JP2001180129A - Sublimation type thermal transfer ribbon and base film therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a base film for a sublimation type thermal transfer ribbon which causes no blur of ink even in high-speed printing, nor wrinkles in the ribbon due to rubbing with a head, but has an excellent printing performance and which causes no blocking on the occasion of manufacturing the sublimation type thermal transfer ribbon. SOLUTION: The base film for the sublimation type thermal transfer ribbon is constituted of a biaxially oriented polyester film of which the main constituent is polyethylene-2,6-naphthalene dicarboxylate. The projection density of projections of a height 1.0 μm or above on the film surface of the biaxially oriented polyester film is 400-2000 pcs./mm2, while that of projections of a height 1.2 μm or above is 100-1000 pcs./mm2. On a temperature-dimensional change curve under a load in the longitudinal direction of the film, besides, a dimensional change to the original length of the film at temperatures to 200 deg.C is less than 1.0%, and the dimensional change to the original length of the film at temperatures up to 230 deg.C is less than 3.0%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a sublimation type thermal transfer ribbon and a base film thereof. More specifically, used for a transfer material for a sublimation type thermal transfer printer,
The present invention relates to a sublimation-type thermal transfer ribbon excellent in printing performance in which the ink is not faded even when printing at high speed and the ribbon does not wrinkle due to rubbing with a head, and a base film thereof.

[0002]

2. Description of the Related Art As a base film of a ribbon for a thermal transfer printer, a film having a specified surface roughness is known (see Japanese Patent Application Laid-Open No. 62-299389). Among the thermal transfer recording methods, the sublimation type thermal transfer recording method has greatly expanded as a recording method capable of easily outputting a high-quality full-color image. Sublimation-type thermal transfer recording system is a sublimation-type thermal transfer ribbon having a structure in which a sublimation-type thermal transfer ink layer composed of a composition in which a thermal sublimation dye is dispersed in a binder is laminated on a base film, By heating with a thermal head from the opposite side of the sublimation type thermal transfer ribbon,
In this method, only the dye in the sublimation-type thermal transfer ink layer is sublimated, and is transferred and absorbed to the image receiving layer of the receiving paper to form a gradation image.

In recent years, as the printing speed has been required to be increased, the temperature of the thermal head at the time of printing has been increased. As a result, the amount of heat received by the sublimation type thermal transfer ribbon has been increased. For this reason, the deformation of the film used for the base material of the ribbon becomes large, and the printing becomes unclear at the time of printing, or wrinkles are generated on the ribbon, and in an extreme case, printing becomes impossible at all. Problems have arisen and this improvement has been required. As a remedy, a heat-resistant layer is formed on the surface of the base film opposite to the surface on which the ink is applied. That is, in the process of manufacturing a sublimation-type thermal transfer ribbon, first, a heat-resistant layer is laminated on a base film wound into a roll, and once wound into a roll. It is coated, slit to a predetermined width, and wound up to produce a sublimation type thermal transfer ribbon. However, in the process of applying the sublimation-type thermal transfer ink layer, there is a problem in that when the film is pulled out from the heat-treated film roll, there is a problem that blocking occurs, and improvement is required.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a base for a sublimation type thermal transfer ribbon which is excellent in printing performance in which the ink is not blurred even when printing at high speed and wrinkles are not generated in the ribbon by rubbing with the head. It is to provide a film. Another object of the present invention is to provide a base film for a sublimation type thermal transfer ribbon which does not cause blocking when producing a sublimation type thermal transfer ribbon.

[0005]

According to the present invention, there is provided a biaxially oriented polyester film comprising polyethylene-2,6-naphthalenedicarboxylate as a main component. The projection density of the projections having a film surface height of 1.0 μm or more is 40
The projection density of the protrusions having a height of not less than 0 / mm ^{2 and not} more than 2000 / mm ² and a height of not less than 1.2 μm is not less than 100 / mm ^{2 and not} more than 1000 / mm ² , and under a vertical load of the film. In the temperature dimensional change curve at
1.0% dimensional change to original length of film up to 0 ° C
The sublimation type thermal transfer ribbon base film is characterized in that the dimensional change with respect to the original length of the film up to 230 ° C. is within 3.0%. Hereinafter, the present invention will be described in detail.

[Polyethylene-2,6-naphthalenedicarboxylate] The base film for a sublimation type thermal transfer ribbon of the present invention comprises polyethylene-2,6-naphthalenedicarboxylate as a main component. The polyethylene-2,6-naphthalenedicarboxylate may be a homopolymer having ethylene-2,6-naphthalenedicarboxylate as all repeating units, or at least 80 mol% of all repeating units may be ethylene-2,6.
-Copolymers which are naphthalenedicarboxylates are preferably used. When the amount of ethylene-2,6-naphthalenedicarboxylate is 80 mol% or more of the total repeating units, the dimensional change at high temperatures is small without extremely losing the original properties of polyethylene-2,6-naphthalenedicarboxylate. It becomes a film.

Suitable copolymerizable components include compounds having two ester-forming functional groups, such as oxalic acid, adipic acid, phthalic acid, sebacic acid, dodecanedicarboxylic acid,
Succinic acid, isophthalic acid, 5-sodium sulfoisophthalic acid, terephthalic acid, 2-potassium sulfoterephthalic acid, 2,7-naphthalenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 4,4'-diphenyldicarboxylic acid, phenylindane Dicarboxylic acids, diphenyl ether dicarboxylic acids and their lower alkyl esters;
Oxycarboxylic acids such as p-oxyethoxybenzoic acid and lower alkyl esters thereof; propylene glycol, 1,2-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol,
1,4-cyclohexanedimethanol, p-xylylene glycol, an ethylene oxide adduct of bisphenol A, triethylene glycol, polyethylene oxide glycol, polytetramethylene oxide glycol,
Neopentyl glycol and the like can be mentioned.

The polyethylene-2,6-naphthalenedicarboxylate is obtained by blocking a terminal hydroxyl group and / or a carboxyl group partially or entirely with a monofunctional compound such as benzoic acid or methoxypolyalkylene glycol. It may be modified with a very small amount of an ester-forming compound having three or more functional groups such as glycerin and pentaerythritol in a range where a substantially linear polymer can be obtained.

[Additives] The base film of the present invention may optionally contain additives such as stabilizers, dyes, lubricants, ultraviolet absorbers and flame retardants. In order to impart a favorable slip property to the film, it is preferable to contain a small amount of inert fine particles. Examples of the inert fine particles include inorganic fine particles such as spherical silica, porous silica, calcium carbonate, silica alumina, alumina, titanium dioxide, kaolin clay, barium sulfate, and zeolite, or organic fine particles such as silicon resin particles and cross-linked polystyrene particles. Can be given. The inorganic fine particles are preferably a synthetic product rather than a natural product because the particle size is uniform, and inorganic particles of any crystal form, hardness, specific gravity, and color can be used.

The average particle size of the above inert fine particles is 0.1 μm.
It is preferably in the range of not less than m and not more than 3.0 μm,
More preferably, it is in the range of 2 μm or more and 2.4 μm. Further, the average particle size of the inert fine particles is preferably smaller than the thickness of the film. If the average particle size of the inert fine particles is smaller than 0.1 μm, a sufficiently large surface roughness cannot be obtained. If the average particle size is larger than 3.0 μm, the film tends to be broken in the stretching step. The content of the inert fine particles is preferably from 0.05% by weight to 0.5% by weight, more preferably from 0.1% by weight to 0.45% by weight.

The inert fine particles to be added to the film may be a single component selected from those exemplified above, or a multi-component containing two or more components. The timing of adding the inert fine particles is not particularly limited as long as it is a stage until the polyethylene-2,6-naphthalenedicarboxylate polymer is formed. For example, the inert fine particles may be added at the polymerization stage. It may be added.

By adding the above-mentioned inert fine particles selected from the average particle size range and the content range, the center line average roughness (Ra) of the film surface is from 60 nm to 130 n.
m or less can be obtained. The center line average roughness (Ra) of the film surface is 60 nm
If it is smaller, sufficient slipperiness cannot be obtained, and it becomes difficult to wind up the film. Also, the center line average roughness (R
When a) is larger than 130 nm, when high-speed printing is performed by a sublimation-type thermal transfer printer, heat conduction is deteriorated, and printing is unclear.

[Film Thickness] The thickness of the base film of the present invention is preferably 0.5 to 5.0 μm. When the thickness exceeds 5 μm, it takes time for heat conduction, which is not suitable for high-speed printing. Conversely, if the thickness is less than 0.5 μm, the strength is low and the workability is poor.

[Temperature Dimensional Change Under Load] In the present invention, a temperature dimensional change curve under a vertical and horizontal load of a base film (hereinafter may be abbreviated as a TMA curve).
With, grip the longitudinal or horizontal ends of the film,
This is a curve in which the film is heated at a constant heating rate while applying a specific constant load, and the temperature is plotted on the horizontal axis, and the dimensional change rate with respect to the original length of the film is plotted on the vertical axis.

In the base film of the present invention, when a temperature dimensional change curve of the film under a longitudinal load is measured, the dimensional change with respect to the original length of the film up to 200 ° C. is within 1.0%; Preferably it is within 0.6% and the dimensional change to the original length of the film up to 230 ° C is within 3.0%, preferably within 1.0%.

If the dimensional change up to 230 ° C. is more than 3.0%, the dimensional stability of the film is deteriorated, resulting in image distortion. Furthermore, dimensional change is 3.0% in the shrinking direction
If it becomes larger, the shrinkage of the film due to the heat of the head during printing increases, the friction with the print head increases, and the film breaks. On the other hand, if it is greater than 3% in the elongation direction, the film will be wrinkled by the heat of the head during printing, so that high-speed printing cannot be performed.

The dimensional change up to 200 ° C. is 1.0%
It is as follows. If it is larger than this, the dimensional stability of the film at the time of low-energy printing deteriorates, causing image distortion, and further printing cannot be performed. Furthermore, the base film of the present invention has a temperature of 200 ° C. and 23 ° C. in the transverse direction.
The dimensional change up to 0 ° C is within 1.0% and 3.
It is preferably within 0%.

[Protrusion Density] The base film of the present invention comprises:
The protrusion density of protrusions having a film surface height of 1.0 μm or more is 4
00 pieces / mm ² or more protrusions density of 2000 cells / mm ² or less and the height 1.2μm or more projections are required to be 100 / mm ² or more 1000 / mm ² or less. The projection density of the projections having a height of 1.4 μm or more is preferably 300 / mm ² or less. Further, when a heat-resistant back coat layer is formed on one surface of the base film, the density of the protrusions having a height of 1.0 μm or more on the surface of the heat-resistant back coat layer is 100 / mm ² or more and 1500 / mm. ² or less and a height of 1.2 μm or more have a projection density of 40 /
It is desirable that the number be not less than mm ^{2 and not} more than 800 pieces / mm ² .
If the projection density of the projections on the base film surface is in the above range, even if the projection density is reduced by forming the heat-resistant backcoat layer, the heat-resistant backcoat layer and the heat-resistant backcoat layer are not applied. The contact area of the surface can be reduced, and blocking does not occur.

When the projection density of the projections having a height of 1.0 μm or more or the projection density of the projections having a height of 1.2 μm or more is lower than the lower limit, the formation of the heat-resistant back coat layer on the raw roll reduces the projection density. After heat treatment after winding,
It is not preferable because it blocks and cannot be peeled off. On the other hand, when the projection density of the projections having a height of 1.0 μm or more or the projection density of the projections having a height of 1.2 μm or more is higher than the upper limit, blocking does not occur. Spots are formed on the surface, and the print is unclear, which is not preferable. Furthermore, breakage occurs frequently during film formation and productivity is deteriorated, which is not preferable.

[Method for Producing Film] The base film of the present invention can be produced by biaxially stretching an unstretched film and heat setting, and more advantageously by performing a relaxation treatment after the heat fixing. be able to. For example, the unstretched film is biaxially stretched at a temperature of Tg to (Tg + 60) ° C. in the longitudinal direction and the transverse direction at a magnification of 3.0 to 6.0 times, and at a temperature of (Tg + 50) ° C. to (Tg + 140) ° C. Heat set for 100 seconds. In addition, Tg represents the glass transition temperature of polyethylene-2,6-naphthalenedicarboxylate. Stretching can be performed by a commonly used method, for example, a method using an IR heater, a method using a roll, or a method using a tenter. The film may be stretched simultaneously in the vertical and horizontal directions, or may be sequentially stretched in the vertical and horizontal directions. You may. In the case where the relaxation treatment is further performed, it is preferable to perform the relaxation treatment until the film is wound around a roll after heat setting. As the relaxation treatment method, a method of reducing the tenter width in the middle of the heat fixing zone and performing a relaxation treatment of 0 to 3% in the film width direction, separating both end portions of the film, and removing the film under a temperature condition of Tg or more and a melting temperature or less. A method of reducing the take-off speed with respect to the supply speed, a method of heating with an IR heater between two transport rolls having different speeds, transporting a film on the heated transport roll, and reducing a speed of the transport roll after the heated transport roll. Method, a method of lowering the take-up speed than the supply speed while transporting the film over the nozzle that blows out hot air after heat setting,
Alternatively, the film is wound on a film-forming machine, and then the film is conveyed onto a heated conveying roll to reduce the speed of the conveying roll, or the roll speed after the heating zone is heated while being conveyed in a heating oven or a heating zone by an IR heater. There is a method of lowering the roll speed before the zone, and any method may be used. It is preferable that the relaxation process is performed by setting the deceleration rate of the take-up side speed to the feed-side speed at 0.1 to 3%. Further, in order to make the thermal dimensional change within the range of the present invention, in addition to the relaxation treatment, the width of the tenter may be increased in the middle of the heat fixing zone, and a tension treatment of 0 to 3% may be performed in the film width direction. Such a treatment is not limited to these methods as long as the thermal dimensional change falls within the scope of the present invention.

[Heat-Resistant Backcoat Layer] In order to prevent sticking of the thermal head portion, the base film of the present invention has a silicone resin and a cross-linked silicone resin on one surface of the film, ie, the surface on which the sublimation-type thermal transfer ink layer is not provided. It is preferable to provide a heat-resistant back coat layer containing acrylate, methacrylate or a polyester copolymer thereof having a functional group obtained by crosslinking with isocyanate, epoxy, melamine, etc., a fluororesin, silicone oil, mineral oil or the like. Among these, a reaction product of an isocyanate and a thermoplastic resin having active hydrogen is preferred. As the active hydrogen-containing thermoplastic resin, for example, polyester resin, polyurethane resin, polyvinyl acetate resin, acrylamide resin, polyvinyl butyral resin,
A thermoplastic resin such as a polyvinyl acetal resin such as a polyvinyl acetoacetal resin is exemplified. Among these, a particularly preferred resin is a thermoplastic resin having active hydrogen as a hydroxyl group, and among them, a polyvinyl acetal resin such as a polyvinyl butyral resin and a polyvinyl acetoacetal resin is particularly preferred.

The heat-resistant back coat layer is preferably formed at the stage of an unstretched film or a longitudinally stretched film during the step of forming the base film. By forming the heat-resistant back coat layer at this stage, it is possible to reduce the heat history when processing into a sublimation type thermal transfer ribbon, and to easily maintain the temperature dimensional change characteristics of the base film within the range of the present invention. Become.

As the method of providing the heat-resistant back coat layer, known methods, for example, a hot melt coating, a solution coating method such as a gravure, reverse or slit die method with a solvent added can be used.

[Sublimation-Type Thermal Transfer Ink Layer] In the present invention, the sublimation-type thermal transfer ink layer is not particularly limited, and a known sublimation-type thermal transfer ink layer can be used. That is,
A binder component, a coloring component, and the like are used as main components, and a softener, a plasticizer, a dispersant, and the like are added in appropriate amounts as needed. Specific examples of the main component include, as binder components, known waxes such as carnauba wax and paraffin wax, celluloses, polyvinyl alcohols, polyvinyl alcohol partially acetalized products, polyamides, and various high-melting polymer materials. Sublimation dyes such as various disperse dyes and basic dyes are used as coloring components. As a method of providing the sublimation type thermal transfer ink layer on the base film, a known method, for example, hot melt coating, gravure with a solvent added, reverse, a solution coating method such as a slit die method and the like may be used. it can.

[Easy Adhesive Layer and Antistatic Layer] In order to strengthen the adhesion between the base film of the present invention and the above-mentioned sublimation type thermal transfer ink layer, the surface of the base film on which the sublimation type thermal transfer ink layer is provided. It is preferable to provide an easy-adhesion layer thereon. In addition, the sublimation type thermal transfer ribbon manufacturing process,
It is preferable to provide an antistatic layer in order to impart an antistatic property in a processing step or a final product. These layers can be formed by applying a coating solution. Further, by applying a coating solution containing an easy-adhesiveness imparting agent and an antistatic agent, it can be provided as one layer having easy-adhesiveness and antistatic properties.

The coating liquid for forming the easy-adhesion layer and the antistatic layer is used as an aqueous solution, an emulsion, or a water-dispersible liquid containing a binder resin. An organic solvent may be used instead of water. Examples of the binder resin include a polyester resin, an acrylic resin, an acrylic-modified polyester resin, a urethane resin, an epoxy resin, a melamine resin, an oxazoline resin, a vinyl resin, and a polyether resin. Such a binder resin also functions as an easy adhesion-imparting agent. Further, in the case of an aqueous coating liquid, a surfactant such as an anionic surfactant, a cationic surfactant, or a nonionic surfactant can be added and used as necessary. Examples of the antistatic agent include an anionic compound, a cationic compound and a conductive compound. Further, other additives such as an ultraviolet absorber, a pigment, an organic filler, an inorganic filler, a lubricant, a blocking inhibitor, a dispersant, and the like can be added to the coating liquid.

The above coating solution is applied to a polyethylene-2,6-naphthalenedicarboxylate film before crystal orientation is completed, for example, an unstretched film, a uniaxially stretched film, or a biaxially stretched film whose crystal orientation is not completed. Can be. Moreover, you may apply to a biaxially stretched film off-line after film formation. The method for measuring and evaluating the characteristic value specified in the present invention will be described below.

(1) Temperature dimension change curve TMA / SS12 manufactured by Seiko Instruments Inc.
Measure using 0C. However, the sample is 15 mm long,
Using a quartz holder, the measurement temperature range is 30 to 280 ° C., the rate of temperature rise is 5 ° C./min, and the load is 5 g using a quartz holder. (2) Film thickness Width (cm), length (cm), weight (g), density (g / c)
m ³ ) and the thickness (μm) is calculated by the following formula to obtain the average thickness. Average thickness (μm) = (weight / (width x length x density)) x 1
0000

(3) Density This is a value measured by a flotation method at 25 ° C. in a density gradient tube using an aqueous solution of calcium nitrate. (4) Surface roughness (center line average roughness Ra), protrusion density Measure both sides of the film with a non-contact surface roughness meter (Kosaka Laboratories, Inc., SurfcorderET-30HK) under the following conditions and calculate the average value. The number of protrusions at each protrusion height is read from the obtained protrusion density graph, and is defined as the protrusion density. Magnification: 10000 times Measurement area: 0.129 mm ² Scan speed: 100 μm / sec Cutoff: 250 μm or more

(5) Film-forming property The film-forming property was evaluated according to the following criteria depending on how much breakage occurs during the film formation. ：: No breakage for 24 hours. Δ: No break or only one break until 8 hours. ×: Frequent breakage occurred, and film formation was impossible. (6) Evaluation of Blocking After applying the heat-resistant back coat layer, the film was wound into a roll and heat-treated at 60 ° C. for 7 days, and the degree of blocking when the film was drawn out was evaluated according to the following criteria. ：: Can be pulled out without any sharpness. Δ: Slight cracking and peeling sound when pulled out. ×: Haritsuki was severe and could not be pulled out.

(7) Printability The image receiving sheet VY · 200 (a brand name of standard paper manufactured by Hitachi, Ltd.) is added to the printer Hitachi VY · 200.
(Product name, manufactured by Hitachi, Ltd.) was printed so that the optical density became maximum. With respect to the produced sublimation type thermal transfer ribbon, printability and wrinkles generated in the ribbon were evaluated according to the following criteria. ：: The image can be printed clearly. Δ: Printing density is not uniform. X: The ribbon is wrinkled and the print is disturbed.

[0032]

The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to the following examples.

Examples 1 to 5 and Comparative Examples 1 to 4 Containing particles having an average particle size shown in Table 1 in an amount shown in Table 1, having an intrinsic viscosity of 0.61 (measured in o-chlorophenol at 25 ° C.) The polyethylene-2,6-naphthalenedicarboxylate (PEN) is melt-extruded into a sheet with an extruder and a T-die, and is adhered to a water-cooled drum to cool and solidify.
An unstretched sheet was obtained. This unstretched film is heated at 144 ° C.
At the temperature shown in Table 1 and at the magnification shown in Table 1. On the side of the longitudinally stretched film on which the sublimation-type thermal ink layer is to be applied, a coating liquid for an easy-adhesion layer having the following composition is applied by a gravure coater so that the coating thickness after drying becomes 0.05 μm. did. Thereafter, the film was stretched in the transverse direction at a temperature of 140 ° C. and at a magnification shown in Table 1, and subjected to a heat-setting treatment and a tension / relaxation treatment in the width direction under the conditions shown in Table 1 to give a width of 100.
A biaxially oriented film having a thickness of 0 mm and a thickness of 2.5 μm was obtained, and its length of 100,000 m was wound around a 6-inch core.
With respect to the obtained base film, the surface roughness, the temperature dimensional change curve under a load in the vertical and horizontal directions were measured, and the dimensional change at 200 ° C. and the dimensional change at 230 ° C. were obtained.

Next, a coating solution for a heat-resistant back coat layer having the following composition was applied by a gravure coater so that the thickness of the coating film became 0.7 μm, and dried at 80 ° C. × 3 seconds. / Min, tension 5 kg / m (49 N /
m), 10,000 at a contact pressure of 50 kg / m (490 N / m)
Winding was performed for 0 m, and heat treatment was performed at 60 ° C. for 7 days. The blocking property of this winding roll was evaluated. And
A coating liquid for a sublimation-type thermal transfer ink layer having the following composition was applied to the surface opposite to the heat-resistant back coat layer with a gravure coater so that the coating film thickness became 1.0 μm, thereby producing a sublimation-type thermal transfer ribbon. . The printability of the produced sublimation type thermal transfer ribbon was evaluated. Table 1 shows the evaluation results.

<Coating Solution for Easy Adhesion Layer> Acrylic-modified polyester 2.78% by weight Epoxy resin 0.02% by weight Nonionic surfactant 0.20% by weight Water 97.00% by weight

<Coating solution for heat-resistant back coat layer> Polyvinyl butyral resin 1.60 parts by weight Polyisocyanate 8.46 parts by weight Phosphate ester surfactant 1.36 parts by weight Talc 0.32 parts by weight Methyl ethyl ketone 38.43 Parts by weight toluene 38.43 parts by weight

<Coating liquid for sublimation type thermal transfer ink layer> Magenta dye (MSRedG) 3.5% by weight Polyvinyl acetoacetal resin 3.5% by weight Methyl ethyl ketone 46.5% by weight Toluene 46.5% by weight

Comparative Example 5 In place of polyethylene-2,6-naphthalenedicarboxylate, particles having an average particle size shown in Table 1 were contained in an amount shown in Table 1, and the intrinsic viscosity was 0.61 (o-at 25 ° C.). Polyethylene terephthalate (measured in chlorophenol) (PE
T), longitudinal stretching was performed in the first stage at 125 ° C. and 2.2
2nd stage 1.1 times at 125 ° C, 3rd stage 115
After three-stage longitudinal stretching of 2.3 times at ℃, a total of 5.6 times, and transverse stretching at 3.8 times at 110 ° C, and then subjected to tension heat treatment at 225 ° C with a fixed length, A sublimation-type thermal transfer ribbon was prepared and evaluated in the same manner as in Example 1 except that 6% relaxation treatment was performed in the transverse direction at a temperature of ° C. Table 1 shows the evaluation results.

[0039]

[Table 1]

[0040]

According to the present invention, it is possible to obtain a base film for a sublimation-type thermal transfer ribbon having good printability, in which no blocking occurs and the ribbon does not wrinkle when formed into a ribbon.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B29L 9:00 B41M 5/26 101A (72) Inventor Shinji Yano 3-37-19 Koyama, Sagamihara City, Kanagawa Prefecture Teijin Limited Sagamihara Research Center (72) Inventor Nobuyuki Harada 1-1-1, Ichigaya-Kaga-cho, Shinjuku-ku, Tokyo F-term in Dai Nippon Printing Co., Ltd. (reference) 2C068 AA08 BB08 2H111 AA15 AA16 AA27 BA03 BA08 BA61 BB02 BB06 BB08 4F071 AA43 AD01 AD06 AF54 AF61 AH16 BA01 BB08 BC01 BC12 BC14 BC15 4F210 AA26 AF16 AG01 AG03 AH81 QC05 QC06 QD08 QW17 QW31

Claims (8)

[Claims] 1. A biaxially oriented polyester film containing polyethylene-2,6-naphthalenedicarboxylate as a main component, wherein the biaxially oriented polyester film has a projection density of 1.0 μm or more on the film surface. The projection density of the projections having a height of 400 μm / mm ² or more and 2000 μm / mm ² or less and a height of 1.2 μm or more is 100 / m 2.
m ² or more 1000 pieces / mm ² or less, and in the longitudinal temperature dimensional change curve under a load of the film, the dimensional change of the original length of the film temperature to 200 ° C. is 1.
A base film for a sublimation type thermal transfer ribbon, wherein the dimensional change with respect to the original length of the film up to 230% is within 3.0%. 2. In the temperature dimensional change curve of the film under a longitudinal load, the dimensional change with respect to the original length of the film up to a temperature of 200 ° C. is within 0.6% and 230%.
The base film for a sublimation type thermal transfer ribbon according to claim 1, wherein a dimensional change with respect to the original length of the film up to ° C is within 1.0%. 3. The film surface has a center line average roughness (Ra) of 60 nm or more and 130 nm or less and a height of 1.4 μm.
^{2. The} base film for a sublimation-type thermal transfer ribbon according to claim 1, wherein the projection density of the projections of m or more is 300 / mm ² or less. 4. The base film for a sublimation-type thermal transfer ribbon according to claim 1, wherein the base film contains inert fine particles having an average particle diameter of 0.1 μm or more and 3.0 μm or less and 0.05% by weight or more and 0.5% by weight or less. 5. The method according to claim 1, wherein the thickness is 0.5 to 5.0 μm.
2. The base film for a sublimation type thermal transfer ribbon according to item 1. 6. The sublimation-type thermal transfer ribbon base film according to claim 1, wherein a heat-resistant back coat layer is provided on one side of the film. 7. A density of protrusions height 1.0μm or more protrusions on the surface of the heat-resistant backcoat layer is 100 pieces / mm ² or more 1500 pieces / mm ² or less and the height 1.2μm or more protrusions Projection density is 40 / mm ² or more and 800 / mm ²
The base film for a sublimation type thermal transfer ribbon according to claim 6, which is the following. 8. A sublimation-type thermal transfer ribbon having a sublimation-type thermal transfer ink layer on one surface of the base film for a sublimation-type thermal transfer ribbon according to claim 1.