JPS61274990A - Image-receiving sheet for thermal transfer recording medium - Google Patents

Abstract

PURPOSE:To provide an image-receiving sheet enhanced in thermal sensitivity and reduced in the adhesiveness to a transfer body, by providing a layer containing at least a plasticizer and a polymer binder on a base material. CONSTITUTION:A part of plasticizers to be used is shown in a table. As an embodiment of a polymer binder, various synthetic polymer compounds such as cellulose acetate, cellulose acetate butyrate, cellulose nitrate or polyacrylonitrile can be designated and the combination of the plasticizer with the polymer binder can be appropriately selected from the viewpoint of the compatibility of both of them. The mixing ratio of the plasticizer to be added is at least 5pts. by wt. of 100pts. of the polymer binder. As the base material, various films, papers or metals can be used.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an image receiving sheet used in a thermal transfer recording method, and particularly to a thermal transfer recording medium coated with an ink material containing a dye as a main component. This invention relates to an image receiving sheet.

[Conventional technology]

In the thermal transfer recording method, a thermal transfer recording medium (hereinafter abbreviated as transfer body) consisting of a color material layer provided on a base material and an image receiving sheet on which an image is formed are superimposed, and a thermal head etc. is used from the base material side of the transfer body. By heating using a heating element, the coloring material is transferred to the surface of the image-receiving sheet and recording is performed. FIG. 1 is a block diagram explaining such a thermal transfer recording method. In FIG. 1, reference numeral 1 is a transfer body, 11 is a base material for the transfer body, 12 is a coloring material layer, 2 is an image receiving sheet, 3.4 show the thermal head and platen roller respectively.

This recording method consists of (1) changing the hue of the coloring material layer]
Multi-color recording and color recording can be easily performed. (2
) Development and fixing are not required, making the device more compact and economical. (3) Unlike inkjet recording and electrophotography, there is no need to use liquid ink or toner material (liquid or powder), so recording is highly reliable. It is being considered for use in the field of color facsimile.

FIG. 2 is a sectional view for explaining the thermal transfer recording medium in more detail. In FIG. 2, numerals 11 and 12 have the same meanings as in FIG. 1, and 13 means a slippery heat-resistant layer. Base material 11
A color material layer 12 is provided thereon. There has also been an attempt to improve the heat resistance of the base material by providing a slippery heat-resistant layer 15 on the opposite side of the coloring material layer. If a coloring material layer is provided by coating a dye-based coloring agent such as a sublimable dye onto a base material using a binder, a transfer medium with good gradation, in which the transfer density can be controlled by applied energy, can be obtained. [Fukuguchi et al., Journal of the Image Electronics Engineers of Japan Vol. 12, No. 1]
8 pages (ttas)). At this time, the image receptor used is a base material coated with a polyester resin. For example, as shown in FIG. 3, 0, that is, FIG. 3 is a sectional view of the image receiving sheet, and in FIG.

Also, as an image receiving sheet, acidic fine particles are coated on a base material together with a polymeric binder (Japanese Patent Application Laid-Open No. 59-142091
Also known are those coated with an organic filler and a heat-softening meltable resin (Japanese Patent Application Laid-open No. 59-214696).

[Problem that the invention seeks to solve]

However, when these image-receiving sheets were used, the recording pulse width was 2 to 8 ms, which required significantly larger applied energy than that of ordinary thermal paper. Therefore, the recording time is long, and it has been desired to improve the thermal sensitivity (Nikkei Electronics, published February 13, 1984, p. 119). Further, there was a problem in that the image receiving sheet and the transfer sheet tended to adhere to each other in areas where the recording area was large. 'An object of the present invention is to provide an image-receiving sheet for a thermal transfer recording medium that has improved thermal sensitivity and has less adhesion to a transfer member.

[Means for solving problems]

To summarize the present invention, the present invention relates to an image-receiving sheet for a thermal transfer recording medium, and is characterized in that a layer containing at least a plasticizer and a polymeric binder is provided on a base material.

The present invention differs from conventional techniques in that a plasticizer is one of the main components.

A plasticizer is a well-known substance that is an auxiliary material that has the function of improving the fluidity of plastic raw material resins and imparting flexibility to molded products.

Although specific materials are shown in Table 1, the present invention is not limited thereto.

Examples of polymeric binders include cellulose acetate,
Cellulose acetate butyrate, cellulose nitrate, ethyl cellulose, polymethyl methacrylate, polystyrene, polyvinyl acetate, polyvinyl butyral, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyester, polyethylene, polypropylene, polyvinychloride, dene, polycarbonate, Examples include various synthetic polymer compounds such as vinyl chloride-vinylizoy chloride copolymer and polyacrylonitrile. The combination of plasticizer and polymer binder can be selected as appropriate from the viewpoint of compatibility between the two. The mixing ratio is 100 parts by weight of the polymer binder (to which it is necessary to add at least 5 parts of the plasticizer).

It is not necessarily clear why an image-receiving layer having such a composition is effective in improving thermal sensitivity, but it is presumed that it is related to the fact that the dye in the transfer material generally has good compatibility with the plasticizer.

Various films, paper, metals, etc. can be used as the base material.

〔Example〕

The present invention will be explained in more detail below with reference to Examples, but the present invention is not limited to these Examples.

Note that in each example, parts mean parts by weight.

Example 1 A paint having the following composition was coated using a 180 μm pm'r (polyethylene terephthalate) 7 (two-wire aper) on a lum and dried at 60°C to produce an image receiving sheet.The coating film thickness was as follows: A transfer body was prepared by applying a paint having the following composition and having a diameter of approximately 2 μm on a 9μ5 OPET film whose back surface had been heat-resistant treated.

The transfer member and image receiver were placed one on top of the other, and an image was formed by heating with a thermal head under the following recording conditions.

As a result, homogeneous dye images having densities ((115 to tag)) corresponding to the dots were obtained at each heating time.

Comparative Example 1 An image-receiving sheet was produced in the same manner as in Example 1, except that a paint having the following composition was used.

When recording was performed in the same manner as in Example 1, it was found that a pulse δ application time of 6 ms was required to obtain a density of 1.5.
Also, in areas with large printing areas, adhesion between the image receiving sheet and the transfer body occurred.

Examples 2 to 6 Image-receiving sheets were produced in the same manner as in Example 1, except that the combinations of plasticizer and polymer binder were changed as shown in Table 2 below. However, the solvent was appropriately selected to dissolve both components. When recording was performed in the same manner as in Example 1, as shown in Table 2, a density of t5 or higher was obtained at a pulse @ 2.5 ms. Furthermore, the gradation reproducibility was also excellent.

Table 2 Furthermore, there was no adhesion between the image receiving sheet and the transfer sheet. The images obtained in Examples 1 to 6 were placed in a quinanone fade meter for 24 hours, and the density reduction was within SX and was excellent.

〔Effect of the invention〕

As explained above, when the image receiving device of the present invention is used,
S1 stone has the advantage of being able to record with high sensitivity, and since there is no adhesion to the transfer material, the recording time is short and running stability is improved.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a thermal transfer recording medium, FIG. 2 is a sectional view of the thermal transfer recording medium, and FIG. 3 is a sectional view of an image receiving sheet. 1... Transfer body 2... Image receiving sheet 5...
Thermal head 4...Platen roller 11...
Transfer body base material 12...Coloring material layer 13...Smooth heat resistance,
@ 21... Base material for image receiving sheet z2... Image receiving layer

Claims (1)

[Scope of Claims] 1. An image-receiving sheet for a thermal transfer recording medium, characterized in that a layer containing at least a plasticizer and a polymeric binder is provided on a base material. 2. The image-receiving sheet for a thermal transfer recording medium according to claim 1, wherein the proportion of the plasticizer to 100 parts of the polymer binder is 5 parts or more by weight.