JPH01108087A - Thermal transfer recording medium - Google Patents

Abstract

PURPOSE:To enable multi-time use and obtain high-quality high-resolution images through application of low energy, by causing a first transfer layer comprising a heat-fusible composition held in through-holes to be thicker than a second transfer layer comprising a heat-fusible composition. CONSTITUTION:An adhesive layer 3 is provided on a substrate 2, a first transfer layer 4 comprising a heat-fusible composition 7 held in through-holes of a porous film 6 is provided on the adhesive layer 3, and a second transfer layer 5 comprising a wax or the like is provided on the first transfer layer 4. The coating thickness of the first transfer layer 4 is greater than that of the second transfer layer 5. Of the heat-fusible composition 7 in the first transfer layer 4 and the heat-fusible composition in the second transfer layer 5, the part 12-1 heated by a heating printing element is brought into a uniform fluid state, and is transferred onto a transfer recording paper 18 while being pressed. At a part 12-2, the heat-fusible composition 7 in the first transfer layer 4 is transferred onto the paper 10 through the small holes by heating and pressing. Further, at a part 12-3 which is subjected to transferring an increased number of times, the heat-fusible compositions are almost completely consumed.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a thermal transfer recording medium used in a thermal printer or a thermal typewriter, and more particularly to a thermal transfer recording medium that can be used many times.

<Prior art and its problems> Most conventional heat-sensitive transfer recording media have a structure in which a heat-melt transfer layer consisting of a heat-melt binder and a coloring material is provided on a base film. It has the following drawbacks. In other words, conventionally, this type of recording medium is
It was a so-called one-time type thermal transfer sheet in which almost no ink layer of the recording medium remained on the base film after one transfer, and only prints with uneven density were obtained after the second use. Therefore, the cost of obtaining a record becomes high, and there is also a problem in terms of information maintenance, since printing only once leaves clear traces of the print on the thermal transfer recording medium. Against this background, studies have been progressing on heat-sensitive transfer recording media that can be used repeatedly. There is a proposal for a thermal transfer material (Japanese Patent Application Laid-Open No. 105579/1983), which has a resin layer and contains hot-melt ink in the pores of the resin layer. It is attracting attention as a means of controlling the amount of ink transferred depending on the size of the ink.However, the quality of the image printed with this recording medium is significantly lower in density than that of a one-time thermal transfer recording medium. The resolution was not sufficient and the image was unclear.

In addition, as one proposal for multiple recordings, there is a proposal for a thermal transfer film in which a porous film layer and a heat-fusible transfer layer are sequentially provided on a base film (Japanese Patent Application Laid-open No. 131296/1983). Although the printing quality is excellent in terms of both density and resolution and is comparable to that of a one-time type thermal transfer recording medium, it is not possible to control the amount of transfer according to the applied energy, so it cannot be used many times.

<Means for Solving the Problems> In view of the above circumstances, the present invention aims to improve the conventional technology of the thermal transfer medium as described above, and improves the thermal sensitivity of the thermal transfer recording medium that can be used many times. It is an object of the present invention to provide a heat-sensitive transfer recording medium that can be used many times and has improved characteristics regarding repeat life, as well as providing high-quality images.

The above object is to provide a first transfer layer in which a hot-melt composition is held in the through-holes of a porous membrane having through-holes on a substrate via an adhesive, and a second transfer layer made of a hot-melt composition in the through-holes. This can be achieved by a thermal transfer recording medium characterized in that at least transfer layers are laminated in this order, and the layer thickness of the first transfer layer is thicker than the layer thickness of the second transfer layer.

When performing thermal recording using this recording medium, first, the transfer paper is placed facing the second transfer layer of the thermal transfer recording medium, and then a pressure medium is used to press both the base of the recording medium and the back surface of the transfer paper. The heat-melting compositions of the first and second transfer layers are partially heated by a heated printed body having means for generating heat energy from the base body in response to an arbitrary image signal. is fluidized, and the heat-melting composition is sequentially transferred from the second transfer layer to the transfer paper side.

Hereinafter, in order to make the present invention more clear, the present invention will be described in detail with reference to the drawings.

FIGS. 1 and 2 are schematic cross-sectional views of an example of the structure of a thermal transfer recording medium of the present invention. As shown in FIGS. 1 and 2, each of the thermal transfer recording media 1 and IB has a heat-fusible composition in the through-holes of the M6.6B through-holes on the base 2 via the adhesive layer 3. A first transfer layer 4.4B holding the object 7゜7B is provided, and wax, colorant,
It is a thermal transfer recording medium in which a second transfer layer 5 made of a binder, oil, etc. is laminated, and the coating thickness of the first transfer layer 4.4B is thicker than the coating thickness of the second transfer layer 5. . 1st
The transfer layer is intended to be used many times, so that the amount of the hot-melt composition transferred at one time can be controlled.
The second transfer layer is provided so that at least the first printing can be performed with low energy and a high resolution image can be formed. The porous films 6 and 6B each have independent holes that penetrate to the second transfer layer 5 and communicating holes that penetrate in a two-dimensional network.

The substrate 2 is a dense, thin, and smooth medium with high thermal conductivity that holds the heat-melt transfer layer and transfers the heat-melt composition 7 to the base 2.
This is to prevent leakage to the back surface 8 and contamination of the heated printed material, etc., and a conventionally known substrate is used. - Examples include polymer films such as polyethylene polypropylene, polyethylene tereftate, polyimide, and aramid, or thin paper materials such as condenser paper, laminated paper, and coated paper. Furthermore, when mechanical strength is taken into account, 2 to 15 (μ
A thickness of m) is preferable, but the thickness is not limited to this.Furthermore, the back surface 8 of the base 2 facing the adhesive layer 3 and in contact with the heated printed body etc. may be subjected to a heat-resistant treatment.

An adhesive layer 3 is provided between the substrate 2 and the first transfer layer 4.4B, and this has the effect of preventing the first transfer FJ 4.4B from peeling off from the substrate 2. The thickness of the adhesive layer 3 is 0.
It is possible to set it in the range of 1 to 5 (μl 1), but when considering thermal sensitivity and adhesive strength, it is 0.3 to 2 (μl
It is preferable to use within the range of 1)).

Specific materials used for the adhesive layer 3 include polyethylene,
Cross-linked polyethylene, chlorinated polyethylene, ethylene-vinyl acetate copolymer, polyethylene terephthalate, polypropylene, polyisobutylene, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polyvinyl alcohol, polyvinyl acetal, fluororesin, acrylic resin, polyacrystalline, Polystyrene, acetal resin polyamide, polycarbonate, cellulose plastic, styrene-acrylonitrile copolymer, acrylonitrile-butadiene-styrene terpolymer, phenol resin, urea resin, eboshiki resin, unsaturated polyester resin, acrylic ester resin, alkyd resin,
Melamine resin, silicone resin, polyurethane, diallyl phthalate resin, polyphenylene oxide, polyimide, polysulfone, chlorinated rubber, hydrochloric acid rubber, cyclized rubber, polyisoprene, polybutadiene, styrene-butadiene copolymer, polychloroprene, nitrile rubber, butyl rubber, acrylic rubber, ethylene-propylene rubber, etc.
One type or a combination of two or more of these may be used. The adhesive layer 3 described above can be formed using coating means such as hot melt coating, solvent coach ink, or emulsion silane coating.

The first transfer layer 4.4B and the second transfer layer 4.4B provided on the adhesive layer 3
As the heat-melting composition used for transfer N5, conventionally known compositions can be used as they are, and are composed of wax, colorant, binder, oil, and the like.

As a colorant, for example, in the case of pigment-based black, carbon black, oil black, etc. can be used, and in the case of color, ordinary ones such as benzine yellow, rhodamine lake B, phthalocyanine blue, etc. can be used. I can do it. Of course, there is no particular restriction on the use of dyes depending on the purpose. Examples of waxes include paraffin wax, microcrystalline wax, carnauba wax, montan wax, wood wax, beeswax, low molecular weight polyethylene wax, synthetic wax, etc. is used. As the binder, ethyl 7-ff acid copolymer, ethylene-vinyl acetate copolymer, polyamide resin, rosin derivative, petroleum resin, acrylic resin, polyester resin, etc. are used. Mineral oil, vegetable oil, etc. are used as the oil.

The second transfer layer 5 is formed by suitably mixing and dispersing a coloring agent and the like in the binder to form a hot-melt, solvent-based, or water-based ink, which is then printed using a gravure method, a roll coater method, or a flexographic printing method. 1 is formed on the transfer layer 4.4B.

The coating amount of the second transfer layer 5 depends on the required coloring density, but in terms of practical energy sensitivity, the coating amount is 0.1 to 1.
It is possible to set it in the range of 0 g/rd, but if you expect high resolution and high density images, set it in the range of 2 to 5 g/rd.
A coating amount of n( is preferred.

- The amount of coating of force cylinder 1 transfer ji4.4B depends on the number of repetitions required, but from the standpoint of practical energy sensitivity, it can be set in the range of 0.2 to 20 g/rrf, and 3 When repeating the application more than once and expecting a high-resolution image, a coating amount of 3 to 10 g/i is preferable. Here, by setting the coating thickness of the first transfer layer F3i 4.4B to be larger than the coating thickness of the second transfer layer 5, the effect of the present invention can be achieved, that is, high-quality multiple recording with lower printing energy than conventional proposals. It is possible to make the most of it. 1st
Pores in transfer layer 464B 1)! 6.68-t-The constituent elements are preferably polymers with a heat resistance temperature of 100°C or higher, such as thermoplastic or thermosetting polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, polyvinyl butyl, Acrylic resin, polyamide, acrylonitrile-vinyl chloride copolymer, cellulose plastic, polyester, polyurethane, synthetic rubber, and mixtures thereof can be used. In order to improve suitability for printing or coating and to improve apparent heat resistance, pigment particles such as calcium carbonate, titanium oxide, silicon oxide, zinc oxide, carbon, etc. may be included as constituent components, and an appropriate solvent, non-solvent or poor solvent may be used. It is possible to use a composition that exhibits a slurry state by washing.

The first transfer layer 4.4B is formed by, for example, appropriately mixing and dispersing the hot-melt composition and a polymer slurry for a porous membrane,
It is made of a solvent-based ink and is formed on the adhesive layer 3 using a gravure method, a roll coater method, or a flexographic printing method.

As described above, the thermal transfer recording medium of the present invention, which can be used many times, is coated with adhesive N3 on the substrate, and then coated with polymer 6.
After forming the first transfer layer 4.4B by coating a slurry of a mixture of 6B and the hot-melt compositions 7 and 7B, the second transfer layer 5 is laminated.

Next, an embodiment of a thermal transfer recording method using the thus obtained thermal transfer recording medium having at least four layers will be described with reference to the drawings.

First, as shown in FIG. 3, after placing the transfer paper 18 facing the second transfer layer 5 of the thermal transfer recording medium 1 as exemplified above, the paper 18 is placed between the heated printing body 9 and the pressure roller 1). After that, a signal generated by the power supply unit 10 is transmitted to the heated print body 9 via an electric circuit to generate heat, and the heat-melting composition 12 at the contact point is transferred to the base 2.
is fluidized by partially propagated heat, deformed under stronger pressure, pushed out through the pores of the porous membrane 6, and reached the transfer paper 18. After that, the thermal transfer recording medium 1 and the transfer paper 18 are conveyed by the conveying roller part 13-a.
.

By peeling off at step 13-b, a transferred image 12a can be obtained.

Next, the principle of multiple use will be explained with reference to FIG.

In FIG. 4, the heated printed body and the pressure roller are omitted, but their positional relationship is as shown in FIG. 3.

In FIG. 4, 12-1, 12-2, 12-3 print in the same position on the thermal transfer recording medium with the same energy,
The transfer form achieved when the number of repetitions increases is schematically explained for convenience. First, the heat-melt composition 7 in the first transfer layer 4 and the heat-melt composition 12-1 in the second transfer layer 5 that have been heated by the heated printing body uniformly become fluid and are pressurized. The image is transferred onto the transfer paper 18 while the image is being transferred.

The transfer principle of the heat-melting composition of the second transfer layer 5 is the same as that of conventionally known one-time type sheets, and a high density, high resolution printed image 12-It can be printed even on plain paper (about the same size as copy paper).
is obtained.

In the portion 12-2, most of the heat-melting composition of the second transfer layer 5 has already been consumed, and the heat-melting composition 7 of the second transfer layer 4 is transferred through the pores by heating and pressure to the transfer paper 18.
This shows how it is transferred to. In the 12-3 portion where the number of repetitions is further increased several times, even the heat-melting composition filled in the thin strip of the porous film 6 is transferred to the transfer paper 18, and the 12-3 portion of the thermal transfer recording medium 1 is transferred to the transfer paper 18. Most of the hot-melt composition was consumed, indicating that the hot-melt composition can be used efficiently and without waste.

<Effects of the Invention> Since the thermal transfer recording medium according to the present invention has the above-described structure, it can be used many times compared to conventional one-time type transfer recording media, and can be used more times than conventional one-time type transfer recording media. It has become possible to obtain high-quality, high-resolution images with lower energy application than the proposed thermal transfer recording material.

<Examples> Examples and comparative examples of the present invention will be described below. Note that the present invention is not limited to these embodiments, and various modifications can be made without departing from the technical idea of the present invention.

<Example 1> On a 6.0 (μm) thick ethylene tereftate film, a coating liquid for an adhesive layer shown in formulation A was solvent coated using a gravure roll coater, and the dry film thickness was 1.0. (μm
) was provided with an adhesive layer.

(Formulation A) Ethylene-vinyl acetate copolymer...5 parts by weight (
(manufactured by Diabond Kogyo Co., Ltd.) Toluene: 95 parts by weight Furthermore, a hot-melt composition containing paraffin wax as a main component and a composition for forming a porous film containing an acrylic resin as a main component shown in Formulation B were processed in a linear mill. The ink for the second transfer layer was prepared by mixing and dispersing using a dispersing machine, and the ink for the second transfer layer was coated on the adhesive layer using a gravure printing method to provide a first transfer layer with a mist of 10 μm.

(Formulation B) Wax emulsion #3o7...50ff
ifi part (manufactured by Bond Wax Co., Ltd.) Emacol Black D-305 10 parts by weight (Sanyo Shiki Co., Ltd.) 40 parts by weight Acrylic emulsion Brimal HA-16 (ROHM & Co., Ltd.)・Japan Co., Ltd.)...40 parts by weight of the water-based emulsion ink shown in Formulation C was then coated on the first transfer layer to form a second transfer layer of 4 μm. A thermal transfer recording medium was obtained.

(Formulation C) Wax emulsion #307...80 parts by weight (Bond Wax Co., Ltd.) Emacol Black D-305...20 parts by weight (Sanyo Shiki Co., Ltd.) This thermal transfer recording medium A thermal transfer paper manufactured by Jujo Paper Industries Co., Ltd. was set in a handy word processor (Bungo m1ni3E manufactured by NEC Corporation), and solid printing was repeatedly performed using the same location on the recording medium for evaluation. The printing speed was set to high quality mode, and the printing voltage was set to medium mode. Next, the reflection density was measured using a Sakura densitometer P[1A-65 (manufactured by Konishiroku Photo Industry Co., Ltd.). As a result, as shown in Table 1, it was possible to print six times with little decrease in density. There was also no stain and the print quality was good.

<Example 2> On a polyethylene tereftate film with a thickness of 6.0 (μm), a gravure roll coater was used to solvent-coat the adhesive layer coating liquid shown in the recipe, and the dry film thickness was 1.0 μm.
An adhesive layer for the lock was provided.

(Formulation D) Urethane resin (manufactured by Dainippon Ink Co., Ltd.) 5 parts by weight Toluene 1 part 951i Further, the ink composition for the first transfer layer shown in Formulation E was prepared in Example 1
The mixture was mixed and dispersed in the same manner as above, and coated on the adhesive layer using a gravure printing method to form a 10 μm first transfer layer.

(Formulation E) Cellulose acetate propionate (manufactured by Sumitomo Bayer Urethane Co., Ltd.) 10 parts by weight Methyl ethyl ketone 53 parts by weight Wax emulsion #307 3 parts by weight (manufactured by Bond Wax Co., Ltd.) Emacol Black D-305...7 parts by weight Next, ink for the first transfer layer shown in Formulation C was used in Example 1.
Coating was carried out in the same manner as above to obtain a thermal transfer recording medium of the present invention.

This thermal transfer recording medium was evaluated in the same manner as in Example 1, and as shown in Table 1, good repeatability characteristics were obtained.

Comparative Example 1 A commercially available repeatable transfer ribbon (CF-KPR132K, manufactured by Matsushita Electric Industrial Co., Ltd.) was evaluated in the same manner as in Example 1.

As shown in Table 1, a sufficient density could not be obtained from the first time, and ink peeling from the surface of the base film was observed.

[BRIEF DESCRIPTION OF THE DRAWINGS] The drawings show examples of the present invention, and FIG. 1 is a schematic cross-sectional view of a thermal transfer recording medium according to the present invention, and FIG. 2 is a schematic cross-sectional view of a thermal transfer recording medium according to another example. A schematic cross-sectional explanatory diagram; FIG. 3 is a cross-sectional explanatory diagram showing the recording method using the thermal transfer recording medium of the present invention; FIG. 4 is a cross-sectional explanatory diagram showing the recording principle when the recording medium shown in FIG. 2 is used. A cross-sectional explanatory diagram is shown respectively. 1.1B...Thermal transfer recording medium 2...Substrate 3...Adhesive layer 4.4B
...First transfer layer 5 ...Second transfer layer 6.6B
... Porous membrane 7.7B ... Heat-melting composition Applicant: Toppan Printing Co., Ltd. Representative Kazuo Suzuki Figure 1 78 6B

Claims (1)

[Claims] (1) A first composition comprising a porous membrane having through-holes with a hot-melt composition held in the through-holes on the base via an adhesive.
At least a transfer layer and a second transfer layer made of a heat-melting composition are laminated in this order, and the thickness of the first transfer layer is equal to the thickness of the second transfer layer.
A thermal transfer recording medium characterized by being thicker than a transfer layer.