JP2001089650A - Film for heat-sensitive transfer ribbon - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a base film of a transfer material for heat-transfer printers which has an excellent handleability such as smoothness, slitting processibility, etc., good mechanical properties and an excellent adhesion to heat-transfer ink layers. SOLUTION: The film for heat-sensitive transfer ribbons is a biaxially oriented polyester film which mainly comprises polyethylene-2,6-naphthalate copolymerized with an isophthalic acid component at a specific ratio. Here, the alternating-current volume resistivity of the melt product of the film is <=6×108 Ωcm, a face orientation factor of the film is from 0.230 to 0.275, and the density of the film is >=1.350 g/cm3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film for a thermal transfer ribbon, and more particularly, to a film for a thermal transfer ribbon mainly comprising copolymerized polyethylene-2,6-naphthalate containing an isophthalic acid component as a copolymer component. .

[0002]

2. Description of the Related Art As a base film for a ribbon for a thermal transfer printer, a film having a specified surface roughness (Japanese Patent Application Laid-Open No. 62-1987).
No. 299389) is known. Among the thermal transfer recording methods, the sublimation transfer recording method has been greatly developed as a recording method capable of easily outputting a high-quality full-color image. In the sublimation type thermal transfer method, the ink layer of the thermal transfer ribbon is composed of a thermal sublimation dye and a binder, and only the dye sublimates from this ink layer by heat, and is adsorbed to the image receiving layer of the transfer receiving paper to form a gradation image. It is a method of forming.

[0003]

In recent years, there has been a demand for a higher printing speed. To increase the printing speed, measures have been taken to efficiently transfer heat from the thermal head to the ink layer during printing. For this reason, the temperature of the thermal head needs to be higher than before, and the base film needs to be thinner. However, simply reducing the thickness of the conventional base film causes various problems.

That is, since the temperature of the thermal head becomes higher, the amount of heat received by the thermal transfer printer ribbon increases, and furthermore, the base film becomes thinner, so that the thermal transfer printer ribbon undergoes greater deformation due to heat. As a result, the problem that the printing becomes unclear due to deformation, the problem that wrinkles occur on the ribbon,
In an extreme case, there arises a problem that printing cannot be performed at all.

[0005] In the sublimation type thermal transfer system, only the dye is sublimated by heat from an ink layer composed of a heat sublimable dye and a binder, and the dye is adsorbed to an image receiving layer of a transfer paper to form an image. At this time, only the dye is sublimated,
In order to prevent the transfer of the binder component to the transfer paper, high adhesiveness between the binder component and the base film is required.
Furthermore, it is essential that this adhesiveness does not cause a decrease in adhesive strength due to environmental changes or aging. If the adhesiveness is insufficient, the binder component migrates to the paper to be transferred, significantly impairing the gradation, and a phenomenon (problem) called overtransfer occurs.

In general, a polyester film has a high degree of crystal orientation and thus poor adhesion, and hardly adheres even if an ink layer is applied directly to the film surface. In order to improve the adhesion of the polyester film, a method of subjecting the film surface to physical and chemical treatments is known. However, this method does not provide sufficient adhesion to the ink layer, and the improvement is desired. It is rare.

[0007] In order to economically produce a film, it is desirable that breakage be reduced during film formation so that the film can be formed stably. Polyethylene terephthalate (hereinafter referred to as “PE
T ") or polyethylene-2,6
Naphthalate (hereinafter sometimes abbreviated as "PEN")
Polyester film represented by, for example, usually, a polymer melted by an extruder is extruded from a die to form a film-like melt, which is quenched on the surface of a rotary cooling drum,
It is manufactured by biaxial stretching in the vertical and horizontal directions. In order to eliminate the surface defects of the obtained film and increase the uniformity of the thickness, it is necessary to increase the adhesion between the film-like melt and the surface of the rotary cooling drum. As a method of improving this adhesion, a wire-like electrode is provided near the extrusion die and the rotary cooling drum to charge the surface of the film-like melt with an electrostatic charge, and the film-like melt adheres to the surface of the rotary cooling drum. There is known a method of quenching while heating (also called an electrostatic casting method).

However, the melting electric resistance of PEN is PET.
Because of the larger size, there are various difficulties in producing a thin PEN film that can be used for a base film of a thermal transfer ribbon by an electrostatic casting method as compared with the case of PET. That is, when forming a PEN film, at the stage of electrostatic casting, in addition to the high melting electric resistance of PEN, since the film-like melt is thin, the surface area of the film-like material per unit area is large. The amount of static charge is reduced.
As a result, the adhesiveness between the film-like melt and the surface of the rotating cooling drum is insufficient, which causes pin-like defects on the film surface, the problem of reduced uniformity of the film thickness, and in extreme cases, the film is broken. Problems arise.

Further, the PEN film has a tear resistance of P
Since it is smaller than the ET film, the PEN film is easily broken when slitting. Film break is PEN
This becomes remarkable when the film is thin, and becomes a problem, for example, in slitting the stretched film or slitting the thermal transfer ribbon in the process of manufacturing the film.

The present invention solves these problems, and when used as a base film for a thermal transfer ribbon, a transfer which is less deformed upon heating, has excellent adhesion to a thermal transfer ink layer, and has excellent gradation. An object of the present invention is to provide a base film for a heat-sensitive transfer ribbon, which can obtain an image, has less breakage even in a thin film when slitting, and has excellent flatness.

[0011]

According to the present invention, the present invention provides ethylene-2,6-naphthalate as a main repeating unit, wherein isophthalic acid component is contained in an amount of 0.1 to 10 mol based on the total amount of all dicarboxylic acid components. %, A copolymer comprising polyethylene-2,6-naphthalate in which a diethylene glycol component is copolymerized by 0 to 3 mol% with respect to the total amount of all glycol components. 6 × and the 10 ⁸ [Omega] cm or less, plane orientation coefficient of the film is 0.230 or more 0.275 or less, the density is achieved by heat-sensitive transfer ribbon film, characterized in that it is 1.350 g / cm ³ or more.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [Polyester] The polyester constituting the thermal transfer ribbon film of the present invention has ethylene-2,6-naphthalate as a main repeating unit, and the isophthalic acid component is 0 with respect to the total amount of all dicarboxylic acid components. .
It is a copolymerized polyethylene-2,6-naphthalate in which a diethylene glycol component is copolymerized in an amount of 1 to 10 mol% and a total ethylene glycol component of 0 to 3 mol% based on the total amount of all glycol components.

The copolymerized polyethylene-2,6-naphthalate (hereinafter abbreviated as "copolymerized PEN") is a polymer having ethylene-2,6-naphthalate as a main repeating unit and is based on the total amount of all dicarboxylic acid components. At least 85 mol%, preferably at least 90 mol%, is a 2,6-naphthalenedicarboxylic acid component, and at least 85 mol%, preferably at least 90 mol%, based on the total amount of all glycol components is an ethylene glycol component. Is preferred.

In the copolymer PEN of the present invention, the isophthalic acid component is contained in an amount of 0.
1 to 10 mol% copolymerized. The upper limit of the copolymerization ratio of the isophthalic acid component is 10 mol%, preferably 8 mol%, and more preferably 7 mol%. The lower limit of the copolymerization ratio of the isophthalic acid component is 0.1 mol%, preferably 0.5 mol%, more preferably 1 mol%. When the copolymerization ratio of the isophthalic acid component is in the above range, the film has excellent delamination resistance and the film has excellent mechanical properties.

When the copolymerization ratio of the isophthalic acid component is 0.1
When the amount is less than mol%, the delamination resistance of the film is not improved, and the film may be broken in the slitting step in the production of a biaxially stretched film or the production of a thermal transfer ribbon. On the other hand, if it exceeds 10 mol%, the crystallinity of the polymer is impaired, and the mechanical strength of the film becomes poor. It is preferable that the copolymerization ratio of the isophthalic acid component is higher than that of the other copolymerization components because the effect of improving the delamination resistance of the film is excellent.

The copolymerized PEN may be produced, for example, by a so-called transesterification reaction method using dimethyl ester of 2,6-naphthalenedicarboxylic acid as a raw material (hereinafter sometimes abbreviated as EI method). Alternatively, it may be produced by a direct polymerization reaction method using 2,6-naphthalenedicarboxylic acid as a raw material (hereinafter, may be abbreviated as a direct polymerization method).
Those manufactured by the EI method with few impurities in EN are preferable.

In order to copolymerize the isophthalic acid component with the copolymerized PEN, for example, a method in which isophthalic acid or an ester-forming derivative thereof is used as a raw material when producing a copolymer can be mentioned. In the case of the above-mentioned direct-gravity method, it is preferable to use isophthalic acid as a raw material.
In the case of the method, isophthalic acid or an ester-forming derivative of isophthalic acid may be used. When isophthalic acid is used, it is preferably added at the time when the transesterification reaction is substantially completed. As the ester-forming derivative of isophthalic acid, dimethyl isophthalate can be mentioned as a preferred example.

In the present invention, the copolymerized PEN has a diethylene glycol component of 0 to 3 mol% based on the total amount of all glycol components. The upper limit of the copolymerization ratio of the diethylene glycol component is 3 mol%, preferably 2.5 mol%, and more preferably 2 mol%. If the copolymerization ratio of the diethylene glycol component exceeds 3 mol%, the effect of improving the delamination resistance of the film becomes large, but the crystallinity of the polymer is impaired, so that the mechanical strength is greatly reduced and the thermal transfer is performed. Deformation occurs during use as a ribbon, resulting in poor print quality.

The smaller the amount of the diethylene glycol component, the better the mechanical properties of the film are, and thus it is preferable. The lower limit of the copolymerization ratio is 0 mol%. However, this diethylene glycol component, during the production of the copolymer,
Since it is copolymerized as a by-product in the course of the production reaction, it is difficult to set the content to 0 mol%. From the viewpoint of productivity of the copolymerized PEN, the lower limit of the copolymerization ratio of diethylene glycol is preferably 0.5 mol%, more preferably 1 mol%.

As described above, since the diethylene glycol component is preferably as small as possible, it is not preferable to add diethylene glycol or its ester-forming derivative as a raw material when producing the copolymerized PEN. Copolymer P
In order to suppress the by-product of diethylene glycol during the reaction in the process of producing EN, the ratio of the molar amount of ethylene glycol to be added to the molar amount of dicarboxylic acid and / or its ester-forming derivative is set to 2.0 to 3.0. It is preferable to be within the range. The shorter the time required for the transesterification reaction, the better.

The copolymerized PEN in the present invention may contain a copolymerized component other than the isophthalic acid component and the diethylene glycol component. These components have the effect of improving the delamination resistance, but significantly lower the Young's modulus. Therefore, it is desirable not to use a large amount. The total amount of the copolymer components other than the isophthalic acid component and the diethylene glycol component is 3 mol% or less, preferably 1 mol% or less, and more preferably 0.1 mol% or less.

As the copolymerization component other than the above-mentioned isophthalic acid component and diethylene glycol component, compounds having two ester-forming functional groups, for example, oxalic acid, adipic acid,
Phthalic acid, sebacic acid, dodecanedicarboxylic acid, succinic acid, 5-sodium sulfoisophthalic acid, terephthalic acid, 2-potassium sulfoterephthalic acid, 2,7-naphthalenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 4,4 ′ -Diphenyldicarboxylic acid, phenylindanedicarboxylic acid, diphenyletherdicarboxylic acid and lower alkyl esters thereof, oxycarboxylic acids such as p-oxyethoxybenzoic acid and lower alkyl esters thereof, propylene glycol, 1,2-propanediol, 3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,2-cyclohexanedimethanol,
3-cyclohexane dimethanol, 1,4-cyclohexane dimethanol, p-xylylene glycol, ethylene oxide adduct of bisphenol A, ethylene oxide adduct of bisphenol sulfone, triethylene glycol, polyethylene oxide glycol, polytetramethylene oxide glycol, Neopentyl glycol and the like can be mentioned.

The copolymerized PEN is, for example, benzoic acid,
Some or all of the terminal hydroxyl groups and / or carboxyl groups may be blocked with a monofunctional compound such as methoxypolyalkylene glycol, or trifunctional or higher functional groups such as glycerin and pentaerythritol in a very small amount. May be modified within a range where a substantially linear polymer is obtained with the ester-forming compound of the formula (1).

[Reaction Catalyst] When the copolymerized PEN is produced by the EI method, a manganese compound can be preferably used as a transesterification catalyst. Examples of the manganese compound include oxides, chlorides, carbonates, and carboxylate salts, and among them, acetate is particularly preferable.

In the process of producing the copolymerized PEN, a phosphorus compound is added when the transesterification reaction is substantially completed,
It is preferred to deactivate the transesterification catalyst. As the phosphorus compound, trimethyl phosphate, triethyl phosphate, tri-n-butyl phosphate and orthophosphoric acid can be preferably used. Of these, trimethyl phosphate is particularly preferred.

As the polycondensation catalyst, an antimony compound can be preferably used, and as the antimony compound, antimony trioxide can be particularly preferably used.

The copolymer PEN in the present invention preferably contains the above catalyst in an amount satisfying the following formulas (1), (2) and (3).

[0028]

(1) 30 ≦ Mn ≦ 100 (1)

[0029]

[Equation 2] 150 ≦ Sb ≦ 450 (2)

[0030]

P / Mn ≧ 1 (3) wherein Mn is the amount of manganese element in the copolymerized PEN (p
pm), Sb is the amount of antimony element in the copolymerized PEN (ppm), and P is the amount of phosphorus element in the copolymerized PEN (pp
m). ]

The content of the manganese element is 3 in the copolymerized PEN.
If it is less than 0 ppm, the transesterification reaction is insufficient,
On the other hand, if it exceeds 100 PPm, it is excessive and uneconomical. On the other hand, when the content of the antimony element is less than 150 ppm, the polycondensation reactivity is reduced and the productivity is deteriorated.
If it exceeds 50 ppm, the thermal stability will be poor, which may lead to cutting of the process during film formation and a decrease in mechanical strength. Further, when P / Mn is less than 1, the intrinsic viscosity may be reduced.

[Additives] In the present invention, the copolymerized PEN
In order to impart preferable lubricity to the film, it is preferable to contain a small amount of inert particles. Examples of such inert particles include inorganic particles such as spherical silica, porous silica, calcium carbonate, silica alumina, alumina, titanium dioxide, kaolin clay, barium sulfate, and zeolite, or organic particles such as cross-linked silicone resin particles and cross-linked polystyrene particles. Particles may be mentioned. The inorganic particles are preferably synthetic products rather than natural products for reasons such as uniform particle size, and inorganic particles of any crystal form, hardness, specific gravity, and color can be used.

The above-mentioned inert fine particles have an average particle size of 0.05.
It is preferably in the range of 5.0 to 5.0 μm. The lower limit of the average particle size is more preferably 0.1 μm, and the upper limit is more preferably 3.0 μm. The content of the inert fine particles is preferably 0.001 to 1.0% by weight. The lower limit of the content is more preferably 0.03% by weight, and the upper limit is more preferably 0.5% by weight. The inert 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.

Among these, preferred examples include spherical silica fine particles having at least two kinds of average particle diameters. The two types of spherical silica fine particles, large and small, have a particle diameter ratio (major axis / minor axis) of 1.0 to 1.2, and an average particle diameter of 0.5 to 5 μm. These are spherical silica fine particles (B) having an average particle size of 0.01 to 1 μm. The lower limit of the average particle size of the spherical silica fine particles (A) is 0.8.
μm, and the upper limit is more preferably 3 μm. The upper limit of the average particle size of the spherical silica fine particles (B) is more preferably 0.7 μm. The average particle diameter of the spherical silica fine particles (A) is preferably larger than the average particle diameter of the spherical silica fine particles (B).

These two types of spherical silica fine particles have a particle size ratio (major axis / minor axis) of 1.0 to 1.2, so that the shape of each individual microparticle is very close to a true sphere. It is distinguished from silica fine particles conventionally known as lubricants, which are ultra-fine lump particles of about 10 nm or aggregated to form aggregates (agglomerated particles) of about 0.5 μm. There is.

The spherical silica fine particles (A) have an average particle size of 0.
If it is less than 5 μm, the effect of improving the slipperiness and workability of the film is insufficient, while if it exceeds 5 μm, the film breaking strength is undesirably reduced. When the average particle diameter of the spherical silica fine particles (B) is less than 0.01 μm, the effect of improving the slipperiness and workability of the film is insufficient.
If it exceeds, the film surface is too rough, and the space factor is undesirably increased. The average particle size of the spherical silica fine particles may be larger than the film thickness as long as the projection height does not deviate from the above range.

The particle size ratio can be determined by the following equation. A specific measuring method will be described later.

[0038]

## EQU4 ## (particle size ratio) = (average major axis of spherical silica fine particles)
/ (Average minor diameter of spherical silica fine particles)

Here, the "average particle size" means the "equivalent spherical diameter" of the particle at a point of 50% by weight of the total measured particles. "Equivalent spherical diameter" means the diameter of an imaginary sphere (ideal sphere) having the same volume as a particle, and can be calculated from an electron micrograph of the particle or measurement by a normal sedimentation method.

The timing of adding the inert particles is not particularly limited as long as it is a stage before the formation of the copolymerized polyethylene-2,6-naphthalate. For example, the inert particles may be added at the polymerization stage. May be added.

[Volume resistivity] In the film for a thermal transfer ribbon of the present invention, an unstretched film having high flatness while suppressing crystallization is produced by bringing a film-like melt into close contact with a rotary cooling drum in a film forming process. . At this time, for the purpose of enhancing the adhesion, an electrostatic adhesion method for imparting an electrostatic charge to the film-like melt can be used. At this time, since the copolymer PEN has a high electric resistance of the melt, the electrostatic adhesion may be insufficient. As a countermeasure, it is necessary to reduce the AC volume resistivity of the melt of the copolymerized PEN to 6 × 10 ⁸ Ωcm or less. In order to make the AC volume resistivity 6 × 10 ⁸ Ωcm or less, for example, 0.1 to 40 mmol%, more preferably 0.2 to 10 mmol, of the bifunctional carboxylic acid component is added to the copolymerized PEN.
Preferably, it contains 1% of a quaternary phosphonium sulphonate having an ester-forming functional group. Although it is not specified as a sulfonic acid quaternary phosphonium salt having the ester-forming functional group, there are 3,5-dicarboxybenzenesulfonic acid tetrabutylphosphonium salt and 3,5-dicarboxybenzenesulfonic acid tetraphenylphosphonium salt. Examples can be given.

[Plane Orientation Coefficient] The film for a thermal transfer ribbon of the present invention has a plane orientation coefficient of 0.230 or more and 0.275 or less. If the plane orientation coefficient exceeds 0.275, the delamination resistance will be poor, and the slit resistance of the film will be insufficient. The plane orientation coefficient is 0.2
If it is less than 3, the mechanical strength of the film will be insufficient.

[Density] The heat-sensitive transfer ribbon film of the present invention has a density of 1.350 g / cm ³ or more.
If the density is lower than this, the mechanical strength is poor and the delamination resistance is poor. On the other hand, the upper limit is not specified, but is preferably 1.362 g / cm ³ or less in order to maintain the surface properties of the film.

[Thermal Shrinkage] In the thermal transfer ribbon film of the present invention, the heat shrinkage in the longitudinal and width directions after the heat treatment preferably satisfies all of the following values (a) to (c) in both directions. . (A) After 150 ° C. × 30 minutes, 3% or less, more preferably 2% or less (b) After 200 ° C. × 10 minutes, 6% or less, more preferably 5% or less (c) After 230 ° C. × 10 minutes, 10% or less, more preferably 6% or less If at least one of these heat shrinkage ranges is not satisfied, the base film shrinks due to rubbing between the base film and the thermal head, resulting in poor dimensional stability and wrinkles. May be.

[Thickness] The film for a thermal transfer ribbon of the present invention preferably has a thickness of 1 to 9 μm.
The upper limit of this thickness is more preferably 6 μm, and the lower limit is more preferably 2 μm. When the thickness is less than 1 μm, elongation deformation, wrinkles, and cutting of the film become remarkable,
The ribbon cannot be used stably. On the other hand, when the thickness exceeds 9 μm, the sensitivity is reduced and the length of the ribbon that can be stored in the ribbon cassette is reduced, so that the usability of the printer deteriorates.

[Easy Adhesive Layer] The heat-sensitive transfer ribbon film of the present invention has a surface on the side where the ink layer is coated, selected from the group consisting of urethane resin, polyester resin, acrylic resin, and vinyl resin-modified polyester resin. It is preferable that an easily adhesive layer made of at least one kind of aqueous resin (water-soluble or water-dispersible resin) is laminated. The lamination of the easily adhesive layer is preferable because the adhesion between the ink layer composed of the sublimable dye and the resin binder and the base film becomes strong. In addition to the above-mentioned aqueous resin, an epoxy resin, a melamine resin, an oxazoline resin, a vinyl resin, or a polyether resin can be used for the easily adhesive layer.

Examples of the components constituting the urethane resin used in the easily adhesive layer include the following polyvalent hydroxy compounds, polyvalent isocyanate compounds, chain extenders, cross-linking agents, and the like. That is, as the polyvalent hydroxy compound, polyoxyethylene glycol, polyoxypropylene glycol, polyethers such as polyoxytetramethylene glycol, polyethylene adipate, polyethylene-butylene adipate, polyesters such as polycaprolactone, polycarbonates,
Acrylic polyols, castor oil and the like can be exemplified. Examples of the polyvalent isocyanate compound include tolylene diisocyanate, phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, and 4,4'-
Examples include dicyclohexylmethane diisocyanate and isophorone diisocyanate. Examples of the chain extender or crosslinking agent include ethylene glycol, propylene glycol, diethylene glycol, trimethylolpropane, hydrazine, ethylenediamine, diethylenetriamine, ethylenediamine-sodium acrylate adduct, 4,4′-diaminodiphenylmethane, and 4,4 ′.
-Diaminodicyclohexylmethane, water and the like. The urethane resin can be obtained by appropriately selecting one or more of these compounds and synthesizing a polyurethane by a conventional polycondensation-crosslinking reaction.

As the components constituting the polyester resin used in the easily adhesive layer, the following polyvalent carboxylic acids and polyvalent hydroxy compounds can be exemplified. That is, as the polyvalent carboxylic acid, terephthalic acid, isophthalic acid, orthophthalic acid, 4,4′-diphenyldicarboxylic acid,
2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid,
2-potassium sulfoterephthalic acid, 5-sodium sulfoisophthalic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, glutaric acid, succinic acid, trimellitic acid, trimesic acid, trimellitic anhydride, phthalic anhydride, p -Hydroxybenzoic acid, monopotassium trimellitate, and ester-forming derivatives thereof, and the like. Examples of the polyvalent hydroxy compound include ethylene glycol, 1,2-propylene glycol, and 1,3.
-Propylene glycol, 1,4-butanediol,
1,6-hexanediol, 2-methyl-1,5 pentanediol, neopentyl glycol, 1,4-cyclohexanedimethanol, p-xylylene glycol, bisphenol A-ethylene glycol adduct, bisphenol A 1,2-propylene glycol Additives, diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polytetramethylene oxide glycol, dimethylolpropionic acid, glycerin, trimethylolpropane, sodium dimethylolethyl sulfonate, potassium dimethylolpropionate, etc. Can be exemplified. As the polyester resin, one or more polyvalent carboxylic acids and one or more polyvalent hydroxy compounds are selected from these compounds, and a polyester is synthesized by a conventional polycondensation reaction. In addition to the above, a composite polymer having a polyester component such as a polyester polyurethane obtained by chain-extending a polyester polyol with an isocyanate is also included in the polyester-based resin referred to in the present invention.

The acrylic resin preferably contains an alkyl acrylate or an alkyl methacrylate as a main component. The content of the acrylic resin is 30 to 90 mol%, and a copolymerizable and functional group-containing vinyl monomer component 10 to 7 is used.
It is a water-soluble or water-dispersible resin containing 0 mol%. Vinyl monomers having a functional group copolymerizable with an alkyl acrylate or an alkyl methacrylate have a carboxyl group or a salt thereof, an acid anhydride group, a sulfonic acid group or a salt thereof, an amide group or an alkylol group as a functional group. It is a vinyl monomer having an amide group, an amino group (including a substituted amino group) or an alkylolated amino group or a salt thereof, a hydroxyl group, an epoxy group and the like. Of these, particularly preferred are a carboxyl group or a salt thereof, an acid anhydride group, an epoxy group and the like. Two or more of these groups may be contained in the resin. Examples of the alkyl group of the alkyl acrylate and the alkyl methacrylate include a methyl group, an ethyl group,
Examples include an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, a 2-ethylhexyl group, a lauryl group, a stearyl group, and a cyclohexyl group.

As the vinyl monomer having a functional group copolymerizable with an alkyl acrylate or an alkyl methacrylate, the following compounds having a functional group such as a reactive functional group, a self-crosslinkable functional group, and a hydrophilic group can be used. . Examples of the compound having a carboxyl group or a salt thereof, and an acid anhydride group include acrylic acid, methacrylic acid, itaconic acid, maleic acid, metal salts of these carboxylic acids with sodium, ammonium salts, maleic anhydride, and the like. . Examples of the compound having a sulfonic acid group or a salt thereof include vinyl sulfonic acid, styrene sulfonic acid, metal salts of these sulfonic acids with sodium and the like, and ammonium salts. Examples of the compound having an amide group or an alkylolated amide group include acrylamide, methacrylamide, N-methylmethacrylamide, methylolated acrylamide, methylolated methacrylamide, ureido vinyl ether, β-ureido isobutyl vinyl ether, and ureido ethyl acrylate. No. Examples of the compound having an amino group or an alkylolated amino group or a salt thereof include diethylaminoethyl vinyl ether, 2-aminoethyl vinyl ether, 3-aminopropyl vinyl ether, 2-aminobutyl vinyl ether, dimethylaminoethyl methacrylate, and dimethylaminoethyl. Vinyl ethers, those whose amino groups are methylolated,
Examples thereof include those quaternized with an alkyl halide, dimethyl sulfate, sultone, or the like. As the compound having a hydroxyl group, β-hydroxyethyl acrylate, β
-Hydroxyethyl methacrylate, β-hydroxypropyl acrylate, β-hydroxypropyl methacrylate, β-hydroxyethyl vinyl ether, 5-hydroxypentyl vinyl ether, 6-hydroxyhexyl vinyl ether, polyethylene glycol monoacrylate, polyethylene glycol monomethacrylate, polypropylene glycol monoacrylate, Examples of the compound having an epoxy group, such as polypropylene glycol monomethacrylate, include glycidyl acrylate and glycidyl methacrylate. Other compounds having a functional group include vinyl isocyanate and allyl isocyanate.
Further, olefins such as ethylene, propylene, methylpentene, butadiene, styrene, α-methylstyrene, vinyl methyl ether, vinyl ethyl ether, vinyl trialkoxysilane, acrylonitrile,
Methacrylonitrile, vinylidene chloride, vinyl chloride, vinylidene fluoride, ethylene tetrafluoride, vinyl acetate, and the like are also examples of the vinyl monomer compound.

The water-soluble or water-dispersible resin of the vinyl resin-modified polyester resin can be synthesized by copolymerizing the vinyl resin in a water-soluble or water-reactive resin of polyester. Examples of the components constituting the polyester include the following polybasic acids or their ester-forming derivatives and polyols or their ester-forming derivatives. That is, as the polybasic acid component, terephthalic acid, isophthalic acid, phthalic acid, phthalic anhydride, 2,6-
Naphthalenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, adipic acid, sebacic acid, trimellitic acid,
Pyromellitic acid, dimer acid and the like. A copolymerized polyester resin is synthesized using two or more of these acid components. In addition, a small amount of an unsaturated polybasic acid component such as maleic acid, itaconic acid, and hydroxycarboxylic acid such as p-hydroxybenzoic acid can be used. Further, as the polyol component, ethylene glycol,
1,4-butanediol, diethylene glycol, dipropylene glycol, 1,6-hexanediol, 1,
4-cyclohexanedimethanol, xylene glycol, dimethylolpropane, poly (ethylene oxide)
Glycol, poly (tetramethylene oxide) glycol and the like. Two or more of these can be used. Examples of the vinyl resin component include vinyl monomers as exemplified below. Examples of the vinyl monomer include alkyl acrylates and alkyl methacrylates (the alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, 2-ethylhexyl, cyclohexyl) Group), 2-hydroxyethyl acrylate, 2-
Hydroxy-containing monomers such as hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, acrylamide, methacrylamide, N-alkylacrylamide, N-alkylmethacrylamide, N, N-dialkylacrylamide, N, N-dialkylmethacrylate (As the alkyl group, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, a 2-ethylhexyl group, a cyclohexyl group, etc.),
N-alkoxyacrylamide, N-alkoxymethacrylamide, N, N-dialkoxyacrylamide,
N, N-dialkoxymethacrylamide (alkoxy groups include methoxy, ethoxy, butoxy, isobutoxy, etc.), N-methylolacrylamide, N-
Amide group-containing monomers such as methylol methacrylamide, N-phenylacrylamide, N-phenyl methacrylamide, glycidyl acrylate, glycidyl methacrylate, epoxy group-containing monomers such as allyl glycidyl ether, acrylic acid, methacrylic acid, itaconic acid,
Monomers containing a carboxy group or a salt thereof such as maleic acid, fumaric acid, crotonic acid, styrenesulfonic acid and salts thereof (sodium salt, potassium salt, ammonium salt, tertiary amine salt, etc.), maleic anhydride, itacone anhydride Monomers of acid anhydrides such as acids, vinyl isocyanates,
Allyl isocyanate, styrene, α-methylstyrene, vinyl methyl ether, vinyl ethyl ether, vinyl trialkoxysilane, alkyl maleic acid monoester, alkyl fumaric acid monoester, alkyl itaconic acid monoester, acrylonitrile, methacrylonitrile, vinylidene chloride, Examples include monomers such as ethylene, propylene, vinyl chloride, vinyl acetate, and butadiene. In addition, these monomers are exemplified, but not limited thereto. These monomers can be copolymerized using one kind or two or more kinds.

The coating solution for forming the easily adhesive layer of the present invention may contain a small amount of organic solvent as long as it does not affect the water-soluble or water-dispersible resin of the above resin and other additives.
This coating liquid can be used by adding a required amount of a surfactant such as an anionic surfactant, a cationic surfactant, or a nonionic surfactant. As such surfactants, those which can lower the surface tension of the aqueous coating solution to 40 dyne / cm or less and promote the wetting of the film of the present invention are preferable. For example, polyoxyethylene alkylphenyl ether, polyoxyethylene-fatty acid ester, sorbitan Examples include fatty acid esters, glycerin fatty acid esters, fatty acid metal soaps, alkyl sulfates, alkyl sulfonates, alkyl sulfosuccinates, quaternary ammonium chloride salts, alkylamine hydrochlorides, betaine surfactants, and the like.

In the easily adhesive layer of the film of the present invention, an isocyanate compound as a cross-linking agent for improving the fixing property (blocking property), water resistance, solvent resistance and mechanical strength,
It may contain an epoxy compound, an oxazoline compound, an aziridine compound, a melamine compound, a silane coupling agent, a titanium coupling agent, a zirco-aluminate coupling agent, or the like. If the resin component has a crosslinking reaction point, a reaction initiator such as a peroxide or an amine, or a sensitizer may be contained in a photosensitive resin or the like. Also,
In order to improve the sticking property and the slipperiness, silica, silica sol, alumina, alumina sol, zirconium sol, kaolin, talc, calcium carbonate, calcium phosphate, titanium oxide, barium sulfate, as inorganic fine particles in the easily adhesive layer,
Carbon black, molybdenum sulfide, antimony oxide sol, and the like may be contained as organic fine particles, such as polystyrene, polyethylene, polyamide, polyester, polyacrylate, ethoxy resin, silicone resin, and fluorine resin. Further, if necessary, an antifoaming agent, a coating improver, a thickener, an antistatic agent, an organic lubricant, an antioxidant, a foaming agent, a dye, a pigment and the like may be contained.

It is preferable that the coating solution for forming the easily adhesive layer is applied to one or both surfaces of the film before the crystal orientation is completed in the film production process of the present invention. Coating may be performed separately from the film manufacturing process, but in this case, dust and dirt are likely to be involved, and that portion becomes a drawback during printing, so that a clean atmosphere is desirable. From the viewpoint of inexpensive production, coating during the production process is preferred. At that time, the solid content concentration of the coating solution is usually 0.1 to 30% by weight, more preferably 1 to 1% by weight.
0% by weight. The coating amount is preferably 0.5 to 50 g per 1 m ^{2 of the} running film.

Known coating methods can be applied. For example, roll coating, gravure coating, roll brushing, spray coating, air knife,
An impregnation method, a curtain coating method, or the like may be applied alone or in combination.

[Film Forming Method] The film for a thermal transfer ribbon of the present invention is preferably a biaxially oriented film. The biaxially oriented film is preferably stretched in a biaxial direction (longitudinal and lateral directions) at a stretching ratio of 2.5 times or more. The stretching ratio in the biaxial direction may or may not be equal.
The film may be a single film or a laminated film.

The film forming method for obtaining the heat-sensitive transfer ribbon film of the present invention is not particularly limited. For example, a normal extrusion temperature, that is, a melting point (hereinafter referred to as Tm) or more (Tm)
+ 70 ° C.) and rapidly cooled on the surface of a rotary cooling drum to have an intrinsic viscosity of 0.4.
An unstretched film of 0 to 0.80 is obtained, and the unstretched film is vertically stretched at a temperature not lower than the secondary transition point (hereinafter referred to as Tg) of copolymerized polyethylene-2,6-naphthalate and not higher than (Tg + 70 ° C.). The film is stretched at a draw ratio of 0.5 to 5.0 times, and after applying the coating material as necessary, a draw ratio of 2.5 to 5.5 times at a temperature of Tg or more and (Tg + 70 ° C.) or less in the lateral direction. And can be obtained by stretching. The biaxially oriented film thus obtained is (Tg + 70
It is preferable to heat-set at a temperature of at least (C) to Tm for 1 to 100 seconds.

The structure of a thermal transfer ribbon using the thermal transfer ribbon film of the present invention will be described.

[Thermal Transfer Ink Layer] When an easily adhesive layer is provided on one side of the film for a thermal transfer ribbon of the present invention, a thermal transfer ink layer is provided on the surface of the easily adhesive layer to prepare a thermal transfer ribbon.

The thermal transfer ink layer is not particularly limited, and a known one can be used. That is,
It is composed of a binder component, a coloring component, and the like as main components, and an appropriate amount of a softening agent, a plasticizer, a derivatizing agent, and the like, if necessary. Specific examples of the main component include, as binder components, known waxes such as carnauba wax and paraffin wax, celluloses, polyvinyl alcohols, partially acetalized polyvinyl alcohol, polyamides, and various low-melting polymer materials. The coloring agent is mainly composed of carbon black, and other various dyes or organic or inorganic pigments are used. Further, the thermal transfer ink layer may contain a sublimable dye. Various disperse dyes and basic dyes can be used as the sublimable dye.

As a method for providing the thermal transfer ink layer on the surface of the easy-adhesion layer of the base material layer, there are known methods, for example, hot melt coating, a solution coating method such as gravure, reverse or slit die method with a solvent added, and the like. Can be used.

[Fusion Prevention Layer] In order to prevent sticking of the thermal head portion, a layer is preferably formed of a polyol, for example, a polyalcohol, a polyisocyanate compound and a phosphoric acid polyester-based compound on the side where the thermal transfer ink layer is not provided. Examples of such a polyalcohol include a polyvinyl butyral resin having a hydroxyl group, a polyester resin, a polyether resin, a polybutadiene resin,
Acrylic polyols, nitrocellulose resins, cellulose acetate resins, cellulose acetate resins, urethane and epoxy prepolymers can be preferably used. Further, the anti-fusing layer may be provided after unstretching or longitudinal stretching, or may be performed after the film is once wound as a biaxial film. By doing this,
After processing into a transfer ribbon, the thermal history applied to the base from the thermal head can be reduced, which is preferable.

[0063]

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. The method for measuring and evaluating the characteristic values will be described below.

(1) Content of diethylene glycol (DEG) The polymer is decomposed using hydrazine hydrate and quantified by gas chromatography.

(2) Film-forming properties When casting by applying a voltage of 7000 V between the polymer and the cooling drum by an electrode placed near the die for extruding the polymer into a film and above the extruded film, No pin-shaped defects (pinner bubble)
Whether or not the film could be stably formed without lowering the uniformity of the thickness was visually observed as the film forming property of the film, and evaluated according to the following criteria. Rank A: Breakage does not occur, and a film can be formed extremely stably. Rank B: Breakage hardly occurs, and stable film formation is possible. Rank C: Breakage sometimes occurs, and film formation is unstable. Rank D: Breakage occurs frequently, and substantially stable film formation is impossible.

(3) AC volume resistivity Measured using the apparatus shown in FIG. The films are stacked so that the measurement sample has a thickness of about 150 μm. Diameter 2
An upper electrode 3 having a diameter of 5.6 cm and a thickness of 0.2 cm capable of holding a parallel gap of 150 μm is arranged on the upper surface of a cylindrical lower electrode 2 of 0 cm, and the measurement sample is inserted so as to be in close contact with the electrode. I do. The lower electrode has a built-in heating device 4 and a temperature detecting end 5, and the variation in the surface temperature of the lower electrode on the measurement surface is within 1 ° C., and the temperature difference with the detecting end is within 2 ° C. at a heating rate of 8 ° C./min. It is configured so that The detected temperature is measured by the reading thermometer 7. The whole of the electrode is placed in the heat insulation box 11. The power supply 8 applies the generated voltage between the two electrodes via the standard resistor 9. The power supply is a power supply that generates 100 V DC when measuring the DC volume resistivity of the film. When measuring the resistivity, it is a power supply generating 100 V and 50 Hz. The current flowing through this circuit is obtained by reading the voltage generated across the standard resistor 9 with an electron meter 10 having an internal impedance of 100 MΩ or more. Measurement of the AC volume resistivity of the film at the time of melting in the present invention, by the above device,
The temperature rise rate of the lower electrode is 8 ° C./min.
Melting point measured by SC + temperature of 20 ° C (polyethylene-
(290 ° C. in the case of 2,6 naphthalate), and the AC volume resistivity Z is obtained from the following equation from the applied voltage E, current I, electrode area S, and electrode interval d. Z = (E / I) × (S / d)

(4) Heat Shrinkage Rate Each set time (150 ° C. is 30) in an oven set at each temperature (150, 200, 230 ° C.) without tension.
The film is held and the dimensional change before and after the heat treatment is calculated as the heat shrinkage ratio by the following equation. Heat shrinkage% = {(L ₀ −L) / L} × 100 L ₀ : distance between gauge points before heat treatment L: distance between gauge points after heat treatment

(5) 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.

(6) Film Thickness When the width of the sample film is W (cm), the length is 1 (cm), the weight is G (g), and the density is d (g / cm ³ ), the film thickness t ( μm) was calculated by the following equation. t = G / (W × 1 × d) × 10000

(7) Plane Orientation Coefficient (NS) The refractive index is measured using an Abbe refractometer and a sodium D line (589 nm) as a light source, and is determined by the following equation. NS = (nMD + nTD) / 2-nZ Here, nMD represents the refractive index in the machine axis direction of the biaxially oriented film, nTD represents the refractive index in the direction (width direction) orthogonal to the machine axis direction, and nZ is the film's refractive index. Indicates the refractive index in the thickness direction.

(8) Slit property A film roll having a length of 2000 m and a width of 500 mm is slit, and a slit product having a length of 200 m and a width of 5 mm is cut into 100 pieces.
Created. The slit property was evaluated by the number of slit products including the cut portion. Rank A (excellent slitting property): Number of slit products including cut section: within 1 Rank B (usable): Number of slit products including cut section: within 4 Rank C (unusable): Slit product including cut section Number of ... 5 or more

(9) Adhesiveness A mending tape 810 manufactured by Sumitomo 3M Co., Ltd. was adhered to the ink layer surface of the produced thermal transfer ribbon to perform rapid peeling, and the adhesiveness was determined as follows depending on the degree of peeling of the ink layer. evaluate. 5: no ink layer peeling at all 4: ink layer peeling area less than 10% 3: ink layer peeling area 10 to 30% 2: ink layer peeling area 30 to 80% 1: ink layer peeling area over 80%

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

[Examples 1 to 4] Dimethyl 2,6-naphthalenedicarboxylate and dimethyl isophthalate were added in the amounts shown in Table 1, and 0.03 parts of manganese acetate tetrahydrate was added to a mixture of 60 parts of ethylene glycol. Was added, and a transesterification reaction was carried out while gradually raising the temperature from 150 ° C. to 240 ° C. During the reaction, when the reaction temperature reached 170 ° C., 0.024 parts of antimony trioxide was added, and the average particle size was further reduced to 1.5 μm.
0.3% by weight of spherical silica (based on final polymer)
And 0.1% by weight of spherical silica having an average particle diameter of 0.3 μm
(To the final polymer) and then at 220 ° C., 0.042 parts of 3,5-dicarboxybenzenesulfonic acid tetrabutylphosphonium salt (2 mmol%
Was added). Subsequently, a transesterification reaction is performed, and after the transesterification reaction is completed, trimethyl phosphate 0.023
Parts were added. Thereafter, the reaction product is transferred to a polymerization reactor,
The temperature was raised to 290 ° C., the polycondensation reaction was performed under a high vacuum of 0.2 mmHg or less, the intrinsic viscosity measured with an o-chlorophenol solution at 25 ° C. was 0.61 dl / g, and the DEG copolymerization amount was 1.1. A mole% of a polyethylene-2,6-naphthalate copolymer was obtained. After drying the polymer at 170 ° C. for 6 hours, it is fed to an extruder, melted at a melting temperature of 310 ° C., and passed through a slit die having an opening of 1 mm, with a surface finish of 0.3 S and a surface temperature of 50 ° C. on a rotating drum. To obtain an unstretched film.

The unstretched film thus obtained was treated with 140
The film was stretched 4.5 times in the machine direction at ℃. On the side of the longitudinally stretched film where the ink layer is not applied, a coating having the following composition is applied with a gravure coater as a fusion preventing layer so that the coating thickness after drying is 0.5 μm, and the ink layer is formed. A coating having the following composition is dried on the side to be coated as an easy-adhesion layer.
Coating was performed with a gravure coater so that the thickness became 1 μm. Subsequently, the film is stretched 3.9 times in the transverse direction at 140 ° C., further heat-set at a maximum temperature of 240 ° C. for 5 seconds, and simultaneously subjected to a 3% tensioning treatment in the width direction to obtain a biaxially oriented copolymer polyethylene having a thickness of 3.0 μm. A 2,6-naphthalate film was obtained.

<Coating composition for anti-fusing layer> Acrylic ester 14.0% by weight Amino-modified silicone 5.9% by weight Isocyanate 0.1% by weight Water 80.0% by weight

<Coating Composition for Easy Adhesive Layer (Acrylic + Polyester + Epoxy)> Acrylic resin 42 solid content% by weight (methyl methacrylate 65 mol% / ethyl acrylate 28 mol% / 2-hydroxyethyl methacrylate 2 mol% / (N-methylol acrylamide 5 mol%) Polyester resin 42 solid weight% (acid component: terephthalic acid 35 mol% / isophthalic acid 13)
Mole% / 5-sodium sulfoisophthalic acid 2 mole%,
Glycol component: ethylene glycol 45 mol% / diethylene glycol 5 mol%) Epoxy crosslinking agent 6 solid content% (N, N, N ', N'-tetraglycidyl-m-xylylenediamine) wetting agent 10 solid content weight% (Lauryl polyoxyethylene) The obtained biaxially oriented copolymerized PEN film was measured and evaluated for AC volume resistivity, longitudinal and lateral heat shrinkage, plane orientation coefficient, density, film forming property and slit property. Next, a thermal transfer ink having the following composition was applied to the surface opposite to the anti-fusing layer with a gravure coater so that the coating film thickness became 1.0 μm, thereby producing a thermal transfer ribbon.

<Thermal transfer ink composition> 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 Ink adhesion of the prepared thermal transfer ribbon And printability were evaluated. Table 1 shows the results of these evaluations.

Example 5 Example 1 was the same as Example 1 except that the content of the isophthalic acid component was 3 mol%, and the stretching ratio was 5.0 times in the vertical direction and 3.8 times in the horizontal direction. In the same manner as in the above, a biaxially oriented copolymerized polyethylene-2,6-naphthalate film having a thickness of 3.0 μm and a thermal transfer ribbon based on the film were obtained. Table 1 shows the results of these evaluations.
Shown in

Comparative Example 1 A biaxially oriented polyethylene-2,6-naphthalate film having a thickness of 3.0 μm and a heat-sensitive transfer base based on the biaxially oriented polyethylene-2,6-naphthalate film in the same manner as in Example 1 except that no isophthalic acid component was contained. I got a ribbon. Table 1 shows the results of these evaluations. As is clear from Table 1,
The film of Comparative Example 1 had unsatisfactory slitting properties.

Comparative Example 2 A biaxially oriented polyethylene-2,6-naphthalate film having a thickness of 3.0 μm and a heat-sensitive transfer based on the same as in Example 1 except that no quaternary phosphonium salt was added. I got a ribbon. Table 1 shows the results of these evaluations. As is clear from Table 1, the film of Comparative Example 2 had an excessively high AC volume resistivity and was poor in film-forming properties.

[Comparative Example 3] A biaxially oriented polyethylene-2,6-naphthalate film having a thickness of 3.0 µm and a base made of the same as in Example 1 except that the draw ratio was set to 4.9 x 5.6. A thermal transfer ribbon was obtained. Table 1 shows the results of these evaluations. As is clear from Table 1, the film of Comparative Example 3 had an excessively large surface orientation coefficient, was poor in film-forming properties, and could not be evaluated for printability.

[Comparative Example 4] 15 mol% of isophthalic acid
In the same manner as in Example 1, a biaxially oriented polyethylene-2,6-naphthalate film having a thickness of 3.0 μm and a thermal transfer ribbon based on the film were obtained in the same manner as in Example 1. Table 1 shows the results of these evaluations. As is clear from Table 1,
The film of Comparative Example 4 had a large heat shrinkage at high temperature and poor printability.

Comparative Example 5 A biaxially oriented polyethylene-2,6-naphthalate film having a thickness of 3.0 μm and a heat-sensitive transfer based on the same were carried out in the same manner as in Example 1 except that the heat setting temperature was 210 ° C. I got a ribbon. Table 1 shows the results of these evaluations. As is clear from Table 1, the film of Comparative Example 5 had a large heat shrinkage at a high temperature, and the printability was unsatisfactory.

[Comparative Example 6]
The same procedure as in Example 1 was carried out except that it was added so that the concentration became 2 mol%.
A naphthalate film and a thermal transfer ribbon based thereon were obtained. Table 1 shows the results of these evaluations. As is clear from Table 1, the film of Comparative Example 6 had low strength, the ribbon was elongated and deformed, the heat shrinkage was large, and the printability was poor.

[0086]

[Table 1]

[0087]

According to the present invention, a transferred image having small deformation of the film upon heating, excellent adhesion to the thermal transfer ink layer, high sensitivity and excellent gradation can be obtained, A film for a thermal transfer ribbon made of biaxially oriented copolymerized PEN having excellent flatness and excellent productivity with little breakage during slitting can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an AC volume resistivity meter.

[Explanation of symbols]

 1: Measurement samble 2: Columnar lower electrode (diameter 20 cm) 3: Upper electrode (diameter 5.6 cm, thickness 0.2 cm) 4: Power supply device 5: Temperature detection end 6: Power supply 7: Temperature display section 8: Power supply 9: Standard resistance 10: Electron meter 11: Heat insulation box

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B29L 7:00 B41M 5/26 101A F-term (Reference) 2H111 AA01 AA15 AA26 AA27 BA07 BA53 BB06 BB08 DA04 4F071 AA45 AA80 AB26 AF11 AF61 AH16 BA01 BB06 BB08 BC01 BC11 BC12 4F210 AA21 AA24 AA26A AA31 AE01 AG01 AG03 QC05 QG01 QG11 QG15 QG18 4J002 CF081 CF091 FD010 GF00 GS00

Claims (3)

[Claims] (1) Mainly ethylene-2,6-naphthalate
Repeat unit, and the total amount of all dicarboxylic acid components
0.1 to 10 mol% of sophthalic acid component, all glycol components
0 to 3 mol of diethylene glycol component based on total amount of
% Copolymerized polyethylene-2,6-naphthale
A film comprising a sheet as a main component, the film
AC volume resistivity of the melt is 6 × 10⁸Ωcm or less
And the plane orientation coefficient of the film is 0.230 or more and 0.275 or more.
Hereinafter, the density is 1.350 g / cm ^ThreeIt is more than
Thermal transfer ribbon film. 2. The thickness is 1 to 9 μm, and 150 ° C. × 3.
The shrinkage rate in the longitudinal direction and the width direction after the 0 minute treatment is 3% or less, respectively, the shrinkage rate in the longitudinal direction and the width direction after the treatment at 200 ° C. × 10 minutes is 5% or less, respectively, and the longitudinal length after the treatment at 230 ° C. × 10 minutes. 10% shrinkage in both the width and width directions
2. The film for a thermal transfer ribbon according to claim 1, wherein: 3. A coating liquid containing at least one aqueous resin selected from the group consisting of a urethane resin, a polyester resin, an acrylic resin and a vinyl resin-modified polyester resin is applied to a film before completion of orientation crystallization, and then dried.
3. The film for a heat-sensitive transfer ribbon according to claim 1, wherein an easily adhesive layer obtained by stretching and heat-setting is laminated on at least one surface.