JP3309171B2 - Thermal transfer sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer sheet,
In particular, it relates to a thermal transfer sheet for 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 Heretofore, when an output print of a personal computer, a word processor, or the like is printed by a thermal transfer method, a thermal transfer sheet in which a heat-fusible ink layer is provided on one surface of a base sheet is often used.
These thermal transfer sheets have a thickness of 10 to 10
Using a paper such as a condenser paper or a paraffin paper of about 30 μm, or a plastic film such as a polyester or cellophane of a thickness of about 3 to 20 μm, a pigment such as a hot-melt wax on one surface of the base sheet. Apply an ink consisting of coloring materials such as dyes with a coating device,
This is provided with a heat-fusible ink layer. Then, a predetermined portion is heated and heated by the thermal head from the back side of the base sheet.
Printing is performed by applying pressure and transferring the hot-melt ink layer to a transfer material such as paper.

However, in such a conventional thermal transfer sheet, the entire portion of the heat-meltable ink layer pressed and heated by the thermal head is transferred to the material to be transferred in a single use. For this reason, when printing was performed again at the same location, a missing portion was formed in the picture. Therefore,
There has been a problem that the consumption of the thermal transfer sheet is large and the running cost is high. To solve this problem,
Various thermal transfer sheets that can be used many times have been developed. For example, a transfer amount adjusting layer made of a thermoplastic resin is provided on a hot-melt ink layer to prevent the transfer of the entire ink layer in the first printing (Japanese Patent Laid-Open No. 2081/1989).
No. 89). A resin layer containing a polycaprolactone-based polymer as a main component is formed between a base sheet and a hot-melt ink layer to prevent the transfer of the entire ink layer in the first printing (Japanese Patent Laid-Open No. No. 45995). However, since the number of printable times is limited for a multiple-time print ribbon, it is necessary to detect the number of prints with a thermal transfer printer to determine whether or not the ribbon can be used, and a thermal transfer sheet having a configuration that enables the use has been devised. Was. For example, each time an end mark of a thermal transfer sheet is detected, a hole is sequentially formed in the sheet, the number of holes is counted, and a notification is issued when the use limit is reached. (Kaihei 3-9869). A cassette in which a thermal transfer sheet is stored is integrally formed with a nail for checking the number of times of use of the multi-ink film, and the user can check the number of times of use by folding the nail after the multi-ink film has made one round (Japanese Patent Laid-Open No. Hei 2 No. 178078)
and so on. In addition, two detection means (near end marks) are provided at both ends in the longitudinal direction so that the thermal transfer sheet can be used many times by reciprocating the thermal transfer sheet (actually open flat 2-1-13).
No. 9755).

[0004]

In order to indicate the number of printings on a thermal transfer sheet capable of printing a large number of times, a method of forming a hole is to generate wrinkles or cut the sheet when inserting a transfer-receiving body. There was a problem. In addition, there is a problem that the method of providing the mark on the cassette is not always accurate because of forgetting to provide the mark. In order to perform printing many times, it is necessary to provide two end marks, and it is necessary to perform the end mark manufacturing process twice, which increases manufacturing loss and ribbon cost. was there. In the case where two near end marks are provided at both ends in the longitudinal direction, two end mark forming devices are required, which increases the loss at the time of manufacturing, increases ribbon cost, and confirms the number of times of use. I couldn't do it.

According to the present invention, a near-end mark of a thermal transfer sheet capable of performing a large number of printings can be manufactured at low cost, and the number of printings can be accurately recorded without damaging the transfer sheet. To a thermal transfer printer (hereinafter, a 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 a configuration capable of detecting the above, and a detecting means therefor.

[0006]

In order to achieve the above object, in the thermal transfer sheet according to the present invention, which can be printed a number of times, near-end marks are provided at both ends at the center in the running direction, and one end is provided at one end. End tape, or lead tape to the other end of the lead tape, or end tape connected,
End tape and lead tape form a reversible thermosensitive recording layer.
It has something.

[0007]

[Function] A multi-time printing thermal transfer sheet, in which a reversible thermo-sensitive sheet provided with a reversible thermo-sensitive recording layer at the end of a multi-time printing thermal transfer sheet provided with a near end mark (hereinafter simply referred to as a reversible thermo-sensitive sheet), When the printer detects that all printing has been completed, the thermal head records data indicating the number of printings on the reversible thermosensitive film, and further,
Runs in the opposite direction and indicates the number of times the thermal transfer sheet has been printed multiple times recorded on the reversible thermosensitive film when the printer detects, with its near-end mark, that all of the thermal print sheets have been printed many times. This is to record data. The record is read by a printer to determine whether the thermal transfer sheet can be used. In addition, the near-end mark provided at the center with respect to the running direction of the end tape or lead tape is located at the center, so it can be read by one detection unit provided at the center of the printer in both directions of reciprocation. Can be done.

The thermal transfer sheet of the present invention slits the thermal transfer sheet printed a number of times to a desired width and length,
A near-end mark can be provided by a single end mark forming device at the center of the end in the traveling direction. The forming method is not limited to the usual gravure printing method, flexographic printing method, silk screen printing method, or marking using a thermal transfer ribbon. In addition, it can be provided by one end mark forming device placed at a fixed position, and the ribbon cost is not increased.

As shown in FIG. 1, the thermal transfer sheet of the present invention has a reversible thermosensitive film having the same width at the beginning and end of the winding in the running direction of the thermal transfer sheet 10. The tape 11 or the lead tape 12 is provided so as to be connected at a joint 15.
The multi-print thermal transfer sheet used in the present invention has a first ink layer 2 on one surface of a base sheet 1 as shown in FIG.
A hot-melt ink layer composed of a second ink layer 3 is provided thereon, and a primer layer 4 is further provided between the base sheet and the ink layer, if necessary. Is provided with a back layer 5. The base sheet 1 may be the same as the base sheet used for the conventional thermal transfer sheet, and is not particularly limited. Examples of preferable base sheet include, for example, plastics such as polyester, polypropylene, cellophane, polycarbonate, cellulose acetate, polyethylene, polyvinyl chloride, polystyrene, nylon, polyimide, polyvinylidene chloride, polyvinyl alcohol, fluororesin, chlorinated rubber, and ionomer. Paper such as film, condenser paper, paraffin paper,
A nonwoven fabric or the like may be used, and a composite of any of these may be used.

The thickness of the base sheet is appropriately selected so that the strength and the thermal conductivity are appropriate according to the material to be used. For example, the thickness is preferably about 2 to 25 μm. Further, a back layer 5 for preventing adhesion of the thermal head and improving the slipperiness can be provided on the back surface of the base film.

The heat-meltable ink layer is composed of two layers, and the first ink layer 2 is composed of a heat-meltable component as a binder and a coloring material, and further contains various additives as necessary. It is.

Examples of the heat-fusible component include waxes such as microcrystalline wax, paraffin wax, various low-molecular-weight polyethylenes, wood wax, carnauba wax, beeswax, spermaceti, Ibota wax and wool wax, fatty acid esters, fatty acid amides, polyamides, and the like. Thermoplastic compounds such as polyester and polyurethane are used. Among these, a thermoplastic substance or wax having a solidification point of 50 to 70 ° C and a melt viscosity at 100 ° C of 10 to 1000 mPas is particularly preferable.

The coloring material can be appropriately selected from known organic or inorganic pigments or dyes. For example, the coloring material has a sufficient concentration, has light resistance and heat resistance, and has discoloration.
Those that do not fade are preferred. Further, it may be a substance that develops color by heating or a substance that develops color when it comes into contact with a component applied to the surface of the transfer-receiving body. Further, the color material is not limited to cyan, magenta, yellow, and black, and colorants of various colors can be appropriately selected and used. In addition, in order to stabilize the adhesion between the base sheet and the first ink layer, the first ink layer may be provided via a primer layer as necessary. The primer can be composed of an acrylic resin, a vinyl copolymer, a polyester resin, a urethane resin, or the like, and the thickness thereof may be the smallest one that forms a layer. It is preferably about 0.0 g / m ² .

The resin used as a binder for the second ink layer provided on the first ink layer is a supercooling resin incompatible with the wax used for the first ink layer, and has a melting point of 58 to 75 ° C. Those having a freezing point in the range of 20 to 55 ° C are preferred. More specifically, the average molecular weight is 100
0 to 40000, preferably 5000 to 30000, and the melt viscosity at 100 ° C. is 100 to 3000.
Those within the range of 0 mPas have an appropriate amount of the first amount during thermal transfer.
Suitable for exuding the ink layer. Examples include polyesters such as polycaprolactone, polyethylene glycol, and modified silicones thereof.

The coloring material used for the second ink layer is the first material described above.
The same materials as those used for the ink layer can be used.

In forming such an ink layer, a wax component as a binder of the first ink layer is dissolved by heating.
A coating solution in which a color material is dispersed is applied to a base sheet by a hot melt coating method to form a first ink layer. Then, a supercooling resin and a color material serving as a binder of the second ink layer are methyl ethyl ketone, acetic acid. A coating solution dissolved in a polar solvent having low solubility in wax such as ethyl as a main component of the first ink layer is applied and dried by a gravure coating method or the like to form a second ink layer. Note that this is an example of a multiple-print thermal transfer sheet, and a multiple-print thermal transfer sheet as described in the related art can also be used.

[0017]

【Example】

[Example 1] (Many-time printing thermal transfer sheet) As a substrate sheet 1, a back layer 5 having the following composition was formed on one surface of a polyethylene terephthalate film (Lumirror manufactured by Toray Industries, Ltd.) having a thickness of 6 µm. Was provided with a primer layer 4 by the gravure coating method and a first ink layer 2 and a second ink layer 3 by the gravure coating method in this order to obtain a thermal transfer sheet. The application amount in terms of solids was 0.3 g / m ² , 2 g / m ² , and 3 g / m ^2.
Was formed. The first ink layer is softened by the heat when applied by the hot melt coating method, but the primer layer is softened, but the form as the layer is maintained. Since the ink for the second ink layer is a solvent system of MEK, MEK does not dissolve waxes, which are the main components of the first ink layer.
The ink layer can maintain the form as a layer. The thermal transfer sheet obtained in this manner, printed multiple times, is slit to a desired width and length, and a thermal transfer ribbon is provided at the center of the end in the running direction.
A near end mark 30 is provided. (Primer composition) ・ 15 parts by weight of melamine resin filler (Nippon Shokubai Co., Ltd. Eposta S) ・ 15 parts by weight of polyester resin (Elitel 3200 manufactured by Unitika Ltd.) ・ 48 parts by weight of toluene ・ 22 parts by weight of MEK [First Composition of Coating Solution for Ink Layer]-Carbon black (Diablack manufactured by Mitsubishi Chemical Corporation) 7 parts by weight-Ethylene / vinyl acetate copolymer (Evaflex 310 manufactured by Mitsui Polychemicals Co., Ltd.) 10 parts by weight-Carnauba wax 9 parts by weight ・ 70 parts by weight of paraffin wax (freezing point = 70 ° C., melt viscosity = 80 mPas) [Composition of coating liquid for second ink layer] ・ 3 parts by weight of carbon black (Diablack manufactured by Mitsubishi Chemical Corporation) 3 parts by weight ・ Placcel H1P (Supercooling component) (Coagulation point = 30 ° C, manufactured by Daicel Chemical Industries, Ltd.) 21 parts by weight ・ Ethylene / vinyl acetate copolymer ( It made well Polychemical Co. Evaflex 45X) 2 parts · MEK 74 parts by weight

(Reversible Thermosensitive Sheet) The reversible thermosensitive sheet 20 provided with the reversible thermosensitive layer of the present invention is used for the lead tape 12 and the end tape 11 as shown in FIG. Substrate sheet 1L as shown
Has a reversible thermosensitive recording layer 2L on one side. If necessary, a primer layer 4L is provided between the base sheet and the reversible thermosensitive recording layer, a protective layer 3L is provided on the surface of the reversible thermosensitive recording layer, and a back layer 5L is provided on the other surface of the base sheet. To form. The base sheet may be the same as the base sheet used for the conventional thermal transfer sheet, and is not particularly limited. Preferred substrate sheets are polyester, polypropylene, cellophane, polycarbonate, cellulose acetate, polyethylene, polyvinyl chloride,
Polystyrene, nylon, polyimide, polyvinylidene chloride, polyvinyl alcohol, fluororesin, chlorinated rubber,
Plastic sheets such as ionomer, condenser paper, paper such as paraffin paper, non-woven fabric, etc.
Further, the base sheet may be a composite sheet of any of these. The thickness of such a base sheet can be appropriately selected so that the strength is appropriate according to the material to be used, and for example, is preferably about 2 to 30 μm.

The reversible thermosensitive recording layer 2L is a recording layer capable of continuously changing from a transparent state to a cloudy state depending on its temperature history. Usually, by heating to a higher clouding temperature T ₂ higher than the specific temperature T _0, then when cooled to T ₀ or less, opaque state is obtained, a transparent temperatures T ₁ which lies between T ₀ and T ₂ in the opaque state heating, in which a transparent state is obtained when subsequently cooled to T ₀ or less. The specific temperature T ₀ is a temperature at which no change occurs in the recording state below T ₀ , and the cloudiness temperature T ₂ is a temperature at which the degree of cloudiness is saturated to the maximum cloudiness above T ₂ , the temperatures T _1, the degree of transparency is at a temperature that changes the maximum one.

As a recording material having such properties, there is a material called a low molecular weight / high molecular weight matrix system. For example, an organic low molecular weight compound is dispersed in a high molecular weight material such as polyester or polyvinyl chloride in a matrix form. It is a thing. Organic low molecular weight compounds include alcohol, glycol, halogenated alcohol, halogenated glycol,
Alkylamine, saturated hydrocarbon, olefin hydrocarbon, acetylene hydrocarbon, halogenated hydrocarbon, halogenated olefin hydrocarbon, halogenated acetylene hydrocarbon, cyclosaturated hydrocarbon, cycloolefin hydrocarbon, saturated or There are unsaturated monocarboxylic acids, saturated or unsaturated dicarboxylic acids, and their esters, amides and ammonium salts. Halogenated allyl carboxylic acids, or their esters, amides, ammonium salts, thioalcohols, thiocarboxylic acids and their esters, amides and ammonium salts, thioalcohol carboxylic acid esters, etc., use these alone or in mixtures. can do.

Examples of the polymer matrix-based material include polyester, polyamide, polyacrylate, polymethacrylate, and silicone resin. As auxiliary materials, polyvinylidene chloride copolymers such as polyvinylidene chloride / acrylonitrile copolymer, polyvinyl chloride, vinyl chloride / vinyl acetate copolymer, vinyl chloride copolymer,
Vinyl acetate-based copolymers, polyesters, and mixtures thereof can be used.

As a method of dispersing a low-molecular organic compound in a high-molecular matrix material, a high-molecular matrix material and a monomer, oligomer or prepolymer of the low-molecular organic compound or a combination thereof are dispersed and polymerized. A method of reacting, a method of dispersing an organic low-molecular compound in a state in which the polymer matrix material is heated to a melting temperature or higher, and a method of dissolving the polymer matrix material in an organic solvent, dispersing the organic low-molecular compound, and evaporating the organic solvent to dryness. Any method can be adopted.
At this time, the low-molecular organic compound does not form a completely molten state in the polymer matrix material, but is in a phase-separated state, and the low-molecular organic compound exists as a fine particle state in the high-molecular matrix material. Is what it is. Extrusion coating of the material thus mixed and dispersed,
By applying on a substrate sheet by a coating device such as hot melt coat, roll coat, gravure coat, etc.
A reversible thermosensitive sheet can be manufactured.

As shown in FIG. 1, the thus obtained reversible thermosensitive sheet is attached to the end of a heat transfer sheet having a near-end mark provided at the center and capable of printing many times, and a back layer of the reversible thermosensitive sheet and a number of times. The heat transfer sheet for printing is adhered with an adhesive tape or the like so that the back surface layer is flush with the back surface layer. The near-end mark can be provided by a printing method such as gravure printing, flexographic printing, or silk-screen printing, or by foil pressing with a transfer film on which aluminum is deposited. Then, an end tape, a thermal transfer sheet that can be printed many times, and a lead tape are wound around a core in this order, and a thermal transfer sheet housed in a cassette is manufactured to be completed in a form usable for a printer.

(Detection of Number of Prints) Next, an example of a mechanism for detecting the number of prints using the thermal transfer sheet configured as described above will be described with reference to FIG. The first outward pass, printing a number of times After printing the thermal transfer sheet and the printer detects the end with the near end mark, the number of printings on the reversible thermosensitive film provided as the end tape is 1
The print mark 21 is made with a thermal head to indicate the time. First return, printing many times again After printing the thermal transfer sheet and the printer detects the other end with the near-end mark, initially the thermal head returns to the reversible thermal sheet on the reversible thermal film provided as lead tape. The print mark 22 representing the number of times of printing is recorded. At this time, it is preferable to distinguish the forward path and the backward path by a method such as providing a notched core as shown in FIG. 5 on one core of the thermal transfer sheet. In the second forward pass, print many times. After printing all the thermal transfer sheets and the printer detects the end, the printer sensor detects the data representing the number of prints recorded on the reversible thermosensitive film. Is recorded, the printer can determine that it is the second outward pass, and then prints a print mark 22 indicating two times of printing on the thermoreversible thermosensitive sheet by the thermal head. This is repeated to mark the print marks 23, 24, 25,... To detect that the printer has reached the prescribed number of times of printing. Then, the result can be notified to the user by a warning display or the like.

(Function of Assisting Detection of Number of Prints) As a function of assisting detection of the number of prints provided in the thermal transfer sheet of the present invention, it is sufficient that the supply side and the winding side can be identified. Any of target, optical means and the like may be used. For example, as shown in FIG. 5, a concave portion and a convex portion provided on a core on a supply side or a winding side, a near-end mark of the present invention provided in advance on a reversible thermosensitive film, and a cassette provided with a heat transfer sheet are provided. Identification notch 3
1 and so on.

(Example of Number of Printed Numbers Detected After Printing and Printer Provided With It) Next, an example of the number of printed times detected after printing and a printer equipped with the same will be described. In the thermal transfer sheet of the present invention in which a reversible thermosensitive sheet is provided at the end of the thermal transfer sheet capable of performing multiple printings, printing is performed by providing a notch in one core as shown in FIG. It is possible to distinguish whether the number of times is odd or even. As the notch detecting means, a limit switch can be used, or another contact or non-contact sensor can be used. When a notch is detected, 0 is added to the count value of the counter, and when no notch is detected, 1 is added to the count value of the counter.

As means for detecting the end of the thermal transfer sheet,
Using a light transmission type sensor composed of light emitting and receiving parts,
The difference in the amount of transmitted light at the end of the thermal transfer sheet that can be printed many times is detected. This sensor, as shown in FIG.
Two thermal transfer sheets are provided so as to be able to detect both ends in the width direction, and when two sensors simultaneously detect that they are transparent, they are identified as the ends. When the printer reaches the end of the thermal transfer sheet, the printer records data representing the number of times of printing with a thermal head. In this data, print marks 21 to 25 as shown in FIG. 2 are recorded as a pattern.

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

[0029]

[Table 1]

The method of detecting the number of times of printing by adding marks has been described above. However, the reversible thermosensitive sheet can erase the written information and perform rewriting repeatedly. With this function, the thermal transfer sheet of the present invention can be used not only for displaying a mark, but also for writing the number of times of printing such as "print once", "print twice", and "end of printing". A person can directly read the number of times of printing without using the printer by setting it on a printer. Also, by using the above-mentioned reversible thermosensitive sheet, unlike the irreversible thermosensitive coloring sheet, these character information can be repeated, erased, and rewritten, so that new information can be recorded and displayed in the same portion. For example, "high print quality", "low print quality",
The print quality such as "printable for customer" or "for elaboration document" can be displayed. In addition, it goes without saying that various features of the present invention that can record and display new information in the same portion as the above are applicable.

[0031]

As described above, in the end detection method of the thermal transfer sheet printed many times, by combining the near-end mark and the reversible thermosensitive sheet, when the printing of the thermal transfer sheet printed many times is completed, the printer detects it and detects the thermal head. By recording the number of prints on the reversible heat-sensitive sheet, and again, when printing all the thermal transfer sheet printed many times,
The printer can detect this, and further, the printer can read the number of prints of the thermal transfer sheet printed multiple times recorded on the reversible thermosensitive sheet, and can detect the number of prints of the thermal transfer sheet, This is to determine whether or not use is possible.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of a thermal transfer sheet in which a multi-time printing thermal transfer sheet provided with a near-end mark and a reversible thermosensitive sheet are connected.

FIG. 2 is a conceptual diagram showing a cross section of a multi-time printing sheet provided with a near end mark at an end in a running direction.

FIG. 3 is a conceptual diagram showing a cross section of a reversible thermosensitive sheet.

FIG. 4 is a diagram showing a thermal transfer sheet of the present invention after data indicating the number of times of printing is recorded on a thermoreversible thermosensitive sheet by a thermal head. (a) A thermoreversible thermosensitive sheet provided with a marking after printing once. (b) A thermoreversible thermosensitive sheet provided with markings after printing twice. (c) A thermoreversible thermosensitive sheet provided with markings after printing three times. (d) A thermoreversible thermosensitive sheet provided with markings after printing four times. (e) A thermoreversible thermosensitive sheet provided with markings after five printings.

FIG. 5 is a diagram in which a heat transfer sheet is provided with a winding core for assisting detection of the number of times of printing.

FIG. 6 is a diagram of a sensor for reading the number of times of printing recorded on a reversible thermosensitive sheet.

[Explanation of symbols]

 Reference Signs List 1 base sheet 1L base sheet of reversible thermosensitive film 2 first ink layer 2L reversible thermosensitive layer 3 second ink layer 3L protective layer of reversible thermosensitive sheet 4 primer layer 4L primer layer of reversible thermosensitive sheet 5 back layer 5L Back layer of reversible thermosensitive sheet 10 Many times printed sheet 11 End tape 12 Lead tape 15 Joint 20 Reversible thermosensitive sheet 21 to 25 Print mark after 1 to 5 times printing 30 Near end mark 31 Notched core 41 42 Sensor No. 43 Emitter 44 Receiver

Continuation of the front page (56) References JP-A-3-1979 (JP, A) JP-A-3-1978 (JP, A) JP-A-6-219065 (JP, A) JP-A-6-239025 (JP) , A) Fully open sho 60-12461 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41M 5/38-5/40 B41J 31/00

Claims (1)

(57) [Claims] 1. A thermal transfer sheet capable of printing many times, wherein near-end marks are provided at both ends of a central portion in a running direction, and an end tape or a lead tape is provided at one end and a lead tape or a lead tape is provided at the other end. Connect end tapes ,
End tape and lead tape form a reversible thermosensitive recording layer.
Thermal transfer sheet characterized by having.