JP2576061C - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION     [Industrial applications]   The present invention directly energizes the thermal head, laser, flash light or electric signal
Thermal transfer is performed by heating the recording material according to the applied signal by means such as
It relates to an image recording material.     [Prior art]   Changes in physical properties and changes in chemical reactivity of materials in response to the application of thermal energy
Regarding the thermal recording method used, many methods have been proposed since ancient times. Inside
But colorless such as crystal violet lactone, fluoran, spiropyran
Dyeing of dyes with phenolic compounds such as bisphenol A and other organic and inorganic acids
Coloring reactions, organic acid metal salts and organic reducing agents such as phenols, metal sulfides,
Thermosensitive color recording system using thermal reaction with a rate agent and an organic sulfur compound, and thermal fusibility
Ink and color materials are transferred to a recording medium such as paper by utilizing changes in thermophysical properties such as thermal sublimation.
In recent years, the thermal transfer recording method has been actively studied, and efforts have been made to improve it. Especially,
The latter thermal transfer recording method enables recording on plain paper and the light resistance of recorded images
Good stability and storage stability, high reliability due to simple recording mechanism, etc.
Application to printers, facsimile machines, copiers, etc.
You.     [Problems to be solved by the invention]   However, in the case of thermal sublimation of the dyeing department, it is reproduced with almost continuous gradation of density While having the advantage of being possible, recording sensitivity, storage stability of the recording medium, fixing of the recording surface image
There are problems with stability, light resistance, etc. In addition, the ink is melted by heat and the
In the case of the method of transferring and recording the corresponding ink, the above problem is reduced, but usually,
Since crystalline wax having a low melting point is used as a binder for the thermal ink layer,
Problems such as reduced resolution due to thermal diffusion and weak transfer / fixed image strength
Have.   In addition, crystalline waxes provide clear color images due to light scattering of the crystalline phase.
It has the disadvantage of being difficult.   Accordingly, an object of the present invention is to provide a thermal transfer recording material having good resolution.
You.   Another object of the present invention is to provide a thermal transfer recording material which enables clear color reproduction.
It is to be.   Still another object of the present invention is to provide a heat-sensitive transfer recording material having good recording sensitivity, transfer and fixing properties.
To provide.     [Means for solving the problems]   As a result of intensive studies, the present invention has made a specific release material a main binder material on a support.
The thermal ink material is applied, and the main binder component is further coated with a conventional crystalline wax.
Apply a thermal ink material changed to a specific amorphous polymer material to form a thermal ink layer.
By doing so, it was confirmed that the above object could be achieved, and the present invention was completed.   That is, the present invention comprises a support and a heat-sensitive ink layer provided on one side thereof.
In a thermal recording material, the thermal ink layer is a laminate of multiple thermal ink materials.
Of the plurality of thermal ink materials, the thermal ink material immediately above the support has a melting point or
Has a releasing agent having a softening point of 50 ° C. or more and 200 ° C. or less as a main binder component,
The main component of the thermal ink material is an amorphous polymer whose glass transition temperature is 40 ° C or higher.
Wherein at least one of the thermal ink materials contains a colorant.
It is a thermal recording material.   In the heat-sensitive recording material of the present invention, the amorphous polymer has a number average molecular weight of 10,000.
It is preferable to use one having 0 or less.   Hereinafter, the constitution of the thermosensitive recording material of the present invention will be described in detail.   Waxes conventionally used as binder materials for thermal ink materials are paraffin.
Wax, carnauba wax, montan wax, beeswax, wood wax,
Anderira wax, low molecular weight polyethylene, α-olefin oligomer and the same
These are copolymers and modified products of these, and if necessary, may be used in addition to mineral oils such as spindle oil
Plastic oils such as vegetable oils such as di-oil and drill oil, dioctyl phthalate and dibutyl phthalate
Fatty acids such as oleic acid and stearic acid, their metal salts, amides and other agents.
Conductors are mixed and dispersed together with dyes and pigments to form thin plastic films and capacitor paper.
By coating on it, a thermal transfer recording material was obtained.   Waxes, which are such conventional binder materials, are crystalline, so that they are heated from about 50 ° C.
When it has a relatively clear melting point in the temperature range of about 150 ° C and is heated above the melting point
, Rapidly changing from a solid phase to a liquid phase. And at a temperature about 30 ° C higher than the melting point,
10^-2It becomes a low viscosity liquid of about 10 poise. In contrast, amorphous polymers
In this case, there is essentially no melting point, and the solidification gradually starts at the glass transition temperature (Tg).
Changes from phase to liquid phase. The viscosity change during this time is basically the WLF type or AND
According to the Lade formula, even at a temperature about 50 ° C. higher than Tg, at most 10^Three-10^Five
The viscosity decreases only up to the poise level. In the case of thermal transfer recording, the transfer and fixing feeling
Since the degree is basically governed by the melt viscosity and melt viscoelasticity of the binder material, the amorphous polymer
The use of carbon as a binder for thermal inks is clearly disadvantageous in sensitivity.   However, the inventors have formed amorphous polymers having a specific molecular weight and Tg.
The bottom layer is a heat-sensitive ink material that uses a release material as a binding material and is used as a binding material.
Then, an ink-sensitive layer using an amorphous polymer as a binder material is laminated and applied on the support.
Can significantly improve image quality and image stability without sacrificing sensitivity
I found that.   The outline is described below together with a representative example.   In the present invention, the measurement is performed by gel permeation chromatography (GPC).
Determined polystyrene equivalent number average molecular weight of about 10,000 or less, differential scanning calorimetry (
Tg measured by the DSC) method is about 40 ° C. or higher, and more preferably a number average molecular weight of about 5
An amorphous polymer having a Tg in the range of about 50 ° C. to 80 ° C. or
When the oligomer is used as the adhesive material, the object can be achieved well. Tg Is less than 50 ° C., particularly less than 40 ° C., blocking of the thermal ink material occurs.
It is easily stiff and lacks storage characteristics and stability during use. When Tg exceeds 80 ° C
Has good thermal stability, but has low sensitivity, so it is practical except for special applications.
Lack. If the molecular weight of the polymer is high even when Tg is within the above range,
It was experimentally confirmed that the sensitivity decreased. This is based on the entanglement of molecular chains, etc.
The number average molecular weight is about 10,000 or less, especially 5
Good transfer and fixing properties were obtained when the average molecular weight was 3,000 or less. The setting of weight average molecular weight
It can vary depending on the use of the thermal transfer recording material. Same as conventional wax-based ink
When it is desired to obtain a binary transfer image, the weight average molecular weight is about 40,000 or less, more preferably
It is desired to reduce the molecular weight distribution to about 10,000 or less. On the other hand, between polymer chains
Using the distribution of cohesive force and relaxation time, it is possible to obtain density gradation and multi-valued transferred images,
When controlling the transfer ink amount for the purpose of repeatedly using it many times,
The average molecular weight does not necessarily need to be reduced, and may be set to about 40,000 or more. Change
Also, the pattern of the molecular weight distribution is necessarily a shape having a single molecular weight peak
It is not necessary, and a distribution shape having a plurality of molecular weight peaks may be used. Also, cross-linking
Alternatively, a branched polymer component may be used in combination. However, if the weight average molecular weight is about 10,000 or more,
If it is set to 40,000 or more, sensitivity becomes disadvantageous.   The chemical composition and structure of the amorphous polymer will of course affect the properties of the thermal ink material.
However, the effect is not as large as the above-mentioned molecular weight and Tg. The values of molecular weight and Tg
If it is within the specified range, it can basically be applied as the thermal ink material of the present invention.
is there.   For example, styrene, vinyltoluene, α-methylstyrene, 2-methylstyrene
, Chlorostyrene, vinylbenzoic acid, sodium vinylbenzenesulfonate, amino
Styrene such as styrene and its derivatives, substituted homopolymers and copolymers, methyl
Methacrylate, ethyl methacrylate, butyl methacrylate, hydroxy
Methacrylic esters such as tyl methacrylate and methacrylic acid,
Relate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate
Acrylates such as acrylates and acrylic acid, butadiene, isoprene, etc.
Dienes, acrylonitrile, vinyl ethers, maleic acid and maleic acid
S Vinyl monomers such as ters, maleic anhydride, cinnamic acid, vinyl chloride and vinyl acetate
If it is a single substance, a copolymer with another monomer can be used.   Examples of the condensation resin include phthalic acid, phthalic anhydride, isophthalic acid, and terephthalic acid.
Talic acid, hexahydrophthalic anhydride, malonic acid, succinic acid, glutaric acid, adipate
Acid, saturated dibasic acid such as sebacic acid, maleic anhydride, fumaric acid, itaconic acid
, An unsaturated dibasic acid such as tetrahydrophthalic anhydride and ethylene glycol;
-Propylene glycol, 1,6-hexanediol, bisphenol A, bis
Phenol A propylene oxide adduct, bisphenol A ethylene oxide
Polyester resins obtained by polycondensation with diols such as adducts may be used.
. In this case, trimellitic acid, glycerin, trimethylolpropane, etc.
A branched or cross-linked polyester may be formed by using a functional compound. Of course,
Cross-linked polymers using polyfunctional monomers such as divinylbenzene in the case of
You may use as. Furthermore, polycarbonate, polyamide, epoxy resin
Fat, polyurethane, silicone resin, fluorine resin, phenol resin, terpe
Resin, petroleum resin, hydrogenated petroleum resin, alkyd resin, ketone resin, cellulose derivative
A body or the like may be used. These amorphous polymers or oligomers are
When used in the form, the copolymer is not a random copolymer,
, Alternating copolymer, graft copolymer, block copolymer, interpenetrating copolymer, etc.
Can be appropriately selected for use. Two or more polymers,
When using a mixture of oligomers, melt mixing, melt mixing, emulsion mixing
In addition to mechanical mixing, such as polymerization, co-polymerization, multi-stage polymerization during polymerization of polymer and oligomer components
It may be mixed by a method or the like.   Releasable material used as binder for thermal ink material applied first to support
Quality is melting point measured by differential scanning calorimetry (DSC) or softening point measured by ring and ball method
At a normal temperature of 50 ° C to 200 ° C, more preferably 60 ° C to 150 ° C.
Solid organic substance or organic / inorganic low molecular weight polymer, melting point or softening
A substance with a relatively low surface energy that suddenly becomes a low-viscosity liquid beyond a point.
When the melting point / softening point is 50 ° C or less, the storage and use stability is lacking.
When the point is 200 ° C. or higher, the thermal energy applied by the normal thermal recording method is As a result, the release effect is not exhibited. In the temperature range of about 100-180 ° C
The melt viscosity drops sharply to about 10 poise or less, more preferably to about 1 poise or less.
And more preferably have a low viscosity and / or critical surface tension of about 40 dyn / cm or less.
Is a substance having a low surface energy of about 30 dyn / cm or less is effective as a mold release substance
It is.   Specifically, for example, higher fatty acids such as palmitic acid and stearic acid;
Fatty acid metal salts such as zincate; fatty acid esters or partially saponified products thereof;
Fatty acid derivatives such as fatty acid amides; higher alcohols and polyhydric alcohols
Derivatives such as ter; paraffin wax, carnauba wax, montan wax,
Waxes such as beeswax, wood wax, candelilla wax; having a viscosity average molecular weight of about
About 1,000 to about 10,000 low molecular weight polyethylene, polypropylene,
Polyolefins such as polybutylene, or olefins and α-olefins
Water Low molecular weight with organic acids such as maleic acid, acrylic acid, methacrylic acid, vinyl acetate
Copolymer, low molecular weight oxidized polyolefin, halogenated polyolefins; lau
A product having a long alkyl side chain such as ril methacrylate or stearyl methacrylate.
Tacrylic acid esters, acrylic acid esters, and acrylics with perfluoro groups
Alone such as acrylates and methacrylates or vinyls such as styrenes
Copolymer with monomer; such as polydimethylsiloxane and polydiphenylsiloxane
Low molecular weight silicone resins and silicone-modified organic substances; furthermore, long-chain aliphatic groups
A cationic surfactant such as an ammonium salt or a pyridium salt, or the like
With long-chain aliphatic group on the surface, nonionic surfactant, perfluoro surfactant
One or more types can be selected from agents and the like.   These release materials used a binder and an amorphous polymer on the support and upper part during heating.
Melts between the thermal ink materials and has a low cohesive force and / or low surface energy effect
To reduce excessive cohesion and adhesion between the thermal ink layer and the support interface
It seems that the recording sensitivity and image quality are improved.   As described above, the present inventors have determined that a release material and an amorphous polymer are used as binder materials.
The recording sensitivity can be improved by applying a heat-sensitive ink material on the support to form a heat-sensitive ink layer.
And improved image quality and image stability.   That is, when only a thermal ink material using a release material as a binder resin is used,
Although advantageous in recording sensitivity, its low cohesion and / or low surface energy
Causes deterioration of fixation to a recording medium such as paper, or spreads an image and lowers resolution.
The color reproducibility is degraded because many release materials are crystalline materials
.   On the other hand, when only a thermal ink material using an amorphous polymer as a binder material is used,
Excellent adhesion stability, resolution and color reproducibility, but high adhesion between support and thermal ink layer
It is disadvantageously sensitive. On the other hand, on the support, first, a release material is used as a binding material.
A thermal ink material to be applied, and then use a thermal ink using an amorphous polymer as a binder material.
In the configuration of the present invention in which the heat-sensitive ink layer is formed by laminating and coating
This is possible because only the function at the support / thermal ink layer interface is needed.
Practical use of light scattering by making it as thin as possible, desirably 2 μm or less in dry film thickness
Reduced to no problem, improved color reproducibility, and amorphous polymer
While heating, the interface between the support and the thermal ink layer interface was
The recording sensitivity can be improved by reducing the adhesion.   Examples of the coloring agent in the heat-sensitive recording material of the present invention include carbon black and oil black.
Black dyes and pigments such as racks and graphite; Pigment Yellow 1 and 3
, 74, 97, and 98 acetoacetic acid arylamide-based monoazo yellow pigments (F
Fast Yellow); CI. Pigment Yellow 12, 13 and 1
Acetoacetic acid arylamide-based disad yellow pigments such as CI. Solvent Y
yellow19, 77, 79, C.I., Disperse Yellow16
Yellow dyes such as CI. Pigment Red 48, 49: 1, 53: 1,
Red or red pigments such as 57: 1, 81, 122 and 5; CI. Solv
red dyes such as ent Red 52, 58 and 8; CI. Pigment Bl
blue dyes and pigments such as copper phthalocyanine and its derivatives and denatured products such as ue15: 3;
It can also be used in conventional printing inks and other coloring applications such as colored or colorless sublimable dyes.
Well-known dyes and pigments can be used.   These dyes and pigments may be used alone or as a mixture of two or more.
Of course, the color tone may be adjusted by mixing with an extender or a white pigment. Furthermore, binding
In order to improve the dispersibility for the material components, the surface of the colorant is Treated with a coupling agent such as a coupling agent, a polymer material, or a polymer dye or polymer
A graft pigment may be used.   In the heat-sensitive recording material of the present invention, a charge control and / or antistatic agent,
Electrifying agent, antioxidant, thermal conductivity improver, magnetic substance, ferroelectric substance, preservative, fragrance, broth
Anti-cking agents, reinforcing fillers, release agents, foaming agents, sublimable substances, infrared absorbers, etc.
It may be used by adding to the inside or outside of the thermal ink material.   As a support, polyester such as polyethylene terephthalate, polyimide
And plastic films such as imide copolymers, fluorine polymers, polypropylene, etc.
Thin sheets and films such as films and condenser papers are conveniently used.   These sheets, films, or rolls have thermal conductivity and heat stability inside
Add thermal property modifier, release agent, antistatic agent, conductive agent, and reinforcing agent to improve the properties
May be used. When recording is performed using a thermal head, etc., the thermal head of the support is used.
To improve heat resistance, running properties, etc., use silicone-based or fluorine-based
A compound, a resin layer, a crosslinked polymer layer, a metal layer, a ceramic layer, or the like may be provided.
Further, the film internal additive may be added to the outer layer. The surface of these supports is smooth
Alternatively, an uneven portion, a thin portion, or the like may be provided. Also, even if it is porous
Good.   The thermal transfer recording material of the present invention may be a release material or an amorphous polymer or
A mixture of ligomer, colorant, and, if necessary, various additives described above,
It is formed by laminating and coating a thermal ink material on a support.   Mixing the thermal ink material can dissolve and / or stably disperse the binder material
A solution and / or dispersion emulsion in a solvent and / or dispersion medium,
Prepared with a mixing and dispersing machine such as a ball mill, sand mill, attritor, and three rolls.
be able to. Further, without using a solvent or the like, the heating type three-roll,
The solvent may be mixed with a pressure kneader or a Banbury mixer. In addition, amorphous
The rimer is polymerized in the presence of colorants, additives, etc.
It may be. The plurality of thermal ink materials prepared in this way are coated on a support.
Use a via coater, wire bar, etc., and apply the solution and / or melt coating method.
Next applied and / or printed.   In addition, the thermal ink material is powdered by spray drying, pulverization, etc.
The support may be powder-coated by an electrocoat method or the like. In this case, powder coat
After that, if necessary, heat, pressurize, and perform solvent treatment to support the heat-sensitive powder ink.
It may be fixed on the body before use. Furthermore, when preparing such a heat-sensitive powder ink,
In the case of an amorphous polymer, the suspension is polymerized in the presence of a colorant, additive, etc.
The powdered ink may be prepared by polymerization by a direct polymerization method such as a dispersion method or a dispersion polymerization method. Ma
Further, as a support, an electrothermal conversion element having a structure similar to that of a thermal head or a photothermal conversion element
Alternatively, a thermal ink layer may be provided directly on the ink.   The thickness of the support film, sheet, and thermal ink layer are appropriately selected according to the application.
The thickness of the support is generally about 1 μm to about 200 μm.
It's easy to do. In order to improve the resolution, the thickness is preferably from about 1 μm to about 10 μm.   The thermal ink layer has a dry coating thickness of each thermal ink material from about 0.1 μm depending on the application.
To about 50μm, usually about 1μm to about 20μm.
Easy to use.   Further, a plurality of types of ink materials having different physical properties may be dividedly coated in the plane layer.   The heat-sensitive recording material formed in this way can be heated head, laser, flash light
Or by heating the paper in response to the applied signal
Flying against a recording medium such as a film in a contact state or a non-contact state
Thus, the thermal ink material is transferred and recorded. Pressurization, to improve recordability
In addition to mechanical force such as foaming, it is also possible to use electric fields, magnetic fields, ultrasonic waves, solvents, etc.
.     【Example】   Hereinafter, the present invention will be described with reference to examples, but the present invention is of course limited by these examples.
It is not something to be done. In the following examples, parts are by weight unless otherwise specified.
You. Example 1   A polyester having a thickness of 6 μm by using the thermal ink materials (a) to (d) having the following composition:
Thermal recording materials 1 to 5 were prepared by coating on a film. [Thermal ink material composition] (A) 85 parts of paraffin wax (melting point = 65 ° C) 5 parts of softener (lubricating oil) Blue pigment (CI Pigment Blue 15: 3) 10 parts   After melt-mixing the above composition at 100 ° C, it is kneaded with a three-roll mill and heat-sensitive.
The ink material (a) was used. (B) 2.7 parts of ester wax (melting point = 74 ° C) Nonionic surfactant 0.3 part 97 parts of distilled water   The above composition was stirred and emulsified at 90 ° C., and a wax having an average wax particle diameter of 0.5 μm was used.
The emulsion was used as an ink-sensitive material (b). (C)   The above composition was kneaded in a ball mill at room temperature for 40 hours to obtain a heat-sensitive material (c).
. (D)   The above composition is kneaded in a ball mill at room temperature for 40 hours to obtain a heat-sensitive ink material (d).
And [Composition of thermal recording material] Thermal recording material 1 (Comparative Example 1)   As shown in FIG. 1, a hot ink material (a) was heated to 110 ° C.
The thickness of the cooled thermal ink layer (2) on the polyester film (1) on the plate
Was applied with a wire bar so as to have a thickness of 3 μm. Thermal recording materials 2 and 3 (Comparative Examples 2 and 3)   After drying the thermal ink material (c) or (d) on a polyester film,
Apply with a wire bar so that the thickness of the heat-sensitive ink layer becomes 3 μm, and record each heat-sensitive
Material 2 (the ink material is (c)), Thermal recording material 3 (the ink material is (d))
(See FIG. 1). Thermal recording materials 4 and 5 (Example 1 and Comparative Example 4)   As shown in FIG. 2, the thermal ink material (b) was dried on the polyester film (1).
Apply with a wire bar so that the wax layer thickness after drying becomes 0.5 μm.
℃ to melt the wax particles to form a uniform wax layer (3), then cooled
.   On the wax layer (3) formed on the polyester film (1), heat-sensitive
The thickness of the ink layer (2) after drying the ink material (c) or (d) is 2.5 μm.
Coating with a wire bar, and the thermosensitive recording material 4 (the ink material is (b) and (b)
c)) and a heat-sensitive recording material 5 (ink materials of (b) and (d)).   The representative recording characteristics of the heat-sensitive recording materials 1 to 5 prepared by the above formula
The following table shows the results of evaluation using an FX-6 thermal transfer printer.   The recording characteristics were evaluated by the following method. Recording sensitivity: Equivalent to thermal head heating element size (１ ／ mm = 125 μm)
Energy applied to the thermal head for recording the transfer dot (= E) A: E <0.7 mJ / dot ；; 0.7mJ / dot<E <0.9mJ / dot Δ: 0.9 mJ / dot<E <1.1mJ / dot ×: 1.1 mJ / dot<E Resolution: How to break vague characters (especially those with a large number of strokes) Transparency: Color turbidity when projected on a screen after being transferred and recorded on an OHP sheet Degree of fixation: Removal of ink and smear around transferred image when rubbed with finger and eraser
Outbreak   As shown in the table, the conventional type (thermal recording material) using wax as a binder for the entire ink layer
Fee 1) is slightly better in recording sensitivity, but may cause character collapse in kanji with many strokes.
May be difficult to read, and if the transferred image is rubbed with a finger,
Occurred. On the other hand, the heat-sensitive recording material 4 according to the present invention has almost the same recording sensitivity as the conventional type 1.
In addition, clear printing without crushing is obtained, and even if the transferred image is rubbed, the ink
Excellent recording characteristics were exhibited without occurrence of peeling or stain. In terms of transparency, Conventional 1
Vivid blue image without turbidity was obtained in contrast to dark blue color
.   In addition, the relationship between the thermosensitive recording materials 2 and 4 and the relationship between 3 and 5 was used to improve the recording sensitivity.
The contribution of the heat-sensitive ink layer using a releasing agent as a binder was confirmed, and the relationship between 2 and 3 was similarly determined.
And the relationship between 4 and 5 confirmed the contribution of number average molecular weight and glass transition temperature control.
. Example 2   6 μm thick polyester having the following composition as the heat-sensitive ink materials (e) and (f):
A thermosensitive recording material 6 was prepared by coating on a film. [Thermal ink material composition] (E)   The above composition is kneaded in a ball mill at room temperature for 30 hours to form a heat-sensitive ink material (e).
And (F) 2.7 parts of ester wax (melting point = 77 ° C) Nonionic surfactant 0.3 part 97 parts of distilled water   The above composition is stirred and emulsified at 95 ° C. to form a wax emulsion, and a heat-sensitive ink
The material (f) was used. [Configuration of Thermal Recording Material 6]   The wax layer thickness after drying the thermal ink material (f) on the polyester film
Apply with a wire bar so that the thickness becomes 0.5 μm, and then heat to 120 ° C and wax
The particles were melted, formed into a uniform wax layer, and then cooled. This wax
Apply the thermal ink material (e) on the layer so that the ink layer thickness after drying becomes 2.0 μm.
A thermosensitive recording material 6 was obtained by laminating and coating with a yaver (see FIG. 2).   When the obtained heat-sensitive recording material 6 was evaluated in the same manner as in Example 1, Comparative Example 1 was obtained.
Of the same size with an applied energy (E = 0.69 mJ / dot) about 1.1 times the
Capable of recording dots, and clearing of the ink even when rubbed with a finger
Strong printing without separation was obtained. Example 3   A thermal ink material (g) having the following composition was applied to a 3.5 μm thick polyester film.
After coating and drying to a dry thickness of 0.2 μm on the
The colorant of the heat-sensitive ink material (e) is a blue pigment (CI Pigment Blue). e 15: 3), red colorant (CI Pigment 57: 1), yellow pigment (C.I.
I. Pigment Yellow 12), each having a dry thickness of 2.0 μm.
m to obtain a thermosensitive recording material (see FIG. 2). (G) 2 parts of 12-hydroxystearic acid 98 parts of methyl ethyl ketone   The recording characteristics of the obtained three-color heat-sensitive recording materials were evaluated in the same manner as in Example 1.
The three colors of blue, red and yellow are extremely sharp and have high resolution and excellent transparency.
Print was obtained. Example 4   As shown in FIG. 3, the thickness is 15 μm and the volume resistivity is 10⁰Ω · cm conductive polycarbonate
Aluminum (5) on one side of the carbonate film (4) by vacuum evaporation to a thickness of 800A
The thermal ink material family (f) of Example 2 was dried and formed on the aluminum surface of the attached support.
After drying, apply with a wire bar so that the thickness of the wax layer becomes 0.5 μm, and dry form a film.
To form a first layer (3), and then as a second layer (2),
The ink layer thickness after drying the ink material (e) with the wire bar is also 5.0 μm.
And dried to obtain a thermosensitive recording material.   This thermosensitive recording material was mounted on a prototype of an energized thermosensitive transfer printer, and various recordings were made.
Extremely smooth even on bond paper and plain paper (high quality paper) when recorded on paper
As a result, a strong print was obtained in which the outline was clear and the ink did not peel off due to rubbing or the like. Example 5   Further, as the lowermost layer (first layer), the thickness of the heat-sensitive ink layer using a release material as a binder
Was evaluated for its effect on recording sensitivity and transparency. Formula of thermal recording material used for evaluation
Are (b), (c) and (d) described in the first embodiment.
Then, the thermal ink material (b) (ink material using a releasing material as a binder) is applied to the first layer.
Is applied in various thicknesses, and then the second layer of the thermal ink material (c) or (d)
) Was adjusted so that the coating thickness of the two layers after drying was 3 μm.   FIGS. 4 (a) and 4 (b) each show the use of a thermal ink material (c) for the second layer.
FIG. 5 shows the relationship between the recording sensitivity and the transparency of the first layer and the ink coating layer in the case of FIG. (A) and (b) show the case where the same thermal ink material (d) is used for the second layer.
And show a similar relationship.   Thermal ink material (b) applied on polyester film (bonds release material
The improvement of recording sensitivity by the heat-sensitive ink material used as an agent) is sufficiently effective when the coating thickness is 0.5 μm.
The effect of recording sensitivity is not improved if the coating thickness is simply increased.
(See FIG. 4 (a) and FIG. 5 (a)).   On the other hand, the transparency deteriorates when the coating thickness of the thermal ink material (b) is increased,
m, it was almost the same as that of the heat-sensitive recording material 1 (see FIG. 4 (b) and FIG.
(See FIG. 5 (b)).   As described above, when the coating thickness of the thermal ink material (b) is 0.5 μm, good
It was found that the recording sensitivity could be improved while maintaining the transparency.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view showing the structure of a conventional thermal transfer recording material, FIG. 2 and FIG. 3 are cross-sectional views each showing the structure of a thermal transfer recording material of the present invention,
FIGS. 4 (a) and (b) are graphs each showing the relationship between the thickness of the first layer, the recording sensitivity, and the transparency of the recording material in which the first layer is composed of only a release material, and FIG. 5 (a). And (b) are graphs showing the relationship between the thickness of the first layer and the recording sensitivity and transparency when another ink material is used for the second layer. Symbols in the drawing: 1 polyester film; 2 thermal ink layer; 3 thermal ink layer (wax layer); 4 conductive polycarbonate film; 5 aluminum layer;
Support.

Claims (1)

11. Claims 1. A heat-sensitive recording material composed of a heat-sensitive ink layer provided support and on one side thereof, which heat sensitive ink layer was laminated two heat sensitive ink material, 2 Of the various types of thermal ink materials, the thermal ink material immediately above the support has a melting point or softening point of a release material having a melting point or softening point of 50 ° C. or more and 200 ° C. or less as a main binder component of 1.5 μm.
In the following layers, the other thermal ink material has a glass transition temperature of 40 ° C. or more and 80 ° C.
A heat-sensitive recording material comprising the following amorphous polymer as a main binder component and at least one heat-sensitive ink material containing a colorant.