JP2611978B2 - Transfer recording medium - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing a transfer recording medium that can be used in a printer, a copying machine, a facsimile, or the like.

[Conventional technology]

In recent years, with the rapid development of the information industry, various information processing systems have been developed, and recording apparatuses and recording media suitable for the respective information processing systems have been developed.

One of the recording devices is a thermal transfer recording device.
In this method, recording is performed on recording paper using an ink ribbon (transfer recording medium) formed by applying a hot-melt ink obtained by dispersing a coloring agent in a hot-melt binder onto a ribbon-shaped support. .

That is, the ink ribbon is overlapped so that the thermal transferable ink layer is in contact with the recording paper, and the ink ribbon and the recording paper are transported between a thermal head and a platen,
By applying pulsed heat according to an image signal by a thermal head from the support side of the ink ribbon and pressing the two together to transfer the melted ink to the recording paper, the ink corresponding to the heat application is printed on the recording paper. An image is recorded.

Since the above-mentioned recording device is small and lightweight, there is no noise and the recording device can record on plain paper.
It has been widely used in recent years.

In recent years, in order to obtain color recording and halftone recording, an image forming element having a different color tone or a different optical density and having a correspondingly different melting point or softening point in the form of fine particles, microcapsules, etc. A method has been devised in which recording is performed by using a transfer recording medium provided in the above-mentioned document.

[Problems to be solved by the invention]

However, when an image is formed using such a conventional transfer recording medium, there have been problems such as generation of noise in the image and formation of a portion where no color appears.

In order to solve this problem, the present invention requires that at least a part of the image forming body is exposed without being covered with a binder for binding the image forming body to the base material. It is intended to provide a transfer recording medium.

[Means for solving the problem]

That is, the present invention is a transfer recording medium comprising an image forming element fixed on a base material by a binder, and the image forming element undergoes a polymerization reaction when heat energy and light energy are applied, A transfer recording medium, wherein a transfer temperature is increased, and at least a part of each of the image forming bodies is exposed from a binder, and the image forming body is , A polymerizable prepolymer, a photoinitiator and a colorant.

FIG. 1 shows a schematic sectional view of an embodiment of the transfer recording medium of the present invention.

In this figure, reference numeral 1 denotes a microcapsule-shaped image forming element formed by covering a core material 1a with a wall material 1b.
Is a base material, and 3 is a binder.

As described above, in the transfer recording medium of the present invention, since each image forming element is exposed without being completely covered with the binder, the image forming element does not hinder the transfer recording. The image is not transferred because the transfer and the binder are transferred together.

The transfer recording medium of the present invention is manufactured, for example, as follows.

In other words, first, a binder is applied on the base material so that the tackiness is maintained, thereby forming a layer of the binder. Next, excess image forming element is sprinkled on this layer. Then, if the sprinkled image forming element that is not in contact with the binder is removed, a transfer recording medium having a structure substantially as shown in FIG. 1 is obtained. As a method of providing a binder on a substrate,
A method such as applying a binder using a blade or an applicator, spraying the binder with a spray, or gravure printing can be used.

Also, as a method of disposing the image forming body on the binder, not only a method of sprinkling, but also a method of placing the binder on a separately prepared support, For example, a method of contacting and transporting a base material provided with a binder on a container in which the binder is provided may be used.

In the transfer recording medium of the present invention, the image forming element body is not limited to the microcapsule-shaped one as shown in FIG. Good. In addition to the materials whose transfer characteristics are changed by the application of light and heat, the materials are heat-meltable wax inks similar to those used in conventional thermal transfer recording media, and resins such as electrophotographic toners. And the like as a main component. In any case, any particles intended to be transferred to recording paper by applying heat and pressure can be used.

As the binder, an epoxy adhesive, polyvinyl alcohol, polyvinylpyrrolidone, polyacrylamide, urethane acrylic adhesive, or the like is preferably used. As a substrate, a PET film, a polyamide film, a polyimide film, a condenser paper, or the like can be used.

Hereinafter, the present invention will be described in more detail with reference to specific examples.

〔Example〕

A heat-sensitive transfer recording medium capable of forming a multicolor image was produced as follows.

<Production of microcapsule> An image forming element was produced in a microcapsule shape.

That is, 10 g of the core material components shown in Tables 1 and 2 were first mixed with 20 parts by weight of methylene chloride, and a surfactant having a HLB value of at least 10 or more, such as a cation or a nonion, and 1 g of gelatin dissolved in water. The resulting mixture was stirred at 8000 to 10,000 rpm with a homomixer while heating at 60 ° C. and emulsified to obtain oil droplets having an average particle diameter of 26 μm.

Stirring was further continued at 60 ° C. for 30 minutes to distill off methylene chloride to reduce the average particle size to about 10 μm. Add 20 ml of water in which 1 g of gum arabic is dissolved, and slowly cool
A microcapsule slurry was obtained by adding NH ₄ OH (ammonia) water to pH 11 or higher, and 1.0 ml of a 20% aqueous solution of glutaraldehyde was slowly added to harden the capsule wall composed of gelatin and gum arabic.

After that, solid-liquid separation was performed with a Nutsche filter, and 35
The resultant was dried at 10 ° C. for 10 hours to obtain a microcapsule-shaped image forming element. This image forming body was a microcapsule in which the core material shown in Tables 1 and 2 was covered with a wall material, and had a particle size of 7 to 15 μm and an average particle size of 10 μm.

The core materials shown in Tables 1 and 2 used here are:
It has a property that an image can be formed when heat energy and light energy are applied. That is, the reaction is started by the application of heat energy and light energy, and the physical properties that govern transfer characteristics change. In other words, the transfer temperature of the image forming body after the reaction is higher than that of the image forming body where the reaction does not proceed. Specifically, the first
When the photoinitiator in the core material shown in the table is heated to 100 ° C. or more and absorbs light in the band around the peak of the curve A in the absorption characteristic graph shown in FIG. 3, it initiates a radical reaction and polymerizes. The transfer temperature of the core material is
What was 60-70 ° C rises to 150 ° C or more. This core material has a magenta color when transferred to form an image. On the other hand, the photoinitiator in the core material shown in Table 2 was 100 ° C.
When it absorbs light in the band around the peak of the curve B in the graph of the absorption characteristics shown in FIG. 3 while being heated as described above, it initiates a radical reaction and polymerizes, and the reaction lowers the transfer temperature of the core material. What was 60-70 ° C rises to 150 ° C. This core material exhibits a blue color when transferred to form an image.

<Production of Transfer Recording Medium According to the Present Invention> On a substrate which is a PET film having a thickness of 6 μm and a width of 70 mm,
The binder was applied using an applicator with a gap set to 0.5 to 1 mil so that the thickness after drying was 0.5 to 1.0 μm, and dried with a dryer for about 10 seconds. After the drying, a mixture of the above two types of microcapsules in a 1: 1 uniform mixture is excessively sprinkled on a layer of the binder that is sticky and has a low fluidity. The image forming body not in contact with the material was wiped off. Thereafter, it was blown at room temperature for 2 to 3 minutes and dried to obtain a transfer recording medium of the present invention. Observation of this transfer recording medium with a microscope revealed that the upper surface of the microcapsules that came into contact with the recording paper was not covered with the binder.

The binder used here has a degree of polymerization of about 1400 and a degree of saponification of about 95
% PVA (polyvinyl alcohol) in a 5 wt% aqueous solution, and 0.15% of a nonionic surfactant: coconut oil fatty acid diethanolamide was added to improve wettability to PET.

<Experimental example> Using the transfer recording medium obtained by the above method, a transfer experiment as described below was performed.

That is, the PET surface of the transfer recording medium is brought into close contact with a hot plate heated to 120 ° C., and each peak wavelength indicated by C and D in FIG.
Each of the desired positions was irradiated with a 10 W fluorescent lamp having a spectral characteristic of 390 nm manufactured by Toshiba Corporation for about 50 mSec. The transfer recording medium after the heating and irradiation was passed between two rollers which were overlaid and pressed against each other so that the transfer recording layer of the transfer recording medium was in contact with the recording paper having a surface smoothness of about 300 seconds. The pressure between the rollers is set at about 25 kg / m ^2, and the surface temperature of the roller in contact with the transfer recording medium in advance 90 to 10
It was heated to 0 ° C. After passing between the rollers, the transfer recording medium and the recording paper were peeled off, and a high quality image of blue and magenta was obtained on the recording paper.

<Comparative example> Nonionic surfactant; 100 parts of 2 wt% aqueous solution of PVA as in Example;
In 20 g of the solution added at a ratio of
8 g of a 1: 1 mixture was dispersed to a thickness of 6
A transfer recording medium was obtained by applying the composition on a substrate which was a PET film having a width of 70 mm and a thickness of 70 μm using an applicator having a gap set to 1 mil and drying it with a dryer for about 10 seconds. In this transfer recording medium, the microcapsule is PE
It was applied almost in a single-layer close-packed state on the T film, but when observed with an optical microscope and an electron microscope, a thin film of PVA covered the capsule. This is shown in FIG.

When a transfer experiment similar to that of the example was performed using this transfer recording medium, the obtained image was blurred, and only an image with a poor image quality such that the color could not be faithfully reproduced was obtained.

[Effect of the Invention] As described above, the transfer recording medium of the present invention has no binder attached to the upper surface of the image forming element on the base material.
A good transfer image with high image quality can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a transfer recording medium of the present invention, FIG. 2 is a schematic sectional view of a conventional transfer recording medium, and FIG. 3 is a graph showing absorption characteristics of a photoinitiator in microcapsules. FIG. 4 is a graph showing the spectral characteristics of the fluorescent lamp. 1: Microcapsule (image forming element) 1a: Core material 1b: Wall material 2: Base material 3: Binder A, B: Absorption characteristics of core material C, D: Spectral characteristics

Claims (2)

(57) [Claims] 1. A transfer recording medium comprising an image forming element fixed on a base material with a binder, wherein the image forming element undergoes a polymerization reaction when heat energy and light energy are applied, A transfer recording medium wherein a transfer temperature is increased and at least a part of each of the image forming bodies is exposed from a binder. 2. The transfer recording medium according to claim 1, wherein the image forming element comprises a polymerizable prepolymer, a photoinitiator and a colorant.