JPS6398484A - Transfer material for thermal recording - Google Patents

Abstract

PURPOSE:To prevent thermal deformation of the title material under high temperatures or high tensions or sticking of the material to a thermal head, by causing an aromatic polyamide film to have specified values of rate of dimensional change under specified conditions, dynamic coefficient of friction with a glass and thickness. CONSTITUTION:A transfer material for thermal recording has a thermal transfer layer provided on one side of an aromatic polyamide film, or has a thermal transfer layer provided on one side of an aromatic polyamide film containing from 1.0 to less than 10.0wt% of carbon back, in which the rate of dimensional change of the polyamide film under a load of 1.0kg/mm<2> at 200 deg.C is not more than 5.0% in at least one direction, the dynamic coefficient of friction of the film with a glass is 0.2-1.0, and the film thickness is 1.0-10.0mum. With this arrangement, the transfer material is prevented from sticking to a thermal head on contact with the head, and can be fed in a non-wrinkled state, thereby realizing a favorable recording quality. The addition of carbon black results in higher uniformity of the surface roughness of the film, and is therefore effec tive for stable feeding of the transfer material.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thermal recording transfer member used in a thermal printer or the like that performs recording by heat melt transfer or heat sublimation transfer.

[Conventional technology]

A heat-sensitive recording transfer body used for recording in which color material is transferred by applying heat is basically composed of a base film and a heat-sensitive transfer layer. Polyester film is often used as the base film, and The thermal transfer layer is transferred by the transfer method.
It consists of a mixture of dye or pigment and sock, or a mixture of sublimable dye and binder resin. However, as the trend toward faster recording speeds, improved print quality, and diversification of color material selections, there are demands for higher temperatures for thermal heads and thinner base films. Due to the characteristics of Under these circumstances, for example, Japanese Patent Application Laid-Open No. 59-165695 discloses the use of a polyimide film as a profiteering film. Further, JP-A-61-86288 discloses the use of an aromatic polyamide film which is cheaper than a polyimide film.

[Problem that the invention seeks to solve]

However, polyimide films are generally very expensive and disadvantageous in terms of printer running costs. In addition, in general, the physical properties of aromatic polyamide films such as heat resistance vary greatly depending on the selection of polymers during synthesis and the conditions under which the film is formed. ,
When used under high tension conditions, thermal deformation or sticking with the thermal head may occur. Furthermore, aromatic polyamide films tend to generate static electricity, and are prone to problems such as wrinkles in the film or ribbon during the process of applying a heat-sensitive transfer ink layer to the film or when used in a thermal printer.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to provide a thermal recording transfer member that is inexpensive and can withstand use under harsher conditions than ever before.

[Means for solving problems]

The present invention provides: (1) A transfer body for thermal recording in which a heat-sensitive transfer layer is provided on one surface of an aromatic polyamide film, which is subjected to a load of 9/mm2 at 200'C, 1,0 of the aromatic polyamide film. The dimensional change rate is 5.0 in at least one direction.
% or more, and the coefficient of dynamic friction with glass is 0.2 or more and 1.0 or less, and the film thickness is 1.0μ or more and 10.0μ
A transfer body for thermal recording, characterized in that: (2) a thermal transfer layer is provided on one surface of an aromatic polyamide film containing 1.0% by weight or more and less than 1000% by weight of carbon black; In the transfer body for use, the temperature of the aromatic polyamide film at 200°C11,○kq/
The dimensional change rate under a load of mm2 is 5.0% or less in at least one direction, the coefficient of dynamic friction with glass is 0.2 or more and 1.0 or less, and the film thickness is 1.
．． The present invention is characterized by a transfer body for thermal recording, characterized in that the particle diameter is 0 μ or more and 10.0 μ or less.

The aromatic polyamide in the present invention is a structural unit of the following formula →
It consists of a polymer containing 50 mol% or more, preferably 70 mol% or more of HN-Ar1-NHOC-Ar2-c○→-. Here, Ar1 and Ar2 are a rogene group, a nitro group, a C1 to C3 alkyl group, a C1 to
C3 alkoxy group, p and q are integers of O to 3.
1-0-1-802-, and Z is a halogen group,
Nitro group, C1-C3 alkyl group, = 5-C1-C3 alkoxy group, m, n, r are integers of ○ to 3, a is O or 1 (1) or (2) It has this structure. This aromatic polyamide is obtained by reacting an acid chloride with a diamine or by reacting an incyanate with a carboxylic acid.

Taking the combination of acid chloride and diamine as an example, the monomers on the acid chloride side include -alephthalic acid chloride, isophthalic acid chloride, d3, and those having halogen, nitro, alkyl, or alkoxy groups in their aromatic nuclei. ,
Examples include 2-chloroterephthalic acid chloride, 2-chloroisophthalic acid chloride, 2,5-dichloroterephthalic acid chloride, 2-nitroterephthalic acid chloride, and 2-methylisophthalic acid chloride. In addition, on the diamine side, p-phenylenediamine, m-phenylenediamine,
4,4°-diaminodiphenylketone, 3,3°-diaminodiphenylketone, 4,4"-diaminodiphenylmethane, 3゜4゛-diaminodiphenylmethane, 3,3
゛-Diaminodiphenylmethane, 4,4゛-diaminodiphenyl ethyl, 3,3°-diaminodiphenyl ether, benzidine, and those having the above-mentioned substituents on their aromatic nuclei, such as 2-chloro-p-phenylenediamine , 2-chloro-metaphenylenediamine, 2-
Examples include meddylene metaphenylene diamine and 3,3-dimethylbenzidine.

Taking the combination of isocyanes 1~ and carboxylic acids as an example, isocyanes 1~ side are phenylene-1,4-diisocyanate, phenylene-1,3-diisocyanate, diphenylketone-4,4°-diisocyanate, diphenylmethane-1- 4,4"-diisocyane-1~, diphenyl ether-4,4°-diisocyanate-1~, diphenylsulfone-4,4°-diisocyanate, and those having the above-mentioned substituents on their aromatic nuclei, for example,
Toluylene-2,6-diisocyanate, toluylene-2,6-diisocyanate
Examples include 2,4-diisocyanate. Further, examples of calebonic acid derivatives include terephthalic acid, isophthalic acid, and those having substituents on their aromatic nuclei.

Among these, a combination of an acid chloride and a diamine, particularly a combination of terephthalic acid chloride and p-phenylenediamine having a chlorine substituent on at least one of the aromatic nuclei, is preferred for achieving the present invention, but of course combinations other than this are preferred. However, it still satisfies the purpose of the present invention.

The present invention needs to contain 50 mol% or more, preferably 70 mol% or more of the basic structural unit represented by the above general formula. If the amount is less than the above range, it will be impossible to form a film with sufficient mechanical properties, and the heat resistance will also decrease, making it impossible to achieve the object of the present invention. The copolymerization component of less than 50 mol% is not particularly limited, and may contain ester bonds, urethane bonds, imide bonds, heterocyclic bonds, and the like. In addition, in order to obtain a film with excellent mechanical properties and heat resistance, the intrinsic viscosity of the polymer (100 ml of N-methylpyrrolidone solution containing 2.5 wt% of lithium bromide in 0.5 l of polymer at 30'C) is required. The measured value) is preferably 0.5 to 6.0.

In addition, the aromatic polyamide of the present invention may contain lubricants, antioxidants, other additives, etc. to the extent that the physical properties of the film are not impaired.
Further, other polymers may be blended.

The film of the present invention has at least one longitudinal or transverse direction under a load of 1 to 5/l'1IIT12, 200
The dimensional change at C must be 5% or less, preferably 2% or less. If there is a dimensional change (shrinkage or elongation) greater than 5%, the film tends to wrinkle at the bottom of the head, making it impossible to print clearly.

Further, it is necessary that the coefficient of dynamic friction of the aromatic polyamide film of the present invention with glass is 0.2 or more and 1.0 or less. The heater mount of the thermal head is generally made of ceramic, and is attached to the non-color material side (film side) of the transfer object.
However, studies have revealed that there is a very good correlation between the running performance of the transfer body within the printer and the coefficient of dynamic friction between glass, which is a type of ceramic, and the film. That is, if the coefficient of dynamic friction with the glass is greater than 1.0, the transfer body may stick or become unable to run.

On the other hand, if it is less than 0.2, that is, if the film surface is rough, the film will scratch the head, or conversely, the film will be scraped, making it unsuitable for practical use.

The film thickness of the present invention needs to be 1 to 10 microns, preferably 2 to 8 microns. If it is thinner than 1 μm, the strength will decrease and it will not be practical. Further, if the thickness is more than 10 μm, heat diffusion increases, making it impossible to locally heat the ink, making clear printing impossible, and increasing the energy required for printing, making it unsuitable for high-speed printing.

The film of the present invention preferably has a strength in at least one direction of the longitudinal direction or the width direction of 8 kq/mm 2 or more, more preferably 10 kg/mm 2 or more. The upper limit is not particularly limited, but is 80 ki/mm2
That's about it. If the strength is less than 8 ki/mm 2 , processability during production of the transfer body is poor, and tearing and wrinkles are likely to occur when used as a transfer body. Furthermore, the elongation of the film is preferably 10% or more, more preferably 15% or more.
100%, and the dimensional change rate under 1 kq/mm2 cargo is preferably 5% or less even at 250'C, and 2
% or less is more preferable.

Further, the moisture absorption rate of the film is preferably 5% by weight or less, and 4% by weight or less.
It is particularly preferable that it is less than % by weight.

This is because if the moisture absorption rate of the film is high, the film will foam when the transfer body is heated by the thermal head, resulting in a problem that the ink transfer will be uneven and the print quality will deteriorate.

It is preferable that the tear propagation resistance of the film be at least 'IOOg/mm in order to prevent the film from breaking during use in a thermal transfer recording device.

Next, the heat-sensitive transfer layer in the present invention is a layer formed by applying a heat-sensitive transfer ink such as a heat-melting ink or a heat-sublimation ink to a film. Thermal transfer ink has a coloring component and a binder component as its main components, and optionally includes additive components such as a softener, a flexibilizing agent, a smoothing agent, a dispersant, and a surface forming agent.

The thickness of the thermal transfer layer is 1 to 20 μm, preferably 2 to 10 μm.
μ.

As the binder component, well-known waxes such as carnauba wax, paraffin wax, and ester wax, and various low-melting point polymers are useful.As the coloring component, carbon black and various organic and inorganic pigments or dyes are useful. are used, but are not limited to these.

Next, a method for manufacturing a transfer body for thermal recording of the present invention will be explained.

Aromatic polyamide films are generally formed using a solution casting method from a polymer solution in which an aromatic polyamide resin is dissolved in an organic solvent.

Polymers can be prepared by solution polymerization, which is carried out by adding monomers to organic solvents such as N-methylpyrrolidone, dimethylacetamide, hexamedylphosphoramide, dimedylformamide, dimethylacetic acid urea, and γ-butyrolactone. It can be polymerized legally or by interfacial polymerization using an aqueous medium. Moreover, an amine catalyst may be added especially when polymerizing diincyanate and dicarboxylic acid.

The polymer solution after polymerization is used either as a film-forming stock solution or when the polymer is poured into water, reprecipitated, isolated, dried, and then dissolved again in an organic solvent to prepare a film-forming stock solution. There is.

When the polymer solution after polymerization is used as it is as a film-forming stock solution, when acid chloride and diamine are used as monomers, it is necessary to neutralize the hydrogen halide produced as a by-product during polymerization. As a neutralizing agent, inorganic bases such as calcium hydroxide, calcium carbonate, lithium carbonate, or their hydrates, and organic bases such as ammonia, ethylene oxide, propylene oxide, triniblamine, jetanolamine, etc. may be used. Can be done.

When an inorganic base or the like is used during neutralization, lithium chloride, calcium chloride, etc. are produced as neutralizing salts, and these inorganic salts act as polymer dissolution aids. For the same reason, when the polymer is isolated after the polymerization described above and redissolved in an organic solvent, an alkali or alkaline earth metal halide such as the above-mentioned inorganic salts may be added. The ratio of these inorganic salts to the polymer is preferably 150 mol % or less based on the amide groups of the polymer in the film-forming stock solution.

When the prepared film-forming raw solution contains a neutralizing salt or an inorganic salt as a solubilizing agent, it is preferable to form a film by a wet method or a wet-dry method.

In the wet method, a method is employed in which the membrane-forming stock solution is directly extruded from a die into a coagulation bath, or is once cast onto a support such as a drum or belt, and then introduced into the bath together with the support. This coagulation bath generally consists of an aqueous medium, but may also contain an organic solvent, an inorganic salt, etc. in addition to water. In the coagulation bath, organic solvents, inorganic salts, etc. in the film-forming stock solution are extracted, and a water-containing glue film is formed. The gel film is then dried in a tenter or the like and heat treated to form the final film.

In the wet-dry method, the film-forming stock solution is cast from a die onto a support such as a drum or an endless bell mill, and heated with hot air to evaporate the solvent, turning the stock solution into a self-retentive gel film. The gel film is then peeled off from the support. At this time, it is necessary to adjust the solvent so that it does not evaporate rapidly from the surface of the stock solution, and generally the temperature is between room temperature and
Drying conditions are set within 300'C and 160 minutes. After completing the first stage of the dry process, the gel film is subjected to solvent and salt extraction in a water-based bath in the same manner as in the wet process, and then dried and heat treated in a tenter to form the final film.

Depending on the basic structural units of the polymer or the types of monomers, it is possible to prepare a film-forming stock solution that does not contain an inorganic salt, and in this case, it is also possible to form a film by a dry method.

The dry method is a method in which the water extraction of solvents and the like in the dry-wet method is omitted, and all organic solvents are evaporated by heating to obtain the final film.

The film formed by the above method is subjected to stretching and heat treatment during the film forming process so that the dimensional change rate under high temperature and load falls within the range of the present invention. Specifically, the stretching ratio is an areal ratio of 0.9 to 9 times (area ratio is the value obtained by dividing the stretched film area by the film area before stretching, where 1.
Values less than 0 mean shrinkage), heat treatment from 250'C
It is possible to obtain a predetermined dimensional change rate by setting these stretching and heat treatment conditions according to the basic structural unit of the polymer.

In the present invention, the method of making the coefficient of dynamic friction between the aromatic polyamide film and the glass fall within the claimed range includes, for example, dispersing fine particles in the film-forming stock solution used to form the film. There is a method of roughening the surface of the formed film to reduce the coefficient of dynamic friction.

The fine particles to be dispersed here are not particularly limited, but silicon oxide, titanium oxide, calcium carbonate, carbon black, alumina, etc., or a mixture thereof can be used. The particle size of the fine particles is 0°005μ or more and 5.0μ or less, preferably 0.010μ or more and 3.5μ
If the particle size is too small, the film surface cannot be roughened and the coefficient of dynamic friction with the thermal head becomes large; if the particle size is too large, fine particles detach from the film surface and adhere to the thermal head, etc. Problems such as The amount of fine particles added is 0.1% by weight based on the weight of the polymer.
The content is less than 10.0% by weight, preferably 0.2% by weight or more and less than 8.0% by weight, and if it is too small, it will not have the effect of roughening the surface, and if it is too large, it will reduce the mechanical properties of the film. become. To disperse fine particles in a film-forming stock solution, the fine particles can be dispersed in advance in a polymerization solvent, the fine particles can be added directly to the film-forming stock solution after it has been prepared, or the fine particles can be dispersed in a solvent or a dilute polymer solution. There are methods such as adding .

Note that among the fine particles, carbon black is particularly preferable. Carbon black has a uniform particle size, so
It is very effective in making the surface roughness of the film uniform and stabilizing the runnability of the thermal transfer body, and also has the effect of preventing the film surface from being charged with static electricity due to the conductivity of carbon black. Can be done.

The carbon black in the present invention may be any carbon black as long as it has conductivity, but furnace black and acetylene black are preferable. Carbon black that has been surface-treated to improve electrical conductivity may also be used. Further, the specific surface area of these carbon blacks is preferably 5Tn2/g~
1000m2/g, particularly preferably 10Tn2/g~9
50 Tr12/g, the average particle diameter of -number particles is preferably 5 mμ to 500 mμ, particularly preferably 10 mμ to 100 mμ, and the carbon purity is preferably 90% or more, more preferably 97% or more.

Next, a heat-sensitive transfer layer is formed on the It,L film of the present invention obtained as described above, but if necessary, the film may be subjected to pretreatment such as corona treatment or glow treatment. Thermal transfer inks include the ones mentioned above, and can be applied by bot-melt coating on one side of the film, or by general-purpose coating methods such as gravure, reverse, and slit die as a solution dissolved in a solvent. .

〔Effect of the invention〕

The present invention is a transfer body for thermal recording using an aromatic polyamide film as a base material, which has excellent physical properties in terms of dimensional stability and coefficient of dynamic friction with a thermal head under high temperature and high load. Because there is
It is possible to prevent problems such as melting and softening when contacting the thermal head, that is, sticking, and since the transfer body runs without wrinkles, it is possible to achieve good recording quality. . Furthermore, adding carbon black can make the surface roughness of the film uniform, which is effective for stabilizing the running properties of the transfer body.
Furthermore, when the amount added is large, it also prevents static electricity, further stabilizing the running performance and greatly improving the recording quality. Furthermore, since these characteristics have been improved, the base film can be made thinner than before, so there is an advantage that a longer transfer material can be stored in the same type of cassette 1.

The heat-sensitive recording transfer material obtained as described above is used in general thermal printers for heat-sensitive transfer recording, and is available in tape-like or sheet-like shapes depending on the type of printer, such as serial printers, line printers, and video printers. used in

[Measurement method]

191 The characteristic values of the present invention are determined by the following measurement method.

(1) Cut the dimensional change rate film to a width of 10 mm and a length of 250 mm, and mark the sample length at 25 mm from both ends.
It was set as m. A weight was attached to one end of this test piece so that the tensile load was 1.0 ki/mm 2 depending on the thickness of the film, and the other end was fixed and hung. This was heated for 5 minutes in a 2oo'c atmosphere, and after cooling, the dimensional change rate was calculated using the following formula.

1 test length (mm) - length after heating (mm) 1 dimensional change rate (%) = ) on a glass plate with a smooth surface, and one side of the film (75 mm side)
was fixed via a U gauge. A weight with a square bottom (60 nm x 60 mm) and a weight of 200 g was placed on this film, and the glass plate was moved horizontally at a constant speed of 150 mm/min in one direction opposite to the side to which the U gauge was connected. At this time, the dynamic friction coefficient was calculated from the tension detected by the U gauge.

(3) Strength and elongation Strength when the film breaks when set in a Tensilon type tensile tester using AS-MD-882 with a test width of 10m1Tl and a test length of 50mm and pulled at a tension speed of 300mm/min. , measure the elongation. Atmosphere is 25℃, 55%
It is RH.

〔Example〕

The present invention will be explained based on examples.

Example 1 50 moles (5,41 ki) of metaphenylene diamine was added to 60 kg of distilled N-methylpyrrolidone (NMP) for 20 minutes.
Dissolved in a 0 fl jacketed stirrer.

After cooling this solution H to 10'C, 50 mol of isophthalic acid chloride (10,15 ki>
Stirring was continued for 2 hours while cooling the mixture to below C. A viscous polymer solution was obtained. Next, calcium hydroxide was added in an amount equal to the amount of hydrochloric acid generated during polymerization to effect neutralization. The solution viscosity after neutralization was 5100 boids (30°C), and the intrinsic viscosity was 1.30.

On the other hand, titanium oxide with a particle size of 1.0 μm was added to NMP prepared separately and stirred to disperse it. This dispersion was added to 40 kq of the above polymer solution and mixed so that the titanium oxide particles were 2.5% by weight based on the polymer to prepare a stock solution for film formation.

This film-forming stock solution was cast onto a metal drum and dried for 10 minutes in an atmosphere of 120'C to obtain a self-retaining gel film. This gel film was continuously peeled off from the drum and introduced into a water bath, where it was subjected to solvent removal and desalination, and then water was dried and heat treated in a tenter to obtain a final film. During this time, the film was expanded by 1.3 times in the longitudinal direction in the water tank.
It was stretched 2.0 times in the width direction in a tenter, and the heat treatment conditions were 330'C for 12 minutes.

200'c, 1, 0kCJ/mm of the obtained film
The dimensional change rate under 2 loads was 1.5%, the coefficient of dynamic friction with glass was 0.53, and the film thickness was 6μ.

A heat-sensitive transfer ink having the following composition was applied to this film using a hot melt coating method using a heated roll to a thickness of 4 mm.
A thermal transfer ribbon was prepared by coating the film onto μ.

Carnauba wax 35 parts Ertel wax 30 parts Carbon black
17 parts polytetrahydrofuran 12
3 parts silicone oil Using this thermal transfer ribbon, the thermal head density is 8 pieces/mm,
When a thermal transfer test was carried out with a pulse width Q of 7 m5ec, printing was possible with the ribbon running in good condition without wrinkles, breaks, sticking, etc., and the printing quality was high.

Comparative Example 1 Using the film forming stock solution of Example 1, the stretching ratio was 2.0 times in the longitudinal direction, 2.3 times in the width direction, and the tenter temperature was 270'.
A film was formed in the same manner as in Example 1 except that C was used.

The resulting film had a dimensional change rate of 5.5%, a coefficient of dynamic friction with glass of 0.52, and a film thickness of 6 μm.

When thermal transfer recording tests 1 to 1 were carried out using this film as a base film in the same manner as in Example 1, the ribbon wrinkled when it came into contact with the thermal head, and good printing could not be achieved.

Comparative Example 2 Regarding 20 kq of the neutralized polymer solution of Example 1, titanium oxide in the stock solution for film forming was 0.03% by weight based on the polymer.
The same operations as in Example 1 were performed except for the following: preparation of stock solution, film formation, production of thermal transfer ribbon, and thermal transfer recording test.

The obtained film at 200 °C11, 0 to 9/mm2
The dimensional change rate under load was 1.7%, and the coefficient of dynamic friction with glass was 1.8, making it an extremely slip-resistant film.

When creating a thermal transfer ribbon using this film as a base material, it had poor operability, such as sticking to rolls, etc., and during thermal transfer recording tests, there were problems with the running performance of the ribbon, such as wrinkles in the transfer recording device.

Furthermore, the recorded print quality was also poor, with many occurrences of unhandled print and smearing.

Example 2 70 mol% 2-chloroparaphenylenediamine and 4.4
-Polymerize in NMP with 30 mol% of diaminodiphenyl ether as a diamine component and 100 mol% of 2-chloroterephthalic acid chloride as an acid chloride component, and neutralize with lithium hydroxide to obtain a polymer concentration of 9.0% by weight and solution viscosity. A polymer solution of 2500 poise (30°C) and an intrinsic viscosity of 2.4 was obtained.

Carbon black was added in an amount of 5% by weight based on the polymer to form a film-forming stock solution, and the solvent drying temperature on the drum was set to 15%.
At 0'C, the stretching ratio was 1.15 times in the longitudinal direction of the film.
A film was formed in the same manner as in Example 1 except that the width was increased by 1.3 times.

The obtained film was heated at 200'C, 1,0 to 9/mm2
The film had a dimensional change rate under load of 0.2%, a coefficient of dynamic friction with glass of 0.40, and a thickness of 6μ, making it difficult to charge static electricity and easy to handle.

When a thermal transfer recording test similar to that in Example 1 was conducted using this film, the transfer ribbon had good runnability and very high quality printing was possible.

Example 3 10 moles of 4.4'-diaminodiphenylmethane (1°9
827kq) and N-methyl-2-pyrrolidone (NMP)
120 was charged into a jacketed stirring tank (volume 2CB1) and stirred and dissolved under a nitrogen atmosphere. Add 2-
Chlorterephtha JI, M chloride 4 mol (0°949
8 kq> and 6 moles of terephthalic acid chloride (1°2181
8 kg) was added while cooling the tank so that the liquid temperature did not rise above 30° C., and stirring was continued for about 2 hours after the addition was completed, and a viscous polymer solution was obtained. This solution was neutralized by adding lithium carbonate in an amount equal to the amount of hydrochloric acid generated during polymerization. The polymer solution after neutralization has a viscosity of 9400 poise (3
0'C), and the intrinsic viscosity was 1.21.

On the other hand, silicon oxide particles with a particle size of 2.5 μm were added to NMP prepared separately, and the mixture was stirred and dispersed. This dispersion was added to half of the above polymer solution and mixed so that the silicon oxide powder was 2% by weight based on the weight of the polymer to prepare a polymer solution for film formation.

This film-forming polymer solution was cast from a die onto a drum with a width of 5 Qcm and a diameter of 1 m, and heated with hot air at 130'C to evaporate the solvent to form a gel-like film, which was continuously peeled from the drum. . The film after peeling was led to a water tank, and while passing through the water tank, the solvent was removed and the salt was desalted. The film was then dried and heat set under tension in a tenter at 300'C. The film was also stretched 1.2 times in the longitudinal direction in a water tank and 1.5 times in the transverse direction in a tenter.

The obtained film has a thickness of 7μ, 200'C, 1r/
The dimensional change rate under a mm2 load was 0.5%, and the coefficient of dynamic friction with glass was 0.42.

Each thermal transfer ink having the following composition was coated on this film to a thickness of 3 μm using a bot melt coating method using a heated roll to obtain a thermal transfer ribbon.

Carnauba wax 30 parts Ertel wax 35 parts Carbon black
17 parts Polite 1 to Lahydrofuran 1
2 parts silicone oil 3 parts Using this thermal transfer ribbon, the thermal head density is 8 lines/mm,
When a thermal transfer test was conducted with a pulse width of 0.7 m5ec, good transfer recording was achieved and no problems such as tape wrinkles or sticking occurred.

Example 4 To the remainder of the polymer solution polymerized and neutralized in Example 3,
A film was prepared by adding carbon black instead of silicon oxide particles, a heat-sensitive transfer ink layer was provided in the same manner as in Example 3, and a transfer recording test was conducted.

The carbon black had a particle size of 40 mμ, and the amount added was 8% by weight based on the weight of the polymer.

The film produced in the same manner as in Example 3 was heated at 200°C,
The dimensional change rate under a load of 1ki/rnn2 was 0.5%, and the coefficient of dynamic friction with glass was 0.25.

This film had good workability without being charged with static electricity on the surface during the film forming process or the thermal transfer ink coating process. Furthermore, even during transfer recording using a thermal printer, the running properties of the prepared thermal transfer tape were good, and high-quality transfer recording could be performed.

Comparative Example 3 Polymerization and neutralization were carried out in the same manner as in Example 3 to obtain a polymer solution. The viscosity of the polymer solution was 9200 poise (30° C.), and the intrinsic viscosity was 1.19.

To half of this polymer solution, 0.05% by weight of silicon oxide with a particle size of 2.5μ based on the weight of the polymer was added, and to the other half, a film was prepared in the same manner as in Example 3 without adding fine particles. A film was formed.

The resulting film, with 0.05% silicon oxide added, had a dimensional change rate of 0.4% under a load of 200'C11ki/mm2, and a coefficient of dynamic friction with glass of 1.8.
The dimensional change rate of the one without the addition of fine particles was 0.6%, and the coefficient of dynamic friction was too large to be measured.

When transfer recording was carried out in the same manner as in Example 3, the thermal transfer ribbons prepared using both films showed wrinkles and stickiness at the thermal head, resulting in extremely disordered transferred images. Ta.

Claims (2)

[Claims] (1) In a transfer body for heat-sensitive recording in which a heat-sensitive transfer layer is provided on one surface of an aromatic polyamide film, the dimensional change rate of the aromatic polyamide film under a load of 1.0 kg/mm^2 at 200°C is at least in one direction. 5.0% in
or less, and the coefficient of dynamic friction with glass is 0.2 or more and 1
．． 0 or less, and a film thickness of 1.0 μm or more and 10.0 μm or less. (2) In a transfer body for thermal recording in which a heat-sensitive transfer layer is provided on one surface of an aromatic polyamide film containing 1.0% by weight or more and less than 1000% by weight of carbon black, the aromatic polyamide film is heated at 200°C, 1. 0kg/mm^
2.The dimensional change rate under load is 5.0% or less in at least one direction, the coefficient of dynamic friction with glass is 0.2 or more and 1.0 or less, and the film thickness is 1.0μ or more and 10.0μ or less. A transfer body for thermal recording characterized by the following.