JPH04153084A - Sublimation type thermal transfer recording method and recording sheet - Google Patents

Abstract

PURPOSE:To enhance the stability of an image and to reduce cost by using a sublimation type thermal transfer material wherein an ink layer forming region is longer than an ink layer-free region and specifying the relation between the feed speeds of a sheet member at the times of recording and reheating. CONSTITUTION:A sublimation type thermal transfer material is formed by providing multicolor ink layers 2 and ink layer-free colorless regions 3 to a base material film 1 and the relation of R<Q is set between the length Q of each ink layer 2 and the length R of each colorless region 3. The sublimation type thermal transfer material (hereinbelow merely referred to as a recording sheet) is sent at speed A and an image receiving sheet 5 is fed at speed B in the same direction and both sheets are held between a platen roller 6 and a thermal head 4 so that the ink layers 2 come into contact with the image receiving sheet 5 and a transfer image is formed to the surface of the image receiving sheet 5 according to an image signal. Herein, A/B is set to N. The formed transfer image is reheated by a head 4 through the colorless regions 3. Herein, C/B is set to M and M>N is set. By this method, the quality and preservability of an image can be enhanced without almost increasing running cost.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a sublimation type thermal transfer recording method, preferably a thermal transfer recording method using a speed difference mode method, and a recording sheet used therein.

[Prior Art] Conventionally, in the R-umbrella type thermal transfer recording method, it has been investigated whether reheating the transferred image has advantages such as making the image surface uniform in gloss and improving dye fixability, as described below. There are also drawbacks.

(1) Providing a reheating device separately from the thermal head increases the size and cost of the device.

(2) Direct heating of the image surface with a thermal head causes contamination of the head.

(3) A method of heating with a thermal head via a ribbon having no ink layer (Q' 1983-7979
．． 31738B, Utility Model Application Publication No. 1-80488), the amount of ribbon consumed increases.

[Problems to be Solved by the Invention] The present invention aims to provide a sublimation thermal transfer recording method that can improve image stability and reduce costs at the same time, and a recording sheet used therein.

[Means for Solving the Problems] The structure of the present invention for solving the above problems is a sublimation thermal transfer recording method and a recording sheet as described in the claims.

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

The recording sheet used in the present invention is as shown in FIG. It has a brief colorless area 3. The ink layer and the colorless area are provided so that when the length of the area where the ink layer is formed is Q1 and the length of the colorless area is R, R<Q.

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

Here, when the image signal is heated by the thermal head 4, a transferred 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 stabilize the image by reheating the transferred image thus formed, as shown in FIG.
It is reheated by the thermal head 4 via the . At this time, the ratio of the speed C of the recording sheet to the speed B of the image receiving sheet 5 is C/B or M.

The base film of the thermal transfer sheet may be any film that has conventionally known heat resistance and strength, and films such as condenser paper, polyester film, polystyrene film, polysulfone film, polyimide film, and polyamide film are used. A conventional adhesive layer or the like may be provided between the base sheet and the ink layer, if necessary, and a conventional heat-resistant lubricant layer may be provided on the back surface of the base sheet, if necessary.

Among these, polyester film is particularly preferred when the speed ratio N between the recording sheet and image-receiving sheet during recording is 1, and polyester film and polyamide film are particularly preferred when there is a speed difference between the two.

The width of these base films is approximately equal to the width of the image to be formed, ie, the image receiving sheet.

In addition, examples of binders that hold sublimable dyes include vinyl chloride resin, vinyl acetate resin, polyamide, polyethylene, polycarbonate, polystyrene, polypropylene, acrylic resin, phenol resin, polyester, polyurethane, Epoquin resin, silicone resin, and fluorine resin. Examples include resin, butyral resin, melamine resin, natural rubber, synthetic rubber, polyvinyl alcohol, and cellulose resin. These resins can be used alone, but several types may be mixed or a copolymer may be used.

In addition, when a 0x mode method (speed difference mode method) is used as a multi-recording method (N<1), a cured resin is preferable, and more preferably a cured resin is used as the binder. Polymer compounds containing active hydrogen used in the urethane forming reaction include polyvinyl butyral, polyvinyl acetal, polyurethane polyol, polyether polyol, polyester polyol, acrylic, Examples include acrylic-polyester copolymers, alkyds, silicone polyesters, and those in which the epoxy group of epoxy is ring-opened with an alkanolamine to form an -OB group. As the isocyanate, di- or tolylene diisocyanate is effective, such as 2.44 lylene diisocyanate), 2,64 lylene diisocyanate, 4.4'-
Examples include diphenylmethane diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, triphenylmethane triisocyanate, isophorone diisocyanate, bisisocyanate methylcyclohexane, and trimethylhexamethylene diisocyanate.

Among these, polyvinyl butyral is particularly desirable because it has a rate interaction with the dye used, and is compatible with barrier properties against dye diffusion and shelf life.

Further, as the isocyanate, commercially available Coronet hL (manufactured by Nippon Polyurethane Co., Ltd.) and Takenate D (manufactured by Takeda Pharmaceutical Co., Ltd.) are preferable because they are easy to handle.

The mixing ratio of the two is preferably in the range of 0.1:I to 1:1, such as the -NGO group of the isocyanate and the 10H group of the compound having active hydrogen.

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

The ink layer thickness is 0.1 to 30 μm, preferably 1.0 to 2
It is 0 μm.

Also, when recording with the 0x mote method as a multi-recording method,
It is preferable to mix a substance with lubricity or mold-releasing properties into the ink layer, and examples of the substance with lubricity or mold-releasing properties (lubricating substances) include petroleum-based lubricating oils such as liquid paraffin, Hydrogen halide, diester oil, silicone oil,
Synthetic lubricating oils such as fluorosilicone oil, various modified silicone oils (epoquin-modified, amino-modified, alkyl-modified, polyether-modified, etc.), silicone-based lubricating substances such as copolymers of silicone and organic compounds such as polyoxyalkylene glycol, Various fluorine-based surfactants such as fluoroalkyl compounds, fluorine-based lubricating substances such as trifluorochloroethylene low polymers, waxes such as paraff, in-wax, polyethylene wax, higher fatty acids, higher fatty alcohols, higher fatty acid amides , higher fatty acid esters, higher fatty acid salts, and the various particles mentioned above as particles having lubricity or heat releasability.

The content of the substance that provides lubricity or mold release properties in the dye transfer contributing layer is preferably 5 to 30% by weight.

If the content is less than 5%, the mold releasability or adhesion prevention effect will be insufficient, while if it exceeds 30%, problems will occur in storage stability.

As the sublimable dye in the sublimation type thermal transfer material of the present invention, 6
Any dye that sublimes or vaporizes at 0° C. or higher and is mainly used in the packaging of thermal transfer recording such as disperse dyes and oil-soluble dyes may be used, such as C, I Disperse Yellow 1.3, 8. 9.16.41.54,60,77.1
16 etc., C11, Disperselet 1.4, 6,
11,15. +7.55, 59.60.73.83, etc., C31, Disperse Blue 3.14. +9.26
．． 5G, 6i1B4.72,99.108, C,1
, Zurgento Yellow 77.116, C1, Zurgent Red 23.25.27, and C1 Solgento Bruno 3f3, 83, 105. These dyes may be used alone or in combination.

The dye concentration of the ink layer is usually 5 to 80%, preferably 10%.
~6096 can be used.

A preferred form of the transfer body formed consists of a repeating unit of four consecutive areas consisting of an ink layer of yellow, magenta, cyan (or even black) colors and an area without an ink layer.

Another preferred form is one in which two continuous regions, that is, a region without an ink layer is formed between each color, and the relationship between the length of each ink layer Q and the length of the region without an ink layer R is a running pattern. For the purpose of reducing cost increase, Q>R is preferable,
In particular, when recording is performed using a multi-purpose speed difference mode method, the effect is greatest when the substrate is a polyamide film.

Further, a generally known release layer may be provided on the surface of the ink layer of the transfer body and on the area without the ink layer.

As the image-receiving sheet, generally known ones are used, and 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. The image-receiving layer is made of dyeable polyester, polycarbonate, polysulfone, polystyrene, polyvinyl alcohol, polyvinyl chloride, polyvinyl acetate, vinyl chloride/vinyl acetate copolymer, polyamide, polyurethane,
Examples include styrene/acrylic copolymers, and vinyl chloride/vinyl acetate copolymer resins and polyester resins are particularly preferred.

Furthermore, if necessary, a release agent such as amino-modified silicone, epoxy-modified silicone, alkyd-modified silicone, etc. can be included in the dye-receiving layer. Use of these silicones further improves the effect of preventing heat fusion with the transfer recording medium. The amount added is preferably 10% by weight or less based on the amount of resin in the receiving layer.

Incidentally, a filler may also be included in the dye-receiving layer. Examples of the filler include white pigments such as silica, titanium oxide, and calcium carbonate, and the amount added thereof is preferably 5 to 60% by weight based on the amount of resin in the receiving layer. In addition, the dye-receiving layer may contain a surfactant, an ultraviolet absorber, an antioxidant, etc. as appropriate.

Furthermore, with respect to curing of the isocyanate marked on the transfer body and the previous dyeing resin, in the case of speed difference recording N<1, it is effective in preventing sticking.

Such a receptive layer may have any thickness, but for boat fishing it is
The thickness is 20 μm.

During recording, it is common to use a thermal head and adjust the applied energy by pulse modulation, and the recording method is a general method in which the recording sheet and image receiving sheet record at the same speed, and a method that reduces running costs. For the purpose, a 0x mode method or the like may be used in which the feeding speed of the recording sheet is a fraction of that of the image receiving sheet.

As mentioned above, images formed in this manner have problems in color density, light fastness, stain resistance, etc., or these problems can be easily solved by the present invention.

Also, regarding the increase in running costs associated with this improvement,
This is alleviated by the present invention.

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

It is preferable to use a thermal head as a heating means and heat the entire surface, but since there are problems such as contamination of the head if the thermal head is used directly, it is preferable to use a transfer member shown in FIG. 1 and heat through the colorless area.

As for other heating means, the heating member is not limited to a thermal head, but it is also possible to use a heat roll, an iron, an infrared lamp, a hot plate, etc. Even when these are used, there is no risk of contamination of the heating member. Due to these problems, it is preferable to use a film having heat resistance and strength as used for the substrate base.

[Example] The present invention will be specifically illustrated by examples below.

Note that the amounts (parts) of each component shown in Examples are parts by weight.

Example 1 Silicone cured resin film as back layer (thickness approximately 1μ■)
A coating liquid for the ink layer (dye transfer layer) [liquid B] having the following formulation was applied to a thickness of approximately 1 μM on a PET film with a thickness of approximately 6 μM, and a 23.0×30 (2) Apply yellow, magenta, and cyan in this order over an area of Ta.

[Liquid B] (Cyan) Polyvinyl butyral (trade name BX-1, manufactured by Sekisui Chemical Co., Ltd. > io part sublimation disperse dye for dicyan, trade name Kayaset 714; manufactured by Nippon Kayaku Co., Ltd.) 6 parts methyl ethyl ketone 95 parts toluene
95 parts (magenta) The dye in the above cyan was MS-RED-G (manufactured by Mitsui Toatsu Dyes), 4 parts Macrolex Red Violet R (Bayer AG), and the same except that 2 parts (yellow) The dye in the above cyan was Poron Brjlliant Yellow S-
6GL (manufactured by Sandoz Co., Ltd.) was the same except that 4 parts of it was used.A mixture having the following composition as an image-receiving paper was sufficiently mixed and dispersed to prepare a dye-receiving layer coating liquid [A].

[A] Liquid Vinyl chloride/vinyl acetate/vinyl alcohol copolymer (VAGH).

Union Carbide Co.) 10 parts Isocyanate (Coronate L; Nippon Polyurethane Kogyo Co., Ltd.) 5 parts Amino-modified silicone (SF-8417° Toshi Silicone Co., Ltd.) 0
．． 5 parts Epoquin-modified silicone (SF-8411; manufactured by Toshi Silicone Co., Ltd.) 05 parts Toluene 40 parts Methyl ethyl ketone 40 parts Next, using a wire bar, apply liquid [A] to synthetic paper (Yupo FP) with a thickness of approximately 150 μm.
G-150, manufactured by Tamago Yuka Synthetic Paper Co., Ltd.) and dried for 1 minute at a drying temperature of 75°C to form a dye-receiving layer with a thickness of about 5 μm, and then stored at 80°C for 3 hours. The image receiving medium of the present invention was prepared by curing the medium.

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

However, during recording, the ink layer and the image-receiving layer are scanned at a constant speed, and when reheating, the area without the ink layer is scanned as the image-receiving layer, and the area that does not have an ink layer is scanned at 1/1/2 during recording.
Scanning was performed at a speed of 2.

The recording conditions are: Thermal head resolution: 6 dots/ll0°; Applied energy: 2.0 mj/dot; Applied power:
0.4 dots/dot, Comparative Example 1 Same as Example 1 except that reheating treatment was not performed Example 2 Same as Example 1 except that the following black ink was used in addition to the three color inks in Example 1. Ink layers were formed in the order of yellow, magenta, cyan, and black to obtain a transfer body.

Black color Poron Br1lliant Blue SR 4 parts 5rdan Red 380 2 parts Fo
ron Br1lliant Yellow S-6O
L 2 parts Polyvinyl butyral 10 parts Methyl ethyl ketone 95 parts Toluene
Recording was carried out in the same manner as in Example 1 using 95 copies or more of recording sheets.

Comparative Example 2 Same as Example 2 except that reheating treatment was not performed Example 3 (Adhesive layer formulation) Polyvinyl alcohol BX-110 coronate and 5 parts toluene 95 parts methyl ethyl ketone 95 parts were coated on the substrate at a thickness of 1 μm. Next (formulation of dye supply layer) Polyvinyl butyral resin BX-1 [manufactured by Antisui Kagaku Kogyo ■] 10 parts sublimable dye Kayaset Blue 14 [manufactured by Nippon Kayaku ■] 20 parts diisocyanate Coronate [Nippon Polyurethane Kogyo ■] ] 3 parts Solvent Toluene 95 parts Methyl ethyl ketone
95 parts (formulation of dye transfer contributing layer) Polyvinyl butyral resin BX-110 parts Sublimation dye
Kayaset Bluff 1410 parts Diisocyanate Coronat 3 parts Epoxy modified silicone oil 5P8411 [manufactured by Thoren Ricone] 3 parts Solvent Toluene
95 parts Methyl ethyl ketone 95 parts After dispersing the composition of the above formulation in a ball mill, 1 μm was applied to the surface.
6) Using a wire bar, apply a dye supply layer to a film thickness of 4.5 μm on a ten aromatic polyamide film having a silicone resin heat-resistant layer with a thickness of The film was coated to a film thickness of 1.08M, and yellow, magenta, and cyan were coated in this order on an area of 5 cm x 30 cm, and the colorless area was 2.5 mm.
Apply yellow, magenta and cyan again at intervals of an area of cm x 30 cm, and repeat this operation to form a continuous film of ink layers, sandwiching the colorless areas.
A recording sheet was prepared by heat curing at 0° C. for 24 hours.

However, for yellow, the cyan color dye Kayaset Blue 14 is used as Poron Brilliant Yellow.
Everything is the same except that it was changed to lowS-8GL4 part.Magenta is Kaya Set Blue 14 in cyan color.
Everything is the same except that MS=Magenta VP was changed. Further, the image receiving paper is the same as in Example 1.

In addition, the printing conditions are Thermal head resolution: 12 dots/l+n.

At applied energy 0.64+nj/dot and applied power 0.16 sh/dot,
During recording, ink sheet feed speed: 1.7 mm/S Image receiver feed speed: 8.5 mIII/S When reheating, area feed speed without ink layer: 0.85 ma+/S Image receiver feed speed: 8.5 mi+/S It was recorded in

Comparative Example 3 The results of printing density, light resistance, and stain resistance are shown in the table below from the same example as in Example 3 except that no reheating treatment was performed.

However, the rate of change in density was calculated after 12 hours of irradiation using a printed density double-reflection densitometer RD-918 (Macbeth Co., Ltd.) and a light fastness test, and a fade meter (Suga Test Instruments).

Stain resistance: The printed surface and synthetic paper Kobo FPG150 (egg oiled synthetic paper) were stacked, and the color density of the back layer was measured after storing a 250 g/40 c weight at 60° C. for 100 hours.

[Effects of the Invention As explained above, the effects of the present invention can be summarized as follows.

(1) By reheating, Density, light resistance, and stain resistance are improved 1, resulting in improved quality.

Furthermore, by using MAN during reheating, the amount of consumption of the reheating member can be reduced, and an increase in running costs can be reduced.

(2) By using a ribbon having a colorless area, it is possible to reheat the thermal head without using any other heating member that would contaminate the thermal head, and furthermore, the increase in running costs can be reduced.

As described above, the combination of 1.2 makes it possible to form an image with improved image quality and storage stability through reheating without increasing running costs.

[Brief explanation of the drawing]

FIG. 1 is a perspective view schematically showing an example of the recording sheet of the present invention. FIGS. 2 and 3 are schematic diagrams of the state in which the method of the present invention is carried out.

Claims (2)

[Claims] (1) A recording sheet having an ink layer containing a sublimable dye on a base film and an image-receiving sheet are superimposed so that the ink layer is in contact with the image-receiving sheet, and the ink layer is heated according to an image signal to receive an image. In a sublimation thermal transfer recording method in which an image is recorded on a sheet and the image is reheated, the speed of the recording sheet = AN, the speed of the image receiving sheet = B, the speed or feed amount of the heating member in direct contact with the image receiving sheet =
A sublimation thermal transfer recording method characterized in that when A/B=N during recording and C/B=M during reheating, M<N. (2) In a sublimation thermal transfer material in which an ink layer is repeatedly formed on a continuous base film and an area without an ink layer is formed adjacent to the ink layer, the length of the area where the ink layer is formed. A recording sheet characterized in that R<Q, where Q is the length of an area without an ink layer.