JP3163099B2 - Sublimation type thermal transfer recording method, and recording sheet and image receiving sheet used therein - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sublimation type thermal transfer recording method, preferably a thermal transfer recording method using a speed difference mode, and a recording sheet and an image receiving sheet used therefor.

[Related Art] Conventionally, in a sublimation type thermal transfer recording method, reheating a transfer image has advantages such as uniform glossiness of an image surface and improvement of dye fixability, but has the following disadvantages. There is also.

(1) Providing an apparatus for reheating separately from the thermal head increases the size and cost of the apparatus.

(2) When the image surface is directly heated by the thermal head, contamination of the head occurs.

(3) A method of heating with a thermal head through a ribbon having a portion having no ink layer (Japanese Patent Laid-Open Nos. 63-7797, 31738)
6. In 1-80468), ribbon consumption will increase.

[Problems to be Solved by the Invention] An object of the present invention is to provide a sublimation-type thermal transfer recording method capable of improving the stability of an image and at the same time reducing the cost, and a recording sheet and an image receiving sheet used therefor.

[Means for Solving the Problems] A configuration of the present invention for solving the above problems is a sublimation type thermal transfer recording method, a recording sheet, and an image receiving sheet as described in the claims.

Preferred embodiments of the present invention will be described with reference to the drawings.

As shown in FIG. 1, a recording sheet used in the present invention has a monochromatic or multicolor ink layer 2 such as yellow (Y), magenta (M), cyan (C) and an ink layer 2 on a base film 1. It has a colorless area 3 without any color. When the length of the area where the ink layer is formed is Q and the length of the colorless area is R, the ink layer and the colorless area are provided such that R <Q.

When recording is performed using this transfer body, as shown in FIG. 2, a sublimable thermal transfer body (hereinafter simply referred to as a recording sheet) 1
Is sent at the speed A in the direction of the arrow, and the image receiving sheet 5 is sent at the speed B in the same direction as the recording sheet. Both sheets are sandwiched between the platen roller 6 and the thermal head 4 such that the ink layer 2 of the recording sheet 1 and the image receiving sheet 5 are in contact with each other.

Here, when heated by the thermal head 4 according to the image signal, a transfer image is formed on the surface of the image receiving sheet 5. Here, the ratio A / B between the speed A of the recording sheet and the speed B of the image receiving sheet 5 is N.

To reheat the transfer image formed in this way to stabilize the image, as shown in FIG. 3, the reheat is performed by the thermal head 4 via the colorless area 3 of the recording sheet. At this time, the ratio C / B of the speed C of the recording sheet to the speed B of the image receiving sheet 5 is M.

As the substrate film 1 of the thermal transfer sheet, any film having conventionally known heat resistance and strength may be used, and films such as a capacitor paper, a polyester film, a polystyrene film, a polysulfone film, a polyimide film, and a polyamide film are used. A conventional adhesive layer or the like may be provided between the sheet and the ink layer as necessary, and a conventional heat-resistant lubricating layer may be provided on the back surface of the base sheet as needed.

Among them, a polyester film is particularly preferable when the speed ratio N between the recording sheet and the image receiving sheet during recording is 1, and a polyester film and a polyamide film are preferable when a speed difference occurs between the two.

The width of the film of these substrates is substantially equal to the width of the image to be formed, that is, the width of the image receiving sheet.

Examples of the binder holding the sublimable dye include vinyl chloride resin, vinyl acetate resin, polyamide, polyethylene, polycarbonate, polystyrene, polypropylene, acrylic resin, phenol resin, polyester, polyurethane, epoxy resin, silicone resin, and fluorine resin. Resin, butyral resin, melamine resin, natural rubber, synthetic rubber, polyvinyl alcohol, cellulose resin, and the like. These resins can be used alone, but several kinds may be mixed or a copolymer may be used.

When the n-times mode method (speed difference mode method) is used as the multi-recording method (N <1), a cured resin is preferable.
More preferably, a binder having a curing reaction product of an isocyanate and a binder having an OH group as a binder is preferable, and as the polymer compound for a binder having active hydrogen used for a urethane formation reaction, polyvinyl is preferable. Butyral,
Polyvinyl acetal, polyurethane polyol, polyether polyol, polyester polyol, acrylic, acrylic-polyester copolymer, alkyd, silicone polyester, epoxy-opened epoxy group with alkanolamine -OH group, etc. As the class, di- or tolylene diisocyanate is effective, for example, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, triphenyl Examples include methane triisocyanate, isophorone diisocyanate, bisisocyanate methylcyclohexane, and trimethylhexamethylene diisocyanate.

Among these, polyvinyl butyral is desirable because it has an interaction between the dye used and the speed, and can achieve both a barrier property against the diffusion of the dye and a ribbon preservability.

Further, as the isocyanate, commercially available Coronate L (manufactured by Nippon Polyurethane Co., Ltd.) and Takenate D (manufactured by Takeda Pharmaceutical Co., Ltd.) are preferable because of easy handling.

The mixing ratio of the two is preferably in the range where the ratio of the —NCO group of the isocyanate to the —OH group of the compound having active hydrogen is 0.1: 1 to 1: 1.

The dye concentration is usually about 5 to 80% by weight, preferably about 10 to 60% by weight.

The thickness of the ink layer is 0.1 to 30 μm, preferably 1.0 to 20 μm.

When recording is performed by the n-times mode method as a multi-recording method, it is preferable to mix a substance having lubricity or releasability in the ink layer, and a substance having lubricity or releasability (lubricious substance) Examples thereof include petroleum-based lubricating oils such as liquid paraffin, synthetic lubricating oils such as hydrogen halide, diester oil, silicone oil, and fluorosilicone oil, and various modified silicone oils (epoxy-modified, amino-modified, alkyl-modified,
Silicone-based lubricating substances, such as copolymers of organic compounds such as polyoxyalkylene glycols and silicones, etc., various fluorine-based surfactants such as fluoroalkyl compounds, fluorine such as ethylene trifluoride-chlorinated ethylene low-polymers Lubricating substances, paraffin wax, waxes such as polyethylene wax, higher fatty acids, higher fatty alcohols, higher fatty acid amides, higher fatty acid esters, higher fatty acid salts, and the above-mentioned particles having lubricity or heat release properties. Various particles.

The content of the substance having lubricity or releasability in the dye transfer contributing layer is preferably 5 to 30% by weight.

If the content is less than 5%, the releasability or the effect of preventing fusion will be insufficient, while if it exceeds 30%, there will be a problem in storage stability.

As the sublimable dye in the sublimation type thermal transfer body of the present invention,
A dye that sublimates or vaporizes at 60 ° C. or higher, and may be any dye that is mainly used in the field of thermal transfer recording such as disperse dyes and oil-soluble dyes, such as CI Disperse Yellow.
CI Disperse Blue, such as 1,3,8,9,16,41,54,60,77,116, CI Disperse Red 1,4,6,11,15,17,55,59,60,73,83 3, 14, 19, 26, 56, 60, 64, 72, 99, 108, CI Solvent Yellow 77, 116, CI Solvent Red 23, 25, 27, etc., CI Solvent Blue 3, etc.
6,83,105 and the like. These dyes are used alone or as a mixture of several kinds.

The dye concentration of the ink layer is usually 5 to 80%, preferably 10 to
It can be used at about 60%.

In a preferred form of the transfer member to be formed, the ink layer is composed of a repeating unit of four continuous areas including a yellow, magenta, cyan (and even black) color and an area having no ink layer.

Another preferred mode is to form two continuous areas, that is, areas having no ink layer between each color,
The relationship between each ink layer length Q and the region length R having no ink layer is preferably Q> R for the purpose of reducing running cost. Particularly, when the substrate is a polyamide film by a multi-purpose speed difference mode method during recording. , The effect is maximized.

Further, a generally known release layer may be provided on the surface of the ink layer in the transfer body and in a region having no ink layer.

As the image receiving sheet, a generally known image receiving sheet is used,
As the substrate, synthetic paper, art paper, high-quality paper, coated paper, gravure paper, baryta paper, cellulose fiber paper, plastic film, etc. are used alone or in a laminate thereof, and as the image receiving layer, polyester having dyeing properties is used. , Polycarbonate, polysulfone, polystyrene, polyvinyl alcohol, polyvinyl chloride, polyvinyl acetate, vinyl chloride / vinyl acetate copolymer, polyamide, polyurethane, styrene / acrylic copolymer, and the like. Polymer resins and polyester resins are preferred.

Also, if necessary, amino-modified silicone in the image receiving layer,
A release agent such as an epoxy-modified silicone and an alkyd-modified silicone can be contained. By using these silicones, the effect of preventing thermal fusion with the transfer recording medium is further improved. The addition amount is based on the resin amount of the image receiving layer.
It is preferably at most 10% by weight.

The image receiving layer may contain a filler. Examples of the filler include white pigments such as silica, titanium oxide, and calcium carbonate. The amount of the filler is preferably 5 to 60% by weight based on the resin amount of the image receiving layer. Others
The image receiving layer may appropriately contain a surfactant, an ultraviolet absorber, an antioxidant and the like.

Further, the curing of the isocyanate and the dyeing resin described above on the transfer body is also effective in preventing sticking when the speed difference recording N <1.

Such an image receiving layer may have any thickness, but generally has a thickness of 5 to 20 μm.

During recording, it is common to use a thermal head and adjust the applied energy by pulse modulation. The recording method is a general method in which the recording sheet and the image receiving sheet are recorded at a constant speed, and a reduction in running cost. For the purpose, an n-fold mode method or the like in which the feeding speed of the recording sheet is a fraction of the image receiving sheet may be used.

As described above, the image formed in this way has problems in color density, light resistance, stain resistance and the like, but can be easily solved by the present invention.

The present invention also reduces the increase in running cost due to this improvement.

That is, the present invention solves the quality problem by reheating the formed image.

It is preferable to use a thermal head as the heating means and heat the entire surface. However, it is preferable to directly heat the thermal head through the colorless region using the transfer body shown in FIG. 1 from the problem of head contamination and the like.

As another heating means, the heating member is not limited to the thermal head, and a heating roll, an iron, an infrared lamp, a hot plate, or the like can be used. From the viewpoint of problems such as the above, the interposition of a film having heat resistance and strength as used for the base substrate is preferable.

[Examples] Hereinafter, the present invention will be specifically described with reference to Examples. In addition,
The amounts (parts) of the components shown in the examples are parts by weight.

Example 1 A silicone cured resin film (about 1 μm thick) was used as a back layer.
m), a coating liquid [liquid B] for an ink layer (dye transfer layer) having the following formulation was applied to a PET film having a thickness of about 6 μm and having a thickness of about 1 μm.
23.0cm × 30cm area, yellow, magenta, cyan in order of 23.0cm as a colorless area
Yellow, magenta and cyan were applied again at intervals of an area of × 15 cm, and this operation was repeated to obtain a continuous film sandwiching the colorless area.

[Liquid B] (Cyan) Polyvinyl butyral (trade name BX-1; manufactured by Sekisui Chemical Co., Ltd.) 10 parts Sublimation disperse dye for cyan (trade name Kayaset 714; manufactured by Nippon Kayaku Co., Ltd.) 6 parts Methyl ethyl ketone 95 parts Toluene 95 parts (magenta Identical except that the cyan dye was 4 parts MS-RED-G (manufactured by Mitsui Toatsu Dye) and 2 parts Macrolex Red Violet R (Bayer).

(Yellow) Same as above except that the cyan dye was 4 parts of Foron Brilliant Yellow S-6GL (Sand).

Further, a mixture having the following composition was sufficiently mixed and dispersed as an image receiving paper to prepare a coating liquid [A] for an image receiving layer.

[A] Liquid Vinyl chloride / vinyl acetate / vinyl alcohol copolymer (VAGH; manufactured by Union Carbide) 10 parts Isocyanate (Coronate L; manufactured by Nippon Polyurethane Industry Co., Ltd.) 5 parts Amino-modified silicone (SF-8417; manufactured by Toray Silicone Co., Ltd.) 0.5 part Epoxy-modified silicone (SF-8411; manufactured by Toray Silicone Co., Ltd.) 0.5 part Toluene 40 parts Methyl ethyl ketone 40 parts Next, the liquid [A] is applied to a thickness of about 150 μm using a wire bar.
m synthetic paper (Yupo FPG-150; manufactured by Oji Yuka Synthetic Paper Co., Ltd.), dried at a drying temperature of 75 ° C. for 1 minute, and a thickness of about 5 μm
After the image receiving layer was formed, it was further stored and cured at 80 ° C. for 3 hours to prepare an image receiving medium of the present invention.

The above ink layer and image receiving layer were superimposed and recorded under the following printing conditions.

However, at the time of recording, the ink layer and the image receiving layer are scanned at a constant speed, and at the time of reheating, an area having no ink layer is an image receiving layer.
Scanning at a speed of 2.

The recording conditions were as follows: thermal head resolution: 6 dots / mm, applied energy: 2.0 mj / dot, applied power: 0.4 W / dot. Comparative Example 1 The same conditions as in Example 1 except that no reheating treatment was performed.

Example 2 In Example 1, the following black ink was used in addition to the three-color ink, and yellow, magenta,
An ink layer was formed in the order of cyan and black to obtain a transfer body.

Black Foron Brilliant Blue SR 4 parts Srdan Red 380 2 parts Foron Brilliant Yellow S-6GL 2 parts Polyvinyl butyral 10 parts Methyl ethyl ketone 95 parts Toluene 95 parts Using the above recording sheet, the same recording as in Example 1 was performed.

Comparative Example 2 Example 2 was the same except that no reheating treatment was performed.

Example 3 (Formulation of adhesive layer) Polyvinyl alcohol BX-1 10 parts Coronate L 5 parts Toluene 95 parts Methyl ethyl ketone 95 parts was applied on a substrate at a thickness of 1 μM, and then (formulation of dye supply layer) polyvinyl butyral resin BX-1 [Sekisui Chemical Co., Ltd.] 10 parts Sublimation dye Kayaset Blue 714 [Nippon Kayaku Co., Ltd.] 20 parts Diisocyanate Coronate L [Nippon Polyurethane Industry Co., Ltd.] 3 parts Solvent Toluene 95 parts Methyl ethyl ketone 95 parts (Prescription of dye transfer contributing layer) Polyvinyl butyral resin BX-1 10 parts Sublimation dye Kayaset Blue 714 10 parts Diisocyanate coronate L 3 parts Epoxy-modified silicone oil SF8411 [Toray Silicone] 3 parts Solvent Toluene 95 parts Methyl ethyl ketone 95 parts Above After dispersing the composition of the formula in a ball mill, 1μ
Using a wire bar, a dye supply layer is applied to a thickness of 4.5 μm on a 6 μm aromatic polyamide film having a m-thick silicone resin-based heat-resistant layer, and a dye transfer contributing layer having a thickness of 1.0 μm is further applied thereon. 5m ×
Apply in the order of yellow, magenta, and cyan in an area of 30 cm, apply yellow, magenta, and cyan again as a colorless area with an area of 2.5 cm x 30 cm, and repeat this operation to sandwich the colorless area. Then, an ink layer of a continuous film was formed, and was thermally cured at 60 ° C. for 24 hours to prepare a recording sheet.

However, the yellow color is the same except that the dye Kayaset Blue 714 in cyan is changed to 4 parts of Foron Brilliant Yellow S-6GL.

Kayaset Blue 714 in cyan for magenta
All were the same except that was changed to MS-Magenta VP. The image receiving paper is the same as in the first embodiment.

 The printing conditions were as follows: Thermal head resolution: 12 dots / mm, applied energy: 0.64 mj / dot, applied power: 0.16 w / dot. At the time of heating, recording was performed under the conditions of a feed speed of an area having no ink layer of 0.85 mm / S and a feed speed of the image receiving body of 8.5 mm / S.

Comparative Example 3 Example 3 was the same as Example 3 except that no reheating treatment was performed.

From the above, the results regarding the print density, light fastness and stain resistance are shown in the table below.

However, printing density: reflection type densitometer RD-918 (Macbeth) Lightfastness test: fade meter (suga test machine)
After irradiation for 12 hours, the concentration change rate was calculated.

Stain resistance: The printed surface and the synthetic paper Copo FPG150 (Oji Oil Chemical Synthetic Paper) were overlapped, and a 250 g / 40 cm ² weight was stored at 60 ° C. for 100 hours, and the coloring density of the back layer was measured.

[Effects of the Invention] As described above, the effects of the present invention are summarized as follows.

(1) By reheating, the concentration, light resistance and stain resistance are improved, and the quality is improved.

By setting M <N at the time of reheating, the amount of consumption of the reheating member can be reduced, and an increase in running cost can be reduced.

(2) By using a ribbon having a colorless region, reheating can be performed without contaminating the thermal head and using another heating member, and further increase in running cost can be reduced.

As described above, the combination of 1 and 2 makes it possible to form an image with improved image quality and storability by reheating with almost no increase in running cost.

When the uppermost layer of the image receiving sheet or the recording sheet contains the release agent, the sticking of the image receiving sheet and the recording sheet can be prevented.

[Brief description of the drawings]

FIG. 1 is a perspective view schematically showing one example of a recording sheet of the present invention. 2 and 3 are schematic views showing a state in which the method of the present invention is performed. DESCRIPTION OF SYMBOLS 1 ... Base film, 2 ... Ink layer, 3 ... Colorless area, 4 ... Thermal head, 5 ... Image receiving sheet, 6 ... Platen roller.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-317386 (JP, A)

Claims (4)

(57) [Claims] A recording sheet having an ink layer containing a sublimable dye on a base film and an image receiving sheet are overlapped so that the ink layer is in contact with the image receiving sheet, and the ink layer is heated according to an image signal. In the sublimation type thermal transfer recording method of recording an image on an image receiving sheet and reheating the image, as a recording sheet, an ink layer is repeatedly formed on a continuous base film, and adjacent to the ink layer. In a sublimation type thermal transfer member having an ink layer-free area formed thereon, a recording sheet in which the length (R) of the area without the ink layer is shorter than the length (Q) of each single color ink layer area constituting the ink layer And recording under the following conditions. Recording sheet speed during recording = A Image receiving sheet speed = B Recording sheet speed during reheating = C A / B = N during recording When C / B = M during reheating, M <N is there. 2. An ink layer comprising a repeating unit of four (or five) continuous areas consisting of yellow, magenta, cyan (and black) colors and an area without an ink layer. A recording sheet used in the recording method described above. 3. The recording sheet according to claim 2, further comprising a release layer in a region where there is no ink layer. 4. The image receiving sheet according to claim 1, wherein the image receiving layer has an image receiving layer on the surface of the substrate, and the image receiving layer contains a release agent.