JPS6228287A - Thermal transfer recording medium - Google Patents

Abstract

PURPOSE:To form a reflectographic black image, by providing an ink layer comprising a dye or pigment which absorbs electromagnetic waves in the visible region but does not absorb electromagnetic waves in the infrared region, on a base. CONSTITUTION:A coloring agent consisting of a dye or pigment which absorbs electromagnetic waves in the visible region but does not absorb electromagnetic waves in the infrared region and a binder which is softened or melted when being heated are mixed with each other to prepare an ink composition. The composition is melted by heating, and the resultant hot melt is applied to the base to provide the ink layer, thereby obtaining the thermal transfer recording medium. The amount of the coloring agent is preferably 2-20% based on the weight of the ink layer, from the viewpoints of color density, quality or the like of the images recorded. The binder is, for example, a low molecular weight polystyrene, and the amount thereof is preferably 1-15% based on the amount of the ink layer.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a thermal transfer recording medium suitable for reflection printing.

PRIOR TECHNOLOGY Thermal transfer recording media are heat-melting recording media whose main components are a coloring agent consisting of various dyes and/or pigments, and a binder that can be softened or melted by heat application, on a transparent or opaque support such as paper or plastic film. One provided with an ink layer is known. When obtaining recorded matter using this type of recording medium, the recording paper is placed on the ink layer surface of the recording medium, and a thermal head is applied from the recording paper side to infrared rays or electromagnetic waves containing infrared rays (in the case of infrared rays or electromagnetic waves, as a support). This is done by heating the ink layer in an image-like manner using a transparent or semi-transparent material (such as transparent or semi-transparent material) and melting and transferring the ink layer in that area onto the recording paper. However, even when reflective printing is performed using such a thermal transfer recording medium, it is difficult to obtain a substantially black image. This is because the colorant used in the ink layer lacks optical suitability for reflective printing.This optical suitability means that it absorbs electromagnetic waves in the visible range, but absorbs electromagnetic waves in the infrared range. It has a property that it does not absorb substantially. Therefore, for example, carbon blank, which is the most common coloring agent, absorbs electromagnetic waves not only in the entire visible range but also in the infrared range, making it unsuitable for reflective printing.

Object The object of the present invention is to provide a thermal transfer recording medium that can form a reflective black image by a simple method.

Structure The thermal transfer recording medium of the present invention has a heat-melting ink layer on a transparent or translucent support, the main components of which are a coloring agent consisting of a dye and/or a pigment, and a binder that can be softened or melted by heat application. The provided thermal transfer recording medium is characterized in that colorants are used in combination so that they absorb electromagnetic waves in the visible range but do not substantially absorb electromagnetic waves in the infrared range.

First, the reflection printing method using the thermal transfer recording medium of the present invention will be explained. In FIG. 1, a transparent intermediate transfer sheet 4 is placed on the ink layer 3 surface of the recording medium 1 of the present invention, in which the heat-melt ink layer 3 as described above is provided on a transparent or translucent support 2. An original 58 containing an infrared absorbing image 6 such as carbon black is densely packed on the support 2 side, and when infrared rays (or electromagnetic waves including infrared rays such as a flash from a xenon lamp) hrf are irradiated from the intermediate transfer sheet 4 side, The infrared rays pass through the intermediate transfer sheet 4, the ink layer 3, and the support 2 in this order,
Picture 11 of manuscript 5! It reaches part 6 and is absorbed [Fig. 1 (a)
]. The image area 6 generates heat from this K, and this heat is transmitted to the ink layer 3 via the support 2, so that the ink 7 in that area
13 is melted and transferred to the transfer sheet 4 [Fig. 1(b)
)].

Since the transferred image 7 thus formed on the intermediate transfer sheet 4 is a mirror image of the image 6 of the original 5, next, the recording paper 8 is brought into close contact with the transferred image 7 surface of the intermediate transfer sheet 4, and a pair of pressures are applied, for example. When the intermediate transfer sheet 4 is passed between the heat rollers 9 and heated again from the side of the intermediate transfer sheet 4 (FIG. 1(C)), the transferred image 7 on the intermediate transfer sheet 4 is bath-melted and transferred to the recording paper 8, and the original 5 is A recorded material having a transferred image 108 which is a normal image with respect to image 6 is obtained [FIG. 1(d)].

Next, materials used in the thermal transfer recording medium of the present invention will be explained.

The coloring agent used in the hot-melt ink layer absorbs electromagnetic waves in the visible range, but does not substantially absorb electromagnetic waves in the infrared range.
4 types or less) are used in combination. Black for single system,
In addition, in the case of two or more colors, red and blue or green,
Although combinations of yellow, red, blue, etc. are used, the present invention is not limited to these combinations. A specific example of a black dye is Sumikalon Diazo Black 5.
G.

Examples of pigments include Mikutacel Black 50H (azo dye), Direct Fast Black (direct dye), and Nigrosine BX%E as pigments.

Specific examples of blue dyes include Kayalon Polyol Brilliant Blue N-BGM (anthraquinone dye), Kayalon Polyol Brilliant Blue BM, Kayalon Polyol Dark Blue 28M (the above are direct pigments), Kayalon Milling Cyanine 5R (acidic Examples of pigments include Victoria Blue Lake, metal-free phthalocyanine, phthalocyanine, and Fast Sky Blue. Specific examples of green dyes include Direct Dark Green B (direct dye) and Eisen Malachite IJ+N (basic dye). Specific examples of red dyes include Rhodamine B10-Damine 6G, Rose Bengal B1 Acid Red R8, Eosin G, Sumikaron Iolet R81 Dianix Fast Violet 3R-vs (the above are anthraquinone dyes), and pigments include Permanent Red 4R1 Brilliant. Fast Scarlet, Brilliant Carmine B8. Permanent Carmine FB, Resolled, No. 7-Manentred F5, Brilliant Carmine 6B1, Pigment Scarlet 3B1, Rhodamine Lake B1, Rhodamine Lake T, Alizarin Lake, Fast Red, Preito Red G Toner, Lionol Red CP-A, etc. . Specific examples of yellow-based dyes include Naratru Yellow S1 Quinoline Yellow Extra Conc, Fast Light Yellow G1 Sunset Yellow, and pigments include Chrome Yellow (yellow), Zinc Yellow Zinc Chromate (zinc amount), and Lemon Yellow (barium chromate). ), Cadmium Yellow, Naphthol Yellow B1 Hansa Yellow 5G, Hansa Yellow 3C, Hansa Yellow G1 Hansa Yellow A, Hansa Yellow'fLN1 Hansa Yellow 81 Benzidine Yellow, Benzidine Yellow G1
Benzidine Yellow GR, Permanent Yellow N0G
1 quinoline yellow lake, fast yellow, etc.

Among the beak coloring agents described above, pigments are preferred in the present invention from the viewpoints of light resistance, color migration properties, dissolution resistance, and the like. In any case, the amount of dyes and/or pigments to be used is suitably 2 to 20%, preferably 5 to 15%, based on the weight of the ink layer, from the viewpoint of color density, quality, etc. of the recorded image.

Next, the binder will be explained. This binder consists of a resin and/or wax that can be softened or melted by applying heat. Here, the application of heat means heat generated in the ink layer by infrared irradiation, that is, heat of the original image generated by infrared irradiation or heat transferred to the ink layer through the support. This heat transfer temperature is about 50 to 120°C. Specific examples of such binders include low molecular weight IT polystyrene, xylene resin, rosin or its conductor, petroleum resin, polycabrolactone, polyamide, polyvinyl acetate,
Five examples include polyester, ethylene-vinyl acetate copolymer, vinyl chloride-vinyl acetate copolymer, styrene-butadiene copolymer, and polyhynylidene chloride. The amount used is approximately 1 to 15 inches, preferably 10 inches or less of the weight of the ink layer.

On the other hand, waxes include carnauna wax, oculie wax, microcrystalline wax, paraffin wax, ceresin wax, montan wax, candelilla wax, rice wax, shellac wax, chuhaku wax, soum wax, beeswax, low molecular weight polyethylene, Examples include polyvinyl stearate. The appropriate amount to be used is 40 to sob, preferably 60% or more of the weight of the ink layer.

In addition to the above ingredients, the heat-melting ink layer may contain mineral oil, animal oil (e.g. whale oil), vegetable oil (
For example, additives such as rapeseed oil, liquid paraffin, silicone oil, and lecithin may be added.

As the heat-resistant support, transparent or translucent sheets such as polyester film, polypropylene film, polyimide film, polycarbonate film, glassine paper, condenser paper, etc. are used. 1su, saha 3~2
An I bank of about 0μ is appropriate.

To produce the thermal transfer recording medium of the present invention, an ink composition containing a colorant and a binder as main components is heated and melted, and this hot melt is applied onto a support; alternatively, the composition is dissolved in a suitable solvent or The ink layer may be dispersed, and the solution or dispersion may be applied onto a support and dried to form a heat-melting ink layer.

The present invention will be explained below using eight embodiments.

Examples 1-2 The following components were mixed and I# melted and dispersed to obtain an ink composition.

Example 1 (Part) Example 2 @ Seiryoku Fast Yellow 2200M ao λ
5 (Dainichiseikasha Rip) Lionor Red C! P-A - (manufactured by Toyo Ink Co., Ltd.) Brilliant Carmine 6B-E 50 7.5
(Same as above) Lionor Blue KU ao a.

(Same as above) Carnano wax 1&0 2&0 Paraffin wax 3a0 4&0 (mp,
Approximately 6a5℃] Petroleum resin 20.0 - Pinyl chloride ~ vinyl acetate copolymer 10.8 10.0
Combined (vinyl acetate 12% by weight) lecithin zo z.

Next, each ink composition was true-melt coated on a 6P thick polyester film to form an ink layer about 3.5 inches thick.

The absorption spectrum of the thermal transfer recording medium of Example 1 obtained as described above is shown in FIG. As is clear from this figure, the color of the ink layer is either black or in the infrared region, i.e. 80
It can be seen that it does not absorb all electromagnetic waves of 0 nm or more.

Next, a 40μ thick polypropylene film was used as an intermediate transfer sheet, and images formed of the intermediate transfer sheet and carbon black were formed on the ink layer and support surface of the thermal transfer recording medium of each example as shown in FIG. The document image is transferred onto the transfer sheet by placing a document in close contact with the transfer sheet, irradiating xenon flash from the transfer sheet side through a glass filter that cuts light of 800 nm or less, and then peeling off the transfer sheet at an acute angle to the recording medium. On the other hand, a mirror-image transfer image was formed. Next, a recording sheet made of plain paper was brought into close contact with the image surface of this intermediate transfer sheet, and passed between a pair of pressure and heat rollers maintained at a surface temperature of 120°C and a roller linear pressure of 5/6I#. A normal image of the original image was formed on the recording paper. The performance of the recorded material is as follows.

*1: Based on MacPeth RD-914.

*2: Visual judgment effect As described above, the thermal transfer recording medium of the present invention absorbs all electromagnetic waves in the visible range, but substantially absorbs no electromagnetic waves in the infrared range. Since these materials are used alone or in combination of two or more, image formation by reflection printing is possible with a simple method.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the reflection printing method using the thermal transfer recording medium of the present invention, and FIG. 2 shows the absorption spectrum of the ink layer of the thermal transfer recording medium prepared in Example 1. l...Thermal transfer recording medium of the present invention having a hot-melting Hjk ink layer 3 provided on the support 2...Intermediate transfer sheet 5...Document 7 having an infrared absorbing image 6...Mirror image Transfer image 8...Recording paper 9...Pressure heat roller 10...Transfer image of normal image hr...Infrared or electromagnetic waves including infrared method Patent applicant Ricoh Co., Ltd. - 6, Amendment Amendment of Contents and Procedures, Original September 30, 1985 1, Indication of Case, 1985 Patent Application No. 167821 2, Name of Invention Thermal Transfer Recording Medium 3, Person Making Amendment Relationship with Case Patent Applicant: Ota, Tokyo Ricoh Co., Ltd. Representative Hama 1-3-6 Nakamagome 1-3-6 (674) 1) Hiro 4, Agent 5, "Subject of amendment" is corrected to "Auricuri Wax." (2) Correct the 6th line from the bottom of page 1O as follows. "Lionol Red Cr'-A-2,5J (3)
The fourth line from the bottom of page 10 is corrected as follows. “Brilliant Carmine 6 B-E 5.0 5.
0J(4) Replace Figure 2 with the attached drawing. 7. List of attached documents (1) Corrected drawings (Fig. 2) 1 copy

Claims (1)

[Claims] 1. A thermal transfer recording medium in which a heat-melting ink layer whose main components are a colorant made of a dye and/or a pigment and a binder that can be softened or melted by heat application is provided on a transparent or translucent support, A thermal transfer recording medium characterized in that a coloring agent is used alone or in combination of two or more kinds so as to absorb electromagnetic waves in the visible range but not substantially absorb electromagnetic waves in the infrared range.