JPH0696309B2 - Thermal transfer ribbon - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to an improvement in a heat-sensitive transfer ribbon, and more specifically, to a heat-sensitive transfer which gives high-quality printing even to a transfer paper having a low surface smoothness. Regarding ribbon. Furthermore, the present invention relates to a heat-sensitive transfer ribbon that gives glossy printing regardless of the surface smoothness of the transfer paper.

[Conventional technology]

When the output print of a computer or a word processor is a thermal transfer system, a thermal transfer ribbon in which thermal ink rows are provided at regular intervals on one side of a base film and a thermal head are used. Conventional thermal transfer ribbons use 10-20μ thick condenser paper or paraffin paper as the base film, or 3-20μ thick plastic film such as polyester or cellophane.
In addition, a heat-sensitive ink row in which a pigment and a solvent are mixed with a binder having a property of being solid at room temperature and melting when heated and transferring to a transfer target paper is provided by coating at regular intervals.

Although the thermal transfer method can print on plain paper,
Not all plain papers can be printed clearly. When the Bekk smoothness is used to express the smoothness of the transferred paper, 10
The best printing is possible with high-quality paper or coated paper that has been subjected to a calendar treatment showing a value of 0 seconds or more, and sufficient printing quality can be obtained even with high-quality paper of about 50 seconds. However, if a transfer paper with a low smoothness that does not reach 50 seconds is used, the sharpness of the print will deteriorate. This is because in the case of a paper having a highly uneven surface, the pressing surface of the thermal head cannot completely contact the ink surface with the paper, and the portions that do not come into contact result in poor transfer.

That is, when printing on rough paper (paper with poor smoothness, smoothness of 50 seconds or less) with the conventional thermal transfer ribbon, ink adheres only to the peaks of the paper, and there are many ink bleeding areas, which is used for rough paper. I couldn't.

Therefore, there is a thermal transfer ribbon for rough paper which has a large coating amount of the thermal ink, but it has a drawback that the thermal ink layer is easily peeled off from the base film because of the large coating amount. Further, when wound in a roll, there is a drawback that the blocking phenomenon that the thermal ink is transferred to the back surface of the base film is likely to occur.

Further, in the case of printing with a color thermal ink, the glossy feeling after printing tends to be preferred. Especially in the United States and Europe. However, the conventional thermal transfer ribbon cannot fully meet this demand.

[Problems to be solved by the invention]

It is an object of the present invention to provide a heat-sensitive transfer ribbon which improves the above-mentioned drawbacks of the conventional heat-sensitive transfer ribbon and gives high-quality printing even to a transfer paper having a low surface smoothness.

Another object is to provide a heat-sensitive transfer ribbon that gives glossy print regardless of the surface smoothness of the transfer paper.

Structure of the Invention [Means for Solving Problems] In the present invention, a heat-sensitive transfer as shown in FIG. 1 in which a base ink film and a heat-sensitive transfer ink line are sequentially provided at regular intervals on one surface of the base film. The present invention solves the above-mentioned drawbacks of the prior art by using a ribbon, and in the present invention, in the thermal transfer ribbon 1, at least one ethylene / vinyl acetate copolymer is waxed at regular intervals on one surface of the base film 4. The main purpose is to sequentially have a sealing ink line 2 formed of an ink containing P and a thermal transfer ink line 3.

Hereinafter, the present invention will be described in detail.

(Base Film) As the base film of the heat-sensitive transfer ribbon of the present invention, any base film that is used as a base film of an ordinary heat-sensitive transfer ribbon can be used. For example, plastic films such as polyester resin, polypropylene resin, cellophane, cellulose triacetate resin, polystyrene resin, polycarbonate resin, and polyimide resin,
Examples include glassine paper, condenser paper, form paper, Indian paper and other papers, metal foils, and composites of the above materials. As the composite, for example, an aluminum / paper composite, metal evaporated paper, metal evaporated plastic film or the like can be mentioned. The thickness of the above base film is preferably thin from the viewpoint of heat conductivity, and is usually 2 to 50 μm, preferably 4 to 20 μm. If it is less than 2 μm, the strength is insufficient and it is difficult to handle, and if it exceeds 50 μm, the resolution of printed images and characters is lowered, which is not preferable in practice.

The thermal transfer ink is prepared by mixing a colorant, a resin, a wax, a solvent and the like.

(Colorant) Among the organic or inorganic dyes or pigments, those having appropriate characteristics as a recording material are preferable as the colorant. For example, it has a sufficient color density, light, heat, humidity,
As a result, it is preferable that the color does not change.

Further, it may be a substance that is colorless when not heated, but that develops color when heated, or a substance that develops color when brought into contact with a substance applied to the transfer target. Cyan, magenta,
In addition to the colorants forming yellow and black, colorants of various other colors can also be used. That is, the heat-sensitive ink is selected and added according to the color to be added to the ink, such as carbon black or various dyes and pigments as a colorant.

(Resin) As the resin, a thermoplastic resin is often used,
Considering the head voltage, melting point, etc., it is preferable to use an appropriate resin alone or in combination.

Specifically, polyethylene, polystyrene, polypropylene, polybutene, petroleum resin, vinyl chloride resin, polyvinyl alcohol, vinylidene chloride resin, methacrylic resin, polyamide, polycarbonate, fluororesin, polyvinyl formal, polyvinyl butyral, acetyl cellulose plastic, nitrocellulose or Polyacetal or the like is used.

(Wax) As the wax, various waxes such as beeswax, spermaceti wax, ivowa wax, wool wax, shellac wax, carnauba wax, montan wax, paraffin wax, candelilla wax, petrolatum or microcrystalline wax are used. Next, the sealing ink, which is a feature of the present invention, contains at least an ethylene / vinyl acetate copolymer and wax, and is specifically composed of the following materials.

(Resin) As the resin, it is preferable to use an ethylene / vinyl acetate copolymer as an indispensable constituent element and, in addition to the melting point and the melt viscosity, a suitable thermoplastic resin in a mixture.

Specifically, polyethylene, polystyrene, polypropylene, polybutene, petroleum resin, vinyl chloride resin, polyvinyl alcohol, vinylidene chloride resin, methacrylic resin, polyamide, polycarbonate, fluororesin, polyvinyl formal, polyvinyl butyral, acetyl cellulose plastic, nitrocellulose or Polyacetal or the like is used.

(Colorant) Among the organic or inorganic dyes or pigments, those having appropriate characteristics as a recording material are preferable as the colorant. For example, it has a sufficient color density, light, heat, humidity,
As a result, it is preferable that the color does not change.

Further, it may be a substance that is colorless when not heated, but that develops color when heated, or a substance that develops color when brought into contact with a substance applied to the transfer target. Cyan, magenta,
In addition to the colorants forming yellow and black, colorants of various other colors can also be used. That is, the filling ink is selected and added according to the color to be added to carbon black or various dyes and pigments as a colorant.

As an embodiment of the present invention, a case where a colorant is not added and a case where a colorant is added are considered. When it is not added, it becomes a transparent ink layer, and when transferred to the transfer paper as a sealing layer, the color of the transfer paper becomes the base as it is, and only the quality of printing on it can be improved.

In addition, when it is inserted, it is used when the color of the transfer portion of the transfer paper is changed to another color. That is, it is possible to improve the yellowing or the like of the color of the transfer target paper, and particularly, a preferable effect is provided when the color ribbon is used. At that time, a white pigment such as titanium white or a dye is preferably used as the colorant. Also, various effects can be obtained even if a color other than white is used.

(Wax) As the wax, various waxes such as beeswax, spermaceti wax, ivorot wax, shellac wax, wool wax, carnauba wax, candelilla wax, paraffin wax, microcrystalline wax or petrolatum are used.

The method for producing a heat-sensitive transfer ribbon using the above-described base film, colorant, resin, and wax will be described below. The colorant, resin, and wax are kneaded to form a composition, and the composition is applied by an appropriate coating method. It may be applied on one surface of the base material. The composition includes a colorant, a resin, and a wax, and the weight of the colorant is 1-80.
%, Preferably 2 to 20%, and optionally other optional ingredients are added and kneaded at room temperature or under heating. Examples of the optional component in the above include a softening agent such as mineral oil or vegetable oil, a thermal conductivity improving agent such as metal powder, an extender pigment such as microsilica, calcium carbonate or kaolin, and a transferability improving property such as polyhydric alcohol. Examples include agents, solvents, diluents, and the like. The solvent or diluent is used when the composition is used as an ink composition for a normal printing method, and is used as benzene, xylene, toluene, trichlene, white spirit, ethyl acetate, n-butyl acetate, methanol, ethanol, isopropanol, n-. Butanol, ethyl cyclohexane, methyl ethyl ketone, ethyl cellosolve, butyl cellosolve,
Examples thereof include cyclohexanone.

That is, any solvent can be used as long as it is a general solvent, but in consideration of the solubility with resins, waxes, colorants, coating suitability, etc., suitable solvents may be used alone or in combination.

That is, as shown in FIGS. 1 and 2, the formation of the sealing ink line 2 and the thermal transfer ink line 3 on the base film is performed by mixing and dispersing the above-mentioned constituent materials and adjusting the viscosity suitable for coating. It is carried out by applying it to the base film 1 using a commonly used coating means (gravure tie coat, gravure reverse coat, roll coat, spray coat, etc.).

As a modified embodiment of the heat-sensitive transfer ribbon of the present invention, a layer for preventing sticking between the base film 1 and the thermal head, which may occur depending on printing conditions, may be provided as shown in FIG. Sticking prevention layer 5
Has a resin and a thermal release agent or a lubricant and a solvent as basic components.

A) Resin A synthetic resin having a glass transition point of 60 ° C or higher is suitable. Typical examples are acrylic resin, polyester resin, phenol resin, fluororesin, polyimide resin, methylmethacrylate resin, vinylidene fluoride resin, vinylidene fluoride-atrafluoroethylene copolymer resin, polyvinyl fluoride resin, acrylonitrile-styrene. Such as a copolymer resin.

A resin obtained by adding a compound having two or more amino groups or diisocyanate or triisocyanate to a thermoplastic resin having an OH group or a COOH group is also suitable. Thermoplastic resins having OH groups or COOH groups are polyester resins, vinyl chloride / vinyl acetate copolymers, polyether resins, polybutadiene resins, acrylic polyols, urethane or epoxy prepolymers having OH groups, nitrocellulose resins, celluloses. It is preferable to select from acetate propionate resin, cellulose acetate butyrate resin, and cellulose acetate resin. These resins may have an OH group or a COOH group in the polymerized unit, or may have one at a terminal or a side chain.

Examples of the diisocyanate added to the thermoplastic resin having the above OH group or COOH group are paraphenylene diisocyanate, 1-chloro-2,4-phenyl diisocyanate,
2-chloro-1,4-phenyl diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 1,5-naphthalene diisocyanate, hexamethylene diisocyanate and 4,4'-biphenylene diisocyanate, examples of triisocyanates Is triphenylmethane triisocyanate and 4,4 ′, 4′-
Trimethyl-3,3 ', 2'-triisocyanate-2,4,6-
It is triphenyl cyanurate and has 2 amino groups.
Examples of compounds having more than one, melamine, methylated melamine, methylated methylol melamine, butylated melamine,
Butylated methylolmelamine, dicyandiamide, guanidine, biguanide, diaminomelamine, guanylmelamine, urea, biuret, ammeline, ammelide, butylated urea and methylated urea, and the guanamines formoguanamine, acetoguanamine, benzoguanamine, phenylacetoguanamine. , Methoxyguanamine and N-methylol acrylamide copolymer polymers can also be used.

When a compound having two or more amino groups is used, ammonium phosphate, triethanolamine, acetamide, urea, pyridine, paratoluenesulfonic acid, sulfanilic acid, guanidine stearate, guanidine carbonate, etc. are used as a curing catalyst. To do. The diisocyanate, trianthocyanate and amino compound may be used alone or as a mixture of two or more thereof, with respect to 100 parts by weight of the thermoplastic resin having an OH group or a COOH group, 5 to 40 parts by weight, preferably 10 to 20 parts by weight. Added. These are cross-linking agents,
The mat layer is cured appropriately and the adhesion of the mat layer to the plastic film is increased.

B) Thermal Release Agents or Lubricants There are those which melt by heating and act as such, and those which act as a solid powder. Those belonging to the former group are waxes such as polyethylene wax and paraffin wax, amides, esters and salts of higher fatty acids, and phosphoric acid esters such as higher alcohols and lecithin. The latter group includes Teflon, fluororesins such as polyvinyl fluoride, guanamine resins, boron nitride, silica, wood flour, talc and the like. Of course, the two groups can be used together. The amount used is such that the above thermal release agent or lubricant accounts for 10 to 50% by weight in the sticking prevention layer.

C) Solvent The solvent is used when the composition is used as an ink composition for a normal printing method, and is benzene, xylene, toluene, trichlene, white spirit, ethyl acetate, n-butyl acetate, methanol, isopropanol, n-butanol,
Examples thereof include ethyl cyclohexane, methyl ethyl ketone, ethyl cellosolve, butyl cellosolve, cyclohexanone and the like.

Depending on the resin, thermal release agent or lubricant, especially methyl ethyl ketone, ethyl acetate methanol, ethanol,
Solvents such as toluene are often used.

The sticking prevention layer 5 is formed on the base film 4 by mixing and dispersing the above-mentioned constituent materials to adjust the viscosity suitable for coating, and then applying a usual coating means (gravure direct coat, gravure reverse coat, roll coat, spray coat). And the like) may be applied to the other surface of the base film 4.

[Action]

As shown in FIG. 1, a sealing ink line 2 which is not provided in the conventional heat-sensitive transfer ribbon is provided, and at least ethylene / vinyl acetate is prepared in advance before transferring the heat-sensitive transfer ink line 3 to a sheet of transfer paper. A sealing ink containing a copolymer and wax is transferred.

First of all, the sealing ink containing at least ethylene / vinyl acetate copolymer and wax is heated and melted by the thermal head to be transferred to the transferred paper so that the sealing ink permeates into the valley portion of the paper. A smooth surface layer can be formed.

Since a smooth surface layer of the sealing ink containing at least ethylene / vinyl acetate copolymer and wax is formed on the transfer paper, the heat-sensitive transfer ink is sequentially transferred and formed thereon. High quality printing with a glossy feeling can be performed regardless of the smoothness of the transfer paper.

〔Example〕

(Sealing ink I) Paraffin wax 10 parts by weight Carnauba wax 10 〃 Ethylene / vinyl acetate copolymer 1 part by weight (Sumitomo Chemical "Sumitate HC-10") (Yellow ink) Paraffin wax 10 parts by weight Carnauba wax 10 〃 Ethylene / Vinyl acetate copolymer 1〃 (Sumitomo Chemical "Smitate HC-10") Yellow pigment (Dainichi Seika 2400) 2〃 (red ink) Paraffin wax 10 parts by weight Carnauba wax 10〃 Ethylene / vinyl acetate copolymer 1〃 ( Sumitomo Chemical "Sumitate HC-10") Carmine 6B 2〃 (indigo ink) Paraffin wax 10 parts by weight Carnauba wax 10〃 Ethylene / vinyl acetate copolymer 1〃 (Sumitomo Chemical "Sumitate HC-10") Phthalocyanine blue 1 〃 (black ink) Carnauba wax 10 parts by weight Paraffin wax 10 〃 Ethylene / vinyl acetate Polymer 1〃 (Sumitomo Chemical "Smitate HC-10") Carbon black 2〃 (Sealing ink II) Paraffin wax 10 parts by weight Carnauba wax 10〃 Ethylene / vinyl acetate copolymer 1〃 (Sumitomo Chemical "Smitate HC-10" )) Titanium oxide 2〃 (anti-sticking agent) Acrylonitrile-styrene copolymer resin 8 parts by weight (Devicel Chemical's Cebian N) Acrylic polyol 32〃 {Denka Polymer TP-5000 50% solution (solvent is ethyl acetate, toluene) , Methyl ethyl ketone)} Teflon powder 3〃 (Daikin Industries Lubron L) Polyethylene wax 3 parts by weight (Adeka Argus mark FC-113) Methyl ethyl ketone 40〃 Toluene 40〃 Example 1 One side of a 6μ thick polyester film (Toray) Dilute with isopropyl alcohol and denatured ethanol The eye stop ink I, yellow ink, red ink, cyan ink,
The black ink was gravure-printed in this order at regular intervals. At this time, the coating amount at the time of drying is 6 g of the sealing ink I.
/ m ² Otherwise it was 3 g / m ² .

Example 2 An isocyanate (Takenate D-204, 50% ethyl acetate solution, manufactured by Takeda Pharmaceutical Co., Ltd.) was used as an anti-sticking agent: Isocyanate =
A mixture of 12: 3 (weight ratio) added and mixed immediately before coating was applied by gravure printing to one side of a 6μ thick polyester film (Toray) so that the dry coating amount was 0.7 g / m ^2. Then, it was dried at a temperature of 100 ° C. to form a sticking prevention layer.

Next, on the surface of the 6 μ polyester film opposite to the sticking prevention layer, the boundary ink is continuous with the sealing ink II diluted with isopropyl alcohol and denatured ethanol, the yellow ink, the red ink, and the indigo ink in this order. Gravure printed so that The dry coating amount at this time was 6 g / m ^{2 for} the sealing ink and 3 g / m ² for the other inks.

Comparative Example 1 The thermal transfer ribbon of Example 1 without the sealing ink I alone.

Comparative Example 2 The thermal transfer ribbon of Example 2 without the sealing ink II.

The thermal transfer ribbons shown in Examples 1 and 2 and Comparative Examples 1 and 2 were tested for transferability using a commercially available thermal transfer printer and plain papers having various smoothnesses.

(Table.1) First, the smoothness before transfer of various papers used for Examples 1 and 2 and Comparative Examples 1 and 2 and the smoothness after transfer of the sealing ink of Examples 1 and 2 were measured. It measured using the smoothness meter. Moreover, the glossiness after transfer of the sealing ink was measured at a measuring angle of 60 ° using a gloss meter (Suga Tester). (Examples 1 and 2)
(Comparative Examples 1 and 2 show the glossiness of the paper) Further, the glossiness is judged to be good if the glossiness is 30 or more, 30
When it was less than, it was considered as defective and marked as x.

The transferability was determined by measuring the degree of ink inking with a halftone dot analyzer “Area Duck 1500” (Konishi Rokusha Kogyo Co., Ltd.) and area dot%. The transferability was judged as good when the area dot% was 80% or more, and bad when it was less than 80%.

As shown in Table 1, even when using plain paper having a low surface smoothness of 7s and 30s, the sealing ink was transferred from the upper part of Examples 1 and 2 and the upper parts of Comparative Examples 1 and 2 By doing
The glossiness was good, and the transferability was also good, which made it practically applicable.

Further, it was found from the lower part of Example 2 and the lower part of Comparative Example 2 that by transferring the sealing ink, the glossiness was further improved and the transferability was further improved.

[Advantages of the Invention] The heat-sensitive transfer ribbon of the present invention is configured as described above, and by using this, high-quality printing can be performed even on a transfer target paper having a low surface smoothness. Thermal transfer can be performed regardless of. Furthermore, glossy printing is possible.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of the thermal transfer ribbon of the present invention. FIG. 2 is a side view of the thermal transfer ribbon of the present invention having a sticking prevention layer. 1: Thermal transfer ribbon 2: Heat-sensitive transfer ink row 3: Sealing thermal transfer ink row 4: Base film 5: Sticking prevention layer

 ─────────────────────────────────────────────────── --- Continuation of the front page (56) References JP-A-59-198196 (JP, A) JP-A-55-7467 (JP, A) JP-A 58-153684 (JP, A) JP-A 61- 86289 (JP, A)

Claims (2)

[Claims] 1. A base ink film having, on one side thereof, at regular intervals a sealing ink line formed by an ink containing at least an ethylene / vinyl acetate copolymer and a wax, and a heat-sensitive transfer ink line. A thermal transfer ribbon. 2. The heat-sensitive transfer ribbon according to claim 1, wherein a layer for preventing sticking to the thermal head is provided on the other surface of the base film.