JPH1170752A - Sublimation type heat transfer body and method for heat transfer recording using this - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent fusing between an ink layer and an image receiving layer from being generated, poor running of a sheet in a speed difference mode method from occurring and crease on a heat transfer body from being generated by making filling ratio of the ink layer contg. a particulate sublimating dye provided on a base at least at a specified ratio. SOLUTION: Filling ratio of an ink layer contg. a particulate sublimating dye provided on a base at least 75%. This ink layer may be constituted of a dye supplying layer wherein a sublimating dye is dispersed in an org. binder and a layer contributing sublimating transfer. In addition, an intermediate layer may be provided between an ink layer and a base. It is possible thereby to improve heat resistance of the ink layer, to prevent fusing between the ink layer of the heat transfer body and an image receiving layer of an image receiving medium from being generated, to obtain a high speed difference in the same film thickness value and to obtain a highly sensitive image at the same amt. of the dye. It is also possible thereby to prevent poor running of a sheet in a speed difference mode method and to prevent crease on the heat transfer body from being generated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sublimation type thermal transfer member used for a copying machine, a printer, and the like, and more particularly, to a thermal transfer method (speed difference mode method) in which the transfer speed of a transfer object is made higher than the transfer speed of a thermal transfer member. The present invention relates to a sublimation-type thermal transfer member suitable for multiple-time recording according to (1).

[0002]

2. Description of the Related Art In recent years, demand for full-color printers has been increasing year by year. The recording method of this full-color printer includes an electrophotographic method, an ink-jet method, and a thermal transfer method. Among them, the thermal transfer method is often used because of easy maintenance and no noise. In this thermal transfer method, an ink layer in which a colorant is dispersed in a hot-melt substance or a thermal transfer sheet (a so-called color ink sheet) in which an ink in which a sublimation dye is dispersed in a resin binder is provided on a substrate. An image is formed by superimposing an image receiving sheet on the image receiving sheet and applying thermal energy controlled by an electric signal from a laser or a thermal head from the recording medium side to transfer the ink of that portion to the image receiving sheet by thermal fusion transfer or sublimation. It is a recording method. By the way, in the thermal transfer recording method, recording media used are roughly classified into a heat melting type and a sublimation transfer type. In particular, in the latter case, the dye is monomolecular in principle in response to heat energy from a thermal head or the like. This method has an advantage that halftones can be easily obtained because the image is transferred by using the method, and is considered to be a method most suitable for a full-color printer. As one of the sublimation type thermal transfer recording methods, the speed of the image receiving sheet is set to n times (n
An n-fold speed difference mode method has been proposed in which recording is carried out a number of times by repeated printing in a state where both sheets are running in the condition of> 1).

However, when the thermal transfer member is heated by the thermal head, fusion occurs between the ink layer of the image receiving sheet and the dye receiving layer of the image receiving sheet, resulting in poor sheet running, wrinkling of the thermal transfer member, and the like. There is. In order to solve the above-mentioned problem, JP-A-2-2073 discloses that
It has been proposed to add a reactant of a reactive silicone oil into the ink layer to keep the energy on the surface of the ink layer low and ensure slippage between the surface of the ink layer and the surface of the receiving layer. However, even this method does not provide a sufficiently satisfactory bone property between the ink layer and the dye receiving layer, and there is still a risk that sticking due to heat fusion may occur.

[0004]

SUMMARY OF THE INVENTION According to the present invention, in the speed difference mode method, there is no fusion between the ink layer and the image receiving layer, and no poor running of the sheet and no wrinkling of the thermal transfer member occur even at a high speed difference. It is an object of the present invention to provide a sublimation type thermal transfer member having a high image density.

[0005]

According to the present invention, in a sublimation-type thermal transfer member in which an ink layer containing a particulate sublimable dye is provided on a substrate, the filling rate of the ink layer is 75% or more. A sublimation-type thermal transfer member is provided.
Further, according to the present invention, there is provided a sublimation-type thermal transfer member characterized in that a dye supply layer containing a particulate sublimable dye and a sublimation transfer contributing layer are provided on a substrate. Furthermore, there is provided a sublimation-type thermal transfer body, comprising an intermediate layer between the ink layer and the substrate. Further, according to the present invention, in the sublimation type thermal transfer recording using the above-described sublimation type thermal transfer body and the transferred body, the thermal transfer recording method wherein the recording speed of the sublimation type thermal transfer body is 1/10 or less of the recording speed of the transferred body. Is provided.

In general, it is known that the density of the ink layer of this type of sublimation type thermal transfer body changes mainly depending on the particle size of the sublimable dye and the drying conditions at the time of film formation. According to the present invention, by setting the filling rate of the ink layer to 75% or more, preferably 90% or more, the heat resistance of the ink layer is improved, and thereby, the difference between the ink layer of the transfer body and the image receiving layer of the image receiving medium is improved. Fusion can be prevented. In addition, the present invention provides a filling rate of 75
% Or more, a high speed difference can be obtained at the same film thickness, and a highly sensitive image can be obtained at the same dye amount. Unlike the ink layer in which the dye is dissolved, the dispersed ink layer in which the particulate dye is present in the ink layer has voids in the ink layer. This is not so much affected by the general constant velocity mode method. However, in the velocity difference mode method, when lateral shear stress is applied to the ink layer, the ink layer strength is reduced, and the ink layer is destroyed or the ink layer is broken. Due to the deformation, the shear separation between the ink layer and the image receiving layer is not performed smoothly, which causes a stick phenomenon. When the filling rate of the ink layer is less than 75%, the strength of the film is insufficient, causing fusion or sticking, and the voids may cause unevenness of the image, thereby achieving the intended object of the present invention. Can not. In the present invention, in order to improve the effect of preventing fusion and the like, it is preferable that the constitution of the ink layer be a dye supply layer and a dye transfer contributing layer. Further, in the present invention, by providing an intermediate layer between the ink layer and the substrate, the effect of preventing sticking and fusion can be further promoted.

The sublimable dyes used in the present invention include:
A particulate dye that sublimates or vaporizes at 60 ° C. or higher,
Any disperse dyes, oil-soluble dyes and the like used in thermal transfer printing may be used. I. Disperse Yellow 1, 3, 8, 9, 16, 41, 54, 60, 77,
116 and the like. I. Disperse thread 1, 4,
6, 11, 15, 17, 55, 59, 60, 73, 83
C. I. Disperse Blue 3, 14, 19,
26, 56, 60, 64, 72, 99, 108, etc.
C. I. Solvent Yellow 77, 116, C.I.
I. Solvent Red 23, 25, 27, C.I.
I. Solvent Blue, such as 36, 83 and 105, can be used as one kind of these dyes, but can be used even if several kinds are mixed.

The high molecular compounds in the intermediate layer, the dye transfer contributing layer and the dye supply layer include polyvinyl butyral, polyvinyl acetal, polyurethane polyol,
Polyether polyol, polyester polyol, acrylic, acrylic-polyester copolymer, alkyd,
Silicone polyesters and epoxy resins in which an epoxy group of an epoxy is opened with an alkanolamine to form an -OH group may be used.
As isocyanates to be contained as necessary, di-
Or triisocyanate is effective, for example, 2,4
-Tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, triphenylmethane triisocyanate, isophorone diisocyanate, bis isocyanate methyl cyclohexane, trimethyl hexamethylene diisocyanate, etc. . Among them, polyvinyl butyral is particularly preferable because it has a suitable interaction with the dye to be used and can achieve both barrier property against dye diffusion and ribbon storage stability. 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 a 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.

When a difference is made between the dye transfer contributing layer and the dye supply layer with respect to the glass transition or softening temperature, 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 preferred. Specifically, syndiotactic 1,2-polybutadiene (JIS RB810, 820, 830 Nippon Synthetic Rubber as a commercial product);
Olefin copolymers and terpolymers containing an acid or non-acidic acid (Dexon XEA-7, Dexon Chemical as commercial products);
00 & 400A, 405, 430, Allied Fibers & Plastics: P-3307 (EV150),
P-2807 (EV250), Mitsui / Dupont Polychemical); low molecular weight polyolefin polyols and derivatives thereof (commercially available products: Polytail H, HE Mitsubishi Kasei Kogyo: brominated epoxy resin (YDB-340, 400, 5)
Novolak type epoxy resin (YDCN-701, 702, 703 Toto Kagaku); Thermoplastic acrylic solution (Tynal LR107)
5, 1080, 1081, 1082, 1063, 107
9 Mitsubishi Rayon); thermoplastic acrylic emulsion (L
X-400, LX-450 Mitsubishi Rayon); polyethylene oxide (Alcox E-30, 45, Alcox R-150, 400, 1000 Meisei Chemical); caprolactone polyol (Braccel H-1, 4, 7,
(Daicel Chemical Industries, Ltd.), etc., and polyethylene oxide and polycaprolactone polyol are particularly useful in practice, and it is preferable to use the above-mentioned thermoplastic or thermosetting resin in a form mixed with one or more of the above. preferable.

In the recording method based on the speed difference mode method, it is necessary to incorporate a lubricating substance in the ink layer or the dye transfer contributing layer, or to provide a lubricating layer on the ink layer if necessary. is there. As the lubricating substance to be contained, oils, waxes, fluorine-based surfactants and the like are used, and among them, modified silicone oils such as epoxy-modified silicone oil, alcohol-modified silicone oil and carboxyl-modified silicone oil are preferable. The content is preferably 5 to 30% by weight of the containing layer. The lubricating layer is formed by adding the above-mentioned lubricant to a silicone graft resin or a silicone resin.

As the base sheet, a film such as a condenser paper, a polyester film, a polystyrene film, a polysulfone film, a polyimide film, and a polyamide film is used.

In the present invention, the dye concentration in the dye transfer contributing layer has the following relationship with respect to the dye concentration relationship and / or the diffusion coefficient of the lower layer in which the particulate sublimable dye is present (dye supply layer). I. Regarding the dye concentration, dye supply layer> dye transfer contributing layer II. Regarding the diffusion coefficient in each layer, dye supply layer> dye transfer contributing layer Regarding the above II, as a specific method of operating the diffusion coefficient, for example, Toyoko Sakai et al., Vol. 30. N
o. 12 (1974): Norihiko Kuroki, "Dye Theory Chemistry," published by Maki Shoten p. 503-1st non-impact printing technology symposium, 3-5. As a method for realizing the above II with reference to these, for example, (1) The diffusion coefficient is influenced by the energy suppression effect on the dye diffusion due to the hydrogen bond between the dye and the organic binder, and the A method using, as a binder of a layer, an organic polymer material containing a large amount of a proton-supplying group or a proton-accepting group that easily forms a hydrogen bond with a sublimation dye. (2) The diffusion coefficient depends on the glass transition or softening temperature of the organic binder in which the dye is dispersed. The diffusion coefficient becomes larger when the glass transition or softening temperature is lower than the temperature characteristics of the layer during printing in this process. Therefore, a method in which a substance having a lower glass transition temperature or lower softening temperature than that of the transition contributing layer is used as the organic binder in the dye supply layer. (3) The dye supply layer contains a plasticizer that is compatible with at least one organic binder in the dye supply layer and is incompatible with all the organic binders in the transfer contributing layer. How to let. (4) A method in which the above methods (1), (2) and (3) are appropriately combined. The method is not limited to these methods as long as the relationship between the diffusion coefficients is satisfied.

As a method for dispersing the sublimable dye, there are a ball mill, a roll mill, a sand grinder and the like. In the present invention, the particle size of the sublimable dye obtained by dispersion has a large effect. Sublimation dye particle size is 0.1 ~ 2.0μ
m, preferably 0.1 to 0.8 μm.

As a method of applying the ink layer containing the particulate dye, there are a roll coater, a nozzle coater, gravure printing, screen printing, a rod coater and the like. The condition of the process of evaporating the solvent from the film) is important. This is because the dispersion state is destroyed during the film formation process, aggregation occurs, and the density tends to decrease due to the formation of cells by convection. In order to prevent this, it is necessary to prevent rapid evaporation of the solvent at the time of film formation. As a method for this, a solvent having a low evaporation rate is used as the solvent of the dispersion. In the present invention, a solvent having an evaporation rate lower (lower) than butyl acetate is preferable. It is also effective to set the liquid solids higher. The ratio of the solvent component is preferably from 50 wt% to 90 wt%.

As a drying condition in a wet state after the application, when the wind is directly applied to the application surface, it is effective to reduce the wind speed, and preferably 20 m / min or less. The temperature is preferably set lower, and is preferably 50 ° C. or lower.

The filling rate (%) of the ink layer in the present invention is:
It is expressed by the ratio between the ideal amount of adhesion calculated from the specific gravity of the material used, the ink layer thickness, and the mixing ratio and the amount of adhesion actually calculated, and is a value obtained by the following equation. Ink layer filling rate (%) = Actual adhesion amount / Ideal adhesion amount × 1
00

The thickness of the ink layer of the thermal transfer member of the present invention is
0.1 to 20 μm, preferably 0.5 to 10 μm, the thickness of the dye transfer contributing layer is 0.1 to 5 μm, preferably 0.1 to 2 μm, and the thickness of the intermediate layer is 0.1 to 10 μm. 2.0
μm, preferably 0.1 to 1.0 μm.

[0018]

Next, the present invention will be described more specifically with reference to examples. All parts shown below are parts by weight.

Example 1 6 μm having a silicone resin-based heat-resistant layer as a base sheet
Using an aromatic polyamide film having a thickness of m, the following ink layer (solution A) was applied with a wire bar to a thickness of 5.0 μm, and then dried under the following conditions: The composition was thermally cured at 80 ° C. for 24 hours to obtain a thermal transfer member. (Solution A) Polyvinyl butyral 10 parts (ESREC BX1, manufactured by Sekisui Chemical Co., Ltd.) Sublimation dye (Kayaset Blue 714, manufactured by Nippon Kayaku) 8 parts Diisocyanate (Takenate D-110N, Takeda Pharmaceutical) 30 parts Epoxy-modified silicone 5 Part (SF-8411, manufactured by Toray Silicone Co., Ltd.) 250 parts of n-butanol Dispersion condition: dispersion method: Pearl mill dispersion (manufactured by Ashizawa Co., Ltd.) Beads: diameter: 1.5 mm Shaft rotation speed: 500 rpm Average particle diameter: 0.6 μm Dry to the touch: Natural leaving (22.0 ° C, 55% humidity)

Example 2 6 μm having a silicone resin-based heat-resistant layer as a base sheet
Using an aromatic polyamide film having a thickness of m, the following ink layer (solution B) was applied by screen printing so as to have a thickness of 5.0 μm, and then dried under the following conditions: touch drying (the wet state is completed); The composition was thermally cured at 80 ° C. for 24 hours to obtain a thermal transfer member. (Solution B) Polyvinyl butyral 10 parts (ESREC BX1, manufactured by Sekisui Chemical Co., Ltd.) Sublimation dye (Kayaset Blue 714, manufactured by Nippon Kayaku) 30 parts Diisocyanate (Takenate D-110N, Takeda Pharmaceutical) 3 parts Epoxy-modified silicone 5 Part (SF-8411, manufactured by Toray Silicone Co., Ltd.) 100 parts of n-butanol Dispersion condition: dispersion method: Pearl mill dispersion (manufactured by Ashizawa Co., Ltd.) Beads: diameter: 1.5 mm Shaft rotation speed: 500 rpm Average particle size: 0.7 μm Drying to the touch: Natural leaving (22.0 ° C., humidity 55%) The density of the obtained thermal transfer member is calculated from the film thickness and the weight. Thickness gauge: K-402B Anritsu Weight scale: AG245 METTLER

Comparative Examples 1 and 2 As in Example 1, a 6 μm-thick aromatic polyamide film having a silicone resin-based heat-resistant layer was used as a base sheet, and a wire bar was used so that the ink layer (solution A) had a thickness of 5.0 μm. , And then dried under touch conditions (wet state is completed) under the following conditions, and thermally cured at 80 ° C for 24 hours to obtain a thermal transfer member. Comparative Example 1 Touch Drying: Cold Air Drying for 5 min (22.5
Comparative Example 2 Touch drying: Warm air drying 5 min (30.0 ° C)
℃, 1m / min)

Comparative Example 3 As in Example 1, a 6 μm-thick aromatic polyamide film having a silicone resin-based heat-resistant layer was used as a base sheet.
The following ink layer (C solution) was coated with a wire bar to a thickness of 5.0 μm, and then dried under touch (to complete the wet state) under the following conditions. Obtained. (Solution C) Polyvinyl butyral 10 parts (ESREC BX1, manufactured by Sekisui Chemical Co., Ltd.) Sublimation dye (Kayaset Blue 714, manufactured by Nippon Kayaku) 8 parts Diisocyanate (Takenate D-110N, Takeda Pharmaceutical) 30 parts Epoxy-modified silicone 5 Part (SF-8411, manufactured by Toray Silicone Co., Ltd.) 250 parts of methanol Dispersion conditions: dispersion method: pearl mill dispersion (manufactured by Ashizawa) Beads: diameter: 1.5 mm Shaft rotation speed: 500 rpm Average particle size: 0.7 μm Touch drying: natural Leave (22.0 ° C, humidity 55%)

Comparative Example 4 As in Example 1, a 6 μm-thick aromatic polyamide film having a silicone resin-based heat-resistant layer was used as a base sheet.
The following ink layer (D solution) was applied with a wire bar so as to have a thickness of 5.0 μm, and then dried under the conditions of touch-drying (wet state is completed). Obtained. (D solution) Polyvinyl butyral 10 parts (ESREC BX1, manufactured by Sekisui Chemical Co., Ltd.) Sublimation dye (Kayaset Blue 714, manufactured by Nippon Kayaku) 8 parts Diisocyanate (Takenate D-110N, Takeda Pharmaceutical) 30 parts Epoxy-modified silicone 5 Part (SF-8411, manufactured by Toray Silicone Co., Ltd.) 250 parts of n-butanol Dispersion conditions: dispersion method: Pearl mill dispersion (manufactured by Ashizawa) Beads: diameter: 2.0 mm Shaft rotation speed: 300 rpm Average particle diameter: 0.9 μm Dry to the touch : Natural leaving (22.0 ° C, humidity 55%)

The thermal transfer member obtained as described above was formulated according to the following formulation (E
Liquid) under the following printing conditions using an image receiving sheet. Table 1 shows the results. (E liquid) Vinyl chloride / vinyl acetate / vinyl alcohol copolymer 10 parts (VACH: manufactured by Union Carbide Co.) Isocyanate (Coronate L: manufactured by Nippon Polyurethane Industry Co., Ltd.) 5 parts Amino-modified silicone 0.5 part (SF-8411) Epoxy-modified silicone 0.5 part (SF-8411, manufactured by Toray Silicone Co., Ltd.) Toluene 40 parts Methyl ethyl ketone 40 parts Printing conditions: applied voltage 160 mV / dot Thermal head 12 dot / mm Maximum pulse width 5 ms Speed difference ( (Image receiving sheet / thermal transfer member) n = 7

[0025]

[Table 1]

Examples 3 and 4 On the ink layer on which Examples 1 and 2 were formed, the following (D)
Liquid) with a wire bar so as to have a film thickness of 0.8 μm, and then thermally cured at 80 ° C. for 24 hours to obtain a thermal transfer member. (Solution F) Polyvinyl butyral 10 parts (S-LEC BX1, manufactured by Sekisui Chemical Co., Ltd.) Diisocyanate (Takenate D-110N, Takeda Pharmaceutical) 30 parts Carboxy-modified silicone 5 parts (SF-8418, manufactured by Toray Silicone Co., Ltd.) n-butanol 90 Parts ethanol 90 parts

Comparative Example 5 On the ink layer on which Comparative Example 1 was formed, (D solution) was further applied with a wire bar to a film thickness of 0.8 μm.
The composition was thermally cured at 0 ° C. for 24 hours to obtain a thermal transfer member.

The thermal transfer medium obtained as described above was subjected to printing and recording under the same image-receiving sheet and printing conditions as in Example 1 except that the speed difference was n = 13. Table 2 shows the results.

[0029]

[Table 2]

Examples 5, 6, 7 6 μm having a silicone resin-based heat-resistant layer as a base sheet
Using an aromatic polyamide film having a thickness of m, the following (Solution G)
After coating with a wire bar to a thickness of 1.0 μm,
Further, Examples 1, 2, and 3 were laminated thereon to obtain a thermal transfer member. (D solution) Polyvinyl butyral 10 parts (ESREC BX1, manufactured by Sekisui Chemical Co., Ltd.) Diisocyanate (Takenate D-110N, Takeda Pharmaceutical) 30 parts Toluene 90 parts Methyl ethyl ketone 90 parts

Comparative Examples 6 and 7 6 μm having a silicone resin-based heat-resistant layer as a base sheet
Using an aromatic polyamide film having a thickness of m, the above (G solution)
After coating with a wire bar to a thickness of 1.0 μm,
Further, Comparative Examples 1 and 5 were laminated thereon to obtain a thermal transfer member.

The thus obtained thermal transfer medium was subjected to printing and recording under the same image receiving sheet and printing conditions as in Example 1 at a speed difference n = 18. Table 3 shows the results.

[0033]

[Table 3]

Example 8 and Comparative Example 8 Using the thermal transfer bodies of Example 7 and Comparative Example 7, printing was performed under the following printing conditions at the following speed differences. Table 4 shows the results. Printing conditions: speed difference n = 6, 8, 10, 12, 14

[0035]

[Table 4]

[0036]

According to the first aspect of the present invention, the heat resistance of the ink layer is improved by setting the filling rate of the ink layer to 75% or more, whereby the ink layer of the transfer body and the image receiving layer of the image receiving medium are improved. Fusion can be prevented, a high speed difference can be achieved at the same film thickness, and a highly sensitive image can be obtained at the same dye amount. According to the second aspect of the present invention, since the ink layer is composed of the dye supply layer and the dye transfer contributing layer, the fusion between the ink layer and the image receiving layer of the image receiving medium can be further reduced. According to the third aspect of the present invention, by providing an intermediate layer between the ink layer and the substrate, the effect of preventing sticking and fusion can be further enhanced. According to the fourth aspect of the present invention, there is no fusion between the ink layer and the image receiving layer, no poor running of the sheet and no wrinkling of the thermal transfer body even at a high speed difference, and thermal transfer recording with high image density is possible.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Hiroki Kuboyama 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd.

Claims (4)

[Claims] 1. A sublimation type thermal transfer body having an ink layer containing at least a particulate sublimable dye, wherein the filling rate of the ink layer is 75% or more. 2. The sublimation type thermal transfer body according to claim 1, wherein said ink layer comprises a dye supply layer in which a sublimable dye is dispersed in an organic binder and a sublimation transfer contributing layer. 3. The sublimation-type thermal transfer member according to claim 1, further comprising an intermediate layer between said ink layer and said substrate. 4. A sublimation-type thermal transfer recording using the sublimation-type thermal transfer body and the transfer-receiving body according to any one of claims 1 to 3,
The recording speed of the sublimation type thermal transfer member is 1/1 / of the recording speed of the transfer member.
A thermal transfer recording method, wherein the number is 10 or less.