JPH0780357B2 - Thermal transfer ribbon - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a thermal transfer ribbon used in a printing apparatus such as a thermal printer that performs printing by thermal transfer.

[Prior Art] Printing using a thermal transfer ribbon is performed by bringing the thermal transfer ribbon into close contact with a printing sheet by a thermal head and causing a desired heating element among a large number of heating elements of the thermal head to generate heat, thereby causing the thermal transfer ribbon to the heating element. The heat-meltable ink portion that is in contact with the support is melted and transferred to the printing paper.

Conventionally, this type of thermal transfer ribbon has been one in which a heat-meltable ink composed of a colorant and a binder agent containing wax as a main component is coated on a support.

[Problems to be Solved by the Invention] As described above, when printing is performed on plain paper with a thermal transfer ribbon in which a heat-meltable ink is applied on a support, the smoothness of the plain paper is Beck's smoothness. Sufficient print quality could not be obtained unless the printing time was up to several tens of seconds.

On the other hand, when correcting typographical errors in thermal transfer printing, since the ink penetrates into the fibers of the printing paper during transfer printing, the method for correcting this is to cover the characters with a white substance with covert power (cover wrap). It is unavoidable that the corrections are unsightly.

[Object of the Invention] The present invention has been made in order to solve the problems of the conventional thermal transfer ribbon as described above, and an object of the present invention is to provide a printing energy range which can be sufficiently realized in a conventional thermal head. Clear printing can be done even on non-smooth printing paper without scratches and omissions, and even if you make a mistake, you can peel off the characters on the printing paper with the same ribbon.
It is to provide a thermal transfer ribbon that can be erased (called lift-off correction).

[Means for Solving the Problems] In order to achieve the above object, the thermal transfer ribbon of the present invention comprises:
A film-like support, an A component composed of an ethylene-vinyl acetate copolymer resin or ethylene-ethyl acrylate, and a melt viscosity at 150 ° C of 10 ³ P (poise) or more which are incompatible with the A component. It is characterized in that it is formed from a component B made of a viscous resin and an ink layer made of a colorant.

[Operation] According to the above configuration, the thermofusible ink melted by the heat from the thermal head is firmly fixed at the contact point of the convex portion of the printing paper at the time of printing, and when the thermal transfer ribbon is peeled off, between the support and the ink layer. Since the film strength of the heat-meltable ink itself is larger than the adhesive force of No. 3, the ink layer in the non-contact portion corresponding to the concave portion of the paper can also be peeled and transferred together.

Further, this heat-melting ink is achieved by the rate-determining (heat-melting property / fluidity, etc.) of the A component at the time of transfer, but the B component, which is transferred along with this, hardly exhibits fluidity. Therefore, the colorant contained in the B component does not penetrate into the fibers of the printing paper. Further, the adhesive force between the printing paper and the ink layer is not so large because it is only the adhesive force of ethylene-vinyl acetate copolymer resin or ethylene-ethyl acrylate.

Therefore, if the unused portion of the ribbon is re-pressed against the ink portion transferred onto the printing paper and the same energy as that at the time of printing is applied, the ink on the printing paper and the ink on the ribbon are fused. At this time, if the ribbon is peeled off while this portion is cooled and solidified, the ink transferred onto the printing paper can be peeled off to the ribbon side again.

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

In FIG. 1, the thermal transfer ribbon 10 is a film-shaped support 11
A peeling layer 12 is formed on top of which an ink layer 13 is further formed.

The film-shaped support 11 used in this embodiment includes polyester, polyimide, and
Polycarbonate, Polysulfone, Polyethersulfone, Polyphenylene sulfide, Polyether-
Examples of the film include a film made of ether ketone or a paper such as condenser paper and glassine paper, and the thickness thereof is about 3 to 20.
It is preferably in the range of μ. Further, as shown in FIG. 1, a sticking prevention layer 14 made of a heat resistant resin such as a silicone resin is provided on the surface opposite to the coated surface of the ink layer 13.

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

A pigment such as carbon black is used as the colorant. In addition, a small amount of a dye is added as an auxiliary agent as needed in order to produce a color that cannot be produced by the pigment alone or to adjust the color tone.

As a binder agent for the ink layer, as a result of diligent studies from the viewpoint of both transfer quality to non-smooth printing paper and lift-off correction performance, it was found that the next frying structure is extremely effective. That is, the ethylene-vinyl acetate copolymer resin or the ethylene-ethyl acrylate resin (component A) is incompatible with the component A and has a melt viscosity of 10 ³ P at 150 ° C.
(Poise) It is a combination with a highly viscous resin (component B) of the above. In addition, the MI value (160
C.) 50 to 500 and softening point 80 to 140.degree. In addition, the transfer quality and the lift-off correction performance are completely inadequate just by mixing the colorant with the component A. By mixing the component B with this and adding the colorant in the component B, both performances are exhibited. To do.

The selection of the B component resin is limited on the assumption that it is incompatible with the A component, from the viewpoints of its heat-resistant fluidity, film-forming property, pigment dispersibility and the like.

For example, when a polybutyral resin is used, the butyral resin alone has a poor affinity with a colorant (mainly carbon black) and its dispersion state is insufficient. Therefore, an ideal ink was obtained by using this together with a vinyl chloride-vinyl acetate-vinyl alcohol copolymer resin.

Further, when polyethylene oxide was used as the B component resin, the state was similar to that of the butyral resin, and in this case, the combined use of vinyl chloride-vinyl acetate copolymer resin was effective.

The above example is a solvent type, but an aqueous type is also possible. In this case, when polyvinyl alcohol is used as the B component resin, the colorant is dispersed in the polyvinyl alcohol, and then the emulsion of the A component resin is mixed, an ink having both of the above properties is produced.

Next, modification of the component A resin will be described. It is effective to add a wax having a melting point of about 60 ° C. to 120 ° C. compatible with the component A in order to meet various printing conditions such as energy application to the thermal head and head pressing pressure. As wax, harafin wax, microcrystalline wax, oxidized paraffin wax, candelilla wax,
Carnauba wax, montan wax, ceresin wax, polyethylene wax, polyethylene oxide wax, castor wax, hydrogenated tallow oil, lanolin, wax, sorbitan stearate, sorbitan palmitate, stearyl alcohol, polyamide wax, oleylamide, stearylamide, hydroxystearin. One or more wax-like substances such as acid, synthetic ester wax, and synthetic gold-containing wax may be mixed.

The peeling layer 12 is made of polyethylene wax having an appropriate melting point (80 to 120 ° C.) and poor adhesion to the film-shaped support 11.

The release layer 12 may be a polyethylene wax alone, but a filler such as bentonite, kaolin, or talc may be added to meet various requirements as an ink ribbon, which changes the release property in a preferable direction. Can be made.

By the way, the ribbon of the present invention can obtain sufficient transferability and lift-off correction performance under most conditions only with the constitutions of the ink layer and the peeling layer, but there are cases where the both properties are not satisfied under special conditions. In this case, as an effective measure, there is a means for further forming an overcoat layer on the ink layer. As the overcoat layer, a resin of the same type as the component A containing no colorant is suitable. By applying this, transferability to rough paper and lift-off correction performance are further improved.

Then, an anti-sticking layer is formed on the back surface according to this embodiment.
A manufacturing process of forming the peeling layer 12 and the ink layer 13 on the support 11 on which the 14 is formed will be described.

(1) Step of forming release layer Polyethylene wax emulsion is diluted with water to obtain a coating liquid. Also, when adding a filler, a three roll mill,
Disperse in the coating liquid using a generally used disperser such as a sentry mill, a sand mill, and a ball mill.

(2) Coating and Drying Step of Release Layer The coating liquid is applied to the film-shaped support 11, for example, a polyester film (thickness: 3.5 μ), by an appropriate coating device. It is dried at 80-100 ° C. In this example, the coating thickness was set to about 1 μm.

(3) Step of producing heat-meltable ink After dissolving ethylene-vinyl acetate copolymer resin or ethylene-ethyl acrylate in a solvent by heating, this is cooled to obtain a crude dispersion liquid in which the resin is deposited.

Separately, a colorant is mixed during the melting of a highly viscous resin that is incompatible with the resin and has a melt viscosity at 150 ° C. of 10 ³ P or more.

Next, both are mixed and the same 3
The dispersion is used as an ink coating liquid by using a commonly used disperser such as the present roll mill, sentry mill, sand mill, and ball mill.

(4) Coating and Drying Step of Ink Coating Liquid The above-mentioned ink coating liquid is coated on the film-shaped support 11 coated with the release layer 12 by the appropriate coating device. Then it is dried at 80-100 ° C. In this embodiment, the ink application thickness is set to 4 to 6 μm.

With the above, the manufacturing process of the thermal transfer ribbon 10 is 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 will be described below.

[Example] A. Release layer a. Release layer component Polyethylene wax emulsion [ME-10 of Chukyo Yushi Co., Ltd.] (solid content concentration 32%) B. Hot-melt ink layer b. Ink component: 1 part by weight Ethylene-vinyl acetate copolymer resin 63 wt% [Evaflex 310 48 wt% from Mitsui / DuPont Polychemical Co., Ltd.] [Evaflex 360 15 wt% from Mitsui / DuPont Polychemical Co., Ltd.] Vinyl chloride-Vinyl acetate-Polyvinyl alcohol Copolymer resin 5 wt% [S-Lec A from Sekisui Chemical Co., Ltd.] Polyvinyl gutyral resin 15 wt% [S-Lec BMS from Sekisui Chemical Co., Ltd.] Oxidized polyethylene wax 5 wt% [Sun Wax E- from Sanyo Chemical Industry Co., Ltd.] 300] Carbon black 12wt% [MA-100 of Mitsubishi Kasei Co., Ltd.] 100wt% in total c. Solvent: 5 parts by weight Methyl isobutyl ketone 100wt% Consisting of the above component a The coating liquid is applied to the support 11 formed of a 3.5 μ polyester film so that the coating thickness is about 1 μ, and the release layer 12 is obtained on the support 11. An ink coating liquid containing the components b and c is applied to the release layer 12 and dried at 80 to 100 ° C. Then, the ink layer 13 having a thickness of about 4 to 6 μm is formed on the peeling layer 12 on the support 11.

When the thermal transfer ribbon 10 manufactured in this way was used to print on a printing paper having Beck's smoothness of 3 to 4 seconds, the ink was also transferred to the concave portions of the printing paper, and the blur was extremely small and sharp and dark. A printed image was obtained.

The process of transferring the heat-meltable ink when printing is performed on the printing paper having low smoothness by using the thermal transfer ribbon 10 according to the present invention will be described with reference to FIGS. 2 and 3.

The thermal transfer ribbon 10 is pressed against the printing paper 16 on the platen (not shown) by the thermal head 15. Then, when the thermal head 15 is energized and the thermal head 15 generates heat,
The heat prevents the sticking layer 14 and the film-like support 11.
Through the release layer 12 and the ink layer 13 through the release layer 1
2 and the ink layer 13 are melted, and the heat-meltable ink in contact with the convex portion of the printing paper 16 adheres to the convex portion. At this time, the conventional ink mainly composed of waxes partially penetrates into the fibers of the printing paper 16, but in the present embodiment, since the thermoplastic resin whose melt viscosity is larger than waxes is used, The printing paper 16 does not penetrate into the fibers.

Next, when power supply to the thermal head 15 is stopped and heat generation is stopped, the ink layer 13 and the peeling layer 12 start cooling. Then, when the thermal transfer ribbon is peeled off from the printing paper 16 in this state (the two layers that have not been completely cooled are in a semi-solidified state), the ink in the semi-solidified state is transferred to the printing sheet 16 starting from the contact portion between the ink and the printing sheet 16. Transcribe.

At this time, the following relationships are established.

F4, F1>F2> F3 F1: Adhesion force of the heat-meltable ink layer 13 to the printing paper 16 F2: Film strength of the heat-meltable ink layer 13 at the boundary between the heated portion and the non-heated portion F3: Heat-meltable ink Adhesion between layer 13 and release layer 12 or adhesion between release layer 12 and support 11 F4: Film strength of heat-meltable ink layer 13 in heated portion Utilizing the film strength of the fusible ink and releasing layer
By utilizing the low adhesion of the polyethylene wax emulsion 12 to the film-like support 11, it is possible to perform printing with high printing quality even on the printing paper 16 having low smoothness without blurring.

Next, the process of erasing erroneously printed characters using the thermal transfer ribbon 10 according to the present invention will be described with reference to FIGS. 4 and 5.

The thermal transfer ribbon (10) is pressed by the thermal head (15) against the ink (17) in the erroneous printing portion on the printing paper (16) placed on the platen (not shown). When the thermal head 15 generates heat in that state, heat is conducted to the peeling layer 12, the ink layer 13 and the ink 17 in the erroneous printing portion through the sticking prevention layer 14 and the film-shaped support 11, and the three of them are melted. . Then, when the power supply to the thermal head 16 is stopped and the heat generation is stopped, the three members are cooled. Then, after a predetermined time has passed,
The ink 17 and the ink layer 13 in the erroneously printed portion are solidified in a state of being in close contact with each other. At this time, the printing paper 16 and the ink 17
The adhesive force with the film-like support 11 is smaller than the adhesive force between the release layer 12, the release layer 12-the ink layer 13, and the ink layer 13-the ink 17 of the erroneously printed character. Then, in this state, when the thermal transfer ribbon 10 is pulled in the direction away from the printing paper 16 as shown in FIG. 5, the ink 17 on the erroneous printing portion on the printing paper 16 is stripped off cleanly without remaining on the printing paper 16. And transferred to the thermal transfer ribbon 10 side.

[Effects of the Invention] As described in detail above, the thermal transfer ribbon according to the present invention comprises a film-shaped support, an A component composed of an ethylene-vinyl acetate copolymer resin or ethylene-ethyl acrylate, and a component of the A component. It is composed of a component B made of a highly viscous resin which does not melt and has a melt viscosity at 150 ° C. of 10 ³ P or more, and an ink layer made of a colorant, and at the time of printing, at the time of peeling the thermal transfer ribbon, Since the film strength of the heat-meltable ink itself is larger than the adhesive force between the support and the heat-meltable ink, the heat-meltable ink in the non-contact portion corresponding to the concave portion of the printing paper is also included. It can be peeled off and transferred, and clear printing can be performed even on printing paper with low smoothness without scratches or omissions, and even when erroneous printing is erased, the ink at the time of erroneous printing is sufficiently peeled to the thermal transfer ribbon side. To take And are possible.

[Brief description of drawings]

FIG. 1 is a sectional view of a thermal transfer ribbon showing an embodiment of the present invention, FIG. 2 is a sectional view showing a transfer state on a printing paper by the thermal transfer ribbon, and FIG. 3 shows a printing paper and a thermal transfer ribbon after printing. A cross-sectional view, FIG. 4 is a cross-sectional view showing a state of erasing erroneously printed ink by a thermal transfer ribbon, and FIG. 5 is a cross-sectional view showing a print sheet and a thermal transfer ribbon after erroneous printing is erased. 10: Thermal transfer ribbon, 11: Support, 13: Ink layer

Claims (3)

[Claims] 1. A film-shaped support, an A component composed of an ethylene-vinyl acetate copolymer resin or ethylene-ethyl acrylate, and a melt viscosity at 150 ° C. which is incompatible with the A component and is 10 ³ P (poise). ) A thermal transfer ribbon formed from the above-mentioned B component made of a high-viscosity resin and an ink layer made of a colorant. 2. As the component B, polyvinyl butyral, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-vinyl alcohol copolymer, polyethylene oxide, polyvinyl alcohol, polycaprolactone, polyester, polyethylene, nitrocellulose,
The thermal transfer ribbon according to claim 1, wherein at least one kind of resin such as cellulose acetate is used. 3. An overcoat layer which contains the component A as a main component and does not contain the colorant, is provided on the ink layer. Thermal transfer ribbon.