JPS6378792A - Transfer recording medium and method for manufacturing transfer recording medium - Google Patents

Abstract

PURPOSE:To obtain a transfer recording medium capable of forming a high grade transfer image to plain paper and capable of performing high speed recording, medium contrast recording and multicolor recording, by thermally fusing an image forming element coated with a heat-meltable coating material to a base material. CONSTITUTION:A base material 1a is contacted with the surface of a hot plate to be heated to a temp. almost equal to the heat-meltable temp. of a coating material 1e and microcapsules are excessively scattered to the base material 1a and, continuously, excessive microcapsules are shaken off. At this time, only the microcapsules contacted with the base material 1a are melted to be adhered to the base material 1a and the other microcapsules not adhered are shaken off. After cooling a transfer recording medium wherein the microcapsules are bonded to the base material in a single layer is obtained. Since a substance disturbing transfer such as a binder is not adhered to the image forming elements of the transfer recording medium, good transfer recording is performed. Further since only the part where the base material is in contact with the image forming elements has bonding strength, the mutual adhesion and superposition of adjacent image forming elements are prevented and all of the image forming elements are arranged to the base material in a single layer with high possibility.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a transfer recording medium that can be used in printers, copying machines, facsimiles, etc., and a method for manufacturing the same.

[Conventional technology]

In recent years, with the rapid development of the information industry, various information processing systems have been developed, and recording methods suitable for each information processing system have also been developed.

One such recording method is the thermal recording method, which has been widely used recently because the equipment used is lightweight, compact, noiseless, and has excellent operability and maintainability. .

Among these thermal recording methods, a thermal transfer recording method has recently attracted particular attention. This recording method is generally
A heat-sensitive transfer medium is used, in which a heat-transferable ink made by dispersing a colorant in a heat-melting binder is coated on a sheet-like support, and the heat-transferable ink layer of the heat-sensitive transfer medium is transferred to the medium to be transferred. By superimposing the ink layer on the transfer medium so as to touch the transfer medium and applying heat from the support side of the thermal transfer medium using a thermal head or the like to transfer the melted ink layer to the transfer medium, a transfer mark according to the heat supply pattern 4 is created. An image is formed on a transfer medium. According to this method, plain paper can be used as the transfer medium.

[Problems to be Solved by the Invention] However, such conventional thermal transfer recording methods are not without drawbacks. In conventional thermal transfer recording methods, the transfer recording performance, that is, the image quality, is greatly affected by the surface smoothness of the transfer medium. Print quality is significantly degraded on low-quality transfer media. Moreover, paper, which is the most common transfer medium, is rather special because it has a high level of smoothness, and ordinary paper has various degrees of unevenness due to entangled fibers. Therefore, in the case of paper with a large surface unevenness, the hot melted ink cannot penetrate into the paper fibers during printing and only adheres to the surface protrusions or their vicinity, resulting in sharp edges of the printed image. The image may not be printed properly, or part of the image may be missing, resulting in poor print quality.

In addition, in conventional thermal transfer recording methods, the transfer of the ink layer to the medium is performed only by heat from a thermal head, or generally by heat that can be supplied from a thermal head.
In addition, in order to convert and supply a large amount of recording signals as heat pulses within a limited time, there is a time lag between the heat pulses of the heat head during recording, and a time lag for cooling the heat head to a predetermined temperature within the heat pulse. Furthermore, it has been theoretically difficult to increase the amount of heat supplied from the thermal head in order to prevent thermal stroke between the heat generating segments that constitute the thermal head surface. Therefore, high-speed recording is difficult with conventional thermal recording methods.

In addition, thermal conduction has a slower response than electricity or light, so it is generally difficult to control thermal pulses to the extent that halftones can be reproduced when recording with a thermal head. Conventional thermal transfer ink layers do not have transfer characteristics capable of expressing gradation, and therefore cannot form halftone recorded images.

Therefore, the applicant used a photothermally sensitive polymer material, and when thermal energy and light energy were applied, the reaction of the polymer rapidly progressed and the transfer material changed irreversibly.
An image forming method and a transfer recording medium have been proposed in which an image is formed based on the difference in characteristics according to an image signal, and the image is transferred to a recording medium.

The present invention is a new transfer recording medium used to solve the problems of conventional surface printing, that is, plain paper, which is most commonly used because of its low surface smoothness, can form high-quality transfer images, and can also be used at high speed. The present invention provides a transfer recording medium capable of recording, halftone recording and multicolor recording, and a method for manufacturing the same.

[Means for solving problems]

That is, the present invention provides a transfer recording medium in which an image forming element coated with a transfer recording material or a heat-melting coating material is thermally fused onto a substrate, and a transfer recording medium in which the transfer recording material is coated with a heat-melting coating material. An image forming element covered with a material. This method of manufacturing a transfer recording medium is characterized in that the ζ material is thermally fused onto the base material by heating it.

The present invention will be described below with reference to the drawings.

FIG. 1 is a schematic sectional view of a typical embodiment of the transfer recording medium of the present invention. In this figure, the transfer recording medium 1 is a microcapsule (image forming element) in which core materials 1c and 1d, which are transfer recording materials, are coated with a heat-fusible coating material 1e, or a microcapsule (image-forming element) that is heat-fused onto a base material 1a. It will be done. 1f is a covering material that contributes to bonding with the base material.

Such a transfer recording medium is manufactured, for example, by the manufacturing method of the present invention as described below.

That is, first, the base material 1 is heated by bringing it into contact with a hot plate or the like, and the temperature is raised to about the thermal melting temperature of the coating material 1c. An excess of microcapsules 2 is sprinkled onto the substrate, followed by shaking off the excess microcapsules. At this time, only the microcapsules that have come into contact with the base material 1a are melted and adhered to the base material 1a, and the other microcapsules are brushed off. After cooling, a transfer recording medium in which the microcapsules are evenly bonded to the base material is obtained as shown in FIG.

In the above-mentioned embodiment, the image forming element was sprinkled on the heated base material 1 in order to arrange it, but is it possible to use it separately? : f. The image-forming element arranged on a sheet support and the heated base material are combined for 1n, or the heated base material is conveyed in contact with a container (containing the image-forming element in advance). You may also use a method such as In the case of Sailor's method, if the binder is arranged more uniformly on the support 1-, the step of brushing it off can be omitted. Since there is no binding material or other substances attached to the forming element that would interfere with transfer, good transfer recording can be achieved by using this transfer recording medium. In addition, since only the areas where the base material and the image forming element are in contact have adhesive strength, adjacent image forming elements do not adhere to each other and overlap, and all image forming elements are formed in a single layer on the substrate. likely to be arranged in

In the transfer recording medium of the present invention, the coating material of the image forming element has heat-melting or heat-softening properties, and is referred to as a transfer recording material.
It is preferable to use something that has affinity for both the base plate and the base plate. Examples of such materials include polyethylene resin, polypropylene resin, polyacrylic acid Nisder resin, polymethacrylate ester resin, vinyl acetate resin, polyvinyl formal resin, polyvinyl butyral resin, polyvinyl chloride resin, polystyrene resin, polyvinylidene chloride resin, Examples include polyacrylonitrile resin, polyvinyl methyl ether resin, polyamide resin, polyvinylpyrrolidone resin, polyvinylphenol resin, polybutadiene resin, polyisoprene resin, silicone resin, copolymers thereof, gelatin, and the like.

Further, the transfer recording material of the image forming element may be one in which the transfer characteristics do not change, and the formation of the image may be performed by applying transfer energy such as heat to a desired portion, or the transfer recording material may be one in which the transfer characteristics do not change. The characteristics change with the application of heat and light, and this state persists until the transfer process.The image is formed by applying transfer energy uniformly after applying light and heat partially, and the difference in transfer characteristics changes. It may be something that appears as an image. Claims 2 and 4 of the present invention indicate the latter aspect.

Further, as the base material, polyethylene terephthalate film, polyimide film, aramid film, etc. are preferably used.

In the present invention, the image forming element is a transfer recording material coated with a coating material, but the present invention can also be applied to a transfer recording medium in which the image forming element is simply a solidified transfer recording material in the form of particles. It is possible to apply However, in this case, if the transfer recording material is one in which the application of light and heat causes a radical reaction and changes the transfer characteristics, the process of applying light and heat may be necessary to prevent the radical reaction from being interfered with by oxygen. It is desirable to take measures to shield the transfer recording material from air.

The present invention will be explained in more detail below using specific examples.

〔Example〕

Example 1 A thermal transfer recording medium capable of forming a multicolor image was manufactured as follows.

First, an image forming element was manufactured in the form of a microcapsule.

That is, +0 mm parts of the core material components of the transfer recording materials shown in Tables 1 and 2 were dissolved in 200 parts by weight of methylene chloride, and granulated to have an average particle diameter of about 1Oμ by a spray drying method.

Table 1 Table 2 32 parts by weight of each of the two types of particles obtained were added to 6.0 parts of a styrene-methyl acrylate-butadiene (=I:4:2) copolymer having a molecular weight of about 8000. Dispersed in 100 parts by weight of kDMF solution, mixed with 2 parts of water while stirring at -20°C.
50 parts by weight was slowly poured down over 90 minutes to form a capsule wall. After leaving these until they reach room temperature,
Ii and dried under reduced pressure. Furthermore, this was passed through a classifier, and the number average particle size was 3.17 μl or less and the volume average particle size was 16 μl.
．． G) U+ and above were excluded.

The two types of microcapsule-shaped image forming elements thus obtained were mixed at a ratio of 1:] and sprinkled on a PET film with a thickness of 6 scales that had been heated to 120°C on a hot plate. Thereafter, the PUT film was immediately peeled off and the unadhered image forming element was brushed off to obtain a transfer recording medium as shown in the schematic cross-sectional view of FIG. In this transfer recording medium, the ratio of the image forming element disposed on the base material was about 92%. In this figure, the core material 1c is made of the core material components shown in FIG. 1, and the core material 1d is made of the core material components shown in FIG.

The image forming element of this transfer recording medium was arranged almost in one layer on the base material.

The core material components (transfer recording materials) shown in 'fa Tables 1 and 2 used herein have the property of forming an image when thermal energy and light energy are applied thereto. That is, a reaction is initiated by the application of thermal energy and light energy, and the physical properties governing the transfer characteristics permanently change. In other words, the transfer temperature of the image forming element in which the reaction has progressed becomes higher than that of the image forming element in which the reaction has not progressed, and this value remains permanently. Specifically, the first
The photoinitiator in the core material components shown in the table was heated to 100°C or higher, and curve A in the absorption characteristic graph shown in Figure 2 was used.
When light in a band around the peak of is absorbed, a radical reaction is initiated and polymerization occurs, and due to this reaction, the transfer temperature of the core material increases from 60 to 70°C to 150°C or more. This core material exhibits a magenta color when transferred to form an image. On the other hand, when the photoinitiator in the core material components shown in Table 2 is heated to 100°C or higher and absorbs light in the band around the peak of curve B in the absorption characteristic graph shown in Figure 2, it causes a radical reaction. The transfer temperature of the core material increases from 60 to 70°C to 150°C or higher due to the reaction.

This core material exhibits a blue color when transferred to form an image.

Experimental Example Using the transfer recording medium obtained by the above method, a transfer experiment as described below was conducted.

That is, the PE7 surface of the transfer recording medium is brought into close contact with a hot plate heated to 90°C, and approximately 25 m from the transfer recording layer surface.
A 20'll + health line fluorescent lamp FL made by Toshiba Corporation has the spectral characteristics shown in Figure 3 from the point where m1!1 was crossed.
20SE was irradiated over a period of about 5 On+Sec.

At this time, only the core material 1c caused a radical reaction and was hardened as shown by diagonal lines. The transfer recording medium after heating and irradiation was passed between two rollers that were superimposed on the recording paper and pressed against each other so that the transfer recording layer of the transfer recording medium was in contact with the recording paper whose surface smoothness was about 300 seconds. The pressure between the rollers is approximately 2
5 kg/+n2, and the surface temperature of the roller in contact with the transfer recording medium was heated in advance to 90 to 100°C. After passing between rollers, the transfer recording medium and recording paper were separated, and a blue transferred image was obtained on the recording paper. The transfer recording medium was magenta in color. Furthermore, when the transferred recording medium was observed with an optical microscope, it was found that the microcapsules using the core material components shown in Table 1 remained in almost the same state as before transfer, and the microcapsules using the core material components shown in Table 2 remained. Only some wall materials and a small portion of blue core material remained.

Example 2 A transfer recording medium was obtained in the same manner as in Example 1 except that a styrene-ethylene-vinyl acetate (=l:3:2) copolymer having a molecular weight of about 5000 was used as the material for the coating material. . In this transfer recording medium, the ratio of the image forming element disposed on the base material was about 92%. When a transfer experiment similar to that in Example 1 was conducted using this medium, good transfer recording was achieved as in Example 1.

Example 3 10 g of the core material components shown in Tables 1 and 2 were each dissolved in 20 parts by weight of methylene chloride, and 2.5 g of gelatin and a surfactant such as a cationic or nonionic surfactant having an HLB value of at least 10 were dissolved. Mix with 200ml of water and add 6
8000~looo00 by homomixer under heating at 0℃
The mixture was emulsified by stirring at rpm to obtain oil droplets with an average particle size of 26.

Stirring was continued at 60°C for 30 minutes, and the methylene chloride was distilled off, reducing the average particle size to about 10. I made it. To this was added 20 ml of water in which gum arabic Ig was dissolved, and after cooling slowly, NH4 ammonia water was added to the mixture to make it 3118 or higher, thereby obtaining a microcapsule slurry.

After that, solid-liquid separation is performed using a Nutsche filter, and vacuum 97. It was dried in a dryer at 35° C. for 10 hours to obtain a microcapsule-shaped image forming element. This image forming element is a microcapsule in which the core materials shown in Tables 1 and 2 are covered with a wall material.
The particle size was 7 to 15 μj, and the average particle size was 1OIAj+.

This image-forming element is sprinkled onto a 6-thick polyimide film that has been preheated to 90°C on a hot plate, and the unadhered image-forming element is shaken off to form an even layer of image-forming element. A transfer recording medium was obtained on which was arranged.

In this transfer recording medium, the ratio of the image forming element disposed on the base material was approximately 90%.

When a transfer experiment similar to that in Example 1 was conducted using this transfer recording medium, good transfer recording similar to that in Example 1 was achieved.

Comparative Example The microcapsule-shaped image forming element obtained in Example 3 was dispersed in a 3* aqueous solution of polyvinyl alcohol, and P
A transfer recording medium was obtained by applying it onto a UT film using an applicator and drying it. In this transfer recording medium,
Approximately 71% of images are placed on the image forming element or substrate.
Met. In this transfer recording medium, the image forming elements were arranged in almost a single layer, but the image forming elements were surrounded by polyvinyl alcohol.

When a transfer experiment similar to that in Example 1 was conducted using this transfer recording medium, a blue transferred image was obtained on the recording paper, but its density was much lower than in Example 1. Further, the transfer recording medium after recording had a dark color, and when observed under a microscope, the microcapsules using the core material components shown in Table 1 remained in almost the same state as in the transfer chamber. on the other hand,
In the microcapsules using the core material components shown in Table 2, about half of the core material remained.

Further, when the recording medium before transfer was observed under a microscope, the upper surface of the image forming element was covered with polyvinyl alcohol as a binder.

(Effects of the Invention) As described above, the transfer recording medium according to the present invention has a high transfer rate of the image forming element because there is no binding material attached to the image forming element, and a high quality image. It is possible to obtain a transferred image. Furthermore, the transfer recording medium according to the present invention has a high proportion of the image forming element disposed on the base material, so that the image quality is even higher.

[Brief Description of the Drawings] Fig. 1 is a schematic cross-sectional view of the transfer recording medium of the present invention, Fig. 2 is a graph showing the absorption characteristics of a photoinitiator in microcapsules, and Fig. 3 is a graph showing the absorption characteristics of a photoinitiator in microcapsules. It is a graph showing the spectral characteristics of. la: j; t, material IC = hardened core material 1d: uncured core material 1e: covering) ■material lf coating materials A and B that contribute to bonding with the rainbow board: spectroscopy of core material components Characteristic

Claims (4)

[Claims] (1) A transfer recording medium in which an image forming element formed by a transfer recording material coated with a heat-melting coating material is heat-sealed onto a base material. (2) The transfer recording medium according to claim 1, wherein the transfer characteristics of the transfer recording material are permanently changed by application of light and heat. (3) A transfer recording medium characterized in that an image forming element formed by a transfer recording material coated with a heat-fusible coating material is thermally fused onto the base material by heating the base material. Production method. (4) The method for manufacturing a transfer recording medium according to claim 3, wherein the transfer characteristics of the transfer recording material are permanently changed by application of light and heat.