JPH0334894A - Thermal transfer material - Google Patents

Abstract

PURPOSE:To obtain a thermal transfer material giving a recording body capable of being detected by a near infrared ray absorbing detector by successively providing a layer containing a near infrared absorber other than carbon black and a layer containing a colorant other than carbon black to a base material. CONSTITUTION:A thermal transfer material is obtained by forming a heat-meltable ink layer to a base material and the heat-meltable ink layer is formed by successively providing a layer containing a near infrared absorber other than carbon black and a color layer containing a colorant other than carbon black. When recording is performed using this transfer material by a thermal head, a character or figure can be obtained as a recording body having sufficient resolving power. The recording body can be detected by a usual near infrared ray absorbing detector and is effective in the collation of the manufacturing lot number or product number applied to various products for the sake of product control and, since an arbitrary colorant can be used in the heat-meltable ink layer, the recording body of a character or mark made easy in visual discrimination and having a beautiful high-grade character or mark matched with a product image can be obtained. As the near infrared absorber, one absorbing an electromagnetic wave having a wavelength of 690-1000nm, for example, a dithiol metal complex, an anthraquinone dye or a cyanine dye can be designated.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a color thermal transfer material having a layer containing a near-infrared absorber that selectively absorbs specific near-infrared rays. The present invention relates to a thermal transfer material that provides a bar code, etc. that is easy to identify, has a beautiful appearance, and has a luxurious feel.

(Conventional technology) Conventionally, barcodes have been attached to products in order to streamline product management in factory automation and POS distribution, but most of the color materials outside the blackboard are detected by barcode readers. Since it does not have sufficient absorption in the wavelength range, the selection range of one color is limited. Therefore, it is not possible to add a barcode with an arbitrary color tone that matches the product image, which detracts from the beauty of the product. Furthermore, it becomes extremely difficult for two people to even perform simple identification of the product.

JP-A-64-30788 proposes a method of adding a near-infrared absorbent other than carbon black to the fully melted 11-in-1 layer. There was a drawback that the effect of infrared absorption was not sufficiently exhibited. Furthermore, the surface of the transfer material obtained by thermal transfer recording using a heat-melting ink layer simply provided on the surface of a heat-melting film peels off at the interface between the smooth heat-melting ink and the heat-melting ink. This results in a highly smooth and glossy surface. However, a glossy surface is generally difficult to read depending on the angle, and a matte printing surface is desired.

(Problem to be Solved by the Invention) As a result of intensive testing and testing of methods for creating barcodes in colors other than black, the present inventors have developed a thermal transfer material for color barcodes that has excellent appearance and light resistance and facilitates visual identification. It provides:

[Structure of the invention]

(Means for Solving the Problems) In other words, the present invention provides a heat-sensitive transfer material in which a heat-fusible ink layer is formed on a base material, wherein the heat-fusible ink layer is a layer containing a near-infrared absorber other than carbon black. This relates to a thermal transfer material in which colored layers containing colorants other than carbon black are sequentially provided, and when this transfer material is used to record with a thermal head, it is possible to record arbitrary characters, figures, etc. with sufficient resolution. It can be obtained as an object. The above-mentioned recorded matter can be detected by a normal near-infrared absorption detection device, and is not only effective for checking the manufacturing number and product number given to various products for product management, but also Since any hue can be used for the ink layer, it is possible to make visual identification easy and to obtain a record of beautiful and luxurious characters and symbols that match the image of the product. The coloring materials that can be used in the heat-melting ink layer are red, green, blue, yellow, crimson, and indigo dyes and pigments.

These include pastel/white/var pigments, fluorescent dyes, gold/silver metal powders, etc., and are not particularly limited.

The near infrared rays of the present invention are usually 690 to 2500 nrn.
It refers to electromagnetic waves in the range of 690 to 1 for one ray and one lid.
It is preferable to use near-infrared rays having a dominant wavelength of 1000 nm.

As the near-infrared absorber according to the present invention, conventionally known wavelength 6
Examples of materials that absorb electromagnetic waves in the range of 90 to 11,000 nm include compounds of the chemical structural formulas shown in Table 1, dithiol metal complexes, anthraquinones, mercaptonaphthol metal complexes, naphthoquinones, and cyanine dyes.

However, depending on the application, near-infrared absorbers with different wavelengths are used, so it is preferable to use one type or two or more types of near-infrared absorbers.

Table 1 Near-infrared absorber and absorption wavelength When a recorded matter made of a heat-sensitive transfer material containing a near-infrared absorber is exposed to sunlight, it deteriorates due to the effect of ultraviolet rays, making it impossible to obtain sufficient effects. In order to prevent these things, a layer containing an ultraviolet absorber can be provided between the base material and the layer containing a near-infrared absorber. The ultraviolet absorber of the present invention has 290
It has the effect of absorbing harmful ultraviolet rays of up to 400 nm, and examples thereof include the compounds shown in Table 2.

Table 2 Ultraviolet absorber In addition, the present invention has a heat-melting ink layer in which a layer containing an ultraviolet absorber and a layer 1 containing a near-infrared absorber other than carbon black are sequentially provided on a base material. In the heat-sensitive transfer material formed by forming, a layer that causes cohesive failure during thermal transfer may be provided between the base material and the heat-melting ink layer,
The transferred printed matter becomes the above-mentioned heat-sensitive transfer material having a matte effect. Note that the layer that causes cohesive failure usually does not contain a coloring material.

According to the present invention, the matting effect is achieved by cohesive failure of a cohesive failure layer containing a specific compound when the ink layer is transferred and peeled off,
This is due to the unevenness of the fractured surface.

Examples of compounds contained in the cohesive failure layer include higher fatty acid amides and derivatives thereof. The cohesive failure layer is disclosed in the specification of Japanese Patent Application No. 62-60215.

In order to provide the near-infrared absorbing layer, heat-fusible ink layer, ultraviolet absorbing layer, and cohesive failure layer of the present invention on a substrate, a hot melt coating method or more preferably a coating solution in which the above compound is dispersed in a medium is used. There is a method of solvent coating. The appropriate coating amount is 0.1 μm to 3 μm. If it is less than 0.1 μm, the effect of each layer will be reduced, and if it is more than 3 μm, the total coating thickness will increase, and when the transfer material is wound into a roll, it will become thick and the energy sensitivity will decrease.

A conventionally known base film can be used as the support of the present invention. For example, polyester film (polyethylene terephthalate, polyethylene naphthalate, etc.)
, polyamide films (such as nylon), polyolefin films (such as polypropylene), and cellulose films (such as triacetate).

There are polycarbonate films, etc. Polyester film is the most preferred because it has excellent heat resistance, mechanical strength, tensile strength, and tensile stability. The thinner the base material is, the better its thermal conductivity is, but from the viewpoint of strength and ease of coating with the ink layer, it is most preferably 3 to 50 microns. Furthermore, a back coat layer made of a heat-resistant resin may be provided on the opposite side of the heat-melting ink layer of the base material.

The heat-fusible ink layer of the present invention can be used without any conventional &lI component. Examples include those made of wax and thermoplastic resins and colored with the above-mentioned dyes and pigments. As Wasokus,
Plant-based wasos such as Candelilla wasox, Karnaha wasox, rice swax, wood wax, jojoba oil, animal-based wasos such as beeswax, lanolin, spermaceti, and synthetic petroleum waxes such as Montane wasx and petrolatum. Synthetic hydrocarbons such as Schwasox 2 polyethylene wax, modified waxes such as Monkwansox derivatives. Hydrogenated waxes such as hydrogenated castor oil and hydrogenated castor oil derivatives; fatty acids such as lauric acid, paltanic acid, stearic acid, stearic acid, and 12-hydroxystearic acid; waxes such as fatty acid amides, fatty acid anilides, and imido waxes; and resins. Preferred examples include acrylic, styrene, rosin, vinyl, acetal, and rubber.

If necessary, a small amount of plasticizer 1 is added to the above hot-melt ink.
Additives such as dispersants, activators, antistatic agents, stabilizers, etc. can be mixed.

(Example) Hereinafter, the present invention will be explained in detail with reference to Examples.

All parts in the examples represent "parts by weight."

Example 1 A near-infrared absorbing ink was obtained by thoroughly dispersing the following Mikai coating liquid in an attritor at room temperature. 6μ of the obtained ink
The film was coated to a thickness of 1.6 μm by gravure coating on a polyethylene terephthalate film.

Add 1 part of ethylene-vinyl acetate copolymer to Ehafrenox manufactured by Mii Polychemical ■ Carnaubawasox (
(manufactured by Noda Wasokuen) 19 parts near-infrared absorber 5C
101756 (manufactured by ICI) 0.2 part toluene
50 parts Methyl isobutyl ketone 29.8 parts Furthermore, average particle size Q, 5 m
A premixed composition below was charged into a 5 lsotorre sand bottle filled with 60% by volume of m glass beads at a speed of 2 lsotorre/min using a gear pump, and the sand bottle was rotated at a speed of 10 m/s. The kneading process was repeated 10 times to obtain a hot-melt ink. Next, -L of the near-infrared absorbing layer
Then, the film was applied to a coating thickness of 5 μm using a gravure coating method to obtain a heat-sensitive transfer material.

Rice wasox (LP-200 manufactured by Noda Wasox) 2
0 parts water-based acrylic resin 8 parts (
Ocryl AP 2 manufactured by Toyo Ink Manufacturing ■ Solid content 27
%) water
40 parts ethanol 2
9 parts Purpurin 4B 3 parts (
Cl Direct Lesotho manufactured by Nippon Kayaku ■ 2) Using the obtained thermal transfer material, a barcode was printed on a smooth recording paper of 100 seconds at ℃ using a Harcode Rahel printer and scanned with a barcode reader with a reading wavelength of 780 nm. It was possible to read it.

In addition, the reflectance at CC780n was measured using a JV-365 spectrophotometer manufactured by Konsei Seisakusho, and the result was 36%.
Met.

Example 2 A heat-sensitive transfer material was prepared using the ink for forming a near-infrared absorbing layer described in F, and the same heat-melting ink and main phase as in Example 1.
Barcode) When the printed material was scanned with a barcode reader with a reading wavelength of 7,800 m, it was possible to read it.

Further, the fouling rate at 780 nm was 75%.

Ethylene-vinyl acetate copolymer 1 part Luna Hawasox 19 parts Near-infrared absorber SIR-1280, 2 parts (manufactured by Mitsui Toatsu Kagakuen) Toluene 50 parts Methyl isobutyl ketone 29.8 parts Example 3 Coating with the following composition The liquid was thoroughly kneaded using three rolls heated to 90 to 120°C to obtain a hot-melt ink.

A near-infrared absorbing layer similar to that in Example 1 was formed on a base material, and then the above heat-melting ink was applied to a thickness of 5 μm using a roll coating method.
A heat-sensitive transfer material was obtained.

Fluorescent pigment pink 20 parts ()
"Evocolor FP-10 manufactured by Hon Shokubai Kagaku Kogyo ■) Ethylene-vinyl acetate copolymer 5 parts Carnauba wax 16 parts Paraffin wax 59 parts When the bar code print was scanned with a bar code reader with a wavelength of 780 nm, it was readable. Ta. Further, the reflectance at 780 nm was measured and found to be 37%.

Example 4 A coating liquid with the following composition was sufficiently dispersed at room temperature using a Dyno gol.
A heat-fusible layer forming ink was obtained. 6 tons of the obtained ink
It was coated on a polyethylene/ntrephthalate film of TM by gravure coating to a coating thickness of 1 μm.

Ethylene-vinyl acetate copolymer 1 part Carnapawasox 19 parts toluene
56 parts Methyl isobutyl ketone 24 parts On top of this, near-infrared absorbing ink similar to Example 2 was applied using a gravure coating method to a thickness of 1.
It was applied to a thickness of 6 μm.

Next, a coating liquid with the following composition was sufficiently dispersed in a dyno tank at room temperature to obtain an ink for forming a colored resin layer. 1μm
It was applied to.

Barb') 74 B 1
(l fil! Styrene acrylic resin
20 parts (MH7025 manufactured by Fujikura Chemical Co., Ltd.) Toluene 50 parts Methyl ethyl ketone 20 parts Furthermore, the coating liquid of F-Kumii was dissolved in a disper to obtain an ink for forming an adhesive resin layer, and the obtained ink was used to form a colored resin layer. A gravure coater was applied to the second layer to a thickness of 0.3 μm using a method to obtain a heat-sensitive transfer material.

Boria 5 resin 10 parts (DPX-640 manufactured by Henkel Jisui) Isobu I Copyl alcohol 90 parts When the barcode print was read and scanned with a barcode reader with a wavelength of 780nm, it was readable and 780nm.
The reflectance at nm was 34%.

Example 5 A coating liquid having the following composition was sufficiently dispersed in an attritor at room temperature to obtain an ultraviolet absorbing ink. Obtained ink: 6 knots
It was coated onto a polyethylene terephthalate film of 1 µm in thickness by gravure coating.

Ethylene-vinyl acetate copolymer 1 part Lunaba Vasox 19 parts Ultraviolet absorber 0.5 part (Japan Chiha Geigy TINUνIN 900) Toluene
50 parts methyl isobutyl ketone
295 parts Example 1
A heat-sensitive transfer material is made by sequentially applying the same near-infrared absorbing ink and heat-melting ink using the gravure coating method, and when the printed matter is scanned with a Harcoat-Rider with a wavelength of 780 nm, it can be read. and 78
The reflectance at 0 nm was 37%.

Furthermore, as a result of examining the light resistance by exposing it to sunlight for three days under clear skies, the absorption rate at 780 nm decreased by about 10%. In addition, as a result of a similar test for Example 1 which does not contain an ultraviolet absorbing layer, the absorption rate at 780 nm was approximately 30.
%, it was confirmed that the light resistance was improved by providing the ultraviolet absorbing layer.

Example 6 A coating liquid with the following composition was dispersed and mixed in an attritor at room temperature,
An ink for forming a cohesive failure layer was obtained. 6μ of the obtained ink
It was coated onto a polyethylene terephthalate film of 1 µm in thickness by gravure coating.

Lithium stearate (melting point 216°C) 1 part Carnapawanox 19 parts Ehaflexox 420 1 part Toluene
79 parts A heat-sensitive transfer material was prepared by sequentially applying the same ultraviolet absorbing ink, near-infrared absorbing ink, and heat-melting ink as in Example 5 on the above cohesive failure layer using a gravure coating method, and a barcode was printed using a barcode label printer. When printed, a matte barcode print was obtained and could be read with a barcode reader with a reading wavelength of 780 nm.

Comparative Example 1 The heat-fusible ink layer of Example 1 was coated by gravure coating.
Coated on μm polyethylene terephthalate film
-5 μm coating. When evaluated using the same method as in Example 1, the reflectance at 780 nm was 97% without being readable.
Met.

Comparative Example 2 The heat-fusible ink layer of Example 3 was coated with a thickness of 6μ by roll coating.
Coating thickness: 5 m on polyethylene terephthalate film
It was applied to μm. When evaluated in the same manner as in Example 1, it could not be read by a barcode reader with a reading wavelength of 780 nm, and the reflectance at 780 nm was 98%.

(Operations and Effects of the Invention) The present invention provides a layer containing a near-infrared absorbing agent other than carbon black and a colored layer containing a coloring agent other than carbon black on a base material, so that the recorded material absorbs near-infrared rays. Provided is a thermal transfer material that can be detected by a detection device. The most significant feature of the present invention is that any coloring material can be used in the hot-melt ink layer.

The point is that you can get barcodes of any color outside the blackboard.

By using the heat-sensitive transfer material of the present invention, it is possible to obtain recorded materials of characters and symbols that are easy to visually identify and have a beautiful and high-class appearance that matches the image of the product. Further, by providing a layer containing an ultraviolet absorber between the base material and the near-infrared absorbing layer, deterioration of the near-infrared absorber due to ultraviolet rays can be suppressed. Furthermore, if necessary, a layer that causes cohesive failure during thermal transfer may be provided between the base material and the near-infrared absorbing layer or the ultraviolet absorbing layer.

A recorded matter having a matte effect can be obtained.

Claims (1)

[Scope of Claims] 1. In a heat-sensitive transfer material formed by forming a heat-fusible ink layer on a base material, the heat-fusible ink layer includes a layer containing a near-infrared absorbent other than carbon black and a color other than carbon black. A heat-sensitive transfer material characterized by sequentially providing colored layers containing an agent. 2. The thermal transfer material according to claim 1, wherein the near-infrared absorbent has a maximum absorption wavelength in the range of 690 to 1000 nm. 3. The thermal transfer material according to claim 1 or 2, characterized in that a layer containing an ultraviolet absorber is provided between the base material and the layer containing a near-infrared absorber. 4. Claims 1 to 3 characterized in that a layer that causes cohesive failure during thermal transfer is provided between the base material and the layer containing the ultraviolet absorber or the layer containing the near-infrared absorber.
Thermal transfer material described. 5. The heat-sensitive transfer material according to any one of claims 1 to 4, further comprising a heat-resistant protective layer formed on the opposite surface of the base material to the heat-melting ink layer.