JPS62108089A - Thermal transfer ribbon - Google Patents

Abstract

PURPOSE:To enable clear printing free of blurring or formation of voids in printed images to be performed even on a non-smooth printing paper, by laminating a topcoat layer comprising a thermoplastic resin having a high melt viscosity and a relatively weak adhesion to printing papers as a main constituent, on an ink layer. CONSTITUTION:A thermal transfer ribbon 10 comprises a releasable layer 12 provided on a film form base 11, an ink layer 13 provided thereon and a topcoat layer 14 provided on the ink layer 13. A binder agent for the ink layer 13 comprises as a main constituent a thermoplastic resin incompatible with constituents of the topcoat layer 14, which comprises as a main constituent and ethylene-vinyl acetate copolymer having a high melt viscosity and a relatively weak adhesion to a printing paper 17. When this thermal transfer ribbon 10 is used to print on a printing paper having a Bekk smoothness of 4sec, an ink is transferred also to recessed parts of the paper, and a sharp high- density printed image having extremely little blur and free of blot can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a thermal transfer ribbon used in a printing device such as a thermal printer that performs printing by thermal transfer.

[Prior art 1] Printing using a thermal transfer ribbon is performed by bringing the thermal transfer ribbon into close contact with the printing paper using a thermal head, and causing a desired heating element among the many heating elements of the thermal head to generate heat. This is done by melting the heat-melting ink portion that is in contact with the support through the support and transferring it to the printing paper.

Conventionally, this type of thermal transfer ribbon has only been coated with a heat-melting ink consisting of a colorant and a binder agent on a support, and the binder agent has been mainly composed of wax.

[Problems to be Solved by the Invention] As mentioned above, when printing on plain paper with a thermal transfer ribbon that is simply coated with heat-melting ink on a support, the smoothness of the plain paper is the Bekk smoothness. Unless the printing time was up to several tens of seconds, sufficient print quality could not be obtained.

The reason for this is that when the surface smoothness of the printing paper is low, as shown in Figure 2, the heat-melting ink cannot come into contact with the recesses on the surface of the printing paper, and ink transfer is not achieved. There are many things that can occur as a result of being mistreated or mistreated.

Is it possible to solve this problem by significantly lowering the melt viscosity of the heat-melting ink, allowing the ink to penetrate from the contact areas of the convex parts of the printing paper, and reach the four non-contact areas? Such ink penetration occurs even in unbroken areas where the ink is transferred, making the outline of the transferred image unclear and giving it a smeared appearance.

[Object of the Invention] The present invention was made in order to solve the problems of the conventional thermal transfer ribbon as described above, and its purpose is to print within the range of printing energy that can be sufficiently realized with the conventional thermal head. The present invention provides a thermal transfer ribbon that can print clearly even on non-smooth printing paper without being treated as a fader, and can print with clear outlines without ink bleeding.

[Means for Solving the Problems] In order to achieve the above object, in the thermal transfer ribbon of the present invention, a thermoplastic resin having high melt viscosity and relatively weak adhesion to printing paper is used on the ink layer. The ink layer is made of a heat-melting ink formed by mixing a coloring agent and a binder agent whose main component is a thermoplastic resin that is incompatible with the top coat layer. It is formed.

[Function] According to the above configuration, the top coat layer melted by the heat from the thermal head is sufficiently fixed at the contact points of the convex portions of the printing paper during printing, and when the thermal transfer ribbon is peeled off, the support and the heat-melting ink are bonded together. Since the cohesive force of the heat-melting ink itself is greater than the adhesion between the sheets, the melted heat-melting ink in the non-contact areas corresponding to the four parts of the paper can also be peeled off and transferred together.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

In FIG. 1, a thermal transfer ribbon 10 has a release layer 12 formed on a film-like support 11, an ink layer 13 formed thereon, and a top coat layer 14 formed on the upper surface thereof.

The film-like support 11 used in this example is a film made of polyester, polyimide, polycarbonate, polysulfone, polyethersulfone, polyphenylene sulfide, polyether-etherketone, etc. with a heat resistance temperature of 150° C. or higher. Alternatively, paper such as capacitor paper, glassine, tit, etc. may be used, and the thickness thereof is preferably in the range of about 3 to 20 μm. Further, as shown in FIG. 1, an anti-sticking layer 15 made of a heat-resistant resin such as silicone resin is provided on the opposite side to the coated surface of the ink layer 13.

The ink layer 13 is composed of a coloring material and a binder agent.

As the coloring material, a pigment such as carbon black is used.

In addition, to bring out the color that cannot be achieved with pigments alone, or to adjust the color tone (if necessary, a small amount of dye is added as an auxiliary agent).

In addition, as a binder agent, compared to the ink layer of conventional thermal transfer ribbons, 15%
A polyamide, polyester, or polyvinyl acetate that has a melt viscosity of about 1 oL to 10' cP (centipoise) at around 0'C and is incompatible with the constituent components of the top coat layer 14 described below.

The main component is a type of thermoplastic resin such as polystyrene, epoxy, acrylic acid, ketone resin, etc., and with rough consideration of its melting point, melt viscosity, printing quality, etc., polyvinylbutyral, vinyl chloride-vinyl acetate copolymer resin , ethyl cellulose, petroleum resin, rosin, hydrogenated rosin, maleic M resin, phenolic resin, etc., as well as polyethylene wax, oxidized polyethylene wax, ester wax, polyamide wax, candelilla wax, carnauba wax,
One or two types of waxy substances such as paraffin wax and microwax may be mixed.

Further, the release layer 12 has a moderate melting point (80 to 12 o'c>
It is made of polyethylene wax and Nisdel wax, which have poor adhesion to the film-like support 11.

Note that wax alone may be used as the release layer 12, but fillers such as bentonite, kaolin, and talc may be added to meet various requirements for the ink ribbon, thereby changing the release property in a favorable direction. be able to.

The top coat layer 14 is mainly composed of an ethylene-vinyl acetate copolymer resin that has high melt viscosity and relatively weak adhesion to the printing paper 17, and also prevents penetration into the printing paper 17 and improves transferability. Metal soap,
Aerosil.

One or more types of thickeners and gelling agents such as bentonite may be mixed. In addition to the ethylene-vinyl acetate copolymer resin, materials that satisfy the above-mentioned conditions include ethylene-methacrylic copolymer resin and ethylene-ethyl acrylate copolymer resin.

Examples thereof include ethylene-α olefin copolymer resin, ethylene chloride resin, and polyethylene.

Next, based on this example, a manufacturing process for forming a peeling pattern 12 and an ink layer 13 on a support 11 having an anti-sticking layer 15 formed on the back surface will be described.

(1) Formation step of release layer The polyethylene wax emulsion is diluted with water to form a coating liquid. In addition, when adding fillers, three-mouth Lumir,
Disperse into the coating liquid using a commonly used dispersing machine such as a sentry mill, sand mill, or ball mill.

(2) Coating and drying process of release layer The coating solution is coated onto a film-like support 11, for example, a polyester film (thickness: 3.5 μm) using an appropriate coating device. Dry it at 80-100°C. In this example, the coating thickness was set to about 1 μm.

(3) Production process of hot-melt ink The colorant and the binder agent whose main component is thermoplastic resin such as polyamide (e) are dissolved or dispersed in a solvent. A generally used dispersing machine such as a three-roll mill, a sentry mill, a sand mill, a ball mill, etc., which is similar to the layer forming process, is used.This dissolved two-dispersion liquid is used as an ink coating liquid.

(4) Coating and drying step of ink coating liquid The ink coating liquid is applied onto the film-like support 11 coated with the release layer 12 using the appropriate coating device.

Then, dry it at 60 to 100°C. In this example, the coating thickness of the ink was set to 3 to 8 microns.

(5) Formation step of top coat layer Ethylene-vinyl acetate copolymer resin and bentonite 1 to 1 are dissolved or dispersed in a solvent. For dispersion, use the above-mentioned stripping + at
Miki roll mill similar to the layer generation process.

A commonly used dispersing machine such as a sentry mill, sand mill, or ball mill is used. This dissolved 2-dispersion liquid is used as a coating liquid.

(6) Coating and Drying Step of Top Coat Layer The coating liquid is coated on the film-like support 11, the uppermost surface of which is coated with the ink layer 13, using the appropriate coating device. Then, it is dried at 60-100°C. In this example, the coating thickness was set to 2 to 5 microns.

The manufacturing process of the thermal transfer ribbon 10 is thus completed, and the thermal transfer ribbon 10 as shown in FIG. 1 is obtained.

Examples of the thermal transfer ribbon according to the present invention are shown below as Example 1 and Example 2.

[Example 1] A, release layer a, release layer component 100 parts by weight of polyethylene wax emulsion [Polylon #393 from Chukyo Yushi Co., Ltd.] 50 wt% [Polylon MEIO from Kyoto Yushi Co., Ltd.] 50 wt% Bentonite 7% Hanging part bo8 diluent water 150 parts by weight B, ink layer C, ink component polyamide [Macromelt 6301 from Henkel Hakusui Ltd.] 22 parts by weight [Persamide DPX93-W from Henkel Hakusui Ltd.] 25 parts by weight polyvinyl butyral 17 Parts by weight [Eslec BLS from Sekisui Chemical Co., Ltd.] Ester wax 20 parts by weight [Wax S from Hoechst] Carbon black 13 parts by weight [MA-7 from Mitsubishi Chemical Industries, Ltd.] d. Solvent isopropyl alcohol 150 parts by weight Toluene
150 parts by weight C, top coat part e, top coat layer component ethylene-vinyl acetate copolymer resin 25 parts by weight [Mitsui DuPont Polychemical Co., Ltd.'s Evaflex 2201 Pentonite 1 to 3 part part f, solvent Toluene: 40 parts by weight Medyl Isobutyl Ketone: 15 parts by weight The above component a is diluted with component b to obtain a coating liquid. This coating liquid is applied to a support 11 made of a 3.5μ polyester film to a coating thickness of approximately 1μ, and a release layer 12 is placed on the support 11.
1 q.

An ink coating liquid consisting of component C and component d is applied onto this release layer 12 and dried at 60 to 100°C.

Then, on the release layer 12 on the support 11, a thickness of 4 to 6 μm is applied.
The ink layer 13 is formed to a certain extent. Roughly, ink layer 13
A coating liquid consisting of C component and f component is applied on top, and 100%
Dry at 'C. Then, on the ink layer 13, a thickness of 2~
A top coat layer 14 having a thickness of about 5 μm is formed.

When the thermal transfer ribbon 10 manufactured in this way was used to print on printing paper with a Beck smoothness of 4 seconds, the ink was transferred even to the concave parts of the printing paper, and the result was sharp with very little fading and no bleeding. A dark printed image was obtained.

Here, the thermal meltability and ink transfer process when printing is performed on printing paper with low smoothness using the thermal transfer ribbon 10 according to the present invention will be explained based on FIGS. 2 and 3.

Thermal head 16 presses thermal transfer ribbon 10 against printing paper 17 on plan 7 (not shown). When the thermal head 16 generates heat, the heat is conducted to the release layer 12 and the ink layer 13 through the sticking anti-th layer 14 and the film-like support 11, and is transferred to the top coat layer 14.
It is transmitted to Release layer 12. The ink layer 13 and the top coat layer 14 are melted, and the top coat layer 14 that is in contact with the convex portions of the printing paper 17 adheres to (partially penetrates) the convex portions together with the heat-melting ink. And thermal head 1
6 stops generating heat, the top coat layer 14 and the ink layer 13 are cooled and solidified on the printing paper 17. At this point, the heated part of the release layer 12 still maintains a molten state, and the ink layer 13 corresponding to this part has a strong cohesive force within it, but the ink layer 13 has a relatively strong cohesion with the release layer 12. The adhesion force is extremely poor (it is significantly smaller than the adhesion force between the ink layer 13 and the release layer 12 in the non-heated portion).

Furthermore, when the thermal transfer ribbon is peeled off, the adhesion between the printing paper 17 and the top coat layer 14 or between the top coat layer 14 and the ink layer 13 is greater than the adhesion between the support 11 and the release layer 12 or between the release layer 12 and the ink layer 13. The adhesive force between the top coat layer 14 and the top coat layer 14 itself is greater, and the cohesive force of the top coat layer 14 itself is also greater.

Therefore, the ink layer 13 in the heated part, that is, the printed image part
As shown in the figure, the image is easily transferred to the printing paper 17 side, including the four parts that are taken over by the top coat layer 14 side and not in contact with the printing paper 17.

Next, the case where erroneous printing is erased using the thermal transfer ribbon 10 according to the present invention will be described based on FIGS. 4 and 5.

The thermal head 16 transfers the thermal transfer ribbon 10 to the plastic
The ink 18 is pressed against the erroneously printed portion on the printing paper 17 placed on the printing paper 17 (not shown). When the thermal head 16 generates heat, the heat passes through the anti-sticking layer 15 and the film-like support 11 to the release layer 12. Ink layer 13. Top-to-first layer 14 and ink 18 in the erroneously printed area
conducts to the surrounding area and melts the surrounding area. Then, when the power supply to the thermal head 16 is stopped, the surrounding area is cooled, and after a predetermined period of time, the ink 18 in the erroneously printed area and the top coat layer 14 harden in close contact with each other. At this time, the adhesion between the printing paper 17 and the ink 18 in the erroneously printed area is between the film-like support 11 and the release layer 12.

This is smaller than the adhesion between the release layer 12 and the ink layer 13, between the ink@13 and the top coat layer 14, and between the top coat layer 14 and the ink 18 in the erroneously printed area. In this state, when the thermal transfer ribbon 10 is pulled in the direction away from the printing paper 17 as shown in FIG. be transferred.

[Example 2] A, release layer a, release layer component: 100 parts by weight of polyethylene wax emulsion, Polylon #393 manufactured by Chugoku Yushi Co., Ltd.] 50 wt% [Polylon ME'10, manufactured by Chugoku Yushi Co., Ltd.] 50 wt% Bentonite 7 parts by weight 200 parts by weight of diluent water B, Ink layer C, Ink component polyamide [Macromelt 6301 from Henkel Hakusui Ltd.] 15 parts by weight [Persamide DPX93W from Henkel Hakusui Ltd.]' 20 parts by weight Polyvinyl chloride - Vinyl acetate copolymer resin 15 parts by weight [Eslec C-5 core amide wax from Sekisui Chemical Co., Ltd. 20 parts by weight [Hoechst's Wax C] Stearic acid amide 10 parts by weight Kyuto [Amide from Naeto Soap Co., Ltd.] S] Carbon black 15 parts by weight Bentonite 5 parts by weight d, Solvent isopropyl alcohol 150 parts by weight Toluene
150 parts by weight C, top coat layer e, top coat layer component ethylene-vinyl acetate copolymer resin 8 parts by weight [Evaflex 220 from Mitsui DuPont Polychemicals Co., Ltd.] 8 parts by weight [Mitsui DuPont Polychemicals Co., Ltd.] EVAFLEX 250] 2 parts by weight Zinc stearate 0.5 parts by weight f, Solvent toluene 50 parts by weight Thermal transfer ribbon 1 manufactured in the same process as Example 1 using each of the above components
When printing was performed using 0, it was possible to obtain print quality equivalent to that of Example 1.

[Effects of the Invention] As detailed above, the thermal transfer ribbon according to the present invention has a top coat on the ink layer that is mainly composed of a thermoplastic resin that has a high melt viscosity and a relatively weak adhesion to printing paper. The layers are laminated, and a release layer is interposed between the film-like support and the ink layer. Further, the ink layer is formed of a heat-melting ink which is incompatible with the top coat layer and is formed by mixing a coloring agent and a binder agent mainly composed of a thermoplastic resin having a large cohesive force. During printing, when the thermal transfer ribbon is peeled off, the adhesion between the printing paper and the top coat layer or between the top coat layer and the ink layer is greater than the adhesion between the support and the peeling layer or between the peeling layer and the heat-melting ink. Due to the large adhesion force and the large cohesive force of the top coat layer itself, the top coat layer and hot melt ink in non-contact areas corresponding to the recesses of the paper can be peeled off and transferred together, resulting in a smooth surface. It is possible to print clearly even on low-quality printing paper with no scratches or omissions, and even when erasing erroneous printing, it is possible to sufficiently peel off the ink in the erroneously printed area to the thermal transfer ribbon side.

[Brief explanation of drawings]

FIG. 1 is an enlarged cross-sectional view of a thermal transfer ribbon showing an embodiment of the present invention, FIG. 2 is a cross-sectional view showing the state of transfer onto printing paper by the thermal transfer ribbon, and FIG. 3 shows the printing paper and thermal transfer ribbon after printing. FIG. 4 is a cross-sectional view showing how the thermal transfer ribbon erases erroneous printing ink, and FIG. 5 is a sectional view showing the printing paper and the thermal transfer ribbon after the erroneous printing is erased.

Claims (1)

[Scope of Claims] 1. A thermal transfer ribbon having a film-like support and an ink layer formed of a hot-melt ink containing a colorant and a binder, the ink layer having a high melt viscosity. , and a top coat layer mainly composed of a thermoplastic resin that has relatively weak adhesion to printing paper is laminated, and the binder agent in the ink layer is mainly composed of a thermoplastic resin that is incompatible with the top coat layer. A thermal transfer ribbon characterized by: 2. The thermal transfer ribbon according to claim 1, wherein the top coat layer is mainly composed of an ethylene-vinyl acetate copolymer resin, and the binder in the ink layer is mainly composed of polyamide. .