JPH06239025A - Heat transfer sheet - Google Patents

Abstract

PURPOSE:To count the number of printings by a heat transfer printer by a method wherein a heat reversible heat-sensitive film having a heat reversible heat-sensitive recording layer formed on its base film is joined to one end of a repeatedly printable heat transfer sheet having a heat transfer ink layer formed on its base film. CONSTITUTION:The heat transfer sheet has a heat reversible heat-sensitive film 102 joined to at least one end of a repeatedly printable heat transfer sheet 101. The repeatedly printable heat transfer sheet 101 has a heat fusible ink layer consisting of first and second ink layers 604 and 605 formed on the upper surface of a base film 602 and, as required, an adhesive layer 3 formed between the base film 602 and the ink layer 604 and further has a rear surface layer 601 formed on the lower surface of the base film 602. On the other hand, the heat reversible heat-sensitive film 102 has a heat reversible heat-sensitive recording layer 704 formed on the upper surface of a base film 702 and, as required, an adhesive layer 703 and a protecting layer 705 formed on the upper surface thereof and further has a rear surface layer 701 formed on the lower surface of the base film 702.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a thermal transfer sheet.
In particular, it relates to a thermal transfer sheet of a thermal transfer printer used as a hard copy output device such as a personal computer or a word processor.

[0002]

2. Description of the Related Art Conventionally, when printing an output print of a personal computer, a word processor or the like by a thermal transfer system, a thermal transfer sheet provided with a heat-meltable ink layer on one surface of a substrate film is often used. A conventional thermal transfer sheet has a thickness of 1 as a base film.
Paper such as condenser paper or paraffin paper with a thickness of 0 to 20 μm, or a plastic film such as polyester or cellophane with a thickness of 3 to 20 μm is used, and a coloring material such as pigment or dye is added to wax on the base film. The mixed ink is applied by a coating device to provide a heat-meltable ink layer. Then, from the back side of the substrate film, a predetermined location is heated and pressed by a thermal head, and the heat-meltable ink layer is transferred to a heat transfer material such as paper for printing.

However, in such a conventional thermal transfer sheet, the thermally fusible ink layer at the location pressed and heated by the thermal head is transferred to the transfer material by one use, and therefore, at the same location. Since only one printing is possible, the thermal transfer sheet consumes a large amount, the running cost is high, and it is not economical. Therefore, various thermal transfer sheets that can be used many times have been developed. For example, (Example 1) A transfer control layer made of a thermoplastic resin is formed on a heat-meltable ink layer to prevent the entire ink layer from being transferred in the first printing (JP-A-1-208189). (Example 2) A resin layer containing a polycaprolactone-based polymer as a main component is formed between a base film and a heat-fusible ink layer (Japanese Patent Laid-Open No. 2-4
No. 5995), and so on. However, since the number of times printing is possible is limited in a multi-time printing ribbon, it is necessary to detect the number of times printing can be performed with a thermal transfer printer to determine whether it can be used. Came. For example, (Example 3) An ink film that can be used a plurality of times is provided each time an end mark of an ink film is detected, and the number of holes is counted and a notification is given when the limit of use is reached (JP-A-3-9869). No. 4), (Example 4) A claw for confirming the number of times of use of the multi-ink film is integrally formed in the ink film cassette, and the user can fold the claw after one cycle of the multi-ink film to enable confirmation of the number of times of use (JP-A-2- 178078), and so on.

[0004]

Data representing the number of printings of a multi-printing thermal transfer sheet is recorded on the thermal transfer sheet itself, and the recorded number of printings data is a thermal transfer printer (hereinafter, the thermal transfer printer is simply referred to as a printer).
It is an object of the present invention to provide a thermal transfer sheet having the above-described detectable structure and a detecting means therefor.

[0005]

In order to achieve such an object, a thermoreversible thermosensitive film comprising a base film and a thermoreversible thermosensitive recording layer formed thereon is heat-transferred onto the base film. A thermal transfer sheet for multi-time printing, which has an ink layer formed thereon, is connected to at least one end, and a function of assisting the detection of the number of times of printing is added as necessary.

[0006]

[Function] A thermoreversible heat-sensitive film is provided on at least one end of a multi-print thermal transfer sheet. When the multi-print thermal transfer sheet is completely printed and the printer detects it, a thermo-reversible thermosensitive film is used. Record the data indicating the number of prints on the film, and print the number of prints on the heat-reversible heat-sensitive film when the printer detects the end of printing on the heat-transfer sheet and prints on the heat-transfer sheet. The data can be read by the printer.

[0007]

【Example】

(Multi-Print Thermal Transfer Sheet) As shown in FIG. 1, the multi-print thermal transfer sheet comprises a multi-print thermal transfer sheet 101 provided with a thermoreversible heat sensitive film 102 on at least one end thereof. An example of a thermal transfer sheet that can be printed many times used in the present invention will be described with reference to FIG. The multi-print thermal transfer sheet used in the present invention has a first ink layer on one surface of a substrate film, and a heat-meltable ink layer composed of a second ink layer on the first ink layer. Accordingly, an adhesive is provided between the base film and the ink layer, and a back layer is provided on the other surface of the base film. The base film 602 may be the same as the base film used in the conventional thermal transfer sheet and is not particularly limited. Specific examples of the preferred substrate film include polyester, polypropylene, cellophane, polycarbonate, cellulose acetate, polyethylene, polyvinyl chloride, polystyrene, nylon, polyimide, polyvinylidene chloride, polyvinyl alcohol, fluororesin, chlorinated rubber, and ionomer. Examples thereof include plastic films, condenser paper, papers such as paraffin paper, non-woven fabrics, and the like, and a substrate film obtained by combining any of these may be used.

The thickness of such a base film can be appropriately selected depending on the material used so that the strength and thermal conductivity are appropriate, and for example, it is preferably about 2 to 25 μm. It is also possible to provide a slip layer on the back surface of the base film to prevent the thermal head from sticking and to improve the slipperiness.

The first ink layer constituting the heat-meltable ink layer contains a wax component as a binder and a colorant, and further contains various additives if necessary.

Examples of the wax component include microcrystalline wax, carnauba wax, paraffin wax, Fischer-Tropsch wax, various low molecular weight polyethylene, wood wax, beeswax, spermaceti wax, ivowa wax, wool wax, ceramic wax, candelilla wax, petro wax. Waxes such as lactam, partially modified wax, fatty acid ester and fatty acid amide are used. Among them, the freezing point is 50 to 70 ° C, and the freezing point is 100 ° C.
A wax having a melt viscosity in the range of 10 to 1000 mPas is preferable.

The colorant can be appropriately selected from known organic or inorganic pigments or dyes,
For example, those having a sufficient coloring density and not discolored or discolored by light or heat are preferable. Further, it may be a substance that develops a color by heating or a substance that develops a color by coming into contact with a component applied to the surface of the transfer target.
Furthermore, the color of the colorant is not limited to cyan, magenta, yellow and black, and colorants of various colors can be used. When the adhesiveness between the base film and the first ink layer is insufficient, the first ink layer may be formed via the adhesive layer. The adhesive layer can be formed of acrylic resin, nylon resin, vinyl chloride copolymer, polyester resin, urethane resin or the like, and the thickness is preferably about 0.1 to 1.0 μm.

The resin used as a binder in the second ink layer formed on the first ink layer is a supercooling resin which is incompatible with the wax used in the first ink layer,
Those having a melting point of 58 to 75 ° C. and a freezing point of 20 to 55 ° C. are preferable. More specifically, the average molecular weight is 10
The melt viscosity at 100 ° C. is 100 to 300.
In the range of 00 mPas, polyester such as polycaprolactone or polyethylene glycol, or
These silicon metamorphisms are considered.

As the colorant used in the second ink layer, the same colorants as those used in the first ink layer can be mentioned.

The formation of such an ink layer is carried out by heating and melting the wax component which is the binder of the first ink layer,
A coating liquid in which a colorant is dispersed is applied onto a base film by a hot melt coating method to form a first ink layer, and then a supercooling resin and a colorant which are binders of the second ink layer are added to methyl ethyl ketone and acetic acid. The second ink layer is formed by coating and drying a coating liquid dissolved in a solvent such as ethyl having a low solubility in wax, which is the main component of the first ink layer, by a gravure coating method or the like. It should be noted that this is an example of the multiple-printing thermal transfer sheet, and it is also possible to use a multiple-printing thermal transfer sheet as shown in the related art.

An example of the method for producing a multi-printed thermal transfer sheet will be described below based on a concrete experimental example. First, inks for a primer layer, a first ink layer and a second ink layer having the following compositions were prepared. (Composition of ink for primer layer) Melamine resin filler (Eposta S made by Nippon Shokubai Co., Ltd.) 15 parts by weight Polyester resin (Elitel 3200 made by Unitika Ltd.) 15 parts by weight Toluene 48 parts by weight MEK 22 parts by weight (Daiichi Ink) Composition of layer ink) Wax ink 28.9 parts by weight Carbon black (Diamond Black manufactured by Mitsubishi Chemical Corporation) 6.6 parts by weight Ethylene / vinyl acetate copolymer (Evaflex 310 manufactured by Mitsui Polychemicals Co., Ltd.) 10.0 parts by weight Carnauba wax 9.0 parts by weight Paraffin wax (freezing point = 70 ° C., melt viscosity = 80 mPas) 70.0 parts by weight (composition of ink for the second ink layer) carbon black (diamond black manufactured by Mitsubishi Chemical Corporation) 12.0 parts by weight Placcel H1P (supercooled component) ) (Manufactured by Daicel Chemical Industries, Ltd., freezing point = 30 ° C.) 80.4 parts by weight Ethylene / vinyl acetate copolymer ( Made well poly Chemical Co., Ltd. Eva flex 45X) 6.6 parts by weight of MEK 276.0 parts by weight

Next, a polyethylene terephthalate film (Lumirror manufactured by Toray Industries, Inc., thickness =
6 μm) on one side of which a back layer is formed, and on the other side, the primer layer ink, the first ink layer ink, and the second ink layer ink are applied in this order and dried to form a primer. A layer and a heat-meltable ink layer having a two-layer structure were formed to obtain a heat transfer sheet. The primer layer and the second ink layer were each dried by the gravure coating method so that the coating amount was 0.3 g / m 2.
^2, was applied at a rate of 2 g / m ^2, although the first ink layer is a primer layer formed by coating at a rate of dry coating amount of 3 g / m ² by a hot-melt roll coating softening when hot melt coating is The layer form is maintained. The ink for the second ink layer is ME
Since MEK is a solvent system of K, it does not dissolve the waxes, which are the main components of the wax ink layer,
The ink layer maintains the layer form. As the multi-time printing thermal transfer sheet, a method and layer structure other than this example can be used.

(Thermo-Reversible Heat-Sensitive Film) Next, an example of the thermo-reversible heat-sensitive film which is another component will be described with reference to FIG. The thermoreversible thermosensitive film used in the present invention is one in which the thermoreversible thermosensitive recording layer 704 is provided on one surface of the base film 702, and, if necessary, the base film and the thermoreversible thermosensitive recording. Adhesive layer 703 between layers
The protective layer 705 can be provided on the surface of the thermoreversible thermosensitive recording layer, and the back layer 701 can be provided on the other surface of the base film. The base film 701 may be the same as the base film used in the conventional thermal transfer sheet and is not particularly limited. Specific examples of the preferred substrate film include polyester, polypropylene, cellophane, polycarbonate, cellulose acetate, polyethylene, polyvinyl chloride, polystyrene, nylon, polyimide, polyvinylidene chloride, polyvinyl alcohol, fluororesin, chlorinated rubber, and ionomer. Examples thereof include plastic films, condenser paper, papers such as paraffin paper, non-woven fabrics, and the like, and a substrate film obtained by combining any of these may be used. The thickness of such a base material film can be appropriately selected depending on the material used so that the strength and thermal conductivity are appropriate, and for example, is preferably about 2 to 30 μm.

The thermoreversible thermosensitive recording layer 702 is a recording layer capable of continuously changing from a transparent state to a cloudy state depending on its temperature history. Usually, when heated to a white turbidity temperature T ₂ or higher higher than a specific temperature T ₀ and then cooled to a temperature T ₀ or lower, a white turbid state is obtained.
Heating to a clearing temperature T ₁ between ₀ and T ₂ and then T ₀
A transparent state is obtained when cooled below. Here, the specific temperature T ₀ is a temperature at which the recorded state does not change at T ₀ or lower, and the cloudiness temperature T ₂ is a temperature at which the cloudiness is saturated to the maximum cloudiness at T ₂ or higher, The transparency temperature T ₁ is a temperature at which the degree of transparency reaches the maximum transparency.

As a recording material having such a property, there is a material called a low-molecular / high-polymer matrix system. For example, an organic low-molecular substance is dispersed in a high-molecular material such as polyester or polyvinyl chloride in a matrix form. It is a thing. As the organic low molecular weight substance, alkanol, alkane diol, halogen alkanol, halogen alkane diol, alkylamine, alkane, alkene,
Alkynes, halogen alkanes, halogen alkenes, halogen alkynes, cycloalkanes, cycloalkenes, cycloalkynes, saturated or unsaturated mono- or dicarboxylic acids or their esters or amides or ammonium salts, saturated or unsaturated halogen fatty acids or their esters Or amide or ammonium salt,
Allylcarboxylic acid or ester or amide or ammonium salt thereof, halogen allylcarboxylic acid or ester or amide or ammonium salt thereof, thioalcohol, thiocarboxylic acid or ester or amide or ammonium salt thereof, carboxylic acid ester of thioalcohol, or these Can be used.

The polymer matrix material is polyester, polyamide, polyacrylate, polymethacrylate, silicone resin or the like. Further, as an auxiliary material, polyvinylidene chloride-vinylidene chloride copolymer such as acrylonitrile copolymer, polyvinyl chloride, vinyl chloride copolymer, vinyl acetate copolymer, vinyl chloride-vinyl acetate copolymer, polyester, A mixture of these and the like can be used.

As a method of dispersing the organic low molecular weight substance in the polymer matrix substance, a method of mixing and dispersing a polymer matrix substance and a monomer or oligomer of the organic low molecular weight substance or a prepolymer, or a substance obtained by combining them and then carrying out a polymerization reaction , A method of dispersing an organic low molecular weight substance in a state in which a polymer matrix substance is heated to a melting temperature or higher, a method of dissolving a polymer matrix substance in an organic solvent and dispersing the organic low molecular weight substance, and then evaporating and drying the organic solvent,
Any method such as the above is possible. At this time, the organic low molecular weight substance is not completely dissolved in the polymer matrix substance, but is in a phase-separated state, and the organic low molecular weight substance exists as fine particles in the polymer matrix substance. The thermoreversible heat-sensitive film is produced by coating the material thus mixed and dispersed on the base film with a coating apparatus such as extrusion coating, hot melt coating, roll coating, and gravure coating.

As shown in FIG. 1, the thus obtained thermoreversible heat-sensitive film is provided on at least one end of a heat-transfer sheet capable of printing many times, with a back layer of the heat-reversible heat-sensitive film and heat transfer for multi-time printing. The back surface layer of the sheet is adhered with an adhesive, a double-sided tape, or the like, wrapped around a core, and then housed in a cassette.

(Detection of Number of Prints) Next, an example of a mechanism for detecting the number of prints using the thermal transfer sheet having the above-described structure will be described with reference to FIG. First pass, multiple times printing After printing all the thermal transfer sheets and the printer detects the end, the printer sensor detects the data indicating the number of prints recorded on the thermoreversible thermosensitive film, but this is the first time, so the recorded data Then, next, data representing the number of printing times is recorded on the thermoreversible thermosensitive film by the thermal head. After the first return pass, multiple prints on the thermal transfer sheet have been completed and the printer has detected another end, the printer's sensor detects the number of prints recorded on the thermoreversible thermosensitive film, but this is also the first time. There is no data, and then the data representing the number of printing times is recorded on the thermoreversible thermosensitive film by the thermal head. At this time, the forward and backward paths can be distinguished by providing a detection mark on one of the thermoreversible thermosensitive films as shown in FIG. 3B. Second printing, multiple times printing After printing all the thermal transfer sheets and the printer detects the end, when the printer sensor detects the data indicating the number of printings recorded on the thermoreversible thermosensitive film, the number of printings this time Since the data representing one time is recorded, the printer can determine that it is the second outward path, and then records the data representing two times of printing on the thermoreversible thermosensitive film by the thermal head. When this is repeated and the printer detects that the specified number of prints has been reached, it notifies the user with a warning display.

(Function for Assisting Detection of Number of Printings) As a function for assisting detection of the number of printings provided in the thermal transfer sheet of the present invention, it is sufficient if the supply side and the winding side can be identified. Optical or optical means may be used. For example, as shown in FIG. 3, recesses and protrusions provided on the core on the supply side or the winding side, detection marks provided in advance on the thermoreversible thermosensitive film, identification provided on the cassette for setting the thermal transfer sheet Notches, etc.

(Example of Print Count Detection Unit After Printing and Printer Equipped with It) Next, an example of print count detection unit after printing and a printer equipped with it will be described. In the thermal transfer sheet of the present invention, which is provided with a thermoreversible thermosensitive film on at least one end thereof and is capable of printing many times, by providing a notch in one core as shown in FIG. 3 as a function of assisting detection of the number of printings. , Whether the number of printing is odd,
It is possible to distinguish whether it is an even number. A limit switch is used as the notch detecting means, but other contact or non-contact sensors can be used. When a notch is detected, 0 is added to the count value of the counter, and when a notch is not detected, 1 is added to the count value of the counter.
A light-transmissive sensor composed of a light emitting / receiving unit is used as a detection unit at the end of the thermal transfer sheet, and a difference in the amount of transmitted light at the end of the thermal transfer sheet capable of printing many times is detected. As shown in FIG. 4, two sensors are provided so that both ends of the thermal transfer sheet in the width direction can be detected. When the two sensors simultaneously detect that they are transparent, they are identified as the ends. . When the end of the thermal transfer sheet is reached, the printer records data indicating the number of prints with the thermal head. This data is recorded as a pattern as shown in FIG. When the thermal transfer sheet is repeatedly used and the end of the thermal transfer sheet capable of printing many times comes, the end of the thermal transfer sheet is not detected immediately because there is a pattern recorded on the thermoreversible thermosensitive film last time. One of the two sensors detects that it is transparent, the other sensor detects that it is transparent, and then both sensors detect that it is transparent. Here, when it is detected that one of the sensors is transparent and then the other is transparent, 2 is added to the count value of the counter. Then, the pattern as shown in FIG. 2 is recorded again by the thermal head.

Table 1 shows the count value and the total value given by the presence or absence of notches and the number of patterns recorded on the thermoreversible thermosensitive film.

[Table 1]

The block diagram of the detecting means shown in FIG. 5 shows an example of a method of storing the total value of Table 3 in the count data memory and outputting it. Two sensors that detect the mark, a sensor that detects the presence or absence of the notch, and a signal that indicates the state of the printer (for example, the rotation of the core) are input to the mark detection determination logic unit. The mark detection determination logic unit is composed of a latch of each input signal, a logical operation unit, etc., and determines the mark detection, and the mark detection signal is input to the printing number counting unit. The printing number counting unit is composed of a counter, a storage device and the like, and outputs the printing number. As described above, the hardware configuration has been described, but a configuration using a microcomputer incorporated in the printer may be used.

Although the method of detecting the number of times of printing by adding the mark has been described above, the thermoreversible thermosensitive film can erase the written information and repeatedly perform rewriting. Due to this function, the thermal transfer sheet of the present invention can be used in various ways. For example, if you write not only the mark but also the number of prints such as “print once”, “print twice”, and “print completed”, the number of prints can be printed without using the thermal transfer sheet in the printer. It is convenient for people to read it directly. By using the thermoreversible thermosensitive film, unlike the non-reversible thermosensitive coloring film, these character information can be repeatedly, erased and rewritten, so that new information can be recorded and displayed in the same portion. Needless to say, the features of the present invention that allows new information to be recorded and displayed in the same portion are not limited to the above, and can be applied in various ways.

[0029]

EFFECTS OF THE INVENTION A thermoreversible thermosensitive film is provided on at least one end of a multi-print thermal transfer sheet, and when the multi-print thermal transfer sheet is completely printed and the printer detects it, the thermo-reversible thermosensitive film is formed. The number of times of printing is recorded, the printing of the multiple times printed thermal transfer sheet is completed again, the printer detects the end, and the number of times of printing of the multiple printed thermal transfer sheet recorded on the thermoreversible thermosensitive film can be read by the printer. Therefore, the number of prints can be detected.

[0030]

[Brief description of drawings]

FIG. 1 is a diagram showing a thermal transfer sheet of the present invention, which is characterized in that a thermoreversible thermosensitive film is provided on at least one end of a multi-print thermal transfer sheet.

FIG. 2 is a diagram showing the thermal transfer sheet of the present invention after recording the data indicating the number of times of printing on the thermoreversible thermosensitive film by the thermal head when the printing of all the thermal printing sheets of a large number of times is completed and the printer detects it. (A) After printing once (b) After printing twice (c) After printing three times (d) After printing four times (e) After printing five times

FIG. 3A is a diagram in which the thermal transfer sheet of the present invention is provided with a winding core that assists detection of the number of times of printing. (B) A diagram in which the thermal transfer sheet of the present invention is provided with detection marks for assisting the detection of the number of times of printing.

FIG. 4 is a diagram showing a sensor that reads data representing the number of prints recorded on a thermoreversible thermosensitive film.

FIG. 5 is a diagram showing a detection means for detecting data representing the number of prints recorded on a thermoreversible thermosensitive film.

FIG. 6 is a configuration diagram of a multi-print sheet.

FIG. 7 is a structural diagram of a thermoreversible thermosensitive film.

[Explanation of symbols]

 101 multi-time printing sheet 102 thermoreversible thermosensitive film 201 data representing the number of times of printing 301 core with notch 302 detection mark 401 sensor 1 402 light emitting unit 403 light receiving unit 404 sensor 2 501 mark detection judgment logic unit 502 printing number counting output unit 601 Back layer 602 Base film 603 Adhesive layer 604 First ink layer 605 Second ink layer 701 Back layer 702 Base film 703 Adhesive layer 704 Thermoreversible thermosensitive film 705 Protective layer

Claims (1)

[Claims] 1. A thermal transfer sheet for multi-use printing comprising a base film and a thermoreversible thermosensitive film comprising the thermoreversible thermosensitive recording layer formed on the base film, and a thermal transfer ink layer formed on the base film. A thermal transfer sheet characterized by being connected to at least one end.