microcrystalline wax, and oxidized wax. Among them, the use of oxidized wax is particularly preferable from the viewpoint of forming protrusions for imparting slipperiness. Examples of the vegetable wax include candelilla wax, carnauba wax, wax, oricure wax, sugar cane wax, rosin-modified wax and the like. In the present invention, a composition comprising the following compounds is particularly preferable. That is, {rosin or disproportionated rosin, or hydrogenated rosin. Α, β-substituted ethylene (α-substituent :: carboxyl, β-substituent: hydrogen or methyl or carboxyl) adduct} ・ alkyl or alkenyl (each having 1 to 10 carbon atoms) 8) Poly (repeating unit: 1 to
6) It is preferable to use an alcohol ester adduct from the viewpoint of slipperiness and releasability, and it is more preferable to use it in a mixed system with the above-mentioned oxidized wax.

The melting point of the laminated film of the present invention is 105 ° C.
Or higher, preferably 120 ° C. or higher, more preferably 135
It is necessary to contain a higher fatty acid metal salt having a temperature of ℃ or higher. When the higher fatty acid metal salt having a melting point of 105 ° C. or more is made to coexist with the wax-based composition in the laminated film, the low melting point ink layer does not impair the sticking prevention effect when used as the backside treatment layer of the thermal transfer material. This has the effect of preventing blocking with
A higher fatty acid metal salt having a melting point of 105 ° C. or higher has 1 carbon atom.
A metal salt of 0 or more higher fatty acid can be preferably used. Examples of the higher fatty acid having 10 or more carbon atoms include lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid and behenic acid, and the metal salts thereof include lithium, sodium, potassium, calcium and zinc. Examples thereof include barium, cadmium, lead, magnesium, aluminum, and complex salts of two or more of these. Among these, higher fatty acid metal salts that can be particularly preferably used include stearic acid and zinc lauric acid,
Examples include calcium and barium salts.

The content of the higher fatty acid metal salt in the laminated film is not particularly limited, but is preferably 15 to 90% by weight, more preferably 25 to 85% by weight, and particularly preferably 40 to.
80% by weight.

That is, the coexistence of the wax composition and the higher fatty acid metal salt in the laminated film withstands a wide range of loads, imparts good printing runnability, and heat resistance of the heat-sensitive transfer material without blocking with the ink layer. It was found that a protective layer was obtained.

In the present invention, when a mixture of the above-mentioned laminated film composition and an oily substance which shows fluidity or paste at room temperature is further added, the printing runnability in the high pulse width region is further excellent. It can be Examples of oily substances include vegetable oils, fats and oils, mineral oils, synthetic lubricating oils and the like. The vegetable oils include linseed oil, kaya oil, saffron oil, soybean oil, cinnamon oil, sesame oil, corn oil, rapeseed oil, tuna oil, cottonseed oil, olive oil, southern oil, camellia oil, castor oil, peanut oil, banana oil. -Mu oil,
Palm oil and the like. Fats and oils include beef tallow, pork oil, sheep oil, cocoa oil and the like, and mineral oils include machine oil, insulating oil, turbine oil, motor oil, gear oil, cutting oil, liquid paraffin and the like. . As the synthetic lubricating oil, those satisfying the requirements described in the Chemical Dictionary (Kyoritsu Shuppan) can be arbitrarily used, and examples thereof include olefin polymer oil, diester oil, and polyalkylene glycol oil. Among these, mineral oil and synthetic lubricating oil, which have good running properties in the high pulse width region, are preferable. Also, a mixed system of these may be used. The oily substance is contained in the laminated film composition in an amount of 1 to 30% by weight, preferably 2 to 20% by weight.
It is preferably contained in the weight percent.

Various additives may be used in combination in the above composition within a range that does not impair the effects of the present invention. Examples thereof include antistatic agents, heat-resistant agents, antioxidants, organic and inorganic particles, pigments and the like. In addition, various additives such as a dispersion aid, a surfactant, a preservative, and an antifoaming agent may be added to the paint for the purpose of improving dispersibility in water or improving coatability.

Further, in the present invention, in order to improve the slipperiness and the effect of preventing sticking, 20 elongated protrusions having a ratio of the lengthwise direction / the lengthwise direction of 3 or more are formed on the surface of the laminated film.
It is effective to have a surface having a number of particles / 100 μm ² or more. Such protrusions can be obtained by applying a mixed water-based coating composition of the above-mentioned laminated film composition to a polyester film before crystal orientation is completed and then stretching it in one direction.
A preferable composition is a petroleum wax from the viewpoint of forming protrusions, and it is particularly effective to use an oxidized wax. Therefore, it is preferable to use a method (in-line coating method) for coating the laminated film of the present invention during the film manufacturing process from the viewpoint of forming protrusions on the surface by the above composition. For that purpose, the laminated film forming coating agent is preferably used in a state of being dissolved, emulsified or suspended in water from the viewpoint of explosion proof property and prevention of environmental pollution. For example, an aqueous dispersion of a wax composition can be obtained by a conventionally known method (for example, JP-A-59-90625). The thickness of the laminated film is not particularly limited, but 0.005 μ from the viewpoint of preventing sticking and contamination of the thermal head.
m or more and 0.3 μm or less, preferably 0.01 μm or more and 0.15 μm or less. The coating method can be carried out by using various coating devices such as a roll coater, a gravure coater, a river coater, a kiss coater and a bar coater. .

Next, as a specific example of the method for producing a laminated polyester film of the present invention, a laminated polyester film for a thermal transfer material will be described as a representative example. PET containing the so-called precipitated particles and inorganic particles (for example, silica having an average particle size of 1 μm) precipitated in the polymerization step is dried by a conventional method, melt-extruded, and the extruded sheet-like melt is cooled and solidified. Make a stretched PET film. This film is heated to 80 to 120 ° C. to be 2.0 to 5.0 in the longitudinal direction.
The film is stretched twice to obtain a uniaxially oriented film. One side of this film is subjected to corona discharge treatment in an air atmosphere, and the treated surface is coated with an aqueous dispersion coating solution containing a wax-based composition diluted to a predetermined concentration and a higher fatty acid metal salt. Then, the coated film is stretched 3 to 5 times in the width direction while being heated to 90 to 140 ° C., and subsequently introduced into a heat treatment zone at 140 to 240 ° C. and heat treated for 1 to 10 seconds. During this heat treatment, a relaxation treatment of 3 to 12% in the width direction may be performed if necessary. The film thus obtained is slit into an appropriate width to give a biaxially oriented laminated polyester film for a heat-sensitive transfer material. When this film is used as a heat-sensitive transfer material, it can be obtained by applying a heat-melting or heat-sublimation type ink to the non-application side and slitting it to a desired width.

The biaxially stretched laminated polyester film for heat-sensitive transfer material thus obtained is provided with an ink layer according to the application, so that various heat-sensitive transfer materials, for example, word processor, facsimile, printer for personal computer, video. Printers, bar code printers, typewriters, plain paper copiers, etc., which are used for printing out characters or images, and to which particularly high load energy is applied. Suitable for printers.

[0024]

[Characteristic Measuring Method and Effect Evaluation Method] The characteristic measuring method and effect evaluating method in the present invention are as follows.

(1) Lamination Thickness A cross section of the biaxially oriented polyester film provided with a coating layer was cut out and measured from a 100,000 times electron microscopic observation photograph.
The thickness was the average of the maximum thickness and the minimum thickness in one visual field, and the average value of 30 measurement points was the laminated thickness.

(2) Protrusion forming property of laminated surface The surface of the laminated surface is photographed with an electron microscope at a magnification of 10,000 times or more,
The shape of the protrusion is determined from the photograph, and the length (long direction) and width (short direction) of the elongated protrusion are obtained. The number of elongated protrusions was determined from the photograph by the number per unit area and converted into (number / mm ² ).

(3) Hot sticking property-1 The following hot-melt ink was applied to the laminated biaxially oriented polyester film on the side opposite to the laminated surface by the hot-melt method to 3-4 μm.
It was applied to a thickness of m to prepare a heat-sensitive transfer material.

[Hot Melt Ink Composition] Carnauba wax 100 parts by weight Microcrystalline wax 30 parts by weight Vinyl acetate / ethylene copolymer 15 parts by weight Carbon black 20 parts by weight Thermal transfer printer BC-8MK manufactured by Autonix
Using II, the thermal head having a head resistance of 500Ω was used to evaluate the applied voltage level at which sticking does not occur when printing is run with a pulse width of 0.5 msec by changing the applied voltage.
An applied voltage of 10 V or higher was regarded as good resistance to sticking. In addition, even if the voltage is less than 10 V, the one in which sticking occurs is marked as [x]. Plain paper was used as the transfer paper.

(4) Hot sticking property-2 A sublimable ink having the following composition was applied to the surface opposite to the laminated surface, dried and then slit into an appropriate width to prepare a heat-sensitive transfer material.

[0030] This heat-sensitive transfer material was run on a sublimation printer (Sharp Color Video Printer-GZ-P11W) under normal use conditions, and judged according to the following criteria (◯) or better.

⊚: No sticking at all, extremely good running performance ○: No problem in running performance, normal printing is possible, but a slight stick sound is generated at the solid printing portion. Δ: Although it is at a readable level. Normal printing is not possible. X: Stick is extremely unreadable (5) Hot stickiness-3 A high-speed thermal transfer printer (KM705A manufactured by Anritsu Corporation) was used using the thermal transfer material prepared in (2) above. Use 1
Observe the sticking condition when printing at a speed of 20 mm / sec, and if the sticking does not occur and normal printing is possible (○), stick sound is generated even if it runs, but there is some distortion or misalignment in printing. The evaluations were evaluated as (Δ) when the occurrence of “B” occurred, and as (X) when the travel failure was caused by the stick.

(6) Head Contamination and Abrasion After printing for 3000 m under the conditions of (2) above, the thermal head was removed, and the contamination and wear of the head was observed with a 100 × optical microscope. . If the contaminated area of the head portion was less than 30%, it was [O], and if it was 30% or more, it was [X], and if it was less than 30%, it could not be removed by wiping with ethyl alcohol. In addition, the state of occurrence of scratches on the thermal head was observed, and those without any scratches were marked with a circle, and those with scratches were marked with a cross.

(7) Inking and ink adhesion Other polyester films are superposed so as to be in contact with the laminated film surface of the biaxially oriented polyester film provided with the laminated film, and a load of 5 kg / 100 cm ² is applied at 70 ° C. Leave for 24 hours. Next, the two films were peeled off, and the ink of the above (2) was applied to the surface of the other polyester film which was in contact with the laminated film surface, and the degree of cissing was observed. The ink is applied by the hot melt method, and the applied thickness is 3-4 μm.
And The one with no repellency was marked with “◯”, and the one with slight repellency was marked with “×”. The ink layer is 20 g /
The case where the peeled area when peeled off with a tape having an adhesiveness of cm ² was less than 20% was designated as [◯], and the case where it was 20% or more was designated as [x]. (8) Ink blocking property The ink layer surface of the heat-sensitive transfer material prepared in (2) above and the surface of the laminated film (heat-resistant protective layer) are brought into contact with each other and superposed on each other at 5 Kg /
The sample was stored under a condition of 50 ° C. and 85% RH under a load of 100 cm ² for 24 hours. After taking out, the load is released and T
The transfer area of the ink layer to the laminated film side when the character peeled is 10
% Or less was considered good.

(9) Wrinkle generation state of heat-sensitive transfer material after printing In the evaluation of (5) above, the wrinkle generation state of the heat-sensitive transfer material after printing was visually observed and judged according to the following criteria.

⊚: No wrinkle generation ○: Fine wrinkles but no effect on the printed image △: Large wrinkles and print effect x: Wrinkles markedly unusable

[0036]

EXAMPLES Next, the present invention will be explained based on examples, but the invention is not necessarily limited thereto.

Example 1 0.15% by weight of precipitated particles having a particle size of 0.5 to 1.5 μm (particles precipitated during the polymerization step), and an average particle size of 1.5
PE containing 0.2% by weight of calcium carbonate particles of μm
T pellets (intrinsic viscosity 0.63 dl / g) were sufficiently vacuum-dried, then fed to an extruder and melted at 280 ° C.
After filtering with a 0 μm cut metal sintered filter, it was extruded into a film from a T-shaped die, and the surface temperature was 30 ° C.
It was wound around the cooling drum of and cooled and solidified. In the meantime, in order to improve the adhesion between the film and the surface of the cooling drum, a wire electrode was arranged on the film side and a DC voltage of 6 KV was applied. The unstretched PET film thus obtained was
The film was heated to 5 ° C. and stretched 3.5 times in the longitudinal direction to obtain a uniaxially stretched film. One side of this film was subjected to a corona discharge treatment in air, and the treated surface had a coating thickness of 0.05 μm after biaxially stretching a water-dispersed coating composition having the following composition by a gravure coat method.
It was applied so that it would be m.

“Coating Composition” (a) Oxide wax aqueous dispersion 40% by weight (solid content ratio) (b) Zinc stearate (melting point 128 ° C.) aqueous dispersion 60% by weight (solid content ratio) The coating liquid has a total solid content of 1.0% by weight.
It was prepared by diluting with water so that

The coated uniaxially stretched film was gripped with a clip and introduced into a tenter, and after water was dried in a preheating step at 110 ° C., it was stretched 4.5 times in the width direction while heating at 120 ° C., Subsequently, heat treatment was performed at 225 ° C. for 5 seconds to obtain a laminated polyester film having a laminated thickness of 0.05 μm and a film thickness of 5 μm. A heat-sensitive transfer material was prepared from this laminated polyester film according to the above-mentioned evaluation method and evaluated.
The results are shown in Tables 1 and 2.

Examples 2 to 5 and Comparative Examples 1 to 2 A laminated polyester film was prepared in the same manner as in Example 1 except that the mixing ratio of the coating compositions (a) and (b) in Example 1 was changed as shown in Table 1. And a thermal transfer material was prepared. The results are shown in Tables 1 and 2.

Comparative Example 3 The coating composition (b) of Example 1 was mixed with stearic acid (melting point 56.
A laminated polyester film was prepared in the same manner as in Example 1 except that the temperature was changed to 0 ° C.). A thermal transfer material using this laminated polyester film was prepared and evaluated. The results are shown in Tables 1 and 2.

Examples 6 to 7 and Comparative Example 4 A laminated polyester film and a heat-sensitive transfer material were prepared in the same manner as in Example 1 except that the component (b) of the coating composition of Example 1 was changed as shown in Table 1. evaluated. The results are shown in Tables 1 and 2.

Example 8 The same as Example 1 except that 20 parts by weight of polyethylene glycol oil was added to 100 parts by weight of the solid content of the coating composition of Example 1 to make a 3% by weight aqueous coating agent. To produce a laminated polyester film. The results are shown in Tables 1 and 2.

Example 9 The PET pellets of Example 1 were mixed with PEN (intrinsic viscosity 0.61).
dl / g) A laminated polyester film was prepared in the same manner as in Example 1 except that the pellets were used. The results are shown in Tables 1 and 2.

[0045]

[Table 1]

[Table 2]

[0046]

EFFECT OF THE INVENTION The present invention provides a polyester film having a wax composition and a laminated film mainly composed of a higher fatty acid metal salt having a melting point of 105 ° C. or more as a main constituent, so that it is resistant to heat when used as a thermal transfer material. The sticking property is excellent, and there is no repelling at the time of inking or blocking with the ink layer, and head contamination and head wear are small.

Claims (5)

[Claims] 1. A laminated polyester film having a wax-based composition and a laminated film mainly composed of a higher fatty acid metal salt having a melting point of 105 ° C. or more on at least one surface of the polyester film. 2. A laminated film having fluidity or paste at room temperature.
The laminated polyester film according to claim 1, further comprising an oily substance having a strike shape. 3. The laminated polyester film according to claim 1, wherein the content of the higher fatty acid metal salt in the laminated film is 15 to 90% by weight. 4. The laminated film forms a surface having 20 or more / 100 μm ² or more elongated protrusions having a lengthwise / shortwise direction ratio of 3 or more. The laminated polyester film described. 5. The laminated polyester film according to claim 1, wherein the polyester film is a film containing polyethylene terephthalate or polyethylene naphthalate as a main constituent.