JP3094544B2 - Laminated polyester film - Google Patents

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, with the development of office automation, various recording systems have been developed. Among them, a heat-sensitive recording system, which has low noise during printing and is easy to operate, attracts attention. Have been. In the thermal recording system, a thermal recording device such as a thermal printer is used to bring the recording paper into contact with a thermal ink layer of a thermal transfer material, and a film is selectively heated 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 this thermal transfer material, a thin-leaf plastic film is generally used in order to increase thermal efficiency.

However, in general, when a plastic film is used as a substrate film of a thermal transfer material, a phenomenon occurs in which the film is partially fused to the thermal head due to the amount of heat given by the thermal head. This phenomenon is called a stick phenomenon, and when this phenomenon occurs, not only does the thermal transfer material not run smoothly, but also there is a problem that the thermal head is significantly contaminated and print clarity is impaired.
In order to avoid this stick phenomenon, it has been proposed to perform various surface treatments on the surface of the plastic film which comes into contact with the thermal head. For example, a device provided with a heat-resistant protective layer such as silicone, melamine, phenol, epoxy, or polyimide (Japanese Patent Application Laid-Open No. 55-7467), a stick prevention comprising an inorganic pigment having high lubricity and a resin having high heat resistance. In some cases, a layer is provided (Japanese Patent Application Laid-Open No. 56-155794).
No.). Further, those provided with a layer comprising a water-soluble or water-dispersible silicone and a resin (JP-A-60-19262)
No. 8), a layer provided with a water-dispersible fluororesin and an aqueous polymer (Japanese Patent Laid-Open No. 60-192630), coating or transferring a wax and / or a liquid or paste-like substance at room temperature. (Japanese Patent Laid-Open No. 59-1)
48697 and JP-A-60-56583).

[0004]

However, those provided with a heat-resistant protective layer have insufficient slippage with the head, so that a low-pulse-width printer or a platen-drive-type printer has poor running properties of the thermal transfer ribbon and print unevenness. There is a drawback that running stops in extreme cases. In addition, a pigment containing an inorganic pigment has a problem in that the life of the head is shortened due to friction with the thermal head and the surface is roughened, so that thermal conductivity is poor and clear printing cannot be obtained. When a silicone resin or a fluororesin is laminated, these resins are easily transferred to the surface to which ink is applied after winding on a roll, which causes problems such as repelling during ink application and poor ink adhesion. Had occurred. A laminated film obtained by applying a wax or the like to a plastic film and drying it is excellent in lubricating action with a thermal head, but poor in slip with a fixed shaft of a printer and the like, resulting in sticking as a result. Had. In particular, in recent years, thermal transfer printers have tended to have higher printing speeds, and the development of thermal transfer materials capable of responding to this trend has been desired.

It is an object of the present invention to overcome the disadvantages described above, ie, without sticks, from low pulse width areas such as word processors, facsimile, bar code printers to video printers. Thermal transfer excellent in runnability over a wide range up to the high pulse width area, with very little head wear and head contamination, no repelling during ink application, excellent ink adhesion, and excellent print clarity An object of the present invention is to provide a laminated polyester film suitable as a base film for materials.

[0006]

The present invention is a laminated film having a layer containing a wax-based composition as a main component on at least one surface of a plastic film, wherein the layer contains 0.1 to 20% by weight. Of the silicon component, and the surface has elongated projections having a length / width ratio of 3 or more.
The main feature is a laminated polyester film characterized by having a number of pieces / 100 μm ² or more.

The term "polyester film" as used in the present invention is a general term for a polymer film having an ester bond as a main linking chain of its main chain. Particularly preferred as a base film for a thermal transfer material is polyethylene terephthalate, Films such as polyethylene 2,6-naphthalate, polyethylene α, β-bis (2-chlorophenoxy) ethane 4,4, -dicarboxylate, polybutylene terephthalate, and the like. In consideration of the above, polyethylene terephthalate film is most preferable. Therefore, hereinafter, description will be made with polyethylene terephthalate film (hereinafter, polyethylene terephthalate film is abbreviated as PET film) as a typical example of polyester film. 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. A part of the acid component and the glycol component may be replaced with a third component as described below.

-Acid component- Isophthalic acid, 2,6-naphthalenedicarboxylic acid, 1,
5-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 4,4, -diphenyldicarboxylic acid, 4,
4, -diphenylsulfonedicarboxylic acid, 4,4, -diphenyletheredicarboxylic 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 and the like.

-Glycol component- propylene glycol, butylene glycol, hexamethylene glycol, decamethylene glycol, neopentylene glycol, 1,1-cyclohexanedimethanol
1,4-so-hexanehexanemethanol, 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.

In addition, known additives in the PET, such as heat stabilizers, oxidation stabilizers, weather stabilizers, ultraviolet absorbers, organic lubricants, pigments, dyes, organic or inorganic fine particles, fillers , An antistatic agent, a nucleating agent, and the like.
Particularly, inorganic and / or organic fine particles are added, and the average surface roughness of the PET film after biaxial orientation is 0.03.
When the thickness is from 0.4 to 0.4 μm, preferably from 0.05 to 0.2 μm, the running property of the present invention can be further improved.
The intrinsic viscosity (measured in orthochlorophenol at 25 ° C.) of the above PET is 0.40 to 1.20 dl / g, preferably 0.50 to 0.80 dl / g, and more preferably 0.1 to 0.80 dl / g.
Those in the range of 5 to 0.75 dl / g are suitable for the content of the present invention.

The PET film is preferably biaxially oriented in view of mechanical strength and dimensional stability. Biaxially oriented PE
A T-film (hereinafter abbreviated as PET-BO) is a non-stretched PET sheet that is stretched about 2.5 to 5.0 times in so-called biaxial directions in the longitudinal direction and the width direction, respectively, and further heat-fixed. It is made by completing crystal orientation, and shows biaxial orientation pattern in wide angle X-ray diffraction. PET
-The thickness of the BO is not particularly limited, but when the laminated polyester film of the present invention is used as a base film for a thermal transfer material, the thickness is 0.5 μm to 30 μm, preferably 1 μm.
It is preferably from m to 10 μm in view of heat transferability and mechanical strength.

When a stretched polyester resin having a glass transition point higher than that of PET is laminated on at least one side of the PET film, wrinkling of the film due to printing energy is less likely to occur. Excellent and particularly preferred. This lamination is preferably provided on the side where the thermal head contacts. A typical polyester having a higher glass transition point than PET is polyethylene 2,6-naphthalate.

According to the present invention, there is provided a laminated film having a layer containing a wax-based composition as a main component on at least one side of the polyester film, wherein the layer contains 0.1 to 2 layers.
20 elongated protrusions containing 0% by weight of a silicon component and having a length / width ratio of 3 or more on the surface / 100
The main component herein is that having a thickness of not less than 5 μm ² , and the weight ratio of the main component in the laminated composition is 5%.
0% or more, preferably 60% or more.

As the wax compound, various commercially available waxes, for example, petroleum wax, vegetable wax, mineral wax, animal wax, low molecular weight polyolefins, etc. can be used and are not particularly limited. However, in the present invention, the use of petroleum wax or vegetable wax is preferred from the viewpoint of stick resistance. Examples of the petroleum wax include paraffin wax, microcrystalline wax, and oxidized wax. Among them, the use of oxidized wax is particularly preferable from the viewpoint of forming protrusions. Examples of the vegetable wax include candelilla wax, carnauba wax, wood wax, ocicle wax, sugarcane wax, and rosin-modified wax. 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 carbon atom)
8) It is preferable to use an ester adduct of poly (repeating unit: 1 to 6) alcohol from the viewpoint of lubricity and releasability, and it is more preferable to use a mixture with the oxidized wax. That is, the present invention is characterized in that fine elongated projections are formed by stretching in one direction after the application of the composition, and from the viewpoint of projection formation, explosion-proof properties, and environmental pollution prevention. A wax dissolved, emulsified or suspended in water is particularly preferred. Such an aqueous dispersion of the wax composition can be obtained by a conventionally known method (for example, JP-A-59-90625). The mixing weight ratio of petroleum wax / vegetable wax is 10/90 to 90/10, preferably 20/80 to 80.
/ 20, more preferably 30/70 to 70/30. The use of the vegetable wax in an amount of 10% by weight or more is intended to impart easy lubricity at high temperatures and release properties, and to obtain a uniform coating film having good uniform dispersibility when emulsified or suspended in water. It is preferred. The reason why the content of the petroleum wax is set to 10% by weight or more is that the lubricity due to the formation of the projections of the coating film is good and the running property at the time of high-speed printing is good.

Further, in the present invention, when a mixture of the wax-based composition and an oily substance is further added, the printing traveling property in a high pulse width region can be particularly excellent. Here, the oily substance is a liquid or paste-like oil at normal temperature, and examples thereof include vegetable oils, fats and oils, mineral oils, and synthetic lubricating oils. Vegetable oils include linseed oil, kaya oil, safra oil, soybean oil, cinnamon oil, sesame oil, corn oil, rapeseed oil, nuka oil, cottonseed oil, olive oil, sasanqua oil, tsubaki oil, castor oil, peanut oil,
Balm oil, coconut oil and the like can be mentioned. 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 polymerized oil, diester oil, and polyalkylene glycol oil. Among these, mineral oils and synthetic lubricating oils having good running properties in a high pulse width region are preferable. Further, a mixed system of these may be used. The oily substance is used in an amount of 1 to 1 based on 100 parts by weight of the wax composition.
It is preferable to add 00 parts by weight, preferably 3 to 50 parts by weight. When the amount of the oily substance is less than 1 part by weight, the running property in a high pulse width region such as a sublimation type printer tends to decrease. Drivability tends to decrease. In the case where the above range is set, sticking does not occur in a printer having a wide pulse width, so that the running property is good, which is particularly preferable.

Various additives can be used in the above composition within a range not to impair the effects of the present invention. For example, antistatic agents, heat-resistant agents, antioxidants, organic and inorganic particles, pigments and the like can be mentioned. Further, various additives such as a dispersing 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 applicability.

Further, the present invention is characterized in that the laminate containing the above-mentioned substance as a main component contains 0.1 to 20% by weight of a silicone component, and the addition of the component makes the laminated surface of the laminate face. The slipperiness is remarkably improved, which is an extremely effective means for high-speed printing and the like. As the silicone to be added, those having dimethylpolysiloxane as a basic skeleton and various modified products thereof can be used.
Is a microemulsion in which water is dispersed in water to an average particle diameter of 0.1 μm or less. As such a microemulsion, silicone BY22-839, BY22-830, manufactured by Toray Dow Corning Silicone Co., Ltd. BY-
22-835 and BY22-840. Among these, a dimethyl silicone microemulsion is particularly preferred in terms of lubricity and inking properties. The amount of silicone added is in the range of 0.1 to 20% by weight, preferably 0.5 to 10% by weight, more preferably 1 to 7% by weight in the laminate.
It is desirable that When the amount is less than 0.1% by weight, the running property of the high-speed printer is insufficient. When the amount exceeds 20% by weight, the laminated film is wound around a roll and the back of the silicone film is stored during storage. It is not preferable because inking failure due to the migration occurs.

According to the present invention, there is provided a mixed laminated composition formed from a microemulsion finely dispersed to 0.1 μm or less, and a silicone composition, particularly a mixed composition of the above wax composition and an oily substance, In addition, they have found an extremely excellent effect due to the synergistic effect of forming the following special projections on the surface.

The center line average surface roughness (Ra1) of the surface on which the laminated film is provided is 0.03 to 0.4 μm, preferably 0.05 to 0.4 μm.
０．２0.2 μm, and the thickness of the laminated film is 0.1 μm.
It is desirably from 005 μm to Ra 1, preferably from 0.01 μm to Ra 1. When Ra1 of the coating film is less than 0.03 μm or when the thickness of the coating film is 0.005 μm
When the thickness is less than m, sticking tends to occur, and when the thickness of the coating film exceeds Ra1, runnability during printing and head contamination tend to occur easily. When Ra1 exceeds 0.4 μm, the stickiness is good, but the clarity of printing tends to be poor.

Further, the present inventors formed the special projections described below on the surface of the layer to be laminated, thereby achieving extremely excellent stick resistance, running properties and releasability, ink applicability, It was found that the layer had excellent adhesion. That is, the present invention is characterized in that the surface of the laminated film made of the above-mentioned composition has 20/100 μm ² or more elongated projections having a ratio of 3 or more in the length direction / width direction or more. By the formation, the sliding with the fixed shaft of the printer at the time of running becomes smooth, the frictional resistance at the time of driving the platen roll is reduced, and the running can be performed smoothly. Also, since the projections are formed mainly of a wax-based composition, they are in a molten state when heated by a thermal head, so unlike projections made of inorganic particles, unlike the projections made of inorganic particles, they do not intervene in air with poor heat conduction, so that extremely clear printing is obtained. It is done. Further, the laminated film formed from the above composition is particularly preferable from the viewpoint of preventing abrasion of the thermal head and the like. Even when the same composition as in the present invention was used, if the projections were not formed, sticking occurred and the running property of the film was significantly impaired. The projection shape is preferably an elongated projection, and the ratio in the length direction / width direction is 3 or more, preferably 4 or more, and more preferably 5 or more. If the projection shape is less than 3, the slip may not be smooth but may partially stick. Although the height of the projection is not particularly limited, it is desirably 0.005 μm to 1 μm, preferably 0.01 μm to 0.5 μm.
If the protrusion height is too high, the print definition in a low pulse width region tends to decrease. The length of the projection is not particularly limited, but is usually preferably about 0.1 μm to 2 μm. The number of elongated projections is 20/100 μm ² or more, preferably 40/100 μm ^{2, and} more preferably 60/100 μm ² .
It is necessary that the thickness be at least μm ² . When the number of the elongated projections is less than 20/100 μm ² , the smoothness at room temperature is poor, and the smooth running property in a printer cannot be obtained. The elongated projections may be arranged in one direction, but are preferably randomly arranged or crossed from the viewpoint of runnability.

The laminated polyester film having such elongated projections is extremely excellent in surface smoothness, and has good running properties in both high-speed printing and low-speed high-pulse printing. Index is 25 ° C 65%
When the RH is 0.15 or less, preferably 0.1 or less, the running property of a high-speed printing type printer is particularly good.
Such lubricity can be changed by the thickness of the laminate and the number of protrusions. That is, if the lamination thickness is too thin or the projections are insufficiently formed, and if the thickness is too large, the lubricity tends to be insufficient. In order to form more preferable projections, it is desirable that the lamination thickness is 0.01 to 0.1 μm.

In order to obtain a laminated film as described above, it is not possible to obtain a laminated film coated on a biaxially stretched polyester film after crystal orientation, but it is applied on a polyester film before crystal orientation and dried or dried. It can be obtained only by a method of performing orientation and heat treatment to complete oriented crystallization. That is, the polyester film before the completion of the crystal orientation is stretched 2.5 to 5.0 times in the longitudinal direction, and thereafter, the surface to be coated is subjected to corona discharge treatment, and various coating apparatuses such as a roll coater and a gravure are applied. While applying and drying using a coater, a reverse coater, a kiss coater, a bar coater, or the like, or after drying, 2.5 to 5 in a direction perpendicular to the longitudinal direction. The film is stretched 0 times, and heat-treated at 140 to 240 ° C as necessary. A laminated film having elongated projections can be obtained by the above method, but in order to form elongated projections arranged at random, a state in which some water remains before stretching, or stretching while humidifying, and during heat treatment It is important to provide some widthwise relaxation.

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 typical example.

The PET containing so-called precipitated particles and inorganic particles (for example, silica having an average particle diameter of 1 μm) precipitated in the polymerization step is dried by a conventional method, melt-extruded, and the extruded sheet-like melt is solidified by cooling. At least make an unstretched PET film. This film is heated to 80 to 120 ° C. and stretched 2.0 to 5.0 times in the longitudinal direction to obtain a uniaxially oriented film. One surface of the film is subjected to corona discharge treatment in an air atmosphere, and a water-dispersed coating liquid containing a wax composition and a silicone component diluted to a predetermined concentration is applied to the treated surface. Then, apply this coated film to 9
The film is stretched 3 to 5 times in the width direction while being heated to 0 to 140 ° C, and then guided into a heat treatment zone at 140 to 240 ° C.
Heat treatment is performed for 10 seconds. During this heat treatment, a relaxation treatment of 3 to 12% may be performed in the width direction as necessary. The film thus obtained is slit into an appropriate width to obtain a biaxially oriented laminated polyester film for a thermal transfer material. When this film is used as a heat-sensitive transfer material, it can be obtained by applying a hot-melt type or heat-sublimation type ink on the non-coated side and slitting it to a desired width. The biaxially stretched laminated polyester film for thermal transfer material thus obtained is provided with an ink layer according to the application,
Various thermal transfer materials, such as word processors, facsimile machines, printers for personal computers, printers for video, printers for bar code, typewriters, presses
It is used for printing out characters or images such as paper-copiers and is particularly suitable for high-speed printers.

[0025]

[Method for measuring characteristics and method for evaluating effects] The method for measuring characteristics and the method for evaluating effects in the present invention are as follows.

(1) Formability of Laminated Surface Protrusions 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 contrast of the photograph, and the length (length) and width of the elongated protrusion are determined. (Short direction) The number of the elongated projections was obtained by taking the number per unit area from a photograph and converting it into (pieces / 100 μm ² ).

(2) Center line average surface roughness (Ra1) Measured in accordance with JIS-B0601-1976. The cutoff value was 0.25 mm.

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

(4) Dynamic friction index HEIDON-14DR-ANL device (Shinto Kagaku Co., Ltd.)
10 mm in an atmosphere of 25 ° C. and 65% RH
Was measured at a point contact with a stainless steel ball. The measurement was performed at a load of 200 g and a running speed of 200 mm / min, and the average value of the frictional resistance from 1 second after the start of the measurement to the end of the measurement was measured from a chart (data recorded every 2.0 msec) measured for 4 seconds. And

(5) Hot Stick Property-1 The following hot melt ink was applied to the laminated biaxially oriented polyester film on the opposite side of the laminated surface by 3-4 μm by a hot melt method.
m to form a thermal 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 Evaluation of thermal transfer printer BC- made by Autonics 8MK
Using a thermal head with a head resistance of 500Ω, the applied voltage was changed and the printing was performed with a pulse width of 0.5 msec.
An applied voltage of 8 V or more was regarded as good stick resistance. Also 8
A stick that occurred even when the voltage was less than V was marked as [x]. Note that plain paper was used as the transfer paper.

(6) Hot Stick Property-2 A sublimation ink having the following composition was applied to the surface opposite to the lamination surface, dried, and slit to an appropriate width to prepare a heat-sensitive transfer material. [Sublimation ink composition] Disperse dye KST-B-136 (manufactured by Nippon Kayaku Co., Ltd.): 4 parts by weight Ethyl hydroxyethyl cellulose: 6 parts by weight Methyl ethyl ketone: 45 parts by weight Toluene: 45 parts by weight The vehicle was run under a normal use condition through a sublimation type printer (SharpColor Video Printer-GZ-P11W), and judged as follows (O) or better when judged as follows. A: No sticking at all, and extremely good running performance. ：: Normal printing can be performed without any problem in running performance, but a slight stick sound is generated in a solid printing portion. Δ: readable level. X: The level at which the stick is extremely illegible.

(7) Hot Stick Property-3 Using the thermal transfer material prepared in the above (5), using a high-speed thermal transfer printer (KM705A manufactured by Anritsu Corporation)
Observe the state of stick generation when printing at a speed of 20 mm / sec. If the stick is not generated and normal printing is possible (（), the stick sounds while running, but the print is discolored or misaligned. Was evaluated as (x), and the one with poor running caused by the stick was evaluated as (x).

(8) Head Stainability and Abrasion After printing for 3000 m under the conditions of (5) above, the thermal head was removed, and the contamination and wear of the head were observed with a 100-fold optical microscope. . When the contaminated area of the head portion was less than 30%, it was evaluated as [O]. When it was less than 30%, it was evaluated as [X]. The occurrence of scratches on the thermal head was observed, and those with no scratches were marked with [○], and those with scratches were marked with [x].

(9) Inking Property, Ink Adhesion Property Another polyester film is superposed on the biaxially oriented polyester film provided with the laminated film so as to be in contact with the laminated film surface, and a load of 50 kg / cm ² is applied at 70 ° C. Leave for 24 hours. Next, the two films were peeled off and the ink of the above (5) was applied to the surface where the other polyester film was in contact with the surface of the laminated film, and the degree of cissing was observed. The ink is applied by the hot melt method, and the coating thickness is 3 to 4 μm.
And Those without repelling were marked with [○], and those with slight repelling were marked with [x]. In addition, the ink layer is 20 g /
The case where the peeling area when peeled with a tape having an adhesiveness of cm ² was less than 20% was evaluated as [［], and the case where the peeled area was 20% or more was evaluated as [x].

[0035]

Next, the present invention will be described with reference to examples, but is not necessarily limited thereto.

Example 1 0.15% by weight of precipitated particles having a particle diameter of 0.5 to 1.5 μm (particles precipitated during the polymerization step) and an average particle diameter of 1.5
PE containing 0.2% by weight of μm calcium carbonate particles
T pellets (intrinsic viscosity: 0.63 dl / g) were sufficiently dried by heating under vacuum, then supplied to an extruder and melted at 280 ° C.
After filtering through a 0 μm-cut metal sintered filter, the mixture was extruded from a T-shaped die into a film, and the surface temperature was 30 ° C.
And cooled and solidified. In order to improve the adhesion between the film and the surface of the cooling drum during this time, 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 at 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 corona discharge treatment in air, and the treated surface was coated with a water-dispersed paint having the following composition by a gravure coat method after biaxial stretching to a thickness of 0.05 μm.
m.

"Coating composition" (a) Aqueous dispersion of oxidized wax: 60 parts by weight (solid content ratio) (b) Aqueous dispersion of vegetable wax ｛hydrogenated rosin / αβ-substituted ethylene (α-substituent: carboxyl, β-substitution) Group: methyl) adduct {. Alkyl (carbon number: 6) poly (repeating unit: 5) alcohol ester adduct: 40 parts by weight (solid content ratio) (c) dimethyl silicone microemulsion ( Silicone B manufactured by Toray Dow Corning Silicone Co., Ltd.
Y22-835): 5 parts by weight (solid content ratio) The coating solution mixed in the above ratio has a total solid content weight ratio of 1.0%.
It was prepared by diluting with water so that

The coated uniaxially stretched film is gripped with a clip and guided into a tenter. After drying the water in a preheating step at 110 ° C., the film is stretched 4.5 times in the width direction while heating at 120 ° C. Subsequently, a heat treatment was performed at 225 ° C. for 5 seconds to obtain a laminated polyester film having a laminated thickness of 0.05 μm, a laminated surface roughness of 0.08 μm, and a film thickness of 5 μm. On the laminated surface of this film, 52 elongated projections / 100 μm 2 having a ratio of the length direction / width direction of 3 or more were formed.
Table 1 shows the results of evaluating this laminated polyester film as a thermal transfer material. This laminated polyester film had no repelling during inking and had good adhesion. In addition, in the print running test,
No sticking occurred at all, and the result was extremely good, and there was no contamination or wear of the head.

Examples 2 to 5 and Comparative Examples 1 to 3 Thermal transfer materials were prepared in the same manner as in Example 1 except that the amount of silicon added was changed.

When no silicone was added and the amount of addition was less than the range of the present invention, the running property of a high-speed printer was insufficient. A problem arose.

[0041]

[Table 1]

Comparative Examples 4 to 6 In the coating composition of Example 1, component (a), component (b),
(C) A water-dispersed coating material was prepared for each component alone, and a thermal transfer material was prepared in the same manner as in Example 1. All of these were insufficient in running property with a high-speed printer. In particular, when only the component (c) was used, the running performance was poor even in a device other than a high-speed printer, and repelling due to inking was remarkable.

Comparative Example 7 One side of a biaxially oriented polyester film having a thickness of 5 μm and a center line average roughness of 0.08 μm was subjected to a corona discharge treatment, and the treated surface was coated with the coating material of Example 1 after drying. .0
It was applied to a thickness of 5 μm and dried at 120 ° C. for 2 minutes to prepare a laminated polyester film. In the same manner as in Example 1, a heat-sensitive transfer material was prepared. On this laminated surface, there was no projection formed in the present invention, and the running property was insufficient in all printers.

Example 6 A heat-sensitive transfer material was prepared in the same manner as in Example 1, except that an aqueous dispersion of mineral oil as an oily substance was added in an amount of 10 parts by weight in terms of solid content. This was excellent in the running property for all printers, and in particular, the running property was good in a sublimation type printer having a high pulse width.

[0045]

[Table 2]

[0046]

According to the present invention, in a laminated film comprising a layer mainly composed of a wax-based composition laminated on at least one side of a polyester film, the layer contains 0.1 to 20% by weight of a silicone component. By forming elongated projections on the surface of the laminate, it was possible to achieve extremely excellent running properties when used as a thermal transfer material. In particular, the coexistence of a silicon component in a specific ratio in the laminated film on which the protrusions are formed can provide a heat-sensitive transfer material having no inking problem and no stick problem even for a high-speed printer.

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B32B 27/36 B41M 5/40 C08J 7/04

Claims (6)

(57) [Claims] 1. A laminated film having a layer mainly composed of a wax-based composition on at least one surface of a polyester film, wherein said layer contains 0.1 to 20% by weight of a silicone component. A laminated polyester film having, on its surface, 20/100 μm ² or more elongated projections having a length / width ratio of 3 or more. 2. The layer according to claim 1, wherein the layer mainly composed of the wax composition is a layer mainly composed of petroleum wax and vegetable wax dissolved, emulsified or suspended in water. Laminated polyester film. 3. The layer mainly composed of the wax composition further contains an oily substance which is dissolved, emulsified or suspended in water, and the weight ratio of the wax composition to the oily substance is 100/1. The laminated polyester film according to claim 1 or 2, wherein the ratio is up to 1/1. 4. The silicone component has an average particle size of 0.1 μm.
The laminated polyester film according to any one of claims 1 to 3, comprising the following microemulsion. 5. A method in which a layer containing a wax-based composition as a main component is applied to the surface of the polyester film before the crystal orientation is completed, followed by drying, stretching and heat treatment to complete the orientation crystallization. The laminated polyester film according to any one of claims 1 to 4, wherein 6. The laminated polyester film according to claim 1, wherein the value of the dynamic friction index between the laminated surface and the stainless steel balls at 25 ° C. and 65% Rh is 0.15 or less.