JP2000280634A - Dye thermal transfer acceptive sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a dye thermal transfer acceptive sheet generating extremely little fading or decoloring in the case a hand cream, an air mousse and also a human sebaceous matter such as sebum secreted from human skin together with sweat are made to adhere on a printed face or an acceptive sheet printed by a sublimable thermal transfer printer. SOLUTION: A dye thermal acceptive sheet is provided with a sheet-shaped substrate and a dye acceptive sheet at least on one face, and an image of 0.35-0.55 reflection optical density is printed on the dye acceptive layer, and the reflection optical density residual rate OD1 before and after a salad oil is brought into contact with the image for 10 minutes and the reflection optical density residual rate OD2 before and after the salad oil is brought into contact therewith for 60 minutes are found, and the dye acceptive layer in which OD1 is 90% or more and OD2/OD1 is 0.95 or more is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dye thermal transfer receiving sheet (hereinafter abbreviated as receiving sheet).

[0002]

2. Description of the Related Art In recent years, the development of a color hard copy of a thermal transfer system, in particular, a sublimation type thermal transfer printer has been developed.
In a sublimation type thermal transfer printer, an ink sheet containing a sublimable dye layer of three colors (yellow, magenta, cyan) or four colors (yellow, magenta, cyan, black) is heated in order by a thermal head, and each color is heated. By controlling the amount of transfer of the dye, transfer formation of a full-color image excellent in density gradation is possible. Such a thermal transfer printer is used for printing images taken by a television image or a video camera on, for example, a postcard-type receiving sheet or a sticker-type receiving sheet. It is also rapidly spreading at home.

In general, prints obtained by a sublimation type thermal transfer printer have excellent density gradation compared with other full-color prints such as a fusion heat transfer system and an ink jet system. Has the image quality closest to silver halide photography. However, the prints obtained by the sublimation-type thermal transfer printer, compared with silver halide photographs and other full-color hard copies described above, when stored for a long time, for example, sunlight, light such as fluorescent lamps, hand cream, hair The image has a disadvantage that the image is easily faded or discolored by moose or oil such as sebum secreted with sweat from human skin. Among them, in particular, fading and discoloration due to the adhesion of oil are usually unavoidable due to handling of prints by hand, and are extremely serious problems.

In order to solve the fading and discoloration of the print on the receiving sheet which occurs when human fat such as hand cream, hair mousse and sebum secreted from human skin together with sweat are attached to the print, a recent work has been carried out. In some sublimation type thermal transfer printers, an ink sheet containing a sublimable dye layer of three colors (yellow, magenta, cyan) or four colors (yellow, magenta, cyan, black) is heated in order by a thermal head. After transfer of dyes of each color, there is a method in which a transparent protective layer called over lamination is further transferred and formed by heating a thermal head. When such an over-laminate protective layer is provided, even if oil adheres to the printing surface of the receiving sheet, it does not directly contact the dye transfer receiving layer, so that the printed matter does not fade or lose color.

[0005] However, when over lamination is performed, the printing time per sheet becomes longer than in the conventional case without over lamination. In addition, the ink sheet is also made of conventional three colors (yellow, magenta, cyan) or four.
Since an over-laminate is added in addition to the sublimable dye layers of the colors (yellow, magenta, cyan, and black), the volume of the ink sheet cartridge and the size of the printer are relatively increased. When the ink sheet cartridge is conventionally kept at the same size, it is necessary to reduce the size of the ink sheet cartridge. As a result, there is a problem that the number of printable sheets per cartridge is reduced. In each case, the cost is increased, which is a serious problem.

[0006] For this reason, the printed material has a characteristic (hereinafter, abbreviated as oil resistance) that does not cause fading or discoloration of the printed matter even if oil adheres to the printing screen, without using the conventional over-lamination type. Although excellent receiving sheets are strongly demanded, such a receiving sheet has not been proposed yet.

[0007]

The present invention relates to a dye thermal transfer receiving sheet. More specifically, the present invention relates to a printing screen (hereinafter abbreviated as a printing screen) of a receiving sheet printed by a sublimation type thermal transfer printer. Provided is a receiving sheet that is extremely resistant to fading and fading even when human fat such as hand cream, hair mousse, or sebum is secreted from human skin with sweat.

[0008]

As described above, the fading and discoloration that occur when human fat such as hand cream, hair mousse, or sebum secreted with sweat from human skin adheres is caused by these oil components. The present inventors have made intensive studies on the grease resistance of a stamped screen in order to achieve the above-mentioned object, since it is caused by contact with the stamped screen.

As a result, the present inventors have found that, in terms of the time of contact with the salad oil and the residual ratio of the reflection optical density before and after the contact, the residual ratio after short contact is good, and
It has been completed that it is necessary that the survival rate does not change even if the time is extended.

That is, according to the present invention, there is provided a dye thermal transfer receiving sheet having a sheet-like support and a dye-receiving layer on at least one side of the support, wherein the dye-receiving layer has an image having a reflection optical density of 0.35 to 0.55. And the residual ratio O of the reflected optical density before and after contacting the image with salad oil for 10 minutes.
D1 and the residual ratio OD2 of the reflection optical density before and after the contact for 60 minutes were determined, and OD1 was 90% or more, and O
A dye thermal transfer receiving sheet comprising a dye receiving layer having D2 / OD1 of 0.95 or more. Also,
It is preferable that the dye receiving layer contains a dye-dyeable resin having a hydroxyl group as a main component, and the dye-dyeable resin is cross-linked with a silicone oil by a cross-linking agent.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The dye thermal transfer receiving sheet of the present invention (hereinafter simply abbreviated as receiving sheet) is characterized by having the above-mentioned residual ratio of reflection optical density. The reflection optical density residual ratio is determined as follows. On the receiving sheet, a gray solid having a reflection optical density (hereinafter, simply referred to as OD) of 0.35 to 0.55 is printed by a sublimation type thermal transfer printer. As the ink ribbon, Matsushita Electric VW-MPA5
0 was used. Various measuring instruments such as a Macbeth densitometer and a Gretac densitometer can be used for measuring the reflection optical density (OD), and a gray solid image can be created by various signal generators or computer software.

[0012] Salad oil is dropped on the gray solid printing screen,
After standing for a minute, the salad oil is wiped off, and the residual ratio is calculated from the OD before and after contact with the salad oil, and is defined as OD1. Similarly, the residual rate was calculated 60 minutes after the salad oil was dropped, and O
D2. In the case of a receiving sheet having an OD1 of less than 90%, when the printing surface is rubbed with a finger, the dye is transferred to the finger, and the image loses its color, resulting in poor quality. Further, if OD2 / OD1 is less than 0.95 even if OD1 is 90% or more, the discoloration of the printing screen at the portion where the fingerprint or the like is attached is remarkable, and the quality is inferior. In the present invention, the measurement was performed using Nisshin Oil Co., Ltd. as a salad oil.

As a method for obtaining a receiving layer satisfying the above conditions, the receiving layer can be obtained by appropriately selecting a material forming the receiving layer, a compounding order of the materials forming the receiving layer, aging conditions, and the like. As a material constituting the receiving layer, a dye-dyeable resin having a hydroxyl group as a main component, a silicone oil, and a crosslinking agent capable of cross-linking the silicone oil and the dye-dyeable resin are contained. This is preferable because a specific residual ratio of reflection optical density is easily obtained.

As the dye-dyeing resin that can be used, any resin having a hydroxyl group can be used, and any resin such as a polyester resin, an acrylic resin, a vinyl chloride resin, and a cellulose resin can be used. As the silicone oil used in the present invention, any material can be used as long as it can be crosslinked with the dye-dyeable resin with a crosslinking agent. For example, various modified oils such as alcohol-modified and amino-modified can be used. The crosslinking agent used in the present invention can be used as long as it has the ability to crosslink the dyeing resin and the silicone oil, and isocyanate compounds and epoxy compounds can be used.

The receiving layer used in the present invention is preferably obtained by preliminarily mixing and reacting a crosslinking agent and silicone oil, and then applying and drying a coating liquid in which a dyeing resin is mixed. The reaction conditions of the cross-linking agent and the silicone oil are not particularly limited, and the reaction may be carried out under heating if necessary. It is difficult to stably obtain the desired OD1 and OD2 by simply mixing the crosslinking agent and the silicone oil with the dye-dyeing resin. First, a silicone oil and a crosslinking agent that reacts with the silicone oil are mixed and reacted, and then mixed with a dye-dyeing resin to finish the coating, thereby obtaining good results. According to such a mixing method, at the present time, the mechanism of obtaining better OD1 and OD2 than paints of the same composition obtained by simultaneously mixing the dye-dyeing resin, the crosslinking agent, and the silicone oil is unknown, Possibly, the cross-linking agent and the silicone oil react during mixing to polymerize, so that a high concentration is present on the surface of the receptor layer, which inhibits the movement of the printed dye.

In the receiving layer of the receiving sheet of the present invention, in addition to the dye-dyeing resin, the crosslinking agent, the silicone oil and the like,
If necessary, other additives such as a colored pigment, a colored dye, a fluorescent dye, a plasticizer, an antioxidant, a pigment, and an ultraviolet absorber may be added as long as the effects of the present invention are not impaired. These additives may be mixed with the main component of the receiving layer and applied, or may be applied as a separate coating layer on and / or below the receiving layer.

The coating amount of the receiving layer is adjusted within the range of 1 to 12 g / m ² , preferably 3 to 10 g / m ² . By the way, if the coating amount of the receiving layer is less than 1 g / m ² , the receiving layer cannot completely cover the surface of the base material, resulting in deterioration of image quality, or adhesion of the receiving layer and the ink sheet due to heating of the thermal head. Fusion problems may occur. On the other hand, when the coating amount of the receiving layer exceeds 12 g / m ² ,
Not only is the effect saturated and uneconomical, but also the strength of the receiving layer is insufficient, or the thickness of the receiving layer is increased, so that the heat insulating effect of the base material is not sufficiently exhibited, and the image density may be reduced.

Examples of the sheet-like support used in the present invention include a paper base such as coated paper, art paper and woodfree paper, a laminated paper obtained by laminating a thermoplastic resin such as polyethylene on a paper base, polyester, nylon and polyolefin. Examples thereof include a plastic film such as polypropylene (for example, polypropylene), and a film having a multilayer structure having a biaxially stretched void mainly composed of a polyolefin resin and an inorganic pigment. In addition to using the above materials alone,
By using a known method such as a dry laminating method, a wet laminating method, or a melt laminating method, a material obtained by laminating two or more of the above materials to form a multilayer structure can be used, and the combination is not limited.

A so-called sticker in which the adhesive used for laminating the above-mentioned bonded substrate is replaced with a pressure-sensitive adhesive and a release agent layer such as a silicone resin is provided on the film surface side in contact with the pressure-sensitive adhesive, Of course, a seal type structure can also be used.

The thickness of the sheet-like support is 100 to 3
00 μm is preferred. By the way, when the thickness is 100 μm or less, the mechanical strength becomes insufficient, and the rigidity of the receiving sheet obtained therefrom and the repulsive force against deformation become insufficient, and the curling of the receiving sheet generated at the time of printing is sufficiently reduced. Cannot be prevented. On the other hand, when the thickness exceeds 300 μm, the thickness of the obtained receiving sheet becomes excessively large, which leads to a decrease in the number of receiving sheets accommodated in the printer, or conversely, an increase in the volume of the printer, thereby reducing the size of the printer. This causes problems such as difficulty.

On the back of the receiving sheet of the present invention, a back coating layer may be provided in order to impart practical properties such as printer runnability and writability of the receiving sheet. As the binder used for the back coating layer, a resin widely used conventionally can be arbitrarily used. For example, an acrylic resin, a styrene-butadiene copolymer resin, a urethane resin, a polyvinyl acetal resin Examples include resins, polyester resins, phenoxy resins, polyvinyl alcohol resins, and cellulose resins such as starch.

Further, an antistatic agent may be included for the purpose of suppressing paper feeding, running trouble, and the like due to electrostatic charging. As the antistatic agent, commercially available anionic, nonionic,
A cationic antistatic agent can be used, and fine powders such as titanium oxide and zinc oxide are mixed with impurities and fired,
Inorganic fine powders such as those having enhanced electronic conductivity can also be used.

Further, if necessary, a pigment, an antifoaming agent, a dispersing agent, a resin crosslinking agent, a colored dye and the like may be appropriately selected and used. By the way, as pigments, silica, kaolin, calcined kaolin, clay, talc, heavy calcium carbonate, light calcium carbonate, titanium oxide, barium sulfate,
In addition to zinc oxide and barium stearate, organic fillers such as polystyrene filler, nylon filler and urea resin filler can be optionally used. The coating amount of the back coating layer is not particularly limited, but is adjusted in the range of 1 to ²⁰ g / m ² , preferably 3 to 15 g / m ² . By the way,
If the coating amount is too small, the effect of the coating layer will not be exhibited, and if it is too large, no further effect can be expected, and the cost will increase, which is not practical.

The receiving layer, the back coating layer and the other coating layers of the receiving sheet of the present invention may be formed by a known coater such as a bar coater, a gravure coater, a comma coater, a blade coater, an air knife coater, and a gate roll coater. It can be formed by coating and drying.

[0025]

The present invention will be described in detail with reference to the following examples, but the scope of the present invention is not limited to these examples.
In Examples, “%” and “parts” all indicate “% by weight” and “parts by weight” unless otherwise specified.

Example 1 A 50 μm thick polyethylene terephthalate (trade name: P
ET S50, manufactured by Teijin Co., Ltd.
A 0 μm multilayer structure film (trade name: YUPO FPG60, manufactured by Oji Yuka Synthetic Paper) was laminated by a dry lamination method using a polyester adhesive to form a sheet-like support.

On one surface, an amino-modified silicone oil (trade name: KF85) was formed to form a dye image-receiving layer.
7, 1 part of Shin-Etsu Chemical Co., Ltd.) and 6 parts of isocyanate-based cross-linking agent (trade name: Coronate L, manufactured by Nippon Polyurethane) were stirred and mixed at room temperature for 30 minutes, and then polyvinyl acetal-based resin (trade name: KS-1, manufactured by Sekisui Chemical) ) 100 parts, polyvinyl chloride resin (trade name: Solvain, manufactured by Nissin Chemical Industry) 50 parts, toluene / MEK = 1/1 diluent was added in sequence, and the mixture was stirred to obtain a coating amount of 4 g / m. Coating was performed with a gravure coater so as to obtain ^2, and the coating was dried. This was aged at 50 ° C. for 5 days to obtain a receiving sheet.

Example 2 In the preparation of the receiving layer solution of Example 1, the mixing ratio of the amino-modified silicone oil and the isocyanate-based cross-linking agent was changed to 1 part of the amino-modified silicone oil and 3 parts of the cross-linking agent. A receiving sheet was obtained in the same manner as in Example 1 except that the remaining 3 parts of the crosslinking agent were added after mixing the other materials.

Example 3 Amino-modified silicone oil of Example 1 (KF857)
Instead of amino-modified silicone oil (trademark: KF
867, manufactured by Shin-Etsu Chemical Co., Ltd.), and a receiving sheet was obtained in the same manner as in Example 1.

Example 4 The procedure of Example 1 was repeated except that an isocyanate-based crosslinking agent (trade name: Coronate EH, manufactured by Nippon Polyurethane) was used instead of the isocyanate-based crosslinking agent (Coronate L). I got a sheet.

Comparative Example 1 A receiving sheet was obtained in the same manner as in Example 1, except that the amino-modified silicone oil and the isocyanate-based crosslinking agent were not mixed in advance in the preparation of the receiving layer solution.

Comparative Example 2 A receiving sheet was obtained in the same manner as in Comparative Example 1 except that the amount of the isocyanate-based crosslinking agent was changed to 10 parts in the preparation of the coating material in Comparative Example 1.

Comparative Example 3 A receiving sheet was obtained in the same manner as in Example 1, except that an alcohol-modified silicone oil (trade name: KF851, manufactured by Shin-Etsu Chemical Co., Ltd.) was used instead of the amino-modified silicone oil of Example 1.

Comparative Example 4 In place of the amino-modified silicone oil of Example 1, an alcohol-modified silicone oil (trade name: SF8427,
A receiving sheet was obtained in the same manner as in Example 1 except that Tore Dow Corning) was used.

The following evaluations were performed on the receiving sheets obtained in the respective Examples and Comparative Examples, and the results are shown in Table 1.

(1) Measurement of OD1 and OD2 The obtained receiving sheet was set on a tray of a sublimation thermal transfer video printer (trade name: NV-MP5, manufactured by Matsushita Electric Industrial Co., Ltd.), and the printing density was 0.35 to 0.55. A gray half solid pattern is printed and a reflection densitometer (trade name: RD-914)
S, manufactured by Macbeth). Note that VW-MPA50 manufactured by Matsushita Electric was used as the link ribbon. Salad oil (trademark: Nisshin Salad Oil, manufactured by Nisshin Oil Co., Ltd.) is dropped on the gray solid printing screen, left for 10 minutes, wiped off the salad oil, and processed with a reflection densitometer (trademark: RD-914S, manufactured by Macbeth) to measure the OD. The OD residual ratio OD1 was calculated. Similarly, the residual rate was calculated 60 minutes after dripping of the salad oil, and was defined as OD2.

(2) Evaluation of resistance to finger rubbing (1) Measurement of OD1 and OD2) The obtained receiving sheet was printed with gray solid printing paper, and the degree of discoloration caused by rubbing the printing screen with a finger was visually observed. Was evaluated. Those without discoloration were marked with “○”, those with little discoloration were marked with “△”, and those with significant discoloration were marked with “x”.

(3) Evaluation of sebum resistance In the same manner as in "(1) Measurement of OD1 and OD2", the obtained receiving sheet was printed with gray solid printing paper, and a fingerprint was applied to the printing screen, and then at room temperature for 3 days. It was left to stand and the degree of discoloration was visually evaluated. Those without discoloration were marked with “○”, those with little discoloration were marked with “△”, and those with significant discoloration were marked with “x”.

[0039]

[Table 1]

[0040]

As described above, the dye thermal transfer receiving sheet of the present invention can be used on a printing screen of a receiving sheet printed by a printer.
Even if human fat such as sebum secreted with sweat from human skin adheres, it is a receiving sheet with extremely little fading or discoloration, and is of extremely high practical value.

Claims (2)

[Claims] 1. A dye thermal transfer receiving sheet having a sheet-like support and a dye-receiving layer on at least one side of the support, wherein the dye-receiving layer has a reflection optical density of 0.35 to 0.5.
55 was printed, and salad oil was brought into contact with the image for 10 minutes.
The reflection optical density residual ratio OD2 before and after the contact for 0 minute was determined, and OD1 was 90% or more and OD2 / OD1.
A dye heat transfer receiving sheet having a dye receiving layer having a dye content of 0.95 or more. 2. The dye thermal transfer receiving sheet according to claim 1, wherein the dye receiving layer is mainly composed of a dye-dyeable resin having a hydroxyl group, and the dye-dyeable resin is cross-linked with a silicone oil by a cross-linking agent. .