JPH03247493A - Heat transfer sheet - Google Patents

Abstract

PURPOSE:To easily identify the content of an article to be adhered with a bar code label with bare eyes by forming most of an ink layer black and part a color. CONSTITUTION:If a heat fusible ink layer is formed on one side surface of a base film 1, a heat transfer sheet is formed at most of the ink layer of a black ink layer 2a and at the other of a color ink layer 2b. Such a sheet is used to print a bar code on a bar code label and to print a special mark corresponding to the content of an article to be attached with the label on the color ink part. Such a label is attached to a package of the article to be able to easily identify what is the content of the article with bare eyes.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a thermal transfer sheet, and more particularly to a thermal transfer sheet capable of printing in two or more colors.

(Prior art and its problems) Conventionally, when printing output prints from computers or word processors using a thermal transfer method, a thermal transfer sheet with a heat-melting ink layer provided on one side of a base film has been used. .

This conventional thermal transfer sheet has a thickness of 1 mm as a base film.
Using paper such as capacitor paper or paraffin paper with a thickness of 0 to 20 LLm, or a plastic film such as polyester or cellophane with a thickness of 3 to 20 μm, a layer of heat-melting ink made by mixing coloring agents such as pigments and dyes with wax is applied. It is manufactured by coating it to provide an even thickness.

The conventional thermal transfer method described above has been used to print a variety of characters, but recently it has been used for printing barcodes on barcode labels because of its simplicity and suitability for small lot printing. It started to be used.

Labels with barcodes printed on them are attached to many products, but when these products are packaged, there is an inconvenience in that the contents of the product cannot be easily identified with the naked eye from the barcode. In some cases, it was required to clearly indicate the contents of the item on a signboard, etc. Such a method degrades the appearance of the packaging and is very complicated. Therefore, an object of the present invention is to solve the problems of the prior art described above, and to make it possible to visually identify the contents of an article to which a barcode label is attached. To provide a thermal transfer sheet capable of printing characters that can be easily identified.

(Means for solving problems) The above objects are achieved by the present invention as described below.

That is, the present invention is a thermal transfer sheet in which a heat-melting ink layer is formed on one side of a base film, characterized in that most of the ink layer is black and a part is chromatic. It is a thermal transfer sheet.

(Function) Most of the ink layer is black, at least a part is chromatic, the black part prints a barcode, and the chromatic part prints a mark indicating the content of the article to which the barcode label is attached. By doing so, even if the article to which the barcode label is attached is packaged, the contents of the article can be easily identified with the naked eye.

(Preferred Embodiments) Next, the present invention will be explained in more detail with reference to preferred embodiments.

FIG. 1 is a diagram illustrating the appearance of the thermal transfer sheet of the present invention, and FIG. 2 is a diagram showing its cross section.

As schematically shown in FIGS. 1 and 2, in the thermal transfer sheet of the present invention, when a heat-melting ink layer is formed on one surface of the base film 1, most of this ink layer is ink-filled with black ink. It is characterized by having a layer 2a and the other layer being a chromatic ink layer 2b.

An article in which a barcode is printed in black on a barcode label using such a thermal transfer sheet, and the barcode label is attached to the top, bottom, or either side of the printed barcode with colored ink. Print a specific mark that corresponds to the content. By attaching such a barcode label to the packaging of an article, the contents of the article can be easily identified with the naked eye.

Further, the chromatic ink portion is not limited to one color, but may be two colors as shown in the third figure, or may be three or more colors.

The thermal transfer sheet of the present invention may be in the form of a continuous sheet, as shown in the first figure, or may be in the form of a single sheet, which is cut into an appropriate size. Further, the width of these thermal transfer sheets varies depending on the printer used, and may be any width.

Further, the black ink layer 2a accounts for 50 to 90% of the film, and the chromatic ink layer 2b accounts for about 1 to 50%.

As the base film l, the same base film used in conventional thermal transfer sheets can be used as is, and other films can also be used, and there are no particular limitations.

Specific examples of preferred base films include polyester, polypropylene, cellophane, polycarbonate, cellulose acetate, polyethylene, polyvinyl chloride,
There are plastics such as polystyrene, nylon, polyimide, polyvinylidene chloride, polyvinyl alcohol, fluororesin, chlorinated rubber, and ionomers, papers such as condenser paper and paraffin paper, and nonwoven fabrics, as well as base films that are composites of these materials. It's okay.

The thickness of this base film may be changed as appropriate depending on the material so that its strength and thermal conductivity are appropriate, but the thickness is preferably, for example, 2 to 25 μm.

The hot-melt ink used in the present invention comprises a colorant and a vehicle, and may further contain various additives as required.

As this coloring agent, carbon black is of course suitable for the black ink layer part, and for other chromatic ink parts,
For example, pigments such as cyan, magenta, and yellow are used.

The vehicle used includes wax as a main component, and mixtures of wax with drying oil, resin, mineral oil, cellulose, rubber derivatives, and the like.

Representative examples of wax include microcrystalline wax, carnauba wax, paraffin wax, and the like. Furthermore, various waxes are used, such as Fischer-Tropsch wax, various low molecular weight polyethylenes, wood wax, beeswax, spermaceti wax, privet wax, wool wax, shellac wax, candelilla wax, vetrolatum, as-needed wax, fatty acid ester, fatty acid amide, etc. It will be done.

Further, in order to provide the hot-melt ink layer with good thermal conductivity and melt transferability, a thermally conductive substance can be blended into the hot-melt ink. Examples of this substance include carbonaceous substances such as carbon black, aluminum, copper, tin oxide, and molybdenum dioxide.

As a method for forming the heat-fusible ink layer on the base film, a gravure printing method is suitable, and other known methods may be used.

A particularly preferred method in the present invention is as shown in FIG.
When forming the black ink layer 2a on the base film 1 on which the chromatic ink layer 2b has already been formed in the previous step, the black gravure plate 3 is immersed in the molten black ink tank 4, and the ink 2
A is placed on the gravure plate 3, and the black ink 2a is transferred to a desired area of the base film 1.

At this time, the black ink 2a in the area corresponding to the chromatic ink layer 2b (which is a non-image area for black ink) is scraped off from the gravure plate 3 by the doctor 5.
The black ink 2a is never transferred onto the chromatic ink layer 2b.

However, if the doctor 5 has poor performance or is worn out, the black ink 2a is also transferred onto the chromatic ink layer 2b, resulting in staining of the chromatic ink layer 2b.

In the present invention, we have discovered a method to effectively solve these problems. That is, in the impression cylinder 6 that presses the base film 1 against the gravure plate 3, a region corresponding to the chromatic ink layer 2b is formed as a recess 7, so that in that region 7, the chromatic ink layer 2b is covered by the gravure roll. 3, even if the performance of the doctor 5 deteriorates and black ink remains in the non-image area 7 of the gravure plate 3, the black ink 2a
is not transferred onto the chromatic ink layer 2b of the base film 1, and the chromatic ink layer 2b is not stained by the black ink 2a.

Subsequently, the obtained film is cut into 2 to 3 equal parts as required to obtain the thermal transfer sheet of the present invention as shown in the first figure.

In the above method, the black ink layer 2a is formed after the chromatic ink layer 2b is formed, but it goes without saying that the order may be reversed.

The thickness of the ink layers 2a, 2b to be formed should be determined so as to balance the required concentration and thermal sensitivity, and should be 0.00000.
It is in the range of 1 to 30 μm, preferably in the range of 1 to 20 μm.

In the present invention, a surface layer (not shown) made of wax may be formed on the ink shoulder. The surface layer forms a part of the transfer film, forms the surface in contact with the transfer paper, seals the printed area of the transfer paper during transfer, prevents scumming, and prevents the ink layer from being covered. It has the function of improving adhesion to transfer paper.

When a heat-sensitive material is used for the base film 1, it is preferable to provide a heat-resistant slipping layer (not shown) on the surface in contact with the thermal head to prevent sticking of the thermal head. The basic components of the heat-resistant slipping layer are a heat-resistant resin and a substance that functions as a heat release agent or a lubricant.

By providing such a heat-resistant slipping layer, sticking will not occur even in thermal transfer sheets based on heat-sensitive plastic films (thermal printing is possible, Benefits such as ease of use can be taken advantage of.

Thermal transfer images generally have glossy and beautiful prints, but the documents may become difficult to read, so matte prints are sometimes desirable. In such a case, for example, as proposed by the applicant (Japanese Patent Application No. 58-208306), an inorganic pigment such as silica, calcium carbonate, etc. is dispersed in a suitable solvent on a base film. It is preferable to form a heat-melting ink layer on top of a matte layer by coating to form a thermal transfer sheet. Alternatively, the base film itself may be matted and used (this is also the technique of Japanese Patent Application No. 1983-208307 proposed by the applicant).

(Effects) According to the present invention as described above, most of the ink layer is black, at least a part is chromatic, the barcode is printed in the black part, and the barcode label is attached to the chromatic part. By printing marks that indicate the contents of the goods,
Even if the article to which a barcode label is attached is packaged, the contents of the article can be easily identified with the naked eye.

Note that the thermal transfer sheet of the present invention is not limited to printing on the above-mentioned barcode labels, but also allows for easy-to-read character printing by printing headings and the like in chromatic ink areas in general character printing.

(Example) Next, the present invention will be described in more detail with reference to Examples. In the text, parts or percentages are based on weight unless otherwise specified.

Example 1 A polyethylene terephthalate film with a thickness of 3.5 μm was used as a base film, and red ink with the following composition was applied on one side of the base film using a gravure printing method at a coating amount of 3.5 g/d for 3 strips with a width of 2 cm. After coating, using a gravure roll as shown in Figure 4, three coats of black ink having the following composition were applied and cooled at a rate of 3.5 g/rrr using a gravure printing method, and this was further divided into three sections. The sheet was cut and wound into a roll to obtain a thermal transfer sheet of the present invention as shown in the first figure.

Red Enoma eyebrow red pigment 15 parts ethylene/
Vinyl acetate copolymer (EVA Flex 310, manufactured by Mitsui Polychemicals) 8 parts paraffin wax (Paraffin 150F, manufactured by Hiki Seiro)
50 parts carnauba wax 25 parts Ouo Kaorunoma 1 Carbon black, (Diablack G, manufactured by Mitsubishi Kasei)
15 parts ethylene/vinyl acetate copolymer (EVA Flex 310, manufactured by Mitsui Polychemicals) 8 parts paraffin wax (paraffin 1
50F, made by Nippon Seiro) 50
25 parts carnauba wax Next, using the above thermal transfer sheet, a barcode label was used as the transfer paper, and a barcode and a red mark were printed using a commercially available barcode printer.

Example 2 A barcode with a green mark was printed on a barcode label in the same manner as in Example 1 except that green ink was used as the chromatic ink in Example 1.

The barcode labels of the above two examples were attached to packages that had the same appearance but different contents.

The different contents of these packages can be easily identified with the naked eye even from a distance.

[Brief explanation of drawings]

FIGS. 1 to 3 are diagrams illustrating a part of the thermal transfer sheet of the present invention, and FIG. 4 is a diagram illustrating the production of those thermal transfer sheets. Two base films: Gravure roll: doctor: recess 2: ink layer 4: ink tank 6; impression cylinder 8: non-image area

Claims (1)

[Claims] (1) A thermal transfer sheet having a heat-fusible ink layer formed on one side of a base film, characterized in that most of the ink layer is black and a portion is chromatic.