JPS62164588A - Transfer medium and its preparation - Google Patents

Abstract

PURPOSE:To enable high quality printing with high resolving power, by providing a light reflecting layer removable by discharge destruction recording on one surface of a light pervious support and successively providing a solid wax layer containing a specific substance, a support and a thermal transfer layer on the other surface thereof. CONSTITUTION:A discharge breakdown recording sheet is formed by providing a light reflecting layer 8 removable by discharge destruction recording on a light pervious support 9. Separately, a thermal transfer sheet is formed by providing a thermal transfer layer 12 to one surface of a support 11 and a transfer medium is formed by adhering and fixing both supports 9, 11 by a solid wax layer 10 containing a photothermal converting substance and a thermally decomposable foaming agent. Various waves with m.p. of about 60 deg. are suitably used in the solid wax layer 10 and, as the photothermal converting substance, a material absorbing infrared flash light emitted from a xenon lamp to convert the same to heat such as carbon or graphite is used.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a transfer medium suitable for printing high-resolution characters or images, and a method for manufacturing the same.

2. Description of the Related Art In recent years, with the development of office automation, various terminals have been required. Among them, there is a great demand for recording devices that convert electrical signals into visible images, so-called printers, but there are few that are satisfactory in terms of performance (for example, inkjet, There are electrophotographic methods, thermal transfer methods, etc., but since they use liquid or powder such as toner, maintenance and operability of the equipment are complicated, and because they use a thermal head, the head life is short and the printing speed is slow. There was a problem.

Therefore, a discharge transfer method is known as a method for obtaining characters or images with relatively high resolution at high speed.

For example, it is shown in Japanese Patent Publication No. 45-19819. Examples include the thermographic copying method and the transfer medium disclosed in Japanese Patent Publication No. 57-22030.

The conventional discharge transfer method will be explained below with reference to the drawings. Second
The figure is a cross-sectional view of a transfer medium, 1 is a support, 2 is a light reflection layer, and 3 is a thermal transfer layer. FIGS. 3 to 5 are diagrams showing a printing process using the transfer medium. , 4 is receiving paper, 5
is a xenon lamp.

6 indicates a flash; the printing process involved removing the light reflective layer 2 according to the information pattern by means of well-known discharge breakdown recording as shown in FIG. 3. Next, a thermal transfer layer 3 was applied as shown in FIG. 4. When the surface and the image receiving paper 4 are brought into close contact with each other and a flash 6 containing infrared rays is irradiated by a xenon lamp 5, the flash rays irradiated onto the areas where the light reflection layer 2 remains are reflected and irradiated onto the areas where the light reflection layer 2 has been removed. The generated flash light passes through the support I, is absorbed by the thermal transfer layer 3, and is converted into heat. This heat heats the heat-melting ink in the thermal transfer layer, and the ink is transferred and fixed onto the image-receiving paper 4 in close contact with the ink. Thereafter, by separating the image receiving paper from the transfer medium, the printed matter shown in FIG. 5 is obtained. When performing color transfer, a transfer medium provided with a photothermal conversion layer 7 as shown in FIG. 6 is required, and color transfer can be performed using the same steps as in the case of black and white.

Problems to be Solved by the Invention However, with the above configuration, the transfer medium becomes a multilayered sheet and the sheet thickness increases, which increases the "stiffness" of the sheet and makes it difficult to bring the transfer medium and image receiving paper into close contact. It becomes difficult. As a result, the quality after transfer is greatly influenced by the surface smoothness of the image receiving paper and the state of close contact between the image receiving paper and the transfer medium. In other words, only the parts of the thermal transfer layer where the transfer medium and the image receiving paper are securely in contact are transferred to the image receiving paper, so in order to obtain high quality characters and images, the surface smoothness of the image receiving paper must be high. Moreover, in order to improve the adhesion between the image receiving paper and the transfer medium, it was necessary to increase the adhesion pressure. Therefore, it is necessary to use high-quality paper with high smoothness as the image receiving paper.
In addition, in order to increase the contact pressure during transfer, the recording device becomes large-scale, leading to an increase in device cost and a decrease in transfer speed. The purpose is to provide a transfer medium that can produce high-resolution characters and images at high speed.

Means for Solving the Problems In order to solve the above-mentioned problems, the transfer medium of the present invention has a light-reflecting layer removable by discharge destruction recording on a light-transmitting support I, and a photothermal conversion layer on the other surface. It has a structure in which a solid wax layer containing a substance and a thermally decomposable blowing agent, a support II, and a thermal transfer layer are provided in this order.

Furthermore, if necessary, a roughening layer containing silica, alumina, etc. is provided between the light-transmitting support (1) and the light-reflecting layer. Furthermore, the method for producing a transfer medium of the present invention includes a discharge breakdown recording sheet in which a light reflective layer removable by discharge breakdown recording is provided on a light-transmissive support (1), and a thermal transfer layer is provided on one surface of the support (II). The thermal transfer sheet is characterized by being adhesively fixed with a solid wax containing a photothermal conversion substance and a thermally decomposable foaming agent so that the supports of the thermal transfer sheet are in close contact with each other.

Function The present invention uses a transfer medium having the above-mentioned structure, removes the light reflection layer in a desired pattern by discharge destruction recording, and prints characters and images on image-receiving paper by irradiating flash light containing infrared rays from a xenon lamp or the like. It is something to do. When irradiated with flash light, the flash light passes through the area where the light reflective layer has been removed and is absorbed by the photothermal conversion material in the solid wax layer directly below the desired pattern, converting the flash light into heat, and the thermal transfer layer is heated by the heat conduction. The hot melt ink is melted and transferred to the image receiving paper. At this time, the solid wax that adhesively fixed the discharge breakdown recording sheet of Support I and the thermal transfer sheet of Support II melted, and the fixed portion of the thermal transfer sheet separated from the discharge breakdown recording sheet.
Only the thermal transfer sheet becomes more likely to adhere to the surface of the image receiving paper. Furthermore, the temperature of the thermally decomposable foaming agent contained in the solid wax layer rises above the foaming start temperature due to the action of the photothermal conversion substance, generating a large amount of thermal decomposition gas, which strongly pushes the thermal transfer sheet against the image receiving paper. Therefore, high-resolution characters and images can be obtained with small contact pressure even on receiving paper with low smoothness. As a result, the size of the recording apparatus can be reduced, and high-speed, high-resolution printing can be achieved even when using image-receiving paper with low smoothness.

EXAMPLE FIG. 1 is a cross-sectional view of the transfer medium of the present invention, and 9 is a light-transmitting support! Made of polycarbonate and heat resistant
Films such as polyimide and polyethylene terephthalate are used.

Reference numeral 8 denotes a light reflection layer, which is a metal vapor deposited film of aluminum, zinc, etc., which can be recorded in any pattern with a conventionally used discharge breakdown recording device.

At that time, in order to improve the discharge characteristics, it is preferable to provide a highly transparent roughened layer containing fine particles of silica, alumina, hydrated aluminum, etc. on the surface of the polyethylene terephthalate film.

10 is a solid wax layer containing a light-to-heat conversion substance and a thermally decomposable blowing agent, and various waxes having a melting point of around 60° C. are commonly used, but microcrystalline wax or the like having adhesiveness and tackiness is preferable.

As the photothermal conversion material, a material such as carbon or graphite that captures a flash of light containing infrared rays emitted from a xenon lamp and converts it into heat is used. Thermal decomposable foaming agents are those that thermally decompose and generate various gases when heated above the foaming start temperature, and a type that generates nitrogen gas, etc., which is not corrosive or corrosive, is preferable.1) Support H Therefore, condenser paper, various resin films, and tracing paper, which are not particular about light transmittance, are used. 12 is a thermal transfer layer containing various waxes, resins, plasticizers, coloring pigments, etc. used in normal thermal transfer.
The transfer medium of the present invention is a mixture of dyes and the like coated with a heat-melt ink having a melting point of 60 to 80°C to a thickness of 3 to 5 μm. It is obtained by adhesively fixing the ink-coated thermal transfer sheets with a solid wax layer containing a light-to-heat conversion substance and a thermally decomposable foaming agent so that the supports are in close contact with each other. This will be explained below using examples.

[Example 1] 10 parts of urethane resin (Crispan 7209 manufactured by Dainippon Ink & Chemicals Co., Ltd.), 2 parts of fine powder silica, and 87 parts of ethyl acetate were thoroughly mixed and dispersed on one side of polyethylene terephthalate with a thickness of 25 μm. Then, a paint containing 1 part of a crosslinking agent (Crispan NX, manufactured by Dainippon Ink and Chemicals Co., Ltd.) was applied at a dry coating weight of 4 g/rd to form a nearly transparent roughened layer. On the other side, aluminum was vacuum-deposited to a thickness of 500 mm to obtain a discharge breakdown recording sheet capable of recording discharge breakdown. Incidentally, the number of parts in this example is by weight unless otherwise specified. Further, on one side of the polyethylene terephthalate film with a thickness of 6 μm, heat-melt ink of the following treatment was applied after drying to 4 μm.
A thermal transfer sheet was obtained by coating the film to a thickness of m.

A toluene dispersion of microcrystalline wax (melting point 75°C) with the following formulation was applied to the surface of the discharge breakdown recording sheet not coated with aluminum vapor deposition to a dry thickness of 2 μm to form a solid wax layer, and a thermal transfer sheet was prepared. The surface of the support not coated with the heat-melting ink was closely fixed to the surface coated with microcrystalline wax of the discharge breakdown recording sheet, and the two sheets were made into one transfer medium.

[Comparative example■]

In the same manner as in Example I, Ill Kaika N was provided on a 25 μm thick polyethylene terephthalate film, and aluminum was further deposited thereon to obtain a sheet capable of recording discharge breakdown. Furthermore, on one side that is not coated with aluminum vapor deposition, apply the heat-melting ink used in Example ① to a thickness of 4 μm.
An integrated transfer medium was obtained.

The transfer media obtained in Example Work and Comparative Example I were subjected to two types of discharge breakdown recording, text and solid, using a normal discharge breakdown recording device at an applied voltage of 45V. Three types of image receiving paper were brought into close contact with the thermal transfer layer of the transfer medium, and a xenon flasher device (Riso Kagaku FX-180) was used.
After irradiating flash light from the light reflective layer side, the image receiving paper and transfer medium were separated and the resulting printed images were compared and examined.Table 1 shows the transfer results. 4 seconds for copy paper, 50 seconds for copy paper, and 300 seconds for thermal transfer paper. The adhesion pressure was calculated by measuring the pressing force between the image receiving paper and the transfer medium.

The evaluation method is based on visual inspection and enlarged photographs (25x).
If the characters were judged to be of high quality with no blurring, it was rated O, if there was some separation, it was Δ, and if there was a break in the line or lack of density, it was rated ×. If it is solid, use Macbeth density needle, 1
・The case where a density of 0 or more was obtained is set as 0.0 As is clear from the transfer results in Table 1, when using the transfer medium of the example of the present invention, if the contact pressure is 100 g/cd or more, the surface smoothness will be improved. High quality printing can be obtained even on bond paper where the printing time is 4 seconds. On the other hand, in the comparative example, there is a clear correlation between contact pressure and print quality, and even for thermal transfer paper, which is a highly smooth paper, contact pressure of 500 g/aa or more is required, and in order to be compatible with copy paper, A close contact pressure of about 1 kg/- is required. Therefore, not only does the recording apparatus become large-scale, but the recording speed also decreases considerably.

(Margins below) Table 1 Evaluation Results The results for the solid density are similar to those for letters, and it is clear that Example 1 has better adhesion between the image receiving paper and the transfer layer, which results in lower smoothness. Relatively good printing is now possible even on image-receiving paper with a low viscosity.

In the case of color transfer, by providing a color transfer layer on a support having a photothermal conversion function, color printing is also possible using the same means as black and white printing. The thermally decomposable foaming agent contained in the solid wax layer preferably has a foaming initiation temperature of 70° C. or higher from the viewpoint of handling, and desirably 150° C. or lower from the viewpoint of transfer energy. In this embodiment, a xenon flash was used as a flash of light for transfer, but the present invention is not limited to this, and any heat ray including infrared rays may be used.

Effects of the Invention As described above, the present invention provides a light-reflecting layer removable by discharge breakdown recording on a light-transmitting support (1), and a solid wax containing a photothermal conversion substance and a thermally decomposable foaming agent on the other side. By creating an integrated transfer medium in which the layer, support II, and thermal transfer layer are sequentially provided, it is easy to handle and achieves high-speed, high-quality printing with good resolution even on receiving paper with low surface smoothness. It is something to do. An integrated transfer medium having such an effect consists of a discharge rupture recording sheet in which a light reflective layer removable by discharge rupture recording is provided on a light-transmissive support I, and a thermal transfer layer on one side of the support II. It can be easily produced by adhesively fixing the thermal transfer sheets with a solid wax containing a light-to-heat converting substance and a thermally decomposable foaming agent so that the supports of the thermal transfer sheets come into close contact with each other.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the transfer medium of the present invention, FIG. 2 is a sectional view of a conventional transfer medium, FIGS. 3, 4, and 5 are sectional views showing the recording method. FIG. 2 is a cross-sectional view of a conventional color transfer medium. 1...Support, 2...Light reflective layer, 3.
...Thermal transfer layer, 4... Image receiving paper, 5...
...Xenon flash, 6...Flash, 7.
...Light-heat conversion layer. Agent's name: Patent attorney Toshio Nakao Haka 1 person 8- Kutan A 10 layer q - 11 branch Pr body 1 10--Ikkou Tahe Mugi Osarao Nasu) (Otsuyo deceased owner of the store.) °U￥1f1) Contains rse, I Akane1teLmany)・Sodl; Comb 1sun 2nd figure Oc. sect regret

Claims (6)

[Claims] (1) A light-reflecting layer removable by discharge destruction recording is provided on one side of a light-transmitting support I, and a solid wax layer containing a photothermal conversion substance and a thermally decomposable foaming agent is provided on the other side of the support. I
I. A transfer medium characterized in that thermal transfer layers are sequentially provided. (2) The transfer medium according to claim (1), wherein a microcrystalline wax is used for the solid wax layer. (3) The transfer medium according to claim (1), wherein the thermally decomposable foaming agent has a decomposition start temperature of 70°C or higher and 150°C or lower. (4) The transfer according to any one of claims (1) to (3), characterized in that a roughened layer is provided between the light-transmitting support I and the light-reflecting layer. Medium. (5) Light-transparent support I A discharge breakdown recording sheet on which a light reflective layer that can be removed by discharge breakdown recording, and support I
A method for producing a transfer medium, which comprises adhesively fixing a thermal transfer sheet with a thermal transfer layer on one side of I using a solid wax containing a photothermal conversion substance and a thermally decomposable foaming agent so that the supports are in close contact with each other. . (6) A method for producing a transfer medium according to claim (5), characterized in that a roughened layer is provided between the light-transmitting support I and the light-reflecting layer.