JPH01209187A - Biaxially oriented polyester film for thermal transfer foil - Google Patents

Abstract

PURPOSE:To suppress drop-out or hot sticking of a thermal transfer foil, by applying a specified coating agent to one side of a biaxially oriented polyester film having a specified thickness and a specified average surface roughness, and setting the electrification potential of the other side of the film to within a specified range. CONSTITUTION:A biaxially oriented polyester film for a thermal transfer foil comprises a layer of a mixture of a thermoplastic and/or thermosetting resin with an organosiloxane on one side of the film, having a thickness of 1-10mum and an average surface roughness of 0.06-0.25mum, with the electrification potential on the other side of the film being in the range of 50-1,500V. If the film thickness is less than 1mum, operability is poor, whereas if the thickness is more than 10mum, thermal conductivity is poor. If the average surface roughness is less than 0.06mum, hot sticking is liable to occur between the back side of the thermal transfer foil and a thermal head, resulting in generation of a larger number of drop-out parts. If the average surface roughness is more than 0.25mum, a larger number of drop-out parts are generated due to defective heat transfer. If the electrification potential is outside the range of 50-1,500V, the number of drop-out parts generated is increased.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a biaxially oriented polyester film suitable for a thermal transfer foil used in a thermal printer or the like, that is, a base material for a thermal transfer ribbon or a thermal transfer sheet. It is.

[Prior art] A coloring material layer (heat-melting or sublimation ink layer) is applied to one side of a thin polyester film, and a coloring material layer (heat-melting or sublimation ink layer) is applied to the other side.
A heat-sensitive transfer foil coated with a layer of heat-resistant resin such as silicone resin is disclosed in Japanese Patent Application Laid-Open No. 56-155794.58-1335.
Publication No. 9 is well known. In addition, the mechanical properties and surface roughness of polyester films used as base materials for thermal transfer foils have been specified (Japanese Unexamined Patent Publication No. 60-2
17194.62-193889] and one in which a layer of a mixture of an aqueous polymer and a lubricant is coated on one side of a film (Japanese Patent Application Laid-open No. 192631/1983) are known.

[Invention or Problem to be Solved] The object of the present invention is to provide a suitable base for obtaining a thermal transfer foil with less occurrence of dropouts (printing of images) and hot sticks (problems where the thermal head sticks to the foil). The purpose is to provide a material film. The principle of thermal transfer is that the heat supplied from the thermal head is transmitted to the thermal transfer foil, and the ink layer on the surface is transferred onto the recording paper, recording images and characters. Sometimes there is no ink or there is a thin area of ink where it should be printed, and this is called dropout. This dropout rarely occurs when a large part of an image or text falls off, but often causes a small portion of the image to be missing or a spotty dropout to occur in the image. Such dropouts often occur when the ink layer is partially missing or when heat transfer from the thermal head becomes uneven for some reason. The purpose of the present invention is to provide a base film for making a heat-sensitive transfer foil that is less likely to cause such dropouts and is also less likely to cause hot stick, which is not satisfied by the above-mentioned conventional technology. It's something that didn't exist.

[Means for Solving the Problems] The present invention has a thickness of 1 to 10 μm and an average surface roughness of 0°06 to
A layer of a mixture of thermoplastic and/or thermosetting resin and organopolysiloxane is applied to one side of the 0.25 μm film, and the charged potential of the opposite surface is 5.
The main feature is a biaxially oriented polyester film for thermal transfer foil, which is characterized by a voltage within the range of 0 to 1500V.

Polyester here is a general term for polymers that have ester bonds as the main bond chain in the main chain, and particularly preferred polyesters include polyethylene terephthalate,
polyethylene? , 6-naphthalate, polyethylene α,
These include β-bis(2-chlorophenoxy>ethane 4,4-dicarboxylate, polybutylene terephthalate, etc.) Among these, polyethylene terephthalate is the most preferable from a comprehensive consideration of quality, economy, etc.

Therefore, hereinafter, we will proceed with the description using polyethylene terephthalate as a representative of polynisdel.

Polyethylene terephthalate (hereinafter referred to as PET) in the present invention
80 mol% or more, preferably 90 mol% or more, more preferably 95 mol% or more, or ethylene terephthalate as a repeating unit, or within this limited amount range, the acid component and/or Alternatively, part of the glycol component may be replaced with a third component as described below.

-Acid component- Isophthalic acid, 2,6-naphthalene dicarboxylic acid, 1.
5-naphthalene dicarboxylic acid, 2,7-naphthalene dicarboxylic acid, 4,4'-diphenyl dicarboxylic acid, 4.4
゛-Diphenylsulfone dicarboxylic phenyl ether dicarboxylic acid, β-hydroxyethoxybenzoic acid, adipic acid, azelaic acid, cepatic acid, hexahydroalephthalic 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, 5-
Sodium sulfoisophthalate monoglycol component - propylene glycol, butylene glycol, hexamethylene glycol, decamethylene glycol, neopentylene gellicol, 1,1-cyclohexane dimetatool, 1,4-cyclohexane dimetatool, 2,2-bis (4-β-hydroxyethoxyphenyl)propane,
Bis(4-β-hydroxyethoxyphenyl)sulfone, diethylene glycol, triethylene glycol, pentaerythritol, trimethylolpropane, polyethylene glycol, etc.

PET also contains known additives, such as heat stabilizers, oxidation stabilizers, weather stabilizers, ultraviolet absorbers, organic lubricants, pigments, dyes, organic or inorganic fine particles, fillers, and release agents. A molding agent, an antistatic agent, a nucleating agent, etc. may be added.

The intrinsic viscosity of PET as mentioned above (measured in orthochlorophenol at 25°C) is between 0.40 and 1.20.
, preferably 0.50 to 0.80, more preferably 0
．． Those in the range of 55 to 0.75 dM/g are suitable for the content of the present invention.

Next, the biaxially oriented polyester film as used in the present invention refers to a polyester sheet or film in an unstretched state.
2 in each of the so-called biaxial directions, the longitudinal direction and the width direction.
It is made by stretching about 5 to 5 times, and shows a biaxial orientation pattern in wide-angle X-ray diffraction.

The thickness of the film of the present invention is in the range of 1 to 10 μm.
- It is necessary that it be within this range, and this range is suitable as a base material for thermal transfer foil. For films thinner than this,
Workability when handling the film is significantly inferior, and heat-sensitive transfer foils based on this film are also mechanically too weak to be put to practical use. Conversely, if the film is thicker than this, the thermal conductivity will be poor and the printing speed will drop significantly. Next, the average surface roughness (Ra) of the film surface of the present invention is 0.06
~0.25 μm, preferably 0.07 to 0.20 μm. If the value of Ra is smaller than this, adhesiveness (
(referred to as hot stick), which often causes dropouts to occur.

Conversely, if the value of Ra is larger than the above range, not only will dropouts occur more frequently due to poor heat transfer, but
The recorded images or characters will have low gloss and the quality of the recording will deteriorate. The Ra value may be the same value on both surfaces of the film, or the Ra value on the front and back surfaces may be the same within the above range.
may have different values. If the Ra values of the front and back surfaces are different, it is better to apply a mixture of a thermoplastic and/or thermosetting resin and organopolysiloxane, which will be described later, to the surface with a larger Ra value. The Ra value of the film can be controlled by the type, amount, particle size, etc. of particles present in the film. The particles may be so-called precipitated particles that are precipitated during the polyester polymerization process, or may be inorganic or organic fine particles added to the polyester. In addition, even polyesters containing the same particles may differ depending on the conditions when making the film, such as extrusion conditions, stretching temperature, stretching ratio, and heat treatment conditions.
The value of Ra can be changed.

Next, the film of the present invention must be coated with a mixture of thermoplastic and/or thermosetting resin and organopolysiloxane on one side. This coated side is the one that comes on the back side (the side opposite to the coloring material layer and the side that comes into contact with the thermal head) when it is made into a thermal transfer foil.
Its presence greatly reduces the occurrence of potsticks and dropouts.

The thermoplastic resin referred to here is not particularly limited, but the following may be mentioned as typical examples. Polyolefin resins, especially modified polyolefin resins modified with acrylic acid, chlorine, etc., polyester resins, especially water-soluble or water-dispersed copolymerized with 0.5 to 15 mol% of sulfonic acid or dicarboxylic acid components containing sulfonic acid metal bases. polyester, acrylic resin, especially -COOHl CON R4R5, -N R4
an acrylic resin having a group selected from R5, (wherein R4 and R5 are hydrogen or an aliphatic hydrocarbon group having 1 to 4 carbon atoms);
Methacrylic resins or copolymers thereof, acrylic resins with perfluoro groups, fluorine resins such as acrylonitrile styrene copolymer resins, fluoroethylene copolymers, thermoplastic polyurethane resins, vinyl acetate resins, or these Examples include copolymers and blends.

In addition, these thermoplastic resins include polyethylene glycol, dicyclohexyl phthalate, diphenyl phthalate, triphenyl phosphate, dimethyl fumarate, benzotriazole, 2,4-dihydroxybenzophenone, tribenzylamine, benzyl, henylin, and phthalophenone, which are solid at room temperature. supercooled substances, or anionic surfactants, cationic surfactants, amphoteric surfactants, nonionic surfactants, fluorine surfactants, organic carboxylic acids and their derivatives, higher aliphatic alcohols,
It is often advantageous to add paraffin, wax, surfactant, or wax to the thermoplastic resin in an amount of 1 part by weight to 50 parts by weight, preferably 3 parts by weight to 25 parts by weight.

Among the above-mentioned thermoplastic resins, particularly suitable for the present invention are:
Shino is an acrylic acid, methacrylic acid copolymer and a thermoplastic polyurethane resin with hydrophilized ends.

In addition, the above-mentioned thermosetting resins are not particularly limited, and typical examples include organic metal compounds that can undergo condensation polymerization such as silane coupling agents and titanium coupling agents, hydroxyl, carboxyl, and amide resins. , amine,
Acrylates, methacrylates, or their copolymers and blends having crosslinkable functional groups such as nitrile and epoxy can be used as epoxy resins, alkyd resins, amines, melamine, diazine, urea, cyclic ethylene urea, and cyclic propylene urea. Examples include those crosslinked with , alkylmelamine, arylmelamine, benzoguanamine, guanamine, aldehyde, isocyanate, etc., crosslinked polyester copolymers, urethane resins, etc., and mixtures thereof, which are particularly preferred in the present invention. These are crosslinked polyester copolymers or crosslinked polyurethane resins. Examples of the organopolysiloxane mentioned above include silicone oil and modified silicone oil into which various functional groups have been introduced. Representative examples of organopolysiloxanes are represented by the following general formulas (a) to (c).

RI+ R"R"'...(c) [where X, Y, and 7 are integers of 1 to 50oo, R is an alkyl group or hydroxyl group having 1 to 100 carbon atoms, Ro is an alkylene group having 1 to 10 carbon atoms, selected from phenylene group, cyclohexylene group, ether group, R+1 is hydrogen,
selected from alkyl groups having 1 to 100 carbon atoms, epoxy groups, amine groups, carboxyl groups, phenyl groups, hydroxyl groups, mercapto groups, polyoxylene alkyl groups, and halogen-containing alkyl groups; Ro"° is 1 carbon number; ~100
, polyoxylene alkyl groups, hydroxyl groups, and halogen-containing alkyl groups.

]. Specific examples include dimethylpolysiloxane oil, amino-modified silicone oil, epoxy-modified silicone oil, epoxy/polyether-modified silicone oil,
Carboxyl-modified silicone oil, polyether-modified silicone oil, alcohol-modified silicone oil,
Alkyl and alkyl/aralkyl modified silicone oil, alkyl/aralkyl/polyether modified silicone oil, fluorine modified silicone oil, alkyl/aralkyl/polyether modified silicone oil,
Examples include higher alcohol ester-modified silicone oil, methylhydrodiene polysiloxane oil, phenylmethyl silicone, and emulsified products thereof. Particularly preferred in the present invention are dimethylpolykiloxane oil, epoxy-modified silicone oil, epoxy-polyether-modified silicone oil, polyether-modified silicone oil, amino-modified silicone oil, and emulsions thereof. Further, two or more of these may be mixed and used in any ratio.

Furthermore, it is particularly preferable to use various crosslinking agents that react with the reactive groups of the silicone oil.

The organopolysiloxane suitable for this application has a viscosity measured at 25°C of 100 centistokes (hereinafter centistokes is abbreviated as C-8) and 5 million C-8 or less, preferably 200OC-S or more and 30o75cms.
The following are preferred.

The mixture of thermoplastic and/or thermosetting resin and organopolysiloxane described above is applied to the back of the film, and the composition ratio of the resin and organopolysiloxane in this coating layer is determined by the weight of the resin. When taken as 100, organopolysiloxane is 5 to 50, especially 10
It is preferably in the range of ~40. As the amount of organopolysiloxane increases or decreases beyond this range, hot stick and dropout tend to worsen.

In addition, known additives such as inorganic or organic fine particles (particle size of about 0.1 to 1 μm), plasticizers, lubricants, surfactants, antistatic agents, etc. are added to this mixture layer. Good too. The mixture layer applied to the back side of this film consists of 1
1 to 10 at 80°C or higher, preferably 200'C or higher
It is desirable that the material has undergone a heat treatment for seconds. Subjecting to such a high temperature thermal history greatly improves hot stick and dropout. Such high-temperature heat treatment is extremely difficult using the usual coating method of applying a coating material to a biaxially oriented polyester film and drying it. Because it is thin, 18
If you apply a high temperature of 0'C or higher, the film will shrink and become wet (C). Therefore, in the process of producing a biaxially oriented polyester film, it is preferable to apply the above mixture, and then stretch and heat treat it.

With this method, 180'C or higher, preferably 2oo
It is possible to carry out high temperature heat treatment at temperatures higher than 'c' without any problems. The thickness of the mixture layer applied to the back side of the film is preferably in the range of 0.02 to 0.8 .mu.m, preferably 0.03 to 0.5 .mu.m. Thicker or thinner than this range, hot stick and dropouts tend to be worse.

Next, the charged potential of the polyester side surface of the film of the present invention (that is, the side on which the coloring material layer is applied) is 50 to 15
00V, preferably within the range of 100-1200V. This charged potential is the amount of static charge on the film surface expressed in volts, and both positive and negative potentials are expressed as absolute values. Whether this charged potential is higher or lower than the above range, when a thermal transfer foil is made using this as a base material, the number of dropouts will increase. This tendency is particularly noticeable when the colorant layer is dissolved in an organic solvent and applied. Control of the charged potential on the film surface depends on the type of roll that comes into contact with the film surface (metal roll, rubber roll, plastic roll, conductive rubber roll, etc.) when winding or slitting the film, the humidity of the atmosphere, the contact type, etc. Whether or not a non-contact static electricity eliminator is installed, how it is installed, and the film winding conditions (
This can be done by adjusting speed, tension, torque, surface pressure, etc.).

Next, a specific example of the method for manufacturing the thermal transfer foil of the present invention will be described.

So-called precipitated particles and inorganic fine particles (
For example, P containing colloidal silica with a particle size of 1 μm)
ET is dried and melt-extruded according to a conventional method, and the extruded sheet-like melt is cooled and solidified to produce an unstretched PET film. This film is heated to 80-120°C,
The film is stretched 2.5 to 5 times in the longitudinal direction to form a uniaxially oriented film. One side of this film is subjected to a corona discharge treatment in a carbon dioxide gas atmosphere, and an emulsion, suspension, or solution of a mixture of a thermoplastic and/or thermosetting resin and an organopolysiloxane is applied to this treated side.

Next, the coated film was stretched 3 to 4.5 times in the width direction while being heated to 90 to 130°C, and subsequently,
1-1 into a heat treatment zone at 180-240'C.
Heat treatment for 0 seconds. During this heat treatment, 3 to 12
% relaxation treatment is better. The heat-treated film is gradually cooled through an intermediate cooling zone, and when it reaches room temperature, it is wound up with a winder to form a mill roll. Ionized air is blown onto the contact area between the film and the roll of the mill roll winding section to control charging. Next, this mill roll is passed through a slitter to form a film product roll of desired width and length. When the product roll is rolled up with a slitter, the material of the roll that comes into contact with the non-11 side of the film (that is, the side on which the coloring material layer is applied on the polyester side) and the amount of ionized air blown onto this contact area are determined. The charged potential on this surface is controlled by the amount of blow (-11). For example, if a rubber roll covered with a Teflon tube is used, the charged potential will increase, and if a conductive rubber roll is used, the charged potential will decrease. When the amount of ionized air is increased, the charged potential decreases.

Since the charged potential on the film surface tends to decrease somewhat with the passage of time, the charged potential immediately after slitting may be set slightly higher than the range of the present invention (of course,
When forming a heat-sensitive transfer foil by applying a coloring material layer immediately after slitting, it is necessary to keep the charged potential within the range of the present invention at that point).

A heat-melting or heat-sublimation coloring material layer is applied to the non-coated side of the film thus obtained, and if necessary, a top coat layer for mold release is further applied thereon, and then, Slit to the required width for serial or line printers to make thermal transfer foil.

Thermal transfer foils made in this way are available in both monochromatic (black) and colored ink, and can be used with word processors, fax machines, computer printers, video printers, barcode ticket machines, and typewriters. -,
It is used for printing out text or images such as plain paper copiers.

[Method for Measuring Properties and Evaluating Effects] The methods for measuring properties and evaluating effects in the present invention are as follows.

(1) Average surface roughness (Ra) Measured according to JIS-BO601-1976. Cutoff (direct was 0.25 mm).

(2) Charge potential on the film surface After unwinding and cutting and removing about 1Qm of the surface layer from the polyester film product roll, start from the new film end and unwind approximately 1m, leaving this 1m hanging directly below the film roll. I made it look like this. The center of this hanging film (approximately 5Q upwards from the film edge)
cm) on the polyester side surface (that is, the non-coated surface) at 10 points in the film width direction (the entire width of the film is divided into 10 equal parts at equal intervals, and the center of each equal part is taken as one point).
were measured. Measurement of electrostatic voltage is carried out by Trek Inc.
.

Electrostatic Voltmeter manufactured by
Model 344 was used, and the distance between the film surface and the probe was about 5 mm.

Treat all measured electrostatic voltages as absolute values (in other words, whether it is -500V or +500V,
By summing the 10 measured values and dividing this by 10, the average value of the absolute value of the charged voltage can be obtained. This value was taken as the surface charge potential of this film.

(3) Evaluation of hot stick and dropout A biaxially oriented PET film coated on one side with a layer of a mixture of thermoplastic and/or thermosetting resin and organopolysiloxane is coated with a layer of a mixture of thermoplastic and/or thermosetting resin and organopolysiloxane. A heat-sensitive transfer foil was prepared by applying a color ink as a coloring material layer, drying it, and then slitting it to an appropriate width.

Disperse dye KST-8-136: 0.4 parts by weight (manufactured by Nippon Kayaku) Ethyl hydroxyethyl: 0.6 Cellulose methyl ethyl ketone: 4.5 Toluene
: 4.5/l This heat-sensitive transfer foil was applied to a thermal printer, and printing was performed using a thermal head on a recording paper coated with the dye-receiving amount. The degree of adhesion between the thermal transfer foil and the thermal head at this time is
Based on comprehensive judgment based on visual judgment and the degree of sound generation, the level of the hot stick was judged in four stages: excellent, good, fair, and poor. In addition, the level of dropout is determined as excellent, good, or good, based on comprehensive judgment of parts of the print that fall off, occurrence of dark and light areas, etc.
It was graded into four levels: acceptable and unacceptable.

[Example] The present invention will be explained based on examples.

Example 1 PET containing 0.15% by weight of precipitated particles (particles precipitated during the polymerization process) with a particle size of 0.5 to 1.5 μm and 0.2% by weight of calcium carbonate particles with a particle size of 1.5 μm After sufficiently vacuum drying the pellets (intrinsic viscosity 0.63 dM/C1), they were fed to an extruder and melt-extruded at 280°C.
After passing through a 10 μm cut metal sintered filter, T
Extrude it into a sheet from a shaped die and heat it to a surface temperature of 50°C.
The mixture was wrapped around a cooling drum and cooled and solidified. In order to improve the adhesion between the sheet and the cooling drum surface during this time,
A wire electrode was placed on the sheet side, and a DC voltage of 6000 V was applied to it. The thus obtained unstretched PET film was heated to 95°C,
It was stretched 3.5 times in the longitudinal direction to obtain a -axis stretched film. One side of this film was subjected to a corona discharge treatment in a carbon dioxide scum atmosphere, and the following water-based coating agent was applied onto the treated surface by a rod coating method.

(Manufacture of water-based paint) The following three components are mixed so that the solid weight ratio of (A)/(B)/(C) is 65/20/15, and water is added to this to form a solid. Further, fluorine-based surfactant was added in an amount equivalent to 1.2% of the total solid weight, and the mixture was stirred and mixed uniformly until the viscosity at 20'C was 10 centipoise. A water-based paint was created.

(A), a water-soluble polyester copolymer having a reactive acrylic group in the side chain (B), a water-soluble amino-modified silicone oil (C), a blocked isocyanate having the following structure; Preheat to 98°C, then 1
The film was stretched 3.9 times in the width direction while heating to 05°C. Next, this film was introduced into hot air at 225°C, and after tension heat setting for 1 second, the film was allowed to shrink by 8% of the original film width in the width direction in the same temperature atmosphere, and then again in the same temperature atmosphere. Heat set under tension for about 1 second at 180°C.
It was gradually cooled through each zone of 1,150°C and 1,100°C, and finally cooled to room temperature, and then led to a winder and wound up into a mill roll. In this winding process, all rolls that come into contact with the non-coated side of the film are grounded metal rolls, and ionized air is flowed through this contact area and the mill roll winding area to prevent strong electrostatic charges. did. Next, this mill roll was passed through a slitter to slit the film to a film width of 600 mm to obtain a film product roll. During this slitting, a conductive rubber roll is used as a lay-on roll to adjust the winding hardness of the product roll, and the roll is brought into contact with the non-coated surface of the film, and
Ionized air was blown onto this area, and the amount of charge on the non-coated side of the film was controlled by the amount of ionized air blown.

The film thus obtained with a thickness of about 6 μm has one side (A
A coating layer of about 0.2 μm was applied to the surface), and the charged potential of the opposite surface (surface B) was 320 V one week after slitting. In addition, the average surface roughness of both surfaces of this film is 0.10μ on side A (measured including the coating layer).
m and B planes were 0.12 μm. Apply sublimation ink to the B side of this film in a dry coating amount of 1 g/m using the method described above.
A heat-sensitive transfer foil was made by coating the film in an amount of 2. As a result of evaluating this heat-sensitive transfer foil using the above-mentioned evaluation method, it was found to be excellent in both hot stick and dropout, and the level was "excellent".

Example 2 A thermoplastic polyurethane emulsion and an amine-modified silicone emulsion were mixed so that the solid content weight ratio was 90/10, and water was added to this to achieve a solid content concentration of 8.
% by weight, add fluorine surfactant in an amount equivalent to 1.2% of the total solid weight, mix and stir uniformly, and adjust the viscosity at 20°C to 8 centipoise. I made a water-based paint. This coating material was applied to a uniaxially stretched film in the same manner as in Example 1, and a film product roll having a width of 600 mm was produced in the same manner as in Example 1.

The thickness of this film is approximately 6 μm, and one side (side A) has approximately 0.
．． A coating layer of 1 μm was applied, and the charged potential on the opposite surface (Side B) was 240 V 10 days after slitting. In addition, the average surface roughness of this film is the A side (
Measured including the coating layer) is 0.11 μm, B side is 0.12
It was μm.

A heat-sensitive transfer foil made using this film in the same manner as in Example 1 was excellent in both hot stick and dropout, and the level was "erosion".

Comparative Example By changing the mill roll winding conditions and slitting conditions in Example 1, films were produced in which the charge potential on the B side was 1920 V and 8 V one week after slitting.

Using these films, heat-sensitive transfer foils were made in the same manner as in Example 1, and these hot sticks and drop rollers 1 to 1 were evaluated. As a result, the hot stick level was "excellent" and no problem with either film, but the dropout was considerably worse, and the dropout level was 1920V.
The results showed that using a 8V film was "not possible," and using an 8V film was "possible."

[Effects of the Invention] The present invention involves applying a specific coating material to one side of a biaxially oriented polyester film having a specific thickness and average surface roughness, and setting the charged potential of the opposite surface to a specific range. This has the effect of reducing dropouts and hot sticks in thermal transfer foils using this film as a base material.

The film of the present invention can be widely used in both sublimation type and heat melting type thermal transfer ribbons or sheets.

Claims (1)

[Claims] Thickness 1-10μm, average surface roughness 0.06-0.25μm
A layer of a mixture of thermoplastic and/or thermosetting resin and organopolysiloxane is coated on one side of the film of m, and the charged potential of the opposite surface is 50 to 150.
A biaxially oriented polyester film for thermal transfer foil, characterized in that the voltage is within the range of 0V.