JPS61137783A - Thermal transfer recording method and recording medium - Google Patents

Abstract

PURPOSE:To achieve thermal transfer recording with high image quality having favorable continuous gradation properties and free of the feeling of surface roughness, by using a recording medium having a surface roughness in terms of a center line average roughness of not higher than a specified value. CONSTITUTION:A thermal transfer recording sheet comprises on the surface of a sheet form heat-resistance base a thermal transfer layer comprising an ink material the viscosity of which is controledly decreased by temperature rise recoding control to provide transferrability to a recording medium, the ink containing solid particles at least some of which has a diameter not smaller than the thickness of the layer so that a rugged surface is formed. In thermaly transferring the thermal transfer layer of the recording sheet onto a recording medium by a thermal recording head, a recording medium having a surface roughness in terms of a center line average roughness of not higher than 0.5mum is used. Accordingly, even in the case of using fine solid particles, the solid particles and the surface of the recording medium are brought into effective contact with each other and penetration and transfer of the molten ink material through the solid particles take place effectively, so that thermal transfer recording with high image quality having excellent continuous gradation properties and free of the feeling of surface roughness is achieved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a thermal transfer recording method useful for recording monochromatic images or full-color images in continuous tone using a thermal recording head, and a recording medium thereof.

Conventional technology A layer comprising an ink material whose viscosity is controlled to be reduced by temperature increase recording control on the surface of a sheet-like heat-resistant substrate to impart transferability to a recording medium. The surface of the thermal transfer layer of a thermal transfer recording sheet has a thermal transfer layer in which an uneven surface is formed by mixing solid particles containing at least particles having a thickness equal to or larger than the thickness of the ink material. ), and a linear thermal recording head is press-fitted on the back surface of the heat-resistant substrate, and when recording is controlled to increase the temperature of the thermal transfer layer 2 by pulse width modulation, the ink material melts and becomes less viscous depending on the amount of heating, and becomes a solid. Penetrates and adheres to the recording medium through the particle surface.

Further, when the thermal transfer note is peeled off from the recording medium, the solid particles adhere to and are transferred to the recording medium while the unpenetrated molten ink material adheres to the surface.

Therefore, the ink material transferred to the recording medium, that is, the transferred recording density, corresponds to the amount of melted ink material, that is, the amount of heating, and is therefore continuous, corresponding to the modulation pulse width of the recording signal applied to the thermal recording head. .

Thus, according to the thermal transfer recording method using this type of thermal transfer recording sheet, it is possible to thermal transfer record a continuous gradation monochrome image or a full color image by overlapping transfer recording using a three primary color method or a four primary color method.

Problems to be Solved by the Invention The ink materials in this type of thermal transfer recording sheet usually include a binder material containing a hot melt material such as wax or an organic resin, and a pigment or dye used in printing ink or paint as a coloring material. Or, it is formed by mixing these mixed coloring materials. The decrease in the viscosity of the ink material in response to temperature increase recording control utilizes the phenomena of melting and lowering the viscosity of the binder.

As the solid particles, fine alumina powder particles and glass powder particles with an average particle size of about 3 μm are used, and these are mixed into the ink material and arranged at a high density of about 10,000 particles per 1 mm 2 .

As mentioned above, effective thermal transfer of the ink material is carried out in units of solid particles. Therefore, it has good continuous gradation,
For thermal transfer recording with high image quality and no roughness, the issue is the effective contact of these solid particles with the surface of the recording medium, and if these conditions are not satisfied, it is necessary to have good continuous gradation and high image quality. thermal transfer recording is difficult.

The present invention was made in view of these problems, and aims to provide a useful thermal transfer recording method and a recording medium for the same.

Means for Solving the Problems In the thermal transfer recording method according to the present invention, when thermal transfer recording is performed on a recording medium (image receptor) by a thermal recording head using the thermal transfer recording sheet, the surface roughness is It is characterized by using a recording medium with a length of 0.6 μm or less.

Further, a thermal transfer recording medium is provided in which the thermal transfer layer is thermally transfer recorded using a thermal recording head using the thermal transfer recording sheet, the surface roughness of which is 0.5 in terms of center line average roughness.
The recording medium is characterized in that it has a diameter of μm or less.

Effect: According to the thermal transfer recording method and its recording medium according to the present invention, even when the above-mentioned fine solid particles are used, the solid particles and the surface of the recording medium are effectively brought into contact, and the molten ink material is transferred through the solid particles. Since penetration and transfer are carried out effectively, thermal transfer recording of high image quality with excellent continuous gradation and no roughness can be achieved.

Example Hereinafter, the present invention will be described in detail with reference to Examples.

An example using a thermal transfer recording sheet having a thermal transfer layer having an uneven surface formed by mixing alumina particles with an average particle size of 3 μm in the ink material will be described below. The density of alumina solid particles that protrude from the surface of the ink material layer and form irregularities is approximately 10,000 per 1 m2 of lXl. The thermal recording head had a recording electrode density of 4 tons)/un, and gradation recording was performed by applying a recording signal by pulse width modulation.

Note that the center line average roughness is defined by J Engineering 5BO601.

[Example 1] When thermal transfer recording is performed using polypropylene synthetic paper (thickness 150 μm) with a center line average roughness of 0.61 μm as a recording medium, the thermal transfer recording density varies depending on the location of the recording medium for a recording signal of the same modulation pulse width. There was large variation, the recorded image was rough and rough, and the halftone reproducibility was poor.

The above polypropylene synthetic paper is supercalendered,
In a recording medium according to an embodiment of the present invention having a center line average roughness of 0.27 μm, variations in thermal transfer recording density are not visually detectable, and thermal transfer recording images are smooth. , exhibits excellent continuous gradation.

[Example 2] When a polyethylene synthetic paper (thickness: 110 μm) with an average roughness of 1.28 μm in the mid-U line was used as a recording medium, the thermal transfer recording density was even higher than that of the untreated polypropylene synthetic paper of [Example 1]. There were large variations in color, roughness in thermal transfer recorded images, and poor halftone reproducibility.

In another embodiment of the recording medium according to the present invention, in which the above-mentioned polyester synthetic paper is supercalendered and has a center line average roughness of 0.22 μm, variations in thermal transfer recording density cannot be visually detected. Thermal transfer recorded images are also smooth and exhibit excellent continuous gradation.

As mentioned above, when the centerline average roughness is 0.5 μm or less, variations in thermal transfer recording density, roughness of recorded images, and halftone reproducibility are greatly reduced, making it impossible to visually detect them. If the average roughness exceeds 0.6 μm, on the contrary, the above-mentioned performance deteriorates rapidly, and good continuous gradation and good recorded image quality cannot be obtained.

Effects of the Invention As described above, in the thermal transfer recording method and the recording medium according to the present invention, the contact between solid particles and the surface of the recording medium is greatly improved, and thermal transfer with good continuous gradation and high image quality can be achieved. A recorded image can be obtained, which has great industrial effects.

Name of agent Patent attorney Toshio Nakao and 1 other person Procedural amendment (method) % formula % ■Indication of case 1982 Patent Application No. 26j 23a 2 Name of invention Thermal transfer recording method and its recording medium 3 Make amendments Relationship with patent cases Patent application
Address 1006 Oaza Kadoma, Kadoma City, Osaka Name (582) Matsushita Electric Industrial Co., Ltd. Representative Yama
Toshihiko Shimo 4 Agent 571 Address 1006 Oaza Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. 5 Date of amendment order Contents of amendment (1) The application is amended as shown in the attached sheet.

(2) As per the engraving and attachment of the specification originally attached to the application (no changes to the contents).

Claims (2)

[Claims] (1) An ink material whose viscosity is controlled to be reduced by temperature increase recording control and transferability to a recording medium is provided on a sheet-like heat-resistant substrate surface, and a layer made of this ink material. A thermal transfer recording sheet having a thermal transfer layer having an uneven surface formed by mixing solid particles containing at least particles having a thickness of at least . 1. A thermal transfer recording method characterized in that a recording medium having a center line average roughness of 0.5 μm or less is used for thermal transfer. (2) A layer consisting of an ink material whose viscosity is controlled to be reduced by temperature increase recording control and transferability to a recording medium is provided on the sheet-like heat-resistant substrate surface, and the layer is made of this ink material. The thermal transfer layer is heated and transfer-recorded with a thermal head using a thermal transfer recording sheet having a thermal transfer layer in which an uneven surface is formed by mixing solid particles containing at least particles with a particle diameter of at least a thickness in the ink material. A thermal transfer recording medium having a center line average roughness of 0.
．． A thermal transfer recording medium characterized by having a diameter of 5 μm or less.