JP3009903B2 - Sublimation thermal transfer recording method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a sublimation type thermal transfer recording sheet, and more particularly to a thermal transfer recording method by an n-fold mode method using a sublimation type thermal transfer recording sheet for multiple printing.

[Prior art] In recent years, the demand for full-color printers has been increasing year by year, and as recording methods of this full-color printer, there are an electrophotographic method, an ink-jet method, a thermal transfer method, and the like. Therefore, a thermal recording transfer system is often used.

This thermal transfer consists of a fixed color ink sheet and an image receiving paper, and heat transfer or sublimation transfer of the ink to the receiving paper with thermal energy controlled by an electric signal from a laser or thermal head to form an image. This is a recording method to be performed.

The thermal transfer recording system is roughly classified into the heat melting transfer type and the sublimation transfer type. In particular, in the latter case, the sublimation dye sublimates in a monomolecular state corresponding to heat energy from a thermal head or the like in principle. It has the advantage that halftones can be easily obtained and the gradation can be controlled arbitrarily, and is considered to be the most suitable method for a full-color printer.

However, in this sublimation transfer recording method, a color ink sheet is used as a recording supply, and heat recording is selectively performed by an image signal. Therefore, in order to obtain one full-color image, yellow, magenta, cyan, (black) (1) Ink sheet is used one by one, and even if there is an unused portion, it is discarded.

Therefore, focusing on this drawback, the ink sheet and the image receiving body are moved at a constant speed in order to improve the drawback by using the ink sheet a number of times, and the constant speed mode method used repeatedly and the running speed of the ink sheet are used. There has been proposed an N-fold mode method in which the first use portion and the second use portion of the color material layer are used while being slightly shifted from each other at a later time than that of the image receiving body.

However, in the sublimation type thermal transfer recording system, sublimation and evaporation reactions are basically zero-order reactions, and in the constant velocity mode, although the amount of dye that can withstand multi-use is included in the ink layer, As the number of prints increases, the transfer density particularly in the high image density area rapidly decreases,
There was a drawback that printing could not be carried out many times.

The thick conventional ink layer uniformly containing a sufficient amount of dye capable of withstanding printing many times causes a sharp decrease in density after the second printing. (1) The dye contributing to transfer is very small on the free surface of the ink layer. It was found that the reason is that the dye is very near the free surface of the ink layer every time the dye is printed every time since the dye is only in the vicinity of the vicinity and (2) the transfer of the dye follows Fick's law.

On the basis of this finding, the present inventors added a dye from the dye supply layer to the lower layer of the dye transfer contributing layer in order to replenish the dye consumed in the upper layer (free surface layer) of the dye transfer contributing layer by printing. It has been proposed to design each layer so that the dye releasing ability is in the relationship of dye supply layer> dye transfer contributing layer so that it can be easily compensated (see Japanese Patent Application No. 63-62866). However, this method provides good results when using a special photographic paper having a receiving layer formed thereon as a transfer object, but always provides a clear and good image when performing thermal transfer to plain paper. Not necessarily.

[Problems to be Solved by the Invention] The present invention overcomes the disadvantages of the prior art, and does not lower the transfer density even after printing many times, and provides a good thermal transfer image layer on plain paper. Using a thermal transfer recording sheet
It is an object of the present invention to provide a thermal transfer recording method using a double mode method.

[Means for Solving the Problems] The present inventors have conducted intensive studies to achieve the above object, and as a result, a dye supply layer comprising (1) a sublimable dye dispersed in an organic binder on a substrate. And a sublimation type thermal transfer recording sheet provided with an ink layer region formed by laminating a dye transfer contributing layer and (2) a dye receptive substance supply layer region composed of a dye receptive substance. A sublimation type thermal transfer recording method using an n-fold mode method, wherein plain paper is used, the dye-receptive substance supply layer area is solid printed on plain paper, and the ink layer area is printed by an n-fold mode method. It has been found that the above object can be achieved by providing.

The present invention is an invention disclosed in Japanese Patent Application No. 63-62866 of the present applicant, i.e., a dye supply layer in which a sublimable dye is dispersed in an organic binder in order from the substrate side, and In a sublimation type thermal transfer medium obtained by laminating a dye transfer contributing layer, the dye supply layer and the dye transfer contributing layer are formed as a single layer on a substrate with the same amount of adhesion in each of the formulations, and each is separately formed. A sublimation-type thermal transfer medium, wherein the amount of dye transferred to each image receiving layer is in the relationship of dye supply layer> dye transfer contributing layer when the same thermal energy is applied to both the image receiving layers. It is an improvement of the invention relating to the present invention.

That is, in the present invention, a dye-receptive substance containing a dye-receptive substance in parallel with an ink layer area on a substrate so that the dye can be transferred well onto plain paper having no special ink-receptive layer. A supply layer region is provided. When forming an image, first, the dye-receiving substance is transferred from the dye-receiving substance supply layer area on the recording sheet onto plain paper, and then the dye-receiving substance is transferred onto the plain paper. The image formation is completed by transferring the sublimable dye from the ink layer area.

Since the ink layer region on the recording sheet of the present invention is the same as the ink layer having a laminated structure of the dye supply layer and the dye transfer contributing layer of the above-mentioned application, the ink layer region will be described only briefly.

The thickness of the dye transfer contributing layer forming the ink layer region is generally 0.05 to 5 μm, preferably 0.1 to 2 μm, and the thickness of the dye supply layer is generally 0.1 to 20 μm.
Preferably it is 0.5-5 μm.

Known dyes, sublimable dyes, binders and the like used in the dye transfer contributing layer and the dye supply layer forming the ink layer region of the present invention can be used.

A specific example of the sublimable dye used in the present invention is 60 ° C.
It is a dye that sublimates or vaporizes as described above, and it is sufficient that the dye is mainly used in thermal transfer printing dyes such as disperse dyes and oil-soluble dyes, and CI Disperse Yellow 1,3,8,9,16,41,
1,4,6,1 of CI disperse thread such as 54,60,77,116
CI Solvents such as 1,15,17,55,59,60,73,83, CI Disperse Blue 3,14,19,26,56,60,64,72,99,108, CI Solvent Yellow 77,116 Red 23,2
5,27 and the like, CI Solvent Blue 36,83,105 and the like, and as anthraquinone-based or azo-based disperse dyes, SOT-BlueG, SOT-Blue2, SOT-Red2G, SOT
-Red 200, SOT-Red 300, SOT-Red 800, SOT-Yellow
5, SOT-Yellow 5G (above, manufactured by Hodogaya Chemical Co., Ltd.), etc., and these dyes can be used alone or in combination of several kinds.

Thermoplastic or thermosetting resins are used for the binder used in the dye transfer contributing layer and the dye supply layer. Among the resins having a relatively high glass transition point or high softening property, for example, vinyl chloride resin , Vinyl acetate resin, polyamide, polyethylene, polycarbonate, polystyrene, polypropylene, acrylic resin, phenol resin,
Polyester, polyurethane, epoxy resin, silicone resin, fluorine resin, butyral resin, melamine resin,
Examples include natural rubber, synthetic rubber, polyvinyl alcohol, and cellulose resin. These resins can be used alone, but several kinds may be mixed or a copolymer may be used.

Further, when making a difference in the glass transition or softening temperature between the dye transfer contributing layer and the dye supply layer, a resin or a natural or synthetic rubber having a glass transition temperature of 0 ° C. or less, or a softening temperature of 60 ° C. or less is preferable. Are syndiotactic 1,2-polybutadiene (commercially available as JSR RB810,8
20,830 Nippon Synthetic Rubber); Olefin copolymer and terpolymer containing acid or non-acidic acid (Dexon XEA-7, Dexon Chemical as commercial products); Ethylene-vinyl acetate copolymer (400 & 400A, 405,403 as commercial products, Allied Fibers &Plastics); P-3307 (EV150), P-2
807 (EV250), DuPont Mitsui Polychemicals); low molecular weight polyolefin-based polyols (derivatives: Polytail H, HE Mitsubishi Kasei Kogyo); brominated epoxy resin (YDB-340,400,500,600 Toto Kagaku); novolak epoxy resin ( YDCN-701,702,703 Toto Chemical); Thermoplastic acrylic solution (Tynalnal LR1075,108)
0,1081,1082,1063,1079 Mitsubishi Rayon); thermoplastic acrylic emulsion (LX-400, LX-450, Mitsubishi Rayon);
Polyethylene oxide (Alcox E-30,45, Alcox R-150,400,1000 Meisei Chemical Co., Ltd.); caprolactone polyol (Placcel H-1,4,7, Daicel Chemical Co., Ltd.) and the like are preferable. In particular, polyethylene oxide,
Polycaprolactone polyol is practically useful, and is preferably used in the form of a mixture of one or more of the above-mentioned thermoplastic or thermosetting resins with the above-mentioned thermoplastic or thermosetting resin.

The dye content of the dye transfer contributing layer is usually 5 to 80%, preferably about 10 to 60%.

The dye content of the dye supply layer is 5 to 80%.
The dye content is preferably 1.1 to 5 times, preferably 1.5 to 3 times, the dye concentration of the transfer contributing layer when a dye concentration gradient is provided between the dye transfer contributing layer and the dye supply layer. .

The dye-receptive substance supply layer area containing the dye-receptive substance, the thermal printing or pressurization of the thermal head is performed by heat and pressure.
It must be easy to transfer, made of a material with a relatively low melting point, and have good dye receptivity. For example,
Examples include low melting polyester, vinyl chloride-vinegar,
Acrylic resins and the like are mentioned, and those having a melting point of 110 ° C. or less are preferable. These may be dissolved in a solvent or the like and applied, but the thickness of the supply layer is 1 to 50 μm, preferably 3 to 20 μm.

If necessary, a release layer made of a silicone-based or Teflon-based binder wax may be provided in advance before applying the binder on the base sheet.

Further, in the recording using the ink layer, the ink layer is easily peeled or fused at the interface between the ink layer and the receiving layer due to the slip recording due to the speed difference, and the running failure is likely to occur. Therefore, the above-mentioned ink layer contains a known substance having lubricity or releasability, or if necessary,
It is also possible to use a heat-resistant resin or a resin that is cured by adding a curing agent as the resin to be used.

Examples of lubricating or releasable substances (lubricating substances) include, for example, petroleum-based lubricating oils such as liquid paraffin, synthetic lubricating oils such as hydrogen halide, diester oil, silicone oil, fluorosilicone oil, and various types of modified oils. Silicone oils (epoxy-modified, amino-modified, alkyl-modified, polyether-modified, etc.), silicone-based lubricating substances of copolymers of organic compounds such as polyoxyalkylene glycol and silicone, various fluorine-based surfactants such as fluoroalkyl compounds, Fluorinated lubricating substances such as ethylene trifluoride ethylene low polymer, paraffin wax, polyethylene waxes, higher fatty acids, higher fatty alcohols, higher fatty acid amides, higher fatty acid esters, higher fatty acid salts, and the aforementioned lubricity or heat There are various particles mentioned as particles having releasability.

As the base sheet, films such as condenser paper, polyester film, polystyrene film, polysulfone film, polyimide film, and polyamide film are used, and a conventional adhesive layer or the like may be provided between the base sheet and the dye supply layer as necessary. A conventional heat-resistant lubricating layer may be provided on the back surface of the base sheet, if necessary.

Although the above description has been made with reference to a recording method using a thermal head, the transfer medium of the present invention is a recording method in which recording heat energy is applied by a method other than the thermal head, for example, a thermal printing plate, a laser beam, or a support. It can also be used for a method using Joule heat generated in a medium such as a body. Of these, the so-called energized thermal transfer method using Joule heat generated in a medium is best known, for example,
It is described in many documents such as USP 4,103,066, JP-A-57-14060, JP-A-57-11080, and JP-A-59-9906.

When used in this energization transfer method, relatively heat-resistant polyester, polycarbonate, triacetyl cellulose, nylon, polyimide, aromatic polyamide and other resins as a support, aluminum, copper, iron, tin, zinc,
A support in which a metal powder such as nickel, molybdenum, silver and the like and / or a conductive powder such as carbon black are dispersed to adjust the resistance value to an intermediate value between an insulator and a good conductor. A support on which a conductive metal is deposited or sputtered may be used. The thickness of these supports is preferably about 2 to 15 microns in consideration of the efficiency of Joule heat conduction.

In the case of using a laser beam transfer method, a material that absorbs laser light and generates heat may be selected as a support.
For example, a conventional heat transfer film containing a light-absorbing conversion material such as carbon, or an absorption layer formed on the front and back surfaces of a support is used.

Hereinafter, the present invention will be described more specifically based on the following examples, but the present invention is not limited thereto.

Example 1 [Formation of Dye Receptive Substance Supply Layer Region] Part by weight Low melting point polyester resin XA-7502 (Melting point: 86 ° C, manufactured by Unitika Ltd.) 30 Silicone oil SF8417 3 (Made by Toray Silicone) Dispersant 2 Solvent Methyl ethyl ketone 60 Toluene 60 The above formulation was sufficiently dispersed to prepare a coating agent for supplying a dye receptive substance.

As shown in FIGS. 2 and 3, the composition having the above formulation was coated with an aromatic polyamide film substrate having a thickness of about 6.5 μm and a width of 210 mm (Toray Co., Ltd.) having a silicone lubricating heat-resistant layer having a thickness of about 0.5 μm on the back side. Co., Ltd. 1 was applied using a wire bar and dried at 100 ° C. for 1 minute to form a dye-receptive substance supply layer region 7 having a thickness of about 5 μm.

[Formation of Ink Layer Area] Part by weight Polyvinyl butyral resin BX-110 (manufactured by Sekisui Chemical Co., Ltd.) Sublimable dye Kayaset Blue 714 (manufactured by Nippon Kayaku Co., Ltd.) Solvent Toluene 100 Methyl ethyl ketone 100 In the dye supply layer formulation, the sublimable dye was 20 parts by weight, in the dye transfer contributing layer formulation, the sublimable dye was 10 parts by weight, and silicone oil SF8417 was added.
(Toray silicone) was added in an amount of 1.5 parts by weight, and each composition was dispersed in a ball mill for 24 hours. Thereafter, 1.5 parts by weight of Coronate L (manufactured by Nippon Polyurethane) was added to the supply layer formulation, and the mixture was sufficiently stirred.

Next, a sublimation type thermal transfer recording sheet S having a structure as shown in FIG. 1 was prepared as follows.

As described above, as shown in FIG. 2, the dye supply layer is formed in parallel with the dye receptive substance supply layer region 7 formed on the aromatic polyamide film substrate (manufactured by Toray Industries, Inc.) 1 using a wire bar. After applying the ink composition for 4 to a thickness of about 3.0 μm, the ink composition for dye transfer contributing layer 5 of the above formulation is further applied thereon to a thickness of about 0.8 μm. 2 was formed, and a sublimation type thermal transfer recording sheet S was manufactured.

[Print Recording Experiment] First, using the sublimation-type thermal transfer recording sheet S and the plain paper 3 provided with the dye-receptive supply layer region 7 and the ink layer region 2 in parallel, The recording density is 6 dots / m from the back of the sheet with the thermal head 6.
Under a printing condition of m and an applied energy of 1.60 mJ / dot, a solid thermal transfer of the dye receptive substance onto plain paper 3 was performed. As a result, a dye receiving layer made of a glossy resin was formed on one side of plain paper.

Next, an applied pressure of 442 m from the back surface of the sublimable ink layer region 2 adjacent to the dye receiving layer solid-transferred onto the plain paper 3
W / dot, maximum applied energy 2.21mJ / dot and
Density steps of 16 gradations were printed and recorded under the printing conditions of the speed ratio n = 5 between the image receiving sheet (plain paper) and the recording sheet. As a result, a good 16-gradation cyan image was formed on the dye receiving layer formed on the plain paper as shown in FIG.

Example 2 [Formation of Dye Receptive Substance Supply Layer Region] A dye receptive substance supply layer region was formed in exactly the same manner as in Example 1.

[Formation of Ink Layer Region] With respect to the cyan ink layer region 2C, an ink layer region was formed in exactly the same manner as in Example 1.

Next, for the magenta ink layer area 2M, instead of cyan Kayaset Blue 714, MS Red G
An ink layer region was formed in the same manner as in Example 1 except that a dye obtained by mixing (Mitsui Toatsu) and Macrolex Red Violet R (Bayer) at a mixing ratio of 2: 1 was used.

Further, for the yellow ink layer area 2Y, Macrolex Ye
An ink layer region was formed in exactly the same manner as in Example 1 except that llow 6G (manufactured by Bayer) was used. (FIG. 3) [Print Recording Experiment] The dye receiving layer was first transferred onto plain paper in the same manner as in Example 1, and the color image pattern was formed in the order of yellow, magenta and cyan in the same manner as in Example 1. As a result of recording, an image was formed under printing conditions with a speed ratio of n = 5.
A good color image with almost no decrease in density was formed.

[Effects of the Invention] As described above, according to the thermal transfer recording method of the present invention, by using a sublimation type thermal transfer recording sheet, the dye receptive substance supply layer region is printed solid on plain paper,
It can be transferred to plain paper with good adhesion without being stretched by the speed difference, and the ink layer area is n in the speed difference mode.
A large number of recordings can be performed without causing a rapid decrease in the transfer density even with an increase in the multiple, and a clear image can be obtained even on plain paper.

[Brief description of the drawings]

FIG. 1, FIG. 2 and FIG. 3 are explanatory views showing the structure of the sublimation type thermal transfer recording sheet of the present invention. FIG. 4 is a graph showing a multi-time printing characteristic of the sublimation type thermal transfer recording sheet of Example 1. DESCRIPTION OF SYMBOLS 1 ... Support, 2 ... Ink layer area 3 ... Plain paper, 4 ... Dye supply layer 5 ... Dye transfer contribution layer, 6 ... Thermal head 7 ... Dye receptive substance supply layer area 2Y ... Yellow sublimable ink layer area 2M: magenta sublimable ink layer area 2C: cyan sublimable ink layer area S: thermal transfer recording sheet

Continuation of the front page (56) References JP-A-1-206094 (JP, A) JP-A-62-297184 (JP, A) JP-A-1-225593 (JP, A) JP-A-63-170091 (JP) JP-A-1-2633084 (JP, A) JP-A-2-107482 (JP, A) JP-A-63-47193 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB Name) B41M 5/38-5/40

Claims (1)

(57) [Claims] An ink layer region comprising: (1) a dye supply layer formed by dispersing a sublimable dye in an organic binder; and a dye contributing layer on a substrate; and (2) at least a dye-receiving layer. A sublimation type thermal transfer recording sheet provided with a dye-receptive substance supply layer region made of a substance is used, and plain paper is used as a transfer-receiving sheet, and the dye-receptive substance supply layer region is solid-printed on plain paper. A sublimation type thermal transfer recording method using an n-fold mode method, wherein the ink layer area is printed by an n-fold mode method.