JPH0267190A - Thermal transfer recording material and its manufacturing method - Google Patents

Abstract

PURPOSE:To obtain a thermal transfer recording material generating no background staining, excellent in transfer properties and imparting good printing grade, in a thermal transfer recording material having an ink layer formed by applying ink in an emulsion state, by fixing the colorant and resin of the ink layer by wax. CONSTITUTION:In a thermal transfer recording material obtained by forming an ink layer 3 at least on a base material 1 by applying ink to said material 1 in an emulsion state, the colorant particles 6 and resin particles 7 of the ink layer 3 are fixed by wax 5. An a result, when this thermal transfer recording material is used, by forming the ink layer by applying ink in an emulsion state and subsequently melting the wax particles, printing generating no background staining and excellent in grade can be obtained.

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a thermal transfer recording material used in a thermal transfer printer and a method for manufacturing the same. [Conventional technology] In recent years, thermal transfer recording has become more popular due to its features such as non-impact, noiseless, maintenance-free, low cost, small size and weight, and color printing.It is used in many fields such as computer terminals and recorders. It is being Such a thermal transfer recording method melts and transfers ink onto a recording paper by heating the surface of the recording material with a thermal head or by heating an energized heat-generating resistive layer with a current-carrying head.
It provides printing or images, and the structure of thermal transfer recording materials includes a base material, a heat-resistant protective layer to prevent sticking, a heat-melting ink layer, and a transferable layer between the ink layer and the base material. It is common to have a structure in which an ink release layer is provided for the purpose of improving the performance, and an adhesive layer is provided on the ink layer if necessary. However, when plain paper is used as the transfer paper, the transferability of this thermal transfer recording method is greatly influenced by the unevenness of the surface of the plain paper, the surface physical properties, the adhesive strength of the ink layer, the permeability, etc. Particularly in the case of paper with large surface irregularities, the thermally molten ink adheres only to the convex portions or the vicinity thereof, resulting in parts of the printed image being chipped off and degrading the print quality. As a means to solve the above problem, JP-A-57-1
No. 66485, JP-A-60-166485, JP-A-Sho 6
Techniques for dispersing ink layer components in water have been devised, as shown in Japanese Patent Laid-Open Nos. 3-3996 and JP-A-63-13782. In other words, it contains a large amount of resin components that can bridge the concave surface of plain paper, and its high viscosity makes it difficult to apply stably with hot melt coating.Even with a poor ink composition, it is coated and formed with an emulsion. By doing so, it is possible to produce 2J with low viscosity. FIG. 2 shows the structure of a conventional thermal transfer recording material in which an ink layer is formed by coating an emulsion.

Problems and Objectives to be Solved by the Invention 1 However, although conventional thermal transfer recording materials have the effect of providing good printing quality even on plain paper, the ink layer formed by coating with emulsion exists in the form of particles. Therefore, the strength of the film was weak, and there was a problem in that during printing, ink in areas other than heat-generating areas was transferred to the paper, causing background smearing. SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and its purpose is to provide a thermal transfer recording material that is free from scumming, has excellent transferability, and has high printing quality, and a method for manufacturing the same. It's about doing. [Means for Solving the Problems 1] In order to solve the above problems, the thermal transfer recording material of the present invention includes:
A thermal transfer recording material comprising an ink layer formed by applying ink in the form of an emulsion onto at least a base material is characterized in that a coloring material and a resin are fixed to the ink layer with wax. Furthermore, the ink layer is formed by coating with an emulsion and then heated at a temperature not lower than the melting point of the wax and lower than the melting point of the resin. [Example 1 Examples of the present invention will be described in detail below, but the present invention is not limited thereto. FIG. 1 shows the structure of the thermal transfer recording material of the present invention. As components of the ink [3, 5 indicates wax, 6 indicates coloring material particles, and 7 indicates resin particles. In addition, waxes include natural waxes such as spermaceti wax, beeswax, lanolin, carnauba wax, candelilla wax, montan wax, and secilene wax, petroleum waxes such as paraffin wax and microcrystazone wax, oxidized waxes, etc. as heat-melting binders. Synthetic waxes such as ester wax, low molecular weight polyethylene, and Fischer-Tropsch wax can be used. Further, as the coloring material, pigments such as carbon black, dyes, etc. can be used. On the other hand, resin components include thermoplastic polyamide resins, polyester resins, epoxy resins, polyurethane resins, polyolefin resins, polyacrylic resins, polyvinyl chloride resins, polyvinyl acetate resins, and cellulose resins. Resin, polyvinyl alcohol resin, petroleum resin, phenol resin, polystyrene resin, rosin, ester gum, ethylene-vinyl acetate copolymer resin, ethylene-α-olefin copolymer resin, α-olefin maleic anhydride copolymer resin , ethylene-methacrylic acid copolymer resin, etc., which have a higher melting point than wax, can be used as appropriate. Regarding drying after coating the ink layer, it is best to dry the resin and colorant at a temperature above the melting point of the wax and below the melting point of the resin so that the resin and coloring material are fixed by the wax. Ink runs out and transferability is poor. As the base material 1, conventionally known films and papers can be used as they are, such as plastic films with relatively excellent heat resistance such as polyester, polycarbonate, triacetyl cellulose, polyamide, polyimide, cellophane, or parchment paper. , condenser paper, etc. can be used. In this example, polyethylene terephthalate with a thickness of about 6 μm was used. In addition, when using a thermal head, the heat resistance of the base material 1 can be improved by providing a heat-resistant protective layer 4 made of silicone resin, fluororesin, epoxy resin, phenol resin, etc. on the surface of the base material 1 that comes into contact with the head. can be improved. In this example, the thickness of the layer mainly composed of silicone resin is 0,
A heat-resistant protective layer 4 with a thickness of 2μ was used. Further, a peeling layer 2 may be provided between the base material and the ink layer 3 for the purpose of improving the adhesion of the ink layer 3 and improving the releasability of the ink during transfer. In this example, a release layer 2 having the following composition was hot-melt coated onto the base material 1 so that the coating thickness was 0.5 μm. Release layer composition Weight % Carnauba wax 95 EVA resin 5 (Example 1) First, on the release layer 2, ink layer components having the following composition were made into an emulsion state, and coated with a coater so that the thickness after drying was about 4 μm. It was coated using. Ink layer composition Melting point °C Weight % Carbon black -120 Paraffin wax
7025 Carnauba wax 8415
EVA resin 120 40 The resin and wax used were emulsions whose nonvolatile content was adjusted to 30%. Next, this ink layer 3 was dried at 90'C for 2 minutes to melt the wax particles 8. (Example 2) On the release layer 2, ink layer components having the following composition were applied in an emulsion state using a coater so that the thickness after drying was about 5 μm. Ink layer composition Melting point °C Weight % Carbon black -120 Carnauba wax
8530 Microcrystalline Wax 7525 Polyethylene Resin 1.4025 As the resin and wax, emulsions each having a non-volatile content of 30% are used. Next, this ink layer 3 is dried at 90° C. for 2 minutes to melt the wax particles 8. (Example 3) Ink layer components having the following composition were applied on the peeling fs and JPI2.
It was made into an emulsion and coated using a coater so that the thickness after drying was about 4 μm. Ink layer composition Melting point °C Weight % Carbon black --20 Paraffin wax
7025 Montan Wax 6530E
EA 130 25, resin,
Each wax is an emulsion whose nonvolatile content is adjusted to 30%. Next, this ink layer 3 was dried at 80° C. for 3 minutes to melt the wax particles 8. (Comparative Example 1) The components of each emulsion ink layer having the following composition were mixed and stirred, and coated onto the peeling N2 using a coater so that the thickness after drying was about 5 μm. Ink layer composition Melting point °C Weight % Carbon black -120 Paraffin wax
7o 52 polyethylene resin 140 2
0EVA resin 12o 8Also, resin,
Each wax is an emulsion whose nonvolatile content is adjusted to 30%. Further, drying after application of the ink layer was not performed. (Comparative Example 2) Ink layer components having the following composition were applied in the form of an emulsion onto Peeling N2 using a coater so that the thickness after drying was approximately 4 μm. Ink layer composition Melting point °C Weight Carbon black --20 Paraffin wax
7o 25 Carnauba Wax 8415E
VA resin 120 40, m JJi
7.Each emulsion of wax was adjusted to have a non-volatile content of 30%. Next, this ink layer 3 was dried at 125° C. for 2 minutes to melt the wax particles 8 and resin particles 7. Thermal transfer recording materials prepared in Examples 1, 2.3, and Comparative Example 1.2 were printed using a thermal printer, and the print quality and degree of background smearing were visually evaluated. The printing paper used was Lancaster bond paper with a Beck smoothness of about 2 seconds. The evaluation results are shown in Table 1. In addition, O in the table,
O1x is an evaluation graded into best, good, and poor. As is clear from the results in Table 1 and above, if the thermal transfer recording material of the present invention is used, the wax particles are melted after coating and forming the ink in the form of an emulsion, so that background smudges do not occur and the quality is maintained. I was able to obtain excellent printing. [Effects of the Invention 1] As explained above, the present invention, in a thermal transfer recording material in which an ink layer is coated and formed in an emulsion state, strengthens the fixation of the coloring material by melting only the wax particles in the ink layer, and improves the adhesion of the coloring material during transfer. To obtain a thermal transfer recording material which suppresses background smudge, has good transferability even on plain paper, and has excellent print quality.

[Brief explanation of the drawing]

FIG. 1 is a structural diagram showing a cross section of the thermal transfer recording material of the present invention. Further, FIG. 2 is a structural diagram showing a cross section of a conventional thermal transfer recording material. 1... Base material 2... Peeling layer 3... Ink layer 4... Heat-resistant protective layer 5... Wax 6... Coloring material particles 7... Resin particles 8... Wax particles A)

Claims (2)

[Claims] (1) A thermal transfer recording material comprising an ink layer formed by coating ink in the form of an emulsion on at least a substrate, characterized in that the colorant and resin of the ink layer are fixed by wax. thermal transfer recording material. (2) The method for producing a thermal transfer recording material according to claim 1, wherein the ink layer is formed by coating with an emulsion and then heated at a temperature higher than the melting point of the wax and lower than the melting point of the resin.