JP2560683B2 - Transferr for thermal recording - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a heat-sensitive recording transfer body which is a recording system for transferring a color material (heat-sensitive ink) by applying heat.

[Prior art]

Conventionally, a thermal recording method has been used as a recording method for full color, etc. in addition to electrophotography, ink jet, and electrostatic recording method. Although this method is somewhat difficult in that the printing or printing speed is slow, it does not generate noise, has relatively low cost, and has good maintainability, and its application field is gradually expanding.

This method provides a transfer ink layer on the surface of a sheet-shaped substrate,
This ink layer is melted or sublimated by the heat of the thermal head and printed on plain paper. At this time, the transfer is performed uniformly, and printing and printing are performed without shading, blurring, and misalignment. Further, in order to make it possible to perform sufficiently dark and clear recording at high speed, various measures have been taken on the thermal transfer member. For example, paper such as capacitor paper has been mainly used as a base material in the past, but image quality is disturbed due to non-uniform transfer of coloring material, and mechanical strength is weak. Mainly used film, especially polyethylene terephthalate (PET) film.

However, when PET film is used as the base material, it melts and deforms significantly. Therefore, measures such as applying an infusible slipping layer to the film to prevent staking with the thermal head have been taken. However, in order to further expand the selection area of the ink layer and further improve the recording speed, there is a limit to the use of a meltable film such as PET, and there is a proposal to use a polyimide film. (Japanese Patent Laid-Open No. 59-165695).

However, the base material of the thermal transfer material is not simply that it has heat resistance, but it is a thin film of 1 to 10μ and has sufficient mechanical properties, chemical resistance, and moisture absorption properties. It is essential to have both of them, and conventionally, no specific proposal has been made for thermal transfer resistance that satisfies these requirements.

An energization method has been proposed as one of the thermal transfer methods. In this method, instead of applying thermal energy to the ink layer by a thermal head, an electric current is passed through a conductive film having a certain electric resistance, and the ink generated in the film is melted or sublimated by heat. For example, USP4, 1
According to 03,066, carbon black is mixed with polycarbonate and used as a film base material of this system. However, this method is inferior in heat resistance of polycarbonate.
Since the compatibility of carbon black and polycarbonate (such as wettability) is poor, the mechanical properties of the polycarbonate film are greatly deteriorated, and it has the drawback that it cannot be put to practical use unless the substrate thickness is thicker than 15μ.

[Object of the Invention]

An object of the present invention is to provide a thermal recording transfer material which solves the above-mentioned various problems and is stable in high speed, print quality, and print quality, and is excellent in handleability without causing tape tears, wrinkles, and the like. In addition, the present invention is intended to provide an electrically conductive transfer member for heat-sensitive recording, which has high printing quality and printing speed.

[Structure of Invention]

The present invention has the general formula 50% by mole or more of the constituent component represented by (where X is a halogen group, a nitro group, a C _{1 to} C ₃ alkyl group, a C _{1 to} C ₃ alkoxy group, and Y is Represents --CH _2- , --O--, and Z represents a halogen group. n and m are integers of 0 to 3, l is 0 or 1, p is an integer of 1 to 4), heat shrinkage at 250 ° C is 5% or less, moisture absorption is 4% or less, and aroma of 1 to 10μ in thickness Thermal recording transfer member having a heat-sensitive transfer ink layer provided on a group polyamide polyamide film, and heat-sensitive recording having a heat-sensitive transfer ink layer provided on the aromatic polyamide film at 1 to 40% by weight of carbon black or alumina. It is characterized by a transfer body for use.

Taking as an example the polymer synthesis of acid chloride and diamine as the monomer constituting the basic constitutional unit of the film, the acid chloride side has 2-chloroterephthalic acid chloride, 2,5 dichloroterephthalic acid chloride, 2, 6-dichloroterephthalic acid chloride, 2-chloroisophthalic acid chloride, 2,6-dichloroisophthalic acid chloride, etc., and the amine side was 4,4'diaminodiphenylmethane, 3,4'diaminodiphenylmethylmethane, 3,4 3 ′
Diaminodiphenylmethane, 4,4'diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 4,4 'diaminodiphenyl ketone, 3,3' diaminodiphenyl ketone, and 3,3 'dimethylbenzidine (Toridine), 3,
3'dichlorbentine etc. Of course, a combination of a carboxylic acid, an amine and an isocyanate may be used instead of the reaction of an acid chloride and an amine, but in general, an acid chloride and an amine are preferable.

In addition, among these combinations of acid chloride and amine, 2-chloroterephthalic acid chloride is used on the acid chloride side and X or Y is used on the amine side like 4,4′diaminodiphenylmethane or 3,3′dimethylbenzidine. Those having an alkyl group (having 1 to 3 carbon atoms, preferably 1 carbon atom) are particularly preferable for achieving the object of the present invention, but of course, other than this combination, the object of the present invention is also satisfied. .

The constitutional unit represented by the above general formula must contain at least 50 mol% or more, preferably 70 mol% or more. Although the copolymerization component is not particularly limited, examples thereof include terephthalic acid chloride and isophthalic acid chloride as the acid chloride component, and paraphenylenediamine, metaphenylenediamine, 2- Examples include chloroparaphenylenediamine, 2-chlorometaphenylenediamine, 2,5 dichloroparaphenylenediamine, and 2-methylparaphenylenediamine.
As long as the copolymerization component achieves the object of the present invention, in addition to these, coexistence of components other than amides such as aliphatic components and hydrazine and imide bonds is not hindered. However, when the content of these copolymerization components exceeds 50 mol%, the solubility of the formed polymer is poor and a precipitation phenomenon occurs, making it impossible to form a film having sufficient mechanical properties, or when the solubility is sufficient. However, it is not possible to obtain a film having tear propagation resistance, low hygroscopicity and heat resistance at the same time, and the object of the present invention cannot be achieved.

The film used in the present invention may be blended with additives such as lubricants and antistatic agents and other polymers to the extent that the physical properties are not impaired. In addition, fine particles such as carbon black and alumina are used to reduce the electric resistance of the film and increase the thermal conductivity.
Addition of -40 wt% is particularly useful as described below.

In order to improve the thermal conductivity and to make the thickness of the base film seemingly thin, the amount of carbon black is about 20 to 35% is the most appropriate range.

The moisture absorption rate of the film used in the present invention is 4% or less, 250
The heat shrinkage rate at ° C is 5% or less, preferably 2% or less (the lower limit is not particularly limited, but about -2% is preferable). Among the mechanical properties, the breaking strength is 10 kg / mm ² or more and the elongation is 10
%, And the tear propagation resistance is preferably 100 g / mm or more and 500 g / mm or less. These mechanical properties may deviate from this range, especially when a large amount of additives are mixed in the film, but when compared with other aromatic polyamide films in which the same additives are mixed in the same amount, tearing is particularly remarkable. Its superiority with respect to propagation resistance remains unchanged.

The main component of the polymer structure of the film constituting the present invention is Particularly but not preferred in the present invention p = 1, n = m = 0, l = 1, Y = -CH 2 structure represented by the - is the Z-Cl It is structure and, p = 1, n = m = 1, x = -CH 3, l = 0, Z = Cl that This structure is useful for expressing this effect. In particular, the former structure is preferred, and the present invention is preferred in the present invention when the density of the film is between 1.310 and 1.365 with the additive removed.

In addition, as a polymer for obtaining a film having particularly high strength, an intrinsic viscosity (polymer 0.5 g is replaced with lithium bromide 2.5 wt
% Of N-methylpyrrolidone in 100 ml of solution 30
The value (measured at ℃) is preferably 0.5 to 3.0. When such a polymer is used, the polymer concentration in the stock solution for film formation is 5 to 40%.
It becomes about wt%. By setting the intrinsic viscosity of the polymer within the above range, the breaking strength is 7 kg / mm ² or more, preferably 10 to 50 k
It is possible to set g / mm ² and elongation to 10% or more, preferably 15 to 100%, and high-speed transfer becomes more preferable.

The carbon black in the present invention is not particularly limited, but it is preferable to use acetylene black, fannes black, lamp black, channel black, or the like. Alternatively, a carbon black surface-treated to improve electric conductivity, thermal conductivity, and dispersibility may be used. These carbon black specific surface area is 5m ² / g~1000m ² / g, particularly preferably from 10m ² / g~950m ² / g, average primary particle size of 5 nm to 500 nm, especially 10mμ~300mμ The carbon purity is preferably 90% or more, more preferably 97% or more.

The alumina in the present invention is not particularly limited,
Alumina sol, high-purity ultrafine-particle alumina oxide, or the like can be used, and the surface of the particles may be surface-treated to stabilize the dispersion. These alumina has a specific surface area of 10m ² / g~1000m ² / g, particularly preferably from 50m ² / g~600m ² / g, average primary particle diameter of 5mμ
˜2000 mμ, particularly preferably 20 mμ to 1000 mμ.

The contents of the above carbon black and alumina in the film can be confirmed by quantifying the ash content remaining after burning the film. Although carbon black and alumina may be aggregated in the film, the particle size of the primary particles can be confirmed by observing the cross section of the film with an electron microscope.

Next, a method for manufacturing the film will be described. The polymer is a low-temperature solution polymerized by adding two kinds of monomers to an organic solvent such as N-methylpyrrolidone, dimethylacetamide, hexamethylphosphoramide, dimethylformamide, tetramethylurea, γ-bryrolactone, or an aqueous medium. It can be prepared by the interfacial polymerization used. When a polymer solution polymerized in an organic solvent is used as it is as a film forming stock solution, hydrogen chloride is generated when acid chloride and diamine are used as monomers. Inorganic bases or their hydrates, ammonia, and ethylene oxide, propylene oxide, or organic bases such as triethylamine and diethanolamine to neutralize them and prevent hydrogen halide from adversely affecting the subsequent film formation process. It is necessary to. The neutralized salt produced by this neutralization acts as a polymer dissolution aid,
Although it enhances the solubility of the polymer, it may be possible to add an alkali or alkaline earth metal halide such as lithium chloride, lithium bromide or calcium chloride. An appropriate amount of addition is 50 mol% or less based on the amide groups of the polymer, that is, 150 mol% or less when combined with the neutralized salt. Depending on the type of basic constitutional unit and the type of copolymerization component, a solubilizing agent is not necessary, or a stable solution can be obtained even if the solubilizing agent is less than the neutralizing salt amount. In some cases, the film-forming property is better, and in that case, the amounts of the polymer and the solubilizing agent can be appropriately controlled by adding the isolated polymer to the dissolution.

The isolated polymer corresponds to the film obtained by film formation, but the polymer solution polymerized in an organic solvent is poured into water for reprecipitation, or the polymer produced by interfacial polymerization is washed. It can also be obtained by drying.

When the stock solution for film formation prepared as described above contains a salt produced by neutralization or an inorganic salt as a dissolution aid, it is preferable to form a film by a wet method or a dry-wet method. When a film is formed by a wet method, a method is adopted in which the stock solution is extruded directly from a die into a bath for film formation, or once extruded onto a support such as a drum and then introduced into the wet bath together with the support.
This bath is generally composed of an aqueous medium and may contain an organic solvent, an inorganic salt or the like in addition to water. However, in general, the water content is 30 wt% or more, preferably 50 wt% or more, the bath temperature is usually 0 to 100 ° C., and the salts and organic solvents contained in the film are extracted. .

When a film is formed by a dry-wet method, the stock solution is extruded from a spinneret onto a support such as a suitable drum or endless belt to form a thin film, and then supplied to a dry process. Then, the solvent is scattered from the thin film layer and dried until the thin film has a self-supporting property. At this time, it is necessary to adjust so that the solvent does not suddenly scatter from the film surface, and it is generally dried at room temperature to 300 ° C within 60 minutes. In some cases, the crystallinity can be improved by heating at 300 ° C. or higher for a short time. The film that has undergone the dry process is peeled from the support and introduced into the wet process, where the salts and organic solvent contained in the film are extracted.

Depending on the amount of the basic constitutional units or the distribution ratio of the copolymerized units, the polymer may be dissolved in the organic solvent without the inorganic salt. In that case, the film can be formed by the dry method. Of course, the film may be formed by the wet method or the dry-wet method as described above. When the film is formed by the dry method, the stock solution is extruded from the spinneret onto a support such as a drum or endless belt to form a thin film, which is peeled from the support after drying until it has self-supporting property. The film is dried (excluding moisture absorbed later) to at least 3% or less to obtain a film.

The film formed as described above is stretched or heat-treated so that the heat shrinkage rate and the moisture absorption rate are within the range of the present invention in the film forming process. Specifically, the draw ratio is an area ratio of 0.9 to 9 times (the area ratio is defined as a value obtained by dividing the film area after drawing by the film area before drawing. 1
The following means shrinkage), and the heat treatment is 250 under tension.
C. to 350.degree. C., 0.1 second to 1 minute, and a combination of the above stretching and heat treatment makes it possible to obtain a predetermined heat shrinkage rate and moisture absorption rate.

In the case of producing films containing fine particles such as carbon black and alumina, these are sufficiently slurried in an organic solvent in advance and then used as a polymerization solvent or a dilute solvent or after preparing a film-forming stock solution. There are methods such as direct addition. In either method, it is important that the particles are agitated sufficiently so that the particles in the film are evenly distributed, and the electrical conductivity of the film produced due to uneven distribution of particles in part of the stock solution may vary depending on the location. It is necessary to keep it unchanged. In addition, 1-40 wt% of these fine particles
% In the method for producing a film containing
It is preferable that it is in the range of 0.9 to 3.0 in order to improve the conductivity and maintain the mechanical properties. Draw ratio is 3.
When it is 0 or more, the surface resistance is remarkably lowered, so that it is not suitable for the purpose of using the additive.

Next, the heat-sensitive transfer ink layer in the present invention may be any known heat-sensitive transfer ink, and specific examples thereof include heat-meltable ink and heat-sublimable ink. The ink layer can be formed by hot-melt coating on one side of the film or by a general-purpose coating method such as gravure, reverse, and slit die as a solution dissolved in a solvent. The ink is mainly composed of a coloring component and a binder component, and if necessary, a softening agent, a flexing agent, a smoothing agent, a dispersant, a surface forming agent and the like as additive components.

Well-known waxes such as carnauba wax and ester wax and various low melting point polymers are useful as the binder component, and carbon black and various organic and inorganic pigments or dyes are useful as the colorant component. It is used, but is not limited to this.

[Operations and Effects of the Present Invention] The thermal recording transfer member of the present invention uses a polymer having a specific structure, and is provided with a thermal transfer ink layer on a film having a specific value of heat shrinkage and moisture absorption. No troubles such as melting and softening when contacting the head, that is, staking does not occur, and the film runs smoothly with almost no wrinkles, and good print quality can be obtained. In addition, since the film has a large resistance to tear propagation, there are no problems of tearing during running, and there are no wrinkles due to moisture absorption during storage. Further, since it has heat resistance, the film base material can be made extremely thin (3 μm or less), so that a long transfer material can be stored in the same type cassette.

Further, since the transfer body of the present invention has good heat resistance and dimensional stability even when heat is transferred from a thermal head to a minute portion at a high speed at the time of transfer, printing speed, which is one of the drawbacks of the thermal transfer method, It is extremely useful for improving the printing speed, but in order to further increase this effect, it is effective to use a film containing 1 to 40% by weight of the above-mentioned fine particles of carbon black or alumina as a base material.

In particular, the carbon black has a good compatibility with the polymer structure of the film used in the present invention, and is easily uniform and dispersed without causing agglomeration or the like to form a uniform film. Therefore, even if the amount added is increased, the mechanical properties of the film are not significantly impaired, and it is possible to increase the electrical conductivity and thermal conductivity with a relatively small amount added.

Increasing the thermal conductivity and efficiently transferring the heat of the thermal head to the ink layer is useful for improving the printing quality, increasing the printing speed, and reducing the equipment size by using less energy. Increasing the thermal conductivity is equivalent to making the film thinner, but making the film thinner not only makes it difficult to handle the ink layer coating process, but also causes thermal head and staking to cause wrinkles. Since it is easy, it is practically preferable to use a thick film having high thermal conductivity. In addition, by adding additives such as carbon black, the sliding performance is greatly improved, and wrinkles and staking problems are solved.

If the electrical conductivity of the film is increased by adding carbon black, the present invention will be useful for so-called energization type thermal transfer applications. In the phenomenon that the resistance heat generated in the film melts or sublimes the ink layer, the balance between the heat resistance and the mechanical properties of the film is important. In the case of the present invention, the film thickness can be set to 1 μ or more and 10 μ or less. It has the features that the printable amount in a cassette of a certain size is large, and that the film does not melt and the printing and printing quality are good.

The amount of carbon black added is preferably 1 to 40 wt%, but if it is less than 1%, it has little effect on the electrical conductivity, and if it is more than 40%, the mechanical properties deteriorate.
In this sense, the range of 5 to 35% is particularly preferable. The volume resistivity is 10 ² to 10 ¹³ Ω · cm, the breaking elongation is 10% or more, preferably 15% or more, and the breaking strength is 7 kg / mm ² or more.

The film of the present invention has a sufficient adhesive force to the ink layer, and the ink layer is not peeled off during thermal transfer to impair the printing quality. A wholly aromatic polyamide film is generally not a film having a very good adhesiveness, and especially when a film substituted with halogen atoms is used after the surface is subjected to a treatment such as corona treatment or glow treatment. However, the film used in the present invention is uniquely excellent in adhesiveness. This tendency is particularly remarkable when a methyl group is included. Of course, if necessary, the surface of the film may be subjected to roller treatment or the like without impairing the object of the present invention.

The method for measuring the physical properties of the film in the present invention is as follows.

(1) Tensile strength / tensile elongation: Tensilon tensile tester type UTM-III type, JIS Z-1702 and ASTM
It was measured according to D 882-67.

(2) Tear propagation resistance: Measured according to JIS P-8116 using a light load tear tester (manufactured by Toyo Seiki).

(3) Heat shrinkage: Cut the film into a width of 10 mm and a length of 250 mm, and mark at 25 mm from both ends at the specified temperature.
After heating for 10 minutes, the test piece was taken out, allowed to cool, and calculated by the following formula.

(4) Moisture absorption rate: A test piece that has been completely dried is placed in a thermo-hygrostat at 75% RH.
It was calculated from the weight change after standing for 48 hours by the following formula.

(5) Volume resistivity: The measurement film was sufficiently pressed between two circular electrodes made of copper having a diameter of 35 mm and made of copper, and the resistivity was calculated by the following formula from the resistivity when an electric current was passed through it.

ρ = (A / d) ・ R _V (Ω ・ cm) where ρ: Volume resistivity (Ω ・ cm) R _V : Measured value of volume resistance (Ω) A: Effective area of electrode (cm ² ) d: Film thickness (cm) [Example] The present invention will be described below based on examples. However, it is not limited to this.

Example 1 100 mol of 4,4'-diaminodiphenylmethane (19.827k
g) and N-methyl-2-pyrrolidone (NMP) 120 to 200
Place in a stirring tank equipped with a jacket and dissolve by stirring under a nitrogen stream. This solution was cooled to 10 ° C or below with brine, and then 100 mol of 2-chloroterephthalic acid chloride (23.74
5 kg) is added dropwise at such an addition rate that the internal temperature does not rise above 30 ° C. After the addition was completed, stirring was continued for about 1 hour, and the solution became extremely viscous. After the polymerization was completed, calcium hydroxide was added in an amount equal to that of the generated hydrochloric acid to obtain the final dope. Dope is solution viscosity
The viscosity was 11,000 poise (30 ℃) and the intrinsic viscosity was 1.18.

This dope was cast on a drum with a width of 50 cm and a diameter of 1 m,
The film containing the solvent and the salt was continuously peeled off from the drum by passing through the orb portion at ℃. The peeled film was introduced into a water tank, immersed for about 10 minutes, desalted and desolvated, then dried in a tenter at 300 ° C under tension and heat set. Residence in the tenter was about 3 minutes. It was also stretched 1.3 times in the longitudinal direction in a water tank and 1.2 times in a tenter.

The obtained film had a thickness of 6μ. A heat-sensitive transfer ink layer having the following composition was applied to the film to a thickness of 2 μm by a Holt melt coating method using a heating roll to obtain a heat-sensitive transfer tape.

Carnauba wax 30 parts Ester wax 35 parts Carbon black 12 parts Polytetrahydrofuran 10 parts Silicone oil 3 parts Using this, thermal head density 8 / mm, pulse width 0.
When a thermal transfer test of 7 msec was performed, good image quality was obtained stably, there were no handling problems such as tape tears and wrinkles, and there was no staking, and smooth operation was possible.

This film has a heat shrinkage of 2 at 300 ℃ and 250 ℃ respectively.
%, 0.2%, moisture absorption rate (75% RH; 48 hours) was 2.3%.
The strength was 20 kg / mm ² , elongation was 85%, and tear propagation resistance was 350 g / mm, which was a film with excellent mechanical properties.

Example 2 0.25 mol of 4,4'-diaminodiphenylmethane (49.57
g) was added to 200 ml of NMP placed in a 500 ml four-necked flask, and dissolved by stirring. After cooling it to below 10 ℃,
-Chlorterephthalic acid chloride 0.125 mol (29.68 g) was added dropwise, and 2,5 dichloroterephthalic acid chloride 0.125 was added.
Molar (33.99g) was added as a solid. One hour after the addition of both monomers, the solution became extremely viscous and the polymerization was completed. Then, the final dope was obtained by neutralizing with quick calcium 0.253 mol (14.14 g).

This dope has a melt viscosity of 9800 poise (30 ° C) and an intrinsic viscosity
It was 1.07. A part of this dope was evenly cast on a glass plate using an applicator and placed in a hot air oven at 150 ° C.
After heating and drying for 10 minutes, it was peeled from the glass, desalted and desolvated in water for 10 minutes. Then, it was heat-set for 5 minutes under tension in a hot air oven at 280 ° C. The thickness of the obtained film was 4 μm. The obtained films had heat absorptions of 300% and 250 ° C of 4.2% and 0.5%, respectively, and a moisture absorption rate of 2.8%. The strength is 27 kg / mm ² , the elongation is 75%, and the tear propagation resistance is 3
70 g / mm, a thermal transfer ink layer similar to that of Example 1 was applied to this film by 2 μm using an applicator, and a thermal transfer test was carried out. As a result, there were no wrinkles, no problems such as standing, and a good tape. Was confirmed.

Comparative Example 1 10.8 g (0.1 mol) of parafene diamine and 250 ml of N-methyl-2-pyrrolidone were placed in a 500 ml four-necked flask and dissolved under a nitrogen stream to give 23.747 g (0.1 mol) of 2-chloroterephthalic acid chloride. The dropping was performed using a dropping funnel so that the polymerization temperature did not exceed 30 ° C. One hour after the completion of dropping, the dope became nonuniform (precipitation of polymer).

To neutralize the hydrochloric acid generated by polymerization, 7.4 g (0.1 mol) of lithium carbonate and 60 ml of N-methyl-2-pyrrolidone were added to this system and reacted at 40 ° C. 1 hour after neutralization,
The heterogeneous dope became viscous and the stirring was continued for 3 hours to complete the neutralization reaction. The obtained dope was in the form of a transparent and uniform viscous solution.

Using an applicator, a part of this dope with a thickness of 3 mm, 30
It was evenly cast on a 0 × 300 mm glass plate, dried in an oven at 100 ° C for 15 minutes, peeled from the glass plate, and desalted and desolvated in water for 20 minutes. Furthermore, this film is 300 under tension.
Heat-treated in a hot air oven at 0 ° C. The thickness of the obtained film was 4 μm.

The mechanical properties of this film are strength 35kg / mm ² , elongation 30%,
The Young's modulus was excellent at 900 kg / mm ² , but the tear propagation resistance was very small at 90 g / mm. When the ink layer of Example 1 was applied to the film and a heat-sensitive transfer test as a tape was conducted, many troubles such as tearing during running occurred.

Comparative Example 2 Polymerization / neutralization was performed in exactly the same manner as in Example 1 except that 4,4′-diaminodiphenylmethane was replaced with metaphenylenediamine to obtain a film having a thickness of 6 μm. 300 of this film
Heat absorption at ℃ and 250 ℃ is 19%, 8.5%, moisture absorption (75% R
H, 48 hours) 5%. A heat-sensitive transfer test was conducted by applying the ink layer of Example 1 to this film, and moisture absorbed by the tape was evaporated at the head portion and condensed around the tape, or the tape after transfer partially due to heat absorption. There were considerable wrinkles and the print quality was adversely affected.

Examples 3 to 7 A certain amount of carbon black was added to 30 g of the dope obtained in Example 1 and mixed with stirring. A part of this dope was uniformly cast on a glass plate with an applicator and dried in an oven at 120 ° C for 8 minutes. After peeling from the glass plate, unrolling in running water for 10 minutes,
After removing the solvent, it was further heat-set for 2 minutes under tension in an oven at 300 ° C. The thickness of the obtained films is 6 μm, and the carbon black content (wt%) in these films and the physical properties are shown in Table 1. All carbon blacks were uniformly dispersed.

The same thermal transfer ink layer as in Example 1 was applied to each of the above films in an amount of 2 μm to fabricate a thermal transfer tape as a prototype, and a thermal transfer test using a thermal head was carried out. As a result, it was stable with a pulse width shorter than the test in Example 1. Printing was obtained and it was found to be effective for improving the recording speed.
There is no tearing or wrinkling of the tape, and the sliding of the tape is improved due to the influence of the fine particles of carbon black, and there are no problems such as staking without the formation of the easy-slip layer. It was

As a result of plotting the applied pulse width and the recording density curve, it was found that the sensitivity increased as the amount of carbon black increased and the energy used was reduced. The amount of carbon black is 1-40 because the mechanical properties do not deteriorate significantly.
%, The object of the present invention was sufficiently satisfied.

After depositing an aluminum layer on the films of Examples 6 and 7, 4 μm of the ink layer of Example 1 was applied, and transfer was carried out by the electrification method. As a result, good print quality was obtained. In addition, we could not find any problems such as wrinkles and tears when the tape was running.

Comparative Example 3 33 g of polycarbonate resin was dissolved in 600 g of dichloromethane. 14 g of carbon black was added to this polymer solution, and the mixture was sufficiently stirred and mixed. A part of this dope was uniformly cast on a glass plate with an applicator and dried in an oven at 70 ° C for 10 minutes to obtain a uniform film with a thickness of 10μ.
The characteristics of the film are shown in Table 1.

An aluminum layer was vapor-deposited on this film, 4 μm of the ink layer of Example 1 was applied, and transfer was carried out by the energization method. As a result, the print quality was good, but the tensile elastic modulus of the tape was too low, and the breakage occurred. Due to mechanical defects such as too small elongation, many problems such as tearing and wrinkling occurred when running the tape.

Comparative Example 4 4,4'-diaminodiphenylmethane 40 mol% and 1,4-
60 mol% of bis (4-aminophenoxy) benzene was used as a diamine component, and 100 mol% of 2-chloroterephthalic acid chloride was polymerized and neutralized in NMP. 28.6% of carbon black was added to this, and the mixture was stirred and mixed, and then uniformly cast onto a glass plate. This was dried at 120 ° C. for 10 minutes, peeled from the glass plate, desalted and desolvated in water, and then heat-set under tension at 300 ° C. for 2 minutes to obtain a 6 μ film.

The heat absorption of this film at 300 ℃ and 250 ℃ is 15% and 6.8, respectively.
%, The strength was 5.2 kg / mm ² , and the elongation was 7.1%, which was very inferior. In addition, when a film not containing carbon black was prototyped under the same conditions as above and the physical properties were measured, heat yields were 16% and 7.2% at 300 ° C and 250 ° C, respectively, and the strength was 23 kg / mm ² ,
The elongation was 70%. The mechanical properties of this polymer are significantly reduced by adding carbon black, and it is considered that the polymer has poor compatibility with carbon black.

An aluminum layer was vapor-deposited on this film, and 4 μm of the ink layer of Example 1 was applied to transfer by an energization method, but tears and wrinkles frequently occurred when the tape was running. Also, the printed matter had a large amount of ink bleeding.

Claims (2)

(57) [Claims] 1. A general formula 50% by mole or more of the constituent component represented by (where X is a halogen group, a nitro group, a C _{1 to} C ₃ alkyl group, a C _{1 to} C ₃ alkoxy group, and Y is Represents --CH _2- , --O--, and Z represents a halogen group. n and m are integers of 0 to 3, l is 0 or 1, p is an integer of 1 to 4), heat shrinkage at 250 ° C is 5% or less, moisture absorption is 4% or less, and aroma of 1 to 10μ in thickness A transfer member for heat-sensitive recording comprising a heat-sensitive transfer ink layer on a group polyamide film. 2. General formula Containing 50 mol% or more of the constituent component represented by (where X is a halogen group, a nitro group, a C _{1 to} C ₃ alkyl group, a C _{1 to} C ₃ alkoxy group, and Y is Represents --CH _2- , --O--, and Z represents a halogen group. n and m are integers of 0 to 3, l is 0 or 1, p is an integer of 1 to 4), heat shrinkage at 250 ° C is 5% or less, moisture absorption is 4% or less, and thickness is 1 to 10μ or less. A transfer material for heat-sensitive recording, in which a heat-sensitive transfer ink layer is provided on an aromatic polyamide film containing 1 to 40% by weight of carbon black or alumina.