JPS62193889A - Transfer ribbon for printer - Google Patents

Abstract

PURPOSE:To contrive higher feedability, durability and transfer properties, by specifying surface characteristics of a biaxially oriented polyester film of the titled ribbon which comprises a transfer ink layer on one side of the polyester film. CONSTITUTION:A transfer ink layer is provided on one side of a biaxially oriented polyester film. The film has a Young's modulus in the machine direction of 450-800kg/mm<2> and coefficients of heat shrinkage in the machine direction and the transverse direction at 150 deg.C of not more than 7%. The surface of the film on which the transfer layer is to be provided has such surface characteristics that a projection distribution curve representing the relationship between the number of projections (Y: pieces/mm<2>) and the projection height (X: mum) measured by a three-dimensional roughness tester does not intersect with a line represented by the Formula log10Y=-1.8X+3.9 in a region represented by log10Y>1.3, and the curve at the part of the maximum of the projection distribution and at the part beyond said part lies in a region represented by log10Y>=-3.6X+2.8. The polyester may be, for example, a polyester comprising an alkylene terephthalate and/or an alkylene naphthalate.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a transfer ribbon for a printer, and more particularly to a transfer ribbon for a printer that has excellent runnability, durability, and transferability.

The base material of the transfer ribbon for conventional printers is a polyester film that has the same properties as chemical resistance, 2 strength, and 2 elastic modulus.

It is widely used because it has excellent properties such as heat resistance, crystallinity, and high contact point.

However, with conventional ink transfer ribbons using biaxially oriented polyester films, the film may be deformed or stretched due to unprinted areas during transfer using the dot impact method, and furthermore, the ink applied to the polyester substrate may The layer is transferred to the opposite side (running surface) of the ribbon, contaminating the running surface of the ribbon, and this gradually accumulates ink on the contact points of the guide posts in the running system, causing problems with the running of the ribbon.
511''#, and in extreme cases, problems such as the ribbon not moving occur, and this problem needs to be improved.

OBJECTS OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and provide a transfer ribbon for printers that has excellent running properties, durability, and transferability.

Structure/Effects of the Invention According to the present invention, there is provided a transfer ribbon for a printer provided with a biaxially oriented poly(I) ester film having a thickness of 1 to 25 μm. The film has a Young's modulus in the longitudinal direction of 450 to 5 oky/mm2
And the heat shrinkage rate at 150℃ in the vertical and horizontal directions is 7.
% or less, and furthermore, the surface of the film on which the transfer ink layer is provided has a protrusion count (Y2/j!I) measured with a three-dimensional roughness meter.
The protrusion distribution curve representing the relationship between I) and protrusion height (X: μm) is 1all. In the area of y>1.3, the following formula (
1) The maximum value of the KMi protrusion distribution and the curve of the part exceeding the maximum value, which does not intersect the line expressed by % formula % ( ), is within the range that satisfies the following formula (2) % formula % (2) This is achieved by a printer transfer ribbon characterized by having surface properties.

The polyester in the present invention is a polyester having an aromatic dicarboxylic acid as the main acid component and an aliphatic glycol as the main glycol component. Such polyesters are substantially linear and have film forming properties, particularly by melt molding. Aromatic dicarboxylic acids include, for example, terephthalic acid, naphthalenedicarboxylic acid, inphthalic acid, nphenoquinethanedicarboxylic acid, diphenyldicarboxylic acid, diphenylneedledicarboxylic acid, diphenylsulfonedicarboxylic acid, diphenylctonedicarboxylic acid, anthracenedicarboxylic acid Acids etc.

Aliphatic glycols include, for example, ethylene glycol, trinotylene glycol, tetramethylene glycol, pentamethylene glycol, hexamethylene glycol,
These include polymethylene glycols having 2 to 10 carbon atoms such as decamethylene glycol, and alicyclic diols such as cyclohexane dimetatool.

In the present invention, polyesters containing, for example, alkylene terephthalate and/or fullkylene naphthalate as main constituents are preferably used. Particularly preferred is a copolymer in which 80 moles or more of the total glyfur component is ethylene glycol, which is λ, thielephthalic acid and/or 7thalene dicarboxylic acid. In this case, the dicarboxylic acid of up to 20 molar of the total acid component can be the above-mentioned aromatic dicarboxylic acids, and also, for example, aliphatic dicarboxylic acids such as 7-divic acid and cepatic acid; cyclohexane-1,
It can be an alicyclic dicarboxylic acid such as 4-dicarboxylic acid. Also, up to 20 moles of the total glycol component can be the above-mentioned glycols other than ethylene glyfur, or for example hydroquinone, resorcinol.

2. Aromatic diols such as 2-bis(4-hydroxyphenyl)propane; aliphatic diols containing aromatics such as lI4-dihydroquinemethylbenzene; polyfulkylene glycols such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol ( Polyoxyalkylene glycol) and the like can also be used.

In addition, the polyester used in the present invention may contain a dicarboxylic acid component and a component derived from an oxycarboxylic acid such as an aromatic oxyacid such as hydroxybenzoic acid; an aliphatic oxyacid such as ω-hydroxycapunic acid; Those containing 20 moles or less based on the total amount of carboxylic acid components are also included. Furthermore, the polyester in the present invention contains a trifunctional or higher functional polycarboxylic acid or a polyhydroxy compound, such as trimellitic acid, pentaerythritol, in an amount within a substantially linear range, for example, an amount of 2 mole or less based on the total acid component. Copolymerized products are included.

The above polyester is known per se, and can be produced by a method known per se.

The above-mentioned polyester has an intrinsic viscosity of about 0 as measured at 35°C as a solution in 0-L:l Robenol.
．． 4 to about 0.9 is preferred.

Moreover, the above-mentioned polyester may contain additives such as a stabilizer 9, a coloring agent, and an antioxidant, if necessary.

The two-wheel oriented polyester film in the present invention is a biaxially oriented film devitrified from the above-mentioned polyester, and the film has a longitudinal Young's modulus of 450 to 5ooK.
9. /=, preferably 500-750 kq/md,
More preferably, it has a characteristic of 520 to 700 kg/-. Note that the longitudinal direction of the film coincides with the longitudinal direction of the ink transfer ribbon. This longitudinal Young's modulus is 45
If it is less than 0 to 9/-, the film tends to stretch and is difficult to recover elastically, so if it is used as a rolling pin to print, the printed area will be plastically deformed due to the printing pressure, resulting in thicker printing than necessary. This is not preferable because the clarity of printing is poor, and the deformation makes it difficult to handle when winding up the transfer ribbon.

Also, when the Young's modulus in the longitudinal direction exceeds sookg/-,
Due to the high rigidity, the film tends to tear due to the pressure of printing, which is undesirable.

Furthermore, the biaxially oriented film must have a heat shrinkage rate (deformation rate when exposed to hot air at 150°C for 30 minutes under no load) of 7 or less in both the longitudinal and transverse directions, preferably Both are 4% or less, more preferably both are 2% or less.

If the heat shrinkage rate of the film exceeds 7%, especially when used as a transfer ribbon for a thermal printer, the ribbon will be severely deformed, resulting in poor print clarity and poor handling when winding the transfer ribbon due to the deformation. Also, even in the dot impact method, if the thermal shrinkage rate exceeds 7%, the printed portion is likely to be deformed, which is undesirable.

Moreover, the thickness of the polyester film in the present invention is 1 to
25 μm is commonly used, preferably 2 to 1 OplN
+More preferably 3 to 8 μm.

If the thickness of the film is thinner than the above-mentioned range, the strength will be insufficient, and it will lack suitability when used as a transfer ribbon, and will also be inferior in terms of processing suitability.On the other hand, if the film is thicker than the above-mentioned range, In particular, the thermal transfer method is undesirable because it takes a long time to transfer heat, making it unsuitable for increasing the recording speed and obtaining clear transferred image quality.

The biaxially oriented polyester film of the present invention satisfies the above-mentioned Young's modulus in the longitudinal direction, heat shrinkage rate, and thickness, and at the same time, the surface on which the transfer ink layer is provided has a three-dimensional roughness (number of protrusions measured with a three-dimensional roughness needle) (Y 2 / The protrusion distribution curve representing the relationship between the protrusion height (X: μm) and the protrusion height (mm2) is 1oft. Y) 1.3
has surface characteristics that do not intersect with the line expressed by the above formula (1) in the area of , and further the maximum value of the protrusion distribution and the curve of the portion exceeding the maximum value satisfy the above formula (2). There is a need. The film surface roughness is expressed as logs.

= -3,6 When the ink layer is coated and the film is rolled up, the ink is easily transferred to the opposite side (running surface) of the film and stains the running surface of the ribbon, which may damage the ribbon running system. The ink gradually accumulates on the contact parts such as guide posts, which obstructs the running of the ribbon and, in extreme cases, causes problems such as the ribbon not moving.
In addition, as a result of poor film slipperiness, 1c during processing
This is not desirable as it may cause wrinkles on the film. In addition, if the surface roughness of the film is rough with a protrusion distribution that intersects with the above formula (g), the sharpness of the print will deteriorate, causing wear of the thermal head, and causing practical problems. So I don't like it.

The above-mentioned film surface was coated with a multi-interference reflection microscope (
The number of protrusions (ke/mm2) and the protrusion height (h: μm) measured with TJ monochromatic light are 1.5≧h > t, o...
10 pieces/mm2 or less 1.0≧h > 0.75
...1~30 pieces/mm20.75≧h>
0.5...15-120 pieces/mm2
0.5≦h > 0.25 ・・・・・・ 80 pieces/
It is preferable to satisfy mm2 or more.

Satisfying this surface property is preferably 1% from the viewpoint of preventing transfer of the ink layer to the opposite side of the film and from the viewpoint of print clarity.

In addition, the maximum protrusion height on the film surface is 3 μm or less, and
It is preferable that it is 1.5 μm or less.

The biaxially oriented polyester film of the present invention further has a friction coefficient of 0.5 on the surface on which the transfer ink layer is not provided.
0.45 or less, 1% KO, 35 to 0.45, and the value of the friction coefficient after 50 consecutive reciprocating tests is less than 150%, further less than 120%, compared to the initial value. It is preferable that This surface forms the running surface, so if the coefficient of friction is too large, the running properties of the ribbon will decrease.
If it is too severe, it may cause ribbon breakage and ink transfer, which is undesirable.

The above-mentioned surface roughness of the biaxially oriented polyester film in the present invention is preferably achieved by adding inert inorganic or organic fine particles to the film. When using these inert fine particles, the average particle size is 0.01-10p.
m particles in an amount of 0.01 to 5% by weight, furthermore, the average particle size is 0.
Preferably, 0.01-1.5% by weight of particles of 0.03-4 μm are added. At this time, the inert inorganic or organic fine particles added may be a single component, or two or more components may be used simultaneously.

In the present invention, the above-mentioned inert fine particles preferably include (1) silicon dioxide (including hydrate, diatomaceous earth, silica sand, quartz, etc.); ■ alumina; ■ containing 30% by weight or more of Sin. silicates (e.g. amorphous or crystalline clay minerals, aluminosilicates (including calcined products and hydrated products), warm asbestos, asbestos, fly ash, etc.), ■Mg
+ ZnZ' and oxides of Ti; θJCa and sulfates of Ba; ■ phosphates of Li, Na, and Ca (including l-hydrogen salts and dihydrogen salts); ■ benzoic acid of Li, Na +, and K Salt; ('! J Ca + B a + Z n +
and Mn terephthalate; (!, 1 Mg.

Ca, Ba + Zn, Cd + Pb, Sr, M
titanate of n, Fe, Co and Ni; [phase] Ba
, and pb Normomate; 0 carbon (e.g. carbon black, graphite, etc.); 0 glass (e.g. glass powder, glass peas, etc.) ◎Ca and Mg carbonate;
(2) Fluorite; and [phase] ZnS are exemplified. More preferably, anhydrous silicic acid, hydrated silicic acid, aluminum oxide,
Aluminum silicate (including calcined products, hydrates, etc.), lithium phosphate, trilithium phosphate, sodium phosphate.

Calcium phosphate, baricum sulfate, titanium oxide.

Examples include lithium benzoate, double salts of these compounds (including hydrates), glass powder, clay (including kaolin, bentonite, clay, etc.), talc, diatomaceous earth, calcium carbonate, and the like.

The polyester containing these inert fine particles can be prepared at any time during the reaction to form the polyester, such as during the transesterification reaction or polycondensation reaction when using the transesterification method, or at any time during the polycondensation reaction when using the direct polymerization method. Phase K can be prepared by adding inert microparticles (preferably as a slurry in Glyfur) into the reaction system. Preferably, inert fine particles are added to the reaction system at the initial stage of the polycondensation reaction, for example, until the intrinsic viscosity reaches about 0.3.

The biaxially oriented polyester film used in the present invention is not particularly limited by its manufacturing method, but usually polyester containing a predetermined proportion of fine particles is melted, extruded into a sheet through a slit-shaped die, and cooled and solidified in a casting drum. It is produced by a method in which an unstretched sheet is obtained, and then the unstretched sheet is biaxially stretched to produce a product (film). At that time, in order to suitably satisfy the requirements of the present invention, the unstretched sheet is first heated in a hot bath and stretched in a uniaxial direction, and then heated in hot air in a direction perpendicular to the stretching direction. A method of stretching is preferred.

In the first stretching in a warm bath, the hot bath is boiling water and the stretching ratio is preferably 2.5 times to 6.0 times, more preferably 3.5 times to 5.5 times. For stretching, the hot air temperature is 60~
The temperature is 120°C, preferably 75 to 110°C, and the stretching ratio is 2.
It is preferably 5 times to 4.0 times, more preferably 2.8 times to 3.7 times. Furthermore, the biaxially stretched film obtained is preferably 150 to 245°C, more preferably 170 to 240°C.
Heat set at a temperature in the range of 1 to 200 seconds.

Furthermore, it is also effective to perform relaxation heat treatment at Kl ~ 30% after heat setting, if necessary, to improve dimensional stability.

The biaxially oriented polyester film thus obtained usually exhibits the same surface properties on both the front and back sides. In this case, the surface on which the transfer ink layer is provided may be a surface or a straight surface.

In the present invention, the transfer ink layer is not limited to 1%, and any known ink layer can be used. That is,
The main components are binder component 2, wrapping component, etc., and appropriate amounts of softener, flexibilizer 1, dispersant, smoothing agent, etc. are added as needed.

To explain more specifically about the above-mentioned principal components, first,
As the binder component, well-known waxes such as carnauba wax and paraffin wax and various low-melting point polymer substances are used.As the coloring agent, carbon black is used as the main ingredient, and various other dyes and organic and inorganic dyes are used. Pigments are used. In some cases, the transfer ink may also include a sublimation type.

The transfer ink layer is formed using the usual methods, such as Grapure and Reverse with the addition of a solvent.

This can be carried out using a solution coating method such as a slit die method, or a true melt coating.

At that time, the biaxially oriented polyester film may be subjected to pretreatment such as a coating discharge treatment or a subbing coat with a binder, if necessary.

The transfer ribbon for printers of the present invention has excellent properties originally possessed by biaxially oriented polyester films, such as high chemical resistance, 9 strength, 1 elastic modulus, heat resistance, and high melting point. This eliminates problems such as ink stains accumulating on the running system such as guide posts and causing the ribbon to not run, and when used for impact printing, it also prevents productivity deformities such as unprinted marks due to printing. This ribbon is small and has excellent transfer image quality.

Example The present invention will be further explained below with reference to Examples.

Note that various physical property values and characteristics in the present invention were measured and defined as follows.

(1) Protrusion distribution measurement method Using a three-dimensional roughness meter (5E-3CK) manufactured by Koita Institute, the needle diameter was 2 μmR and the needle pressure was 30 M? + measurement length 1 tm,
Sampling pitch 2μm, cantoff 0.25tl
+20,000x vertical magnification, 200x horizontal magnification,
The protrusion distribution was measured under the condition of 150 scans, and the protrusion height x eAfi) was defined as the O level at the point where the area ratio from the reference level was 70% (Protrusion height 2 level), and the difference from that height was calculated. is the protrusion height, and the corresponding number of protrusions is plotted on the y-axis.

The chuck distance is 100 mm and the pulling speed is 10 mm/min.

It was pulled in an Instrotsutive universal tensile tester at a chart speed of 500 n+/min. Young's modulus was calculated from the tangent to the rising portion of the obtained load-elongation curve.

(3) Number of surface protrusions Aluminum is uniformly vacuum-deposited on the surface of the film to a thickness of 400 to 5ooX or less, and the opposite non-deposited surface (
Cordion was applied to the film surface), pasted, and dried.

Tl monochromatic light multiple interference reflection microscope (e.g. Carl
An arbitrary 100 cIi of the aluminum vapor-deposited surface was observed at a magnification of 100 times using a micrometer (manufactured by Zetas JENA). The number of protrusions with interference fringes generated corresponding to the protrusion height of the protrusions in the microscopic field of view was counted.

(4) Heat shrinkage rate: 300 film samples cut out to a width of 20 μm.Hanged without load on a heated circulating hot air blower for 30 minutes, then taken out and allowed to cool, then read the length between gauge marks. The difference from the original length is expressed as a percentage of the original length.

(5) Ink transferability Carbon black 15 parts by weight Carnauba wax 35 g Ester wax on one side of a 10 μm thick film
32 Polytetrahydrone 1
3. A transfer sheet-like material obtained by applying a transfer ink composition consisting of silicone oil 51 using the Grapure method to a layer thickness of 18 μm.
Cover a film sample of 0I111I width x 20 mouth length,
The surface of the hindlimb sample that was repeatedly pressed 20 times with a hard chromium-treated roll having a diameter of 5α and lkp was traced with a cotton swab moistened with ethyl alfur on the surface that was in contact with the transfer ink layer, and the degree of ink adhesion to the cotton swab (stain level) was measured. was visually evaluated on a five-point scale.

<5-level evaluation> ◎...No ink adhesion is observed ○...
・・・・Almost no ink adhesion is observed △・・・・
・・Ink adhesion is recognized to a certain degree×・・・・Ink adhesion is recognized to a considerable extent××・・・・・・
Severe ink adhesion was observed (6) Runability Measurement was carried out as follows using the apparatus shown in Figure IK. Figure 1
In the middle, l is a load cell, 2 is a plastic fixed rod (outer diameter 5Hφ) with a surface roughness of about 0.5 μm, and 3 is a load (JOO&
r)+5+6 indicates a sample fixture, and 4 indicates a sample (ribbon).

A sample with a width of 8 dragons (a transfer ink layer having the composition shown in (4) above) was applied in an environment of a temperature of 20°C and a humidity of 60%
The surface opposite to the surface coated with the transfer ink (coated to a thickness of μm) (travel surface) is brought into contact with the fixing rod 2 at 90'', and the speed is 3 seconds.
The coefficient of friction was read by reciprocating the length of 30 mouths of a p-docel horizontally at a speed of 2 degrees.

The running performance was judged in three stages by comparing the friction coefficient obtained immediately after the start of measurement with the Nljr% coefficient obtained during 50 consecutive reciprocating runs.

<Three-stage judgment> ○...The friction coefficient after 50 repeated reciprocating runs is less than 120 inches compared to the initial friction coefficient, and the friction coefficient does not increase much due to repeated running.

△...Relative to the initial friction coefficient. The friction coefficient when running back and forth 50 times is 12o% or more and less than 150%, and!
! ! ! A slight increase in the coefficient of friction is observed due to repeated running.

x: The friction coefficient during repeated reciprocating running at 50[il] with respect to the initial friction coefficient is 150 or more, and a significant increase in the friction coefficient is observed with repeated running.

(7) Print clarity The transfer ink layer consisting of the composition shown in (4)K above was coated with 18μ
Using an electric typewriter (IBM82C), type the letters rQJ on the opposite side of the ink-coated surface of the transfer ribbon coated to a thickness of m on regular typewriter paper. The quality, thickness, and shading of the print were visually judged in three stages. (Three-stage judgment) ○... The print is not thick, there are no shading spots, and it is clear. △... The print is slightly thick. However, first of all, it is clear. Using this method, the same spot was struck five times in a row, and the marks on the film were visually evaluated on a three-grade scale.

<Three-stage judgment> ○... Almost no scratches are observed △... Some scratches are visible ×... The scratches are clearly visible Example 1 Ethylene Glyfur (hereinafter abbreviated as EG) ) After adding 10 parts by weight of kaolin (average particle size 1.2 μm) to 90i parts, mixing and stirring were performed to obtain a slurry.

Next, add dimethyltereph clay+・i o o parts by weight and E
After transesterifying G70 parts by weight using 0.035 parts by weight of manganese acetate tetrahydrate as a catalyst in a conventional manner, the kaolin obtained above (concentration 0.4 parts per polymer) was added under stirring. did.

Subsequently, 0.03 parts by weight of trimethyl phosphate and 0.03 parts by weight of antimore trioxide were added, and then a polycondensation reaction was carried out in a conventional manner under high temperature vacuum to obtain polyethylene terephthalate pellets having an intrinsic viscosity of 0.620.

After drying the polyethylene terephthalate (hereinafter abbreviated as PET) pellets at 170°C for 3 hours, the pellets are fed to an extruder hopper and melted at a melting temperature of 280 to 300°C. The product was formed and extruded on a rotating cooling drum with a surface temperature of 20° C. to obtain an unstretched film with a thickness of about 110 μm.

Subsequently, as shown in FIG. 2, this unstretched film is preheated with four heating rolls 31, 32, 33, and 34, and immediately the film is heated in a hot water bath 37.
5 and the roll 36 and stretched 3.9 times in the transverse force direction 1c, and then heat-treated at 230°C for 15 seconds to form a 7.5μ
A biaxially oriented film with a thickness of m was obtained. Note that the stretching speed at this time was 20 m and 7 minutes.

Young's modulus of this film, heat shrinkage rate at 150°C 1 surface roughness protrusion distribution curve, maximum protrusion height.

Also, when the ink layer was applied to form a transfer ribbon, the ink transferability, runnability, print clarity, and fill evaluation were also good. These results are shown in Table IK.

Example 2 The same conditions as in Example 1 were carried out except that calcium carbonate (average particle size 1.5 μm) was added as an additive lubricant at 0% and 4 times f1% per polymer, and a 7.5 μm biaxial An oriented film was obtained.

The surface protrusion distribution curve of this biaxially oriented film was rougher than that of the film obtained in Example 1, and as a result, the ink transferability and runnability were even better, and the overall evaluation was also very good8. These results are shown in Table-1.

Example 3 Among the stretching ratios of Example 2, the longitudinal magnification was 4.2 times and the horizontal magnification was 3.
A biaxially oriented film with a thickness of 7.2 μm was obtained in the same manner as in Example 2, except that the heat setting temperature after the 2-fold and 1-1 transverse stretching was 235° C.

The eyes were also very good.

Example 4 Using the polymer of Example 1 (other than that, Example 3 and r=+
- Processed under stretching and heat setting conditions to obtain a biaxially oriented film with a float of 7.3 μm.

The results are shown in Table 1, and all items were good.

Example 5 A biaxially oriented film having a thickness of 7.5 μm was obtained by stretching and heat setting under the same conditions as in Example 2 except that the heat setting temperature was 215° C.

The results are shown in Table 1, and all items were good.

Example 6 During inversion, 0.45% by weight of calcium carbonate (average particle size 1.5 μm) and silica (average particle size 0) were added as lubricants.
．． 6 μm) with 0.25 weight It%.

Stretched 4.5 times in the machine direction, followed by 3.6 times in the transverse direction.
The thickness was 7.2 μm by carrying out the same procedure as in Example 1 except for double stretching.
A biaxially oriented film was obtained.

The results were as shown in Table IK, and all items were good.

Example 7 In Example 6, silica (average particle size 2.0 μm) was added to 0.0 μm.
1% by weight and 0.4% kaolin (average particle size o, 51 μm)
A thickness of 7 was obtained in the same manner as in Example 6, except that a 1i quantity was used.
．． A 2 μm biaxially oriented film was prepared.

The results were as shown in Table IK, and all items were good.

Comparative Example 1 The unstretched film obtained in Example 1 was preheated at 75°C, and further heated with one infrared heater with a surface temperature of 900°C from 15 m above between low speed and high speed rollers. The film was stretched 3.3 times by the difference in surface speed of a high-speed roller, then fed to a stenter, and stretched 3.8 times in the transverse force direction 1c by 10'cK. The obtained biaxially stretched film was further
The film was heat-set at ℃ for 15 seconds to obtain a film having a thickness of 7.7 μm.

The evaluation results for each item after coating the obtained biaxially oriented film and the ink layer to form a ribbon are as shown in Table 2, and the ink transferability and runnability were at a reasonably good level. , the degree of film deformation and print clarity were poor, and the overall evaluation was also poor.

Comparative Example 2 The unstretched film obtained in Example 2 was biaxially stretched under the stretching conditions of Comparative Example 1, and then heat-set at a temperature of 215°C to a thickness of 7
．． A biaxially oriented film of 7 μm was obtained.

The evaluation results of the obtained biaxially oriented film and ribbon are shown in Table-
As shown in No. 2, the ink transferability and runnability were at a better level than in Comparative Example 1, but the overall evaluation was poor.

Comparative Example 3 An unstretched film obtained by adding 1% of kaolin (average particle size 0.5 μm) to the polymer as an additive lubricant was adjusted to a longitudinal stretching ratio of 3.6 times in Comparative Example 1. A biaxially oriented film with a thickness of 7.5 μm was obtained by stretching and heat setting under the same conditions as in Comparative Example 1, except that the heat setting temperature was 230° C.

The characteristics of the obtained biaxially distributed film are as shown in Table 2, and the surface protrusion distribution curvature was below the preferred range, the ink transferability and runnability were poor, and the overall evaluation was poor. -That's it.

Comparative Example 4 Calcium carbonate (average particle size 1.5 μm) as added lubricant
An unstretched film obtained by adding 0.8% by weight of 0.8% by weight to the polymer was subjected to a comparative device with a longitudinal stretching ratio of 4.2 times, a horizontal stretching ratio of 3.5 times, and a heat setting temperature of 230 ° C. The other conditions were the same as in Comparative Example 1 to obtain a biaxially oriented film with a thickness of 7.5 μm.

The evaluation results for each item of the obtained biaxially oriented film are shown in Table 2.
As shown in FIG. 2, the number of curves in the distribution of different surface protrusions was too coarse, the print clarity was poor, and the overall evaluation was poor.

Comparative Example 5 Calcium carbonate (average particle size 1.5 μm) as added lubricant
Thickness 15 obtained by adding 90.4 N per polymer
An unstretched film of 0 μm was heated at low speed under the conditions of Comparative Example 1 using an infrared heater with a surface temperature of 750°C.

Stretched 3.0 times in the longitudinal direction at the surface speed ratio of high-speed rolls,
Next, it was stretched in the transverse direction at a draw ratio of 3.7 times in hot air at 95°C, and further stretched in the machine direction again at a draw ratio of 1.8 times by heating with an infrared heater with a surface temperature of 1000°C, and then 220' C. to obtain a biaxially oriented film with a thickness of 7.5 μm.

The items of the obtained biaxially oriented film are as shown in Table 2. When printing with a printer, the film was torn in the vertical direction due to the printing pressure.

Clear printing was not possible and the overall evaluation was poor.

Comparative Example 6 A biaxially oriented film with a thickness of 7.5 μm was obtained by processing under the same conditions as in Comparative Example 2 except that the heat setting temperature was 180° C.

The properties of the obtained biaxially oriented film are as shown in Table 2. The film was severely deformed due to the printing pressure, the printing was thick, and the clarity was poor, so the overall evaluation was poor. Ta.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of an apparatus for measuring transfer ribbon runnability, and FIG. 2 is a schematic diagram of a longitudinal stretching machine used in an example of the present invention. FIG. 3 is a diagram showing the relationship between the height of protrusions on the film surface (Y: μm) determined by a three-dimensional roughness meter and the number of protrusions (X: ke/-).

Claims (1)

[Claims] 1. A transfer ribbon for a printer comprising a biaxially oriented polyester film with a thickness of 1 to 25 μm and a transfer ink layer provided on one side, the film having a Young's modulus in the longitudinal direction of 450 to 8.
00kg/mm^2 and 150 in the vertical and horizontal directions
The heat shrinkage rate at °C is 7% or less, and the surface of the film on which the transfer ink layer is provided has a number of protrusions (Y: x/mm^2) and a protrusion height (X: In the area where log_1_0Y>1.3, the protrusion distribution curve representing the relationship with μm) is expressed by the following formula (1) log_1_0Y=-1.8X+3.9 (
The maximum value of the protrusion distribution and the curve of the portion exceeding the maximum value that do not intersect the line represented by 1) are expressed by the following formula (2) log_1_0Y≧−3.6X+2.8 (
2) A transfer ribbon for a printer, characterized by having surface characteristics within a range that satisfies the following. 2. The surface of the polyester film on which the transfer ink layer is to be provided has a number of protrusions (ke/mm^2) and a protrusion height (h: μm) measured with a multiple interference reflection microscope (Tl monochromatic light) of 1.5≧h> 1.0...10 pieces/mm^2 or less 1.0≧h>0.75...1~30 pieces/mm^
20.75≧h>0.5...15-120 pieces/
mm^20.5≧h>0.25...80 pieces/m
The transfer ribbon for a printer according to claim 1, which satisfies m^2 or more. 3. The surface of the polyester film on which the transfer ink layer is not provided has a coefficient of friction of 0.5 or less, and the value of the coefficient of friction after 50 consecutive reciprocating tests is 15% lower than the initial value.
The transfer ribbon for a printer according to claim 1 or 2, wherein the transfer ribbon has a content of less than 0%.