JPH0448358B2 - - Google Patents

Description

[Detailed description of the invention]

<Industrial Application Field> The present invention relates to a transfer material for printers, and more particularly to a transfer material for printers that is excellent in durability, transferability, dimensional stability, runnability, and print clarity. <Prior Art> The basic structure of a transfer material for a printer consists of a base and an ink layer coated on one side of the base. Conventionally, biaxially oriented polyester films have been widely used as this substrate because of their excellent properties such as chemical resistance, strength, elastic modulus, heat resistance, crystallinity, and high melting point. By the way, transfer materials for printers are increasingly being used repeatedly, and the number of times they are used repeatedly is also increasing year by year.For example, with conventional biaxially oriented polyester film, the print area during transfer using the dot impact method is There were problems such as deformation and elongation of the film due to unprinted areas, and deformation due to heat in the thermal transfer method. In addition, the ink layer applied to the polyester film is transferred to the opposite surface (running surface), staining the running surface of the ribbon, and this can cause running problems such as gradual accumulation of ink on contact parts such as guide posts of the running system. Ta. Furthermore, when used repeatedly, so-called ink depletion occurs, causing problems such as the ink's clarity gradually worsening and eventually becoming unable to be transferred, and for this reason, thickening the ink layer reduces the clarity of the print. Another problem arises. <Object of the Invention> The object of the present invention is to solve the above-mentioned problems and provide a transfer material for printers that is suitable for repeated use and has excellent durability, transferability, dimensional stability, runnability, and print clarity. It is in. <Effects/Structure of the Invention> According to the present invention, an object of the present invention is to
In a transfer material for printers in which a transfer ink layer with a thickness of 3 to 25 μm is provided on one side of a 25 μm biaxially oriented polyester film, the Young's modulus in the longitudinal direction of the biaxially oriented polyester film is as follows (a) to (d) (b) is 450 to 800 Kg/ ^mm2 , (b) The heat shrinkage rate at 150℃ in the longitudinal and transverse directions is 7.
(c) The protrusion distribution curve representing the relationship between the number of protrusions (Y: pieces/mm ² ) and the protrusion height (X: μm) measured with a three-dimensional roughness meter on the film surface is log ₁₀ Y ＞1.3, the line expressed by the following formula (1) log ₁₀ Y = -1.8 is in a range that satisfies the following formula (2) log ₁₀ Y ≧ −3.6 A printer characterized in that the part has an average circular equivalent diameter of 0.05 to 3 μm, an average depth of 0.05 to 1.5 μm, and a number of the parts is in the range of 2000 to 100000 pieces/mm ² This is achieved by using a transfer material. The polyester in the present invention is a polyester containing an aromatic dicarboxylic acid as a main acid component and an aliphatic glycol as a main glycol component. Such polyester is substantially linear;
It also has film-forming properties, particularly film-forming properties by melt molding. Examples of aromatic dicarboxylic acids include terephthalic acid, naphthalene dicarboxylic acid, isophthalic acid, diphenoxyethane dicarboxylic acid, diphenyl dicarboxylic acid, diphenyl ether dicarboxylic acid, diphenyl sulfone dicarboxylic acid, diphenyl ketone dicarboxylic acid, and anthracene. Dicarboxylic acids and the like can be mentioned. Examples of aliphatic glycols include polymethylene glycols having 2 to 10 carbon atoms such as ethylene glycol, trimethylene glycol, tetramethylene glycol, pentamethylene glycol, hexamethylene glycol, decamethylene glycol, and alicyclic glycols such as cyclohexanedimethanol. Examples include group diols. In the present invention, polyesters containing, for example, alkylene terephthalate and/or alkylene naphthalate as a main component are preferably used. Among such polyesters, for example, polyethylene terephthalate, polyethylene-2,6-naphthalate,
For example, a copolymer in which 80 mol% or more of the total dicarboxylic acid component is terephthalic acid and/or 2,6-naphthalene dicarboxylic acid and 80 mol% or more of the total glycol component is ethylene glycol is particularly preferred. In this case, up to 20 mol% of the dicarboxylic acid of the total acid component can be the above-mentioned aromatic dicarboxylic acids; for example, aliphatic dicarboxylic acids such as adipic acid and sebacic acid; fatty acids such as cyclohexane-1,4-dicarboxylic acid. dicarboxylic acids and the like. Also, 20 mol% of total glycol components
The following can be the above-mentioned glycols other than ethylene glycol, or aromatic diols such as hydroquinone, resorcinol, 2,2-bis(4-hydroxyphenyl)propane, etc.;
Aliphatic diols containing aromatics such as 1,4-dihydroxymethylbenzene; polyalkylene glycols (polyoxyalkylene glycols) such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, etc. can also be used. In addition, the polyester used in the present invention includes, for example, an aromatic oxyacid such as hydroxybenzoic acid;
Also included are those containing a component derived from an oxycarboxylic acid such as an aliphatic oxyacid such as -hydroxycaproic acid in an amount of 20 mol % or less based on the total amount of the dicarboxylic acid component and the oxycarboxylic acid component. Furthermore, the polyester in the present invention contains a trifunctional or higher functional polycarboxylic acid or a polyhydroxy compound, such as trimellitic acid, in an amount within a substantially linear range, for example, an amount of 2 mol % or less based on the total acid components.
Copolymerized pentaerythritol is also included. The above polyester is known per se, and can be produced by a method known per se. The polyester preferably has an intrinsic viscosity of about 0.4 to about 0.9 as measured as a solution in o-chlorophenol at 35°C. Moreover, the above-mentioned polyester may contain additives such as stabilizers, colorants, and antioxidants, as required. The biaxially oriented polyester film in the present invention is a biaxially oriented film manufactured from the above-mentioned polyester. This film has a longitudinal Young's modulus of 450 to 800 Kg/mm ² , preferably 500 to 750 Kg/mm ² . Note that the longitudinal direction of the film coincides with the longitudinal direction of the ink transfer ribbon. If the Young's modulus in the longitudinal direction is less than 450Kg/ ^mm2 ,
Because the film stretches easily and elasticity recovery is difficult,
When used as a transfer ribbon for printing, the printing part undergoes plastic deformation due to printing pressure, resulting in poor print clarity such as printing thicker than necessary, and poor handling when winding the transfer ribbon due to this deformation. So it's not desirable. Furthermore, if the Young's modulus in the longitudinal direction exceeds 800 Kg/mm ² , the rigidity is so strong that the film tends to tear due to printing pressure, which is not preferable. Further, the thickness of the polyester film in the present invention is generally 1 to 25 μm, preferably 2 to 25 μm.
It is 10 μm, 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 time to transfer heat, making it unsuitable for increasing the recording speed and obtaining clear transferred image quality. The biaxially oriented polyester film in the present invention has the above-mentioned longitudinal Young's modulus and thickness, but
Furthermore, the number of protrusions (Y: pieces/mm ² ) and the protrusion height (X:
The protrusion distribution curve representing the relationship between log ₁₀ Y>
In the area of 1.3, surface characteristics that do not intersect the line expressed by the following formula (1) and are in a range where the maximum value of the protrusion distribution and the curve of the part exceeding the maximum value satisfy the following formula (2) has. log ₁₀ Y=-1.8x+3.9...(1) log ₁₀ Y≧-3.6X+2.8...(2) Does the film surface roughness fall below the straight line expressed by the formula log ₁₀ =-3.6X+2.8? Alternatively, if the protrusion distribution crosses in areas exceeding the maximum value (particularly in areas with large protrusion heights that intersect and go downwards), the film may not be as smooth when wound onto a roll after applying the ink layer. The ink is easily transferred to the opposite surface (running surface), staining the ribbon running surface, and this gradually accumulates ink at the contact parts such as guide posts of the ribbon running system, impeding the ribbon running, and causing extreme damage. In such a case, troubles such as the ribbon not moving may occur, and the slipperiness of the film may deteriorate, resulting in wrinkles in the film during processing, which is undesirable. In addition, if the surface roughness of the film is so rough that it exhibits a protrusion distribution that intersects the above equation (1), the sharpness of the print will deteriorate and the thermal head will be abraded, causing practical problems. This is not desirable. Furthermore, the number of protrusions (protrusions/mm ² ) measured with a multiple interference reflection microscope (Tl monochromatic light) on the above film surface
and protrusion height (h: μm) 1.5≧h＞1.0...10 pieces/mm ² or less 1.0≧h＞0.75...1 to 30 pieces/mm ² 0.75≧h＞0.5...15 to 120 pieces/mm ² 0.5≧h＞0.25...It is preferable to satisfy 80 pieces/mm ² or more. Satisfying this surface property is particularly preferable from the standpoint of preventing or reducing transfer of the ink layer to the opposite surface of the film and from the standpoint of print clarity. In addition, the maximum protrusion height on the film surface is 3μm or less,
Furthermore, it is desirable that the thickness be 1.5 μm or less. The above-mentioned surface roughness of the biaxially oriented polyester film in the present invention is due to the presence of inert inorganic materials in the film.
It is preferable to form by adding organic fine particles or the like. When using this inert fine particle,
0.01 to 5% by weight of particles with an average particle size of 0.01 to 10 μm,
Furthermore, it is preferable to add particles having an average particle size of 0.03 to 4 μm in an amount of 0.01 to 1.5% by weight. 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 are preferably silicon dioxide (including hydrates, diatomaceous earth, silica sand, quartz, etc.); alumina;
Silicates containing 30% by weight or more of _SiO2 (e.g. amorphous or crystalline clay minerals, aluminosilicate (including calcined products and hydrates), hot asbestos, zircon, fly ash, etc.), Mg, Zn , Zr and
Oxide of Ti; Sulfate of Ca and Ba; Li, Na
and Ca phosphates (including monohydrogen salts and dihydrogen salts); benzoates of Li, Na, and K; Ca, Ba,
Terephthalates of Zn and Mn; Mg, Ca, Ba,
Titanates of Zn, Cd, Pb, Sr, Mn, Fe, Co and Ni; Chromates of Ba and Pb; Carbon (e.g. carbon black, graphite, etc.); Glass (e.g. glass powder, glass beads, etc.); Ca as well as
Examples include Mg carbonate; fluorite; and ZnS. More preferably, anhydrous silicic acid, hydrated silicic acid, aluminum oxide, aluminum silicate (including calcined products, hydrates, etc.), monolithium phosphate, trilithium phosphate, sodium phosphate, barium phosphate, titanium oxide, and lithium benzoate. , double salts (including hydrates) of these compounds, glass powder, clay (including kaolin, bentonite, clay, etc.), talc, diatomaceous earth, calcium carbonate, and the like. Polyesters containing these inert particulates are usually reacted to form polyesters by
For example, inert fine particles (preferably as a slurry in glycol) are added to the reaction system at any time during the transesterification reaction or polycondensation reaction when using the transesterification method, or at any time when using the direct polymerization method. It can be manufactured by adding. Preferably, inert fine particles are added to the reaction system at the beginning of the polycondensation reaction, for example, until the intrinsic viscosity reaches about 0.3. Further, the biaxially oriented polyester film of the present invention must have a heat shrinkage rate of 7% or less in the longitudinal direction and the transverse direction when heat treated at 150°C for 30 minutes, preferably 4% or less, particularly preferably 4% or less. 2
% or less. If this thermal shrinkage rate is greater than 7%, not only will the width shrinkage during the relaxation treatment increase, but also thick spots will worsen due to shrinkage during the process of processing into a transfer material for printers, that is, during the coating, drying, etc. , which is not preferable because it causes a decrease in yield and the like. In addition, if this thermal shrinkage rate is less than 0%, wrinkles will occur on the heating roll in the case of a method in which relaxation is performed by the speed difference between two rolls, and the base film will remain in the roll shape as a transfer material for printers. If the roll is left to stand until it is processed, wrinkles will occur in the vertical direction on the roll surface, and furthermore, wrinkles will occur on the surface of the intermediate product roll during the process of processing the transfer material for printers, which is not preferable. It is presumed that these wrinkles occur when the lateral thermal expansion of the film is greater than the thermal contraction. Furthermore, there are problems when using the ribbon, especially when it is used as a transfer ribbon for thermal printers, if the heat shrinkage rate is outside the above range, the ribbon will be severely deformed.
Not only does the clarity of the print deteriorate, but the deformation also makes it difficult to wind and handle the transfer ribbon.Also, even in the dot impact method, if the heat shrinkage rate exceeds 7%, deformation of the printed part is likely to occur. This is not desirable. Further, it is preferable that the biaxially oriented polyester film has a heat shrinkage rate of 0.1% or less in the longitudinal direction, more preferably 0.08% or less when exposed to hot air at 70° C. for 1 hour under no load. A transfer material for a printer processed using such a film as a base is less likely to cause curling during processing steps, particularly during drying, aging, etc., and is more preferable in order to suppress transfer of ink to the opposite surface (running surface). Further, the biaxially oriented polyester film of the present invention has many minute concave portions, and the concave portions have an average equivalent circular diameter of 0.05 to 3 μm and an average depth of 0.05 μm.
~1.5μm, and the number is 2000~100000/
Must be in the range of mm ² . The average equivalent circular diameter of the concave portion is preferably 0.1 to 2 μm, more preferably 0.3 to 1.5 μm. If this diameter is less than 0.05 μm, the ink retention effect described below will be small, and if it exceeds 3 μm, depending on the combination with the depth, this may lead to a decrease in the strength of the film as a substrate, which is not preferable. Furthermore, the average depth of the concave portion is 0.1~
It is preferably 1.3 μm, more preferably 0.3 to 1 μm.
If the depth of this concave portion is shallower than 0.05 μm, the ink reservoir described later will not be sufficient, while if it is deeper than 1.5 μm, the substrate may be cut, which may cause a problem of lowering the film strength, which is not preferable. Furthermore, the number (frequency) of concave parts is 4000 to 70000
The number of particles/mm ² is preferably 5,000 to 50,000 pieces/mm ² . As mentioned above, with conventional transfer ribbons for printers, the ink layer applied to the base polyester film is transferred to the opposite surface (running surface) and stains the running surface of the ribbon. Gradual accumulation of ink can cause running troubles, but it is said to be effective to prevent or reduce the occurrence of these running troubles by making the applied ink layer as thin as possible. . However, if this ink layer is made thinner,
Transfer ribbons for printers that can be printed multiple times may not have sufficient amount of ink to be transferred when printed multiple times, and as the number of times printing increases, the clarity of the print gradually fades, and eventually the ink runs out. A fundamental problem arises. The running trouble due to ink stains and the problem of ink shortage are largely related to the amount of ink applied to the film substrate, and both are contradictory phenomena with respect to the amount of ink. The present invention solves these phenomena by forming concave portions on the surface of the polyester film of the base, and increasing the amount of ink retained while keeping the ink layer thin with the concave portions. When a polyester film is produced under normal film forming conditions, the surface condition of the film exhibits the same quality and performance on both sides. The same applies to the concave portions on the film surface.
Therefore, depending on the size and number of the concave portions on the opposite side, when the transfer ribbon is rolled up,
Because the ink surfaces are in contact with each other, more ink transfer may occur than on a film surface without recesses. In order to eliminate this trouble, the size, number, etc. of the recessed portions in the present invention are specified. The biaxially oriented polyester film 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 die, cooled and solidified in a casting drum to form an unstretched sheet, and then the unstretched sheet is stretched biaxially. The film is then made into a stretched film, and then subjected to heat treatment (heat setting), adjustment treatment for the heat shrinkage rate in the lateral direction,
It is produced by vertical relaxation treatment in pairs. In this case, in order to suitably satisfy the requirements of the present invention,
For example, the first stage stretching is performed at a temperature (e.g. longitudinal stretching temperature
T ₁ ) is in the range of (Tg − 10) to (Tg + 45) °C (however, Tg: glass transition temperature of polyester),
It is preferable that the stretching ratio is 2.5 to 6.0 times, or even 3.5 to 5.5 times, and the second stage stretching is performed at a temperature (for example, transverse stretching temperature: T ₂ ) of (T ₁ +15) to (T ₁ +40).
℃ range, and the stretching ratio is 2.5 to 4.0 times, and even 2.8 times.
It is preferable to set it to ~3.7 times. Further, the obtained biaxially stretched film is preferably heat set at a temperature in the range of 150 to 240°C, more preferably 170 to 240°C, for about 1 to 200 seconds. Furthermore, the thermal shrinkage rate in the transverse direction is usually adjusted by adjusting the heat treatment conditions in a tenter, and then a longitudinal relaxation treatment is performed. Adjustment of the heat shrinkage rate in the transverse direction is usually performed before the longitudinal relaxation treatment. It is usually adjusted during heat treatment in a tenter. For example, if the heat shrinkage rate in the lateral direction is insufficient, it is recommended to stretch the film in the width direction during the above heat treatment, and if the heat shrinkage rate is too large, it is recommended to relax the film in the width direction during the above heat treatment. good. More specifically, when the heat treatment temperature is 160℃, it is recommended to relax the entire width by 9 to 13%, and when the heat treatment temperature is 170℃
When the temperature is 180℃, it is recommended to relax 5 to 11%, when the temperature is 180℃, it is recommended to relax 1 to 8%, and when the temperature is 200℃, it is recommended to tense or relax 0 to 5%.
At 205℃, it is best to stretch or relax by 3 to -2%, and at 220℃, it is recommended to stretch or relax by 1 to -6%.
It is best to stretch or relax. Methods for loosening in the longitudinal direction include, for example, a floating treatment method using air force, heating under low tension, and relaxing in a non-contact state; relaxing by giving a speed difference between a heating roll and a cooling roll, each having a nip roll. There are two methods: a method in which the clip holding the film is loosened in the vertical direction by gradually reducing the speed of movement of the clip holding the film in the tenter, but any method can be used as long as it can be relaxed in the vertical direction. . The temperature when relaxing in the longitudinal direction is (Tg + 20) °C or higher (heat treatment temperature - 30) °C or lower, preferably (Tg
+30)°C or more (heat treatment temperature -40)°C or less.
At temperatures lower than (Tg + 20) °C, the thermal shrinkage rate near Tg cannot be sufficiently lowered, and at temperatures higher than (heat treatment temperature - 30) °C, although the amount of relaxation in the longitudinal direction is large, the shrinkage in the lateral direction is also large. This not only makes it impossible to satisfy the heat shrinkage rate in the lateral direction, which is one of the objectives of the present invention, but also deteriorates the mechanical properties in the lateral direction, worsens thickness unevenness, and reduces the relaxation rate in two ways. In the case of a method using a speed difference between rolls, it is not preferable because scratches occur in the lateral direction on the film surface due to width shrinkage on the heated rolls. The amount of relaxation in the longitudinal direction varies depending on the heat treatment temperature, but if the film tension at the time of relaxation is 10Kg/ ^cm2 or more80
For example, in the case of a method in which relaxation is performed by a speed difference between two rolls, the speed of the cooling roll is adjusted relative to the heating roll so that the ^weight is 20 kg/cm ² or ^less , preferably 20 kg/cm 2 or more and 60 kg/cm 2 or less. It is preferable to adjust. If the film tension is less than 10 Kg/cm ² , the film will sag and wrinkles will occur, and if the tension is greater than 80 Kg/cm ² , the heat shrinkage rate cannot be lowered sufficiently. Due to the above-described relaxation treatment, the thermal shrinkage rate in the longitudinal direction at a temperature equal to or higher than the temperature of the relaxation treatment does not affect the curling edge of the coated material. According to conventional longitudinal relaxation, contraction occurs not only in the longitudinal direction but also in the lateral direction, and therefore the thermal shrinkage rate in the lateral direction also becomes small. To form minute concave portions on the film surface,
For example, if the temperature is lowered and the stretching ratio is further increased in the longitudinal stretching conditions of the biaxial stretching conditions, the skin mainly containing the inert fine particle additives will be torn and the additives will fall off and be deposited on the surface of the biaxially oriented film. Since the phenomenon of forming concave portions occurs, a method utilizing this phenomenon, such as a method in which the biaxially oriented polyester film is immersed in an alkaline solution such as an aqueous solution of caustic soda or a method in which the surface is treated with the alkaline solution, is preferably used. In the present invention, the transfer ink layer is constructed by appropriately adding a softener, a flexibilizing agent, a dispersant, a smoothing agent, etc., as necessary, in addition to the binder component and the coloring component. Ink components include waxes such as carnauba wax, paraffin wax, and n-fatty acid alkyl esters, binder components such as vinyl chloride polymers, vinyl chloride-vinyl acetate copolymer polymers, colorants, and other components. It will be done. As the coloring agent, carbon black is usually used as the main ingredient, and various other dyes or organic or inorganic pigments are used. Another example is one in which nigrosine, methyl violet, alkali blue, etc. are used as a coloring agent, and three to four types of water, castor oil, glycerin, alcohol, vaseline, oleic acid, paraffin, etc. are combined in appropriate amounts. In some cases, the transfer ink may also include a sublimation type. The transfer ink layer can be formed by a conventional method, for example, a solution coating method such as a gravure, reverse or slit die method, or hot melt coating with the addition of a solvent. that time,
The biaxially oriented polyester film may be subjected to pretreatment such as corona discharge treatment or subbing coating with a binder, if necessary. The thickness of the ink layer is 3-35 μm. If the ink layer is too thick, the ink layer will be transferred (transferred to the back side of the transfer material) when the transfer material is wound into a roll, which is not preferable. Examples of commonly used transfer ink compositions are as follows. Transfer ink composition: [A] Type carbon black 18 parts by weight Paraffin wax (mp ~ 40°C) 50 Carnauba wax 15 Ethylene-acrylic acid copolymer (90/10)
15 〃 Stearic acid 2 〃 [B] Type paranitroaniline red 15 parts by weight Paraffin wax (mp ~ 40℃) 50 〃 Carnauba wax 19 〃 Ethylene-vinyl acetate copolymer (85/15) 15 〃 Cross-linked polyethylene Beads (particle size 0.5μ) 1 〃 [C] Type carbon black 20 parts by weight Vaseline 30 〃 Glycerin 30 〃 Solid rosin wax 10 〃 Water 10 〃 The printer transfer material of the present invention does not cause transfer spots even after repeated use. The ink layer that does not cause any
In addition to its high melting point, it has a running surface that is particularly difficult for ink to transfer, maintaining suitable running properties, and when used for impact applications, there is almost no plastic deformation such as leftover impressions due to printing even after repeated use. , and is useful as a transfer material with excellent transfer image quality. <Examples> 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 Using a three-dimensional roughness meter (SE-3CK) manufactured by Kosaka Laboratory, needle diameter 2μmR, needle pressure 30mg, measurement length 1mm, sampling pitch 2μm, cutoff 0.25mm, vertical magnification 20,000 times. , the profile of the protrusions on the film surface is imaged three-dimensionally (stereoscopically) under the conditions of 200x lateral magnification and 150 scans. When the profile is cut in a plane perpendicular to the thickness direction of the film, the plane where the total cross-sectional area of the profile of each protrusion is 70% of the area of the measurement area of the film is defined as the reference level (O level). )
Let y be the number of protrusions that are cut when the plane is parallel to the plane of the reference level and separated by a distance x in the height direction of the protrusions. A protrusion distribution curve can be drawn by sequentially increasing or decreasing x, reading the number of y at that time, and plotting it on a graph. (2) Young's modulus Cut the film into 10 mm wide and 15 cm long pieces and pull them using an Instron type universal tensile tester at a chuck spacing of 100 mm at a tensile speed of 10 mm/min and a chatch speed of 500 mm/min. Calculate Young's modulus from the tangent to the rising part of the elongation curve. (3) Number of surface protrusions Aluminum is uniformly vacuum-deposited on the surface of the film to a thickness of 400 to 500 Å or less, and collodion is applied to the opposite non-vapor-deposited surface (film surface) and attached, followed by drying. 100 Tl using a monochromatic light multiple interference reflectance microscope (e.g. Carl Zeiss JENA).
An arbitrary 100 cm ² of the aluminum-deposited surface is observed at double magnification, and the number of protrusions with interference fringes generated corresponding to the protrusion heights in the microscope field is counted. (4) Heat shrinkage rate 300mm for a film sample cut out to a width of 20mm
Mark a gauge at the distance, and heat it to 70℃ or 150℃.
Hang it with no load on a circulating hot air blower heated to Display the percentage as a percentage. Heat shrinkage rate (%) = (original length) - (length after heating) / (original length) x 100 (5) Ink transferability Thickness of the layer of transfer ink composition on one side of the film
A film sample of 10 mm width x 20 cm length was coated with the resulting transfer sheet using a gravure method to give a thickness of 10 μm, and the sample was transferred after being repeatedly pressed 20 times with a hard chrome-treated roll of 1 kg in diameter and 5 cm in diameter. The surface in contact with the ink layer is traced with a cotton swab moistened with ethyl alcohol, and the degree of adhesion of ink to the cotton swab (degree of staining) is visually evaluated on a five-point scale. <5-level evaluation> ◎...No ink adhesion is observed ○...Ink adhesion is hardly observed △...Ink adhesion is observed to some extent ×...Ink adhesion is observed to a considerable extent ××……Severe ink adhesion is observed (6) Print clarity Using an electric typewriter IBM82C, the side opposite to the ink-coated surface of the transfer ribbon coated with a transfer ink layer of 10 μm thick was "Q"
Repeat 20 letters on regular typewriter paper.
Strike twice or ten times, the clarity of the printed "Q",
The thickness of the print and the degree of change in shading are visually judged in four stages. <4-level judgment> ◎...The print does not become thicker even after repeated typing 20 times.
There are no shading spots and the print is clear. Even if you press it 10 times, the print does not get thicker.
There are no shading spots and it is clear.△...As the number of repetitions increases, the print becomes a little thicker, and the shading spots are a little more noticeable, but the clarity is maintained to be fair.×...As the number of repetitions increases Therefore, the print is quite thick, and there are strong shading spots in some parts, resulting in a lack of sharpness. (7) Degree of film deformation The same spot was printed 10 times in a row using the method shown in (6) above. The marks on the film are visually judged in three stages. 〈Three-level judgment〉 ○... Almost no scratches are observed △... Some scratches are visible ×... Some scratches are visible (8) Measurement of film surface concavities The sample (film) is Aluminum was deposited to a thickness of approximately 500 angstroms using a vacuum evaporation device (FEE-4X) manufactured by Denshi Co., Ltd., and observed with a scanning electron microscope (EMM-3000) manufactured by Elionix Co., Ltd. The size and depth were measured, and the number was observed in terms of per mm ² . Example 1 Ethylene glycol (hereinafter abbreviated as EG) 90
After adding 10 parts by weight of calcium carbonate (average particle size 0.6 μm) to the parts by weight, mixing and stirring were performed to obtain a slurry. Next, 100 parts by weight of dimethyl terephthalate and
After transesterifying 70 parts by weight of EG in a conventional manner using 0.035 parts by weight of manganese acetate tetrahydrate as a catalyst, the kaolin obtained above (concentration 0.4% by weight to polymer) was added under stirring. Subsequently, 0.03 parts by weight of trimethyl phosphate and 0.03 parts by weight of antimony 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. This polyethylene terephthalate pellet
After drying at 170℃ for 3 hours, feed it to the extruder hopper.
The molten polymer is melted at a melting temperature of 280-300℃ and passed through a 1mm slit die to give a surface finish of 0.3S.
The film 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. The unstretched film thus obtained was heated at 70°C.
preheated at 100°C, and further heated with one IR heater with a surface temperature of 700°C from 15mm above between the low speed and high speed rolls.
It was stretched twice, rapidly cooled, and stretched once. Next, the single-stage stretched film was stretched 3.9 times in the transverse direction at a temperature of 110°C in hot air, and then heat treated at 230°C for 15 seconds.
A biaxially oriented film with a thickness of 7.5 μm was obtained. In addition,
The stretching speed at this time was 20 m/min. Next, this biaxially oriented film is heated with a heated roll.
After heating to 120℃, by adjusting the tension corresponding to the shrinkage according to the heat treatment temperature between the film and the cooling roll, the longitudinal heat shrinkage rate of the obtained film when treated at 70℃ for 1 hour can be adjusted to approximately It was set at 0.06%. Young's modulus, heat shrinkage rate,
Table 1 shows the surface roughness protrusion distribution curve, surface concave shape, number, etc. Transfer ink composition on one side of biaxially oriented film:
Type [C] was coated using a gravure method so that the layer thickness was 10 μm, and the resulting transfer sheet was slit to obtain a transfer material (transfer ribbon). As shown in Table 1, the characteristics of this transfer material are ink transferability,
Both the degree of film deformation and the print clarity were at a good level. Example 2 A biaxial film with a thickness of 7.2 μm was prepared in the same manner as in Example 1, except that the stretching ratio was 4.2 times in the longitudinal direction and 3.2 times in the lateral direction, and the heat setting temperature after the lateral stretching was 235° C. An oriented film was obtained, and a transfer material was also obtained. The results are shown in Table 1, and all items were very good. Example 3 In Example 1, 0.45% by weight of calcium carbonate (average particle size 0.8 μm) and silica (average particle size 0.8 μm) were added as lubricants.
A biaxially oriented film with a thickness of 7.2 μm was obtained in the same manner as in Example 1, except that it was stretched 4.5 times in the longitudinal direction and then 3.6 times in the transverse direction, using 0.25% by weight of 0.6 μm), and further transferred. I got the material. The results are shown in Table 1, and all items were good. Example 4 A biaxially oriented film of 7.5 μm was obtained under the same conditions as in Example 1 except that 0.55% by weight of kaolin (average particle size 1.2 μm) was added to the polymer as an additive lubricant. I got it. The results are shown in Table 1, and all items were good. Comparative Example 1 In Example 2, the film was stretched in the machine direction, then stretched in the transverse direction, and further heat-treated to obtain a biaxially oriented film, and then the relaxation treatment in the machine direction was not performed. The obtained biaxially oriented film had a high longitudinal heat shrinkage rate at 70°C for 1 hour, and curling occurred after the ink layer was applied, resulting in increased ink transfer to the opposite side (running surface) of the film. The running performance was also poor. The results are shown in Table-1. Comparative Example 2 In Example 3, the first stage (longitudinal direction) stretching temperature condition was preheated at 75°C, further heated with one IR heater with a surface temperature of 900°C, and then Comparative Example 1
Similarly, no longitudinal relaxation treatment was performed after biaxial stretching. The obtained biaxially oriented film had a high thermal shrinkage rate in the longitudinal direction at 70°C for 1 hour, and curling occurred after the ink layer was applied, resulting in increased ink transfer to the opposite side (running surface) of the film. Moreover, the clarity of the ink was also poor. Comparative Example 3 In Example 1, calcium carbonate (average particle size
A biaxially oriented film of 7.5 μm was obtained under the same conditions except that 0.35% by weight of kaolin (average particle size 0.4 μm) was added to the polymer instead of 0.6 μm). Using this, a [C] type ink composition was applied to a thickness of 10 μm in the same manner as in Example 1 to obtain a transfer ribbon. These properties are as shown in Table 1, and the ink transfer properties were insufficient and the running properties were unsatisfactory. Example 5 In Example 3, 0.45% by weight of calcium carbonate (average particle size 1.5 μm) and 0.25% by weight of silica (average particle size 0.6 μm) were used as additive lubricants, and the first stage (longitudinal direction) stretching temperature condition was 75%. Preheat to ℃ and then
Heated with one IR heater with a surface temperature of 900℃,
Otherwise, a biaxially oriented film was obtained under the same conditions as in Example 3. Thereafter, the film was immersed in a 20% by weight aqueous sodium hydroxide solution at 80°C for 5 minutes, washed with water and dried, and then ink composition of type [C] was applied.
It was coated to a thickness of 10 μm and made into a transfer ribbon using a conventional method. The quality characteristics of the film meet the required level,
Further, sufficient concave portions could be formed on the surface, and the degree of deformation, ink transferability, and print clarity as a transfer material were good. The results are shown in Table-1.

【table】

【table】 [Brief explanation of the drawing]

Figure 1 shows the height of protrusions on the film surface (X: μm) and the number of protrusions (Y: pieces/mm ² ) determined using a three-dimensional roughness meter.
FIG.

Claims (1)

[Claims] 1. A transfer material for a printer comprising a biaxially oriented polyester film having a thickness of 1 to 25 μm and a transfer ink layer having a thickness of 3 to 25 μm on one side, wherein the biaxially oriented polyester film has the following (a): ～(d) (a) Young's modulus in the longitudinal direction is 450 to 800 Kg/ ^mm2 , (b) Thermal shrinkage rate at 150℃ in the longitudinal and transverse directions is 7.
(c) The protrusion distribution curve representing the relationship between the number of protrusions (Y: pieces/mm ² ) and the protrusion height (X: μm) measured with a three-dimensional roughness meter on the film surface is log ₁₀ Y ＞1.3, the line expressed by the following formula (1) log ₁₀ Y = -1.8 is in a range that satisfies the following formula (2) log ₁₀ Y ≧ −3.6 A printer characterized in that the part has an average circular equivalent diameter of 0.05 to 3 μm, an average depth of 0.05 to 1.5 μm, and a number of the parts is in the range of 2000 to 100000 pieces/mm ² transfer material. 2. The number of protrusions (protrusions/mm ² ) and protrusion height (h: μm) measured using a multiple interference reflection microscope (Tl monochromatic light) on the surface of a biaxially oriented polyester film is 1.5≧h＞1.0...10 protrusions/mm ² or less 1.0≧h＞0.75...1 to 30 pieces/mm ² 0.75≧h＞0.5...15 to 120 pieces/mm ² 0.5≧h＞0.25...80 pieces/mm ² or more Claim 1
Transfer material for printers described in section. 3.1 of biaxially oriented polyester film at 70℃
The transfer material for a printer according to claim 1, wherein the transfer material for a printer has a longitudinal heat shrinkage rate of 0.1% or less when heat treated under no load for a time.