JPH0694232B2 - Method for manufacturing heat transfer sheet for sublimation transfer recording - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to a thermal transfer sheet, and more specifically, a thermal transfer sheet used in combination with a thermal transfer sheet for performing thermal printing according to image information by a thermal head or a laser. Regarding the seat.

TECHNICAL BACKGROUND OF THE INVENTION AND PROBLEMS THEREOF In order to obtain an image according to image information by a thermal head or a laser, a thermosensitive coloring paper has been mainly used conventionally. In this heat-sensitive color-developing paper, a colorless or light-colored leuco dye and a developer provided on the base paper are brought into contact with each other by heating to obtain a color-developed image. As such a color developer, a phenolic compound, a zinc salicylate derivative, rosin and the like are generally used. However, the above-mentioned thermosensitive coloring paper has a fatal defect that the obtained colored image is erased when stored for a long period of time,
Further, color printing is limited to two colors, and a color image having continuous gradation cannot be obtained.

On the other hand, in recent years, heat-sensitive transfer paper in which a heat-melting wax layer in which a pigment is dispersed is provided on a base paper has begun to be used. When the heat-sensitive transfer paper and the transfer-receiving paper are superposed and heat printing is performed from the back surface of the heat-sensitive transfer paper, the wax layer containing the pigment is transferred onto the transfer-receiving paper to obtain an image. According to such a printing method, a durable image can be obtained, and a multicolor image can be obtained by printing a plurality of times using a thermal transfer paper containing pigments of three primary colors. It is not possible to obtain a photographic image having continuous gradation.

By the way, in recent years, there has been an increasing demand for directly obtaining an image such as a photograph from an electric signal, and various attempts have been made.
One of such attempts is a method of displaying an image on a CRT and photographing it with a silver salt film, but when the silver salt film is an instant film, there is a drawback that running costs increase, and When the silver salt film is a 35 mm film, there is a drawback that it is not immediate because development processing is required after photography. As another method, an impact ribbon method or an inkjet method has been proposed, but the former has a drawback that the image quality is poor, and the latter requires image processing, so it is difficult to easily obtain an image like a photograph. It has the drawback of being difficult.

In order to eliminate such a defect, a thermal transfer sheet provided with a sublimable disperse dye layer having a property of being transferred by heating is used in combination with a heat transferable sheet, and the sublimable disperse dye is controlled on the heat transferable sheet. There has been proposed a method of shifting to obtain an image like a photograph with gradation. According to this method, an image having continuous gradation can be obtained from a television signal by a simple process, and a device used at that time is not complicated, and therefore, it is attracting attention. As one of the conventional techniques close to such a method, there is a dry transfer printing method of polyester fiber. In this dry transfer printing method, a dye such as a sublimable disperse dye is dispersed or dissolved in a synthetic resin solution. As a paint, apply this paint to thin paper etc. in a pattern and dry it to make a heat transfer sheet.This heat transfer sheet is superposed on polyester fiber which is a heat transfer sheet and heated closely to dye the disperse dye on the polyester fiber. Is a method of obtaining an image.

However, it is not possible to obtain a high density color image by superposing the thermal transfer sheet and the thermal transfer sheet made of polyester fiber as described above and heating and printing the thermal transfer sheet with a thermal head or the like. The reason is that the surface smoothness of the polyester fiber cloth is not good, but it is considered to be mainly due to the following reason. That is, in the usual dry transfer printing method or wet transfer printing method, the transfer of the sublimable dye onto the polyester fiber cloth is carried out for a sufficient heating time, whereas heating by a thermal head or the like is usually performed. It is very short, as a result of which the dye does not migrate well onto the fabric. By the way, in the dry transfer printing method, the transfer of the dye is achieved by heating at 200 ° C. for about 1 minute, whereas the heating by the thermal head is as short as about several msec at 400 ° C.

In order to solve such problems and obtain an image with sufficient density, the receptive layer of the heat transfer sheet is formed of a resin having a low glass transition point and high affinity with a dye, for example, a polyester resin (Vylon: Toyobo). It is under consideration. In this case, the dye easily penetrates into the receiving layer even with the heating energy of the thermal head, and a high-density image may be obtained.

However, in the above cases, when the thermal transfer sheet and the thermal transfer sheet are overlapped and heated and then both sheets are peeled off, the thermal transfer layer of the transfer sheet itself adheres to the receiving layer of the thermal transfer sheet. It is peeled off and transferred, and it becomes unusable at all. The cause is considered as follows.

(I) Polyethylene terephthalate (PET) is generally used as the base film of the thermal transfer sheet,
There are few binders for the transfer layer that adhere firmly to this base film.

(II) In order to obtain a high image density, it is necessary to use a resin having a low glass transition point and a low softening point as the receiving layer of the heat transfer sheet, but such a resin is generally softened by the energy applied by the thermal head. And show tackiness.

As a result of further research based on these facts, the present inventors have found that the above-mentioned drawbacks can be solved at once by using a heat transfer sheet having a specific configuration, and the present invention is completed. I arrived.

DISCLOSURE OF THE INVENTION Object of the Invention and Outline thereof The present invention is intended to solve the drawbacks associated with the prior art, and provides a thermal transfer sheet having a thermal transfer layer containing a heat transfer dye and a thermal transfer sheet having a specific structure. By using them in combination, it is intended to achieve the following objects.

(A) The thermal transfer layer of the thermal transfer sheet and the thermal transfer layer of the thermal transfer sheet are not thermally fused during the thermal transfer, and therefore the thermal transfer layer of the thermal transfer sheet adheres to the receiving layer of the thermal transfer sheet and peels off. To provide a thermal transfer sheet that does not.

(B) To obtain a color-developed image having high density, resolution, and continuous gradation directly from an electric signal as in a photograph.

In order to achieve the above object, in the present invention,
There is provided a thermal transfer sheet provided with a receiving layer having the following properties, and the thermal transfer sheet is used in combination with the thermal transfer sheet.

That is, the method for producing a heat transferable sheet according to the present invention,
In producing a thermal transfer sheet for sublimation transfer having a receiving layer on a substrate, which receives the dye transferred from the thermal transfer sheet when heated, a receiving layer containing a curable silicone oil The resin composition for forming is applied onto the base material and dried to form a receptor layer containing a dye-permeable release agent composed of a cured product of a curable silicone oil.

DETAILED DESCRIPTION OF THE INVENTION Hereinafter, preferred embodiments of the present invention shown in the drawings will be described.

As shown in FIG. 1, the heat transferable sheet 1 of the first aspect of the present invention is configured by providing a receiving layer 3 on a base material 2. As shown in FIG. 2, the heat-transferable sheet 1 of the second aspect of the present invention has a receptive layer 3 provided on a substrate 2, and a release agent on at least a part of the receptive layer 3. A layer 4 is provided and configured.

The release agent layer 4 may be provided on the entire surface of the receiving layer 3, but may be provided only on a part of the receiving layer 3 as shown in FIG.

The base material 2 has a role of holding the receiving layer 3, and since heat is applied during the thermal transfer, it is desirable that the base material 2 has a mechanical strength that does not hinder the handling even in a heated state.

Specific examples of such a base material 2 include flexible thin layer sheets such as condenser paper, glassine paper, sulfuric acid paper, highly sized paper, and plastic film. Of these, capacitor paper and polyethylene terephthalate film are often used, and when importance is attached to heat resistance, capacitor paper is mainly used, and when importance is attached to breakage resistance during handling by a mechanical device, polyethylene terephthalate film is used. Mainly used. The thickness of the base material 2 is usually 3 to
The thickness is 50 μm, preferably about 5 to 15 μm.

As described above, the receiving layer 3 of the heat-transferred sheet 1 has a function of receiving the dye transferred from the heat-transfer sheet when heated, and specifically, the following materials are used.

(A) Those having an ester bond Polyester resin, polyacrylic acid ester resin, polycarbonate resin, polyvinyl acetate resin, styrene acrylate resin, vinyl toluene acrylate resin, etc.

(B) Polyurethane resin etc.

(C) Those having an amide bond Polyamide resin and the like.

(D) Those having a urea bond, such as urea resin.

(E) Others having a highly polar bond Polycaprolactone resin, styrene-maleic anhydride resin, polyvinyl chloride resin, polyacrylonitrile resin, etc.

In addition to the above synthetic resins, mixtures or copolymers thereof may be used.

The receiving layer 3 can also be formed from two types of resins having different properties. For example, the first region of the receiving layer is formed of a synthetic resin having a glass transition temperature of −100 to 20 ° C. and a polar group, and the second region of the receiving layer is formed of a synthetic resin having a glass transition temperature of 40 ° C. or higher. Can be formed. Both the first region and the second region are exposed on the surface of the receiving layer, the first region occupies 15% or more of the surface, and the first regions exist in islands independent of each other. The longitudinal length of each section is 0.5 to 200.
It is preferably μm.

In the heat-transferable sheet 1 of the first aspect of the present invention, the dye-permeable release agent is contained in the receiving layer 3 made of the resin as described above.

As such a release agent, solid waxes, fluorine-based or phosphoric acid ester-based surfactants, silicone oils and the like are used. These compounds are preliminarily added to the resin forming the receptive layer, and the resulting resin mixture solution is coated on a substrate and dried to obtain a receptive layer. Each of the release agents will be specifically described below. To do.

The solid wax is preferably dispersed as fine particles in the resin forming the receiving layer 3. Therefore, it is preferable that the solid wax is treated with a ball mill, a sand mill or the like before being added to the resin. As the solid wax, polyethylene wax, amide wax, Teflon powder, etc. are used. The solid wax is added to the resin in an amount of 5 to 50% by weight, preferably 10 to 20% by weight, based on the weight of the resin. 5% by weight
If it is less than the above range, a sufficient releasing effect may not be obtained, and the thermal transfer layer may thermally adhere to the receiving layer. On the other hand, if the amount added exceeds 50% by weight, the dye transferred from the thermal transfer layer at the time of heating cannot be sufficiently received, so that the resulting image may not have sufficient resolution.

A fluorine-based or phosphoric acid ester-based surfactant is also added as a release agent in the resin forming the receiving layer. It is considered that the surfactant added to the resin partially appears on the surface of the receiving layer, and thus a releasing effect is obtained. As such a surfactant, specifically, as a phosphate compound, Plysurf A208S,
Prysurf A210G, Prysurf DB-01 (above Daiichi Kogyo Seiyaku), Gaffac RS-410, Gaffac RA-600, Gaffac RE610 (above Toho Chemical Industry), and fluorine-based surfactants as Unidyne DS501 and Unidyne DS502 ( Daikin Industries, FC430, FC431 (Sumitomo 3M), etc. This surfactant is contained in the resin in an amount of 0.5 wt.
Added in an amount of ~ 10% by weight. If the amount added is less than 0.5% by weight, a sufficient releasing effect cannot be obtained. If the addition amount exceeds 10% by weight, the surface of the receiving layer becomes sticky,
Dust easily adheres to the surface, and when the transfer layer and the receiving layer come into contact with each other, the dye in the transfer layer migrates to the receiving layer without heating, resulting in background staining.

Silicone oils are also added as a release agent in the resin forming the receiving layer. As silicone oil,
Oily ones can be used, but curable ones are preferable. Examples of the curable silicone oil include a reaction curable type, a photocurable type, and a catalyst curable type. Of these, reaction-curable silicone oils are particularly preferable.

When such a curable silicone oil is used as a release agent, the surface of the receiving layer may be sticky or dust may be attached, as compared with the case of the surfactant-based release agent described above. Therefore, it can be used in a large amount. The curable silicone oil can be added to the resin in an amount of 0.5 to 30% by weight based on the weight of the resin. If the amount added is less than 0.5% by weight, a sufficient releasing effect may not be obtained and the thermal transfer layer may thermally adhere to the receiving layer. On the other hand, if the amount added exceeds 30% by weight, the dye transferred from the thermal transfer layer during heating cannot be sufficiently received, so that the resulting image may not have a sufficient recording density.

The reaction-curable silicone oil is preferably a reaction-cured amino-modified silicone oil and epoxy-modified silicone oil. Specific examples of the amino-modified silicone oil include KF-39 manufactured by Shin-Etsu Chemical Co., Ltd.
3, KF-857, KF-858, X-22-3680, X-22-3801C etc. are used, while epoxy-modified silicone oil is KF.
-100T, KF-101, X-60-164, KF-103, etc. are used.

KS70 as a catalyst or photocurable silicone oil
5F-PS (catalyst), KS705F-PS-1 (catalyst), KS720, KS770-P
Examples include L-3 (catalyst) and KS774-PL-3.

As described above, the heat transferable sheet 1 according to the second aspect of the present invention is provided with the receiving layer 3 made of the resin on the base material 2,
Further, the release agent layer 4 is provided on at least a part of the receiving layer 3, and the release agent layer 4 is obtained by dissolving or dispersing the release agent in an appropriate solvent. It can be formed by applying the obtained solution or dispersion on the receiving layer 3 and then drying.

The thickness of the release agent layer is 0.01 to 5 μm, preferably 0.05 to
It is preferably 2 μm. Release agent layer thickness is 0.01μ
If it is less than m, a sufficient releasing effect cannot be obtained, while 5 μm.
When it exceeds, the permeability of the dye is hindered, which is not preferable.

As described above, the release agent layer 4 may be provided on the entire surface of the receiving layer 3, but may be provided only on a part of the receiving layer 3. In general, it is difficult to print a description or the like on the release agent layer, but it is possible to print it on the receiving layer. Therefore, when it is necessary to print on the heat transferable sheet, it is preferable to provide the release agent layer only on a part of the receiving layer.

The thermal transfer sheet 1 as described above is used in combination with the thermal transfer sheet. As shown in FIG. 4, a typical thermal transfer sheet 5 is constructed by providing a thermal transfer layer 7 on one surface of a support 6, and the thermal transfer layer 7 is included in the thermal transfer layer 7 when it is heated. The coloring material is transferred onto the heat transfer sheet.

Examples of such coloring materials include disperse dyes having a relatively small molecular weight of about 150 to 400, oil dyes, certain basic dyes, and intermediates that can be converted into these dyes. The heat transfer temperature, the heat transfer efficiency, the hue, the color rendering property, the weather resistance and the like are selected and used from among them.

The coloring material is dispersed in an appropriate synthetic resin binder that forms the thermal transfer layer, and provided on the support 6. As such a synthetic resin binder, it is usually preferable to select a binder that has high heat resistance and does not hinder the transfer of the coloring material that occurs when heated. For example, the following binders are used.

(I) Cellulose-based resin Ethyl cellulose, hydroxyethyl cellulose, ethyl hydroxycellulose, hydroxypropyl cellulose, methyl cellulose, cellulose acetate, cellulose acetate butyrate, etc.

(II) Vinyl resin Polyvinyl alcohol, polyvinyl acetate, polyvinyl butyral, polyvinyl pyrrolidone, polyester, polyacrylamide, etc.

Among the above synthetic resin binders, polyvinyl butyral resin or cellulose resin is preferable from the viewpoint of heat resistance and the like.

To provide the thermal transfer layer 7 on the support 6, the color material and the synthetic resin binder are kneaded together with a solvent or a diluent to prepare a coating composition for the thermal transfer layer, which is applied to the support 6 by an appropriate printing method or coating method. Should be provided in. In addition,
If desired, any additive may be added to the coating composition for the thermal transfer layer.

The basic structure of the thermal transfer sheet is as described above,
When the surface of the support is directly heated by a contact-type heating means such as a thermal head, as shown in FIG. 5, a lubricant such as wax or a lubricant such as wax is provided on the side of the support 6 where the thermal transfer layer is not provided. By providing the slippery layer 8 containing a release agent, it is possible to prevent fusion between the heating means such as a thermal head and the support and improve the slip.

The thermal transfer sheet and the thermal transfer sheet prepared as described above are laminated facing each other so that the thermal transfer layer of the thermal transfer sheet and the receiving layer of the thermal transfer sheet are in contact with each other, as shown in FIG. By applying thermal energy corresponding to the image information to the interface of (3), the coloring material in the thermal transfer layer can be transferred to the receiving layer according to the thermal energy.

The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

<Example-1> An ink composition for forming a receiving layer having the following composition was prepared, and coated on a base material, synthetic paper, YUPO FPG ^# 150, so that the dry coating amount was 4.0 g / m ² , and then dried. Then, a heat-transferred sheet was obtained.

Polyester resin: Vylon 200 (Toyobo): 1 part by weight Amino-modified silicone: KF-393 (Shin-Etsu Chemical Co., Ltd.): 0.03 parts by weight Epoxy-modified silicone: X-22-343 (Shin-Etsu Chemical Co., Ltd.)
………… 0.03 parts by weight Methyl ethyl ketone / toluene / cyclohexanone (weight ratio 4: 4: 2) ………… 9.0 parts by weight Next, an ink composition for forming a thermal transfer layer having the following composition was prepared and heat-treated on the back surface. A thermal transfer sheet was obtained by applying to a 9 μm thick PET so that the dry coating amount was 1.0 g / m ² and drying.

Disperse dye: KST-B-136 (Nippon Kayaku) ……………… 0.4 parts by weight Ethyl hydroxyethyl cellulose (Hercules) ………… 0.6 parts by weight Methyl ethyl ketone / toluene (weight ratio 1: 1) …………… 9.0 Parts by weight The thermal transfer layer of the obtained thermal transfer sheet and the receiving layer of the thermal transfer sheet are superposed in a state of facing each other, heated from the thermal transfer sheet side with a thermal head, printed, and then both sheets are peeled off. , The receiving layer and the transfer layer were easily peeled off, no peeling of the transfer layer resin to the receiving layer occurred, and a recorded image having continuous gradation was obtained.

<Example-2> An ink composition for forming a receiving layer having the following composition was prepared, and coated on a synthetic paper, YUPO FPG ^# 150, which was a base material, so that the dry coating amount was 4.0 g / m ² , dried, and received. Layers were formed.

Polyester resin: Vylon 200 (Toyobo) ……………… 1.0
Parts by weight Methyl ethyl ketone / toluene (weight ratio 1: 1) 9.0 parts by weight Next, a solution for forming a release agent layer having the following composition is applied to a mybar ^# 6.
Using the above, coated on the polyester resin layer, 100
Dry at 5 ° C for 5 minutes.

Amino-modified silicone: KF-393 1.0 parts by weight Epoxy-modified silicone: X-22-343 1.0 parts by weight Ethanol 25.0 parts by weight Isopropyl alcohol 23.0 parts by weight The release agent layer forming solution has a dry coating amount of about 0.15 g /
It was applied to give m ² . When this was recorded under the same printing conditions as in Example-1, thermal fusion of the thermal transfer layer to the receiving layer did not occur, and a good release paper was shown.

<Example-3> A polyester solution having the same composition as in Example-2 was applied to the entire surface of A5 size (148 mm x 210 mm) synthetic paper YUPO FPG ^# 150 and dried to form a receptive resin layer (dry. Coating amount 4.0g
/ m ² ).

Then, a release agent layer ink composition having the same composition as in Example-2 was applied to a half A6 size area by a gravure printing method,
After drying, a release agent layer was formed (release agent layer thickness: 0.1μ
m).

Next, sublimation transfer recording was carried out in the same manner as in the above-mentioned examples only on the portion where the release agent layer was formed. In this case as well, peeling of the transfer layer did not occur at all, and good releasability was exhibited. .

Next, thermal transfer printing with a wax was performed on the remaining polyester resin layer only with a thermal transfer printer TN5000 (Toshiba Corp.), and a clear black print was obtained, confirming the writing property.

<Example-4> An ink composition for forming a receiving layer having the following composition was prepared, applied to a synthetic paper YUPO FPG ^# 150 as a base material, and dried at 100 ° C for 10 minutes (dry coating amount: about 4.5 g / m ² ).

Polyester resin: Vylon 103 (Toyobo Tg = 47 ℃) …… 0.8 parts by weight EVA polymer plasticizer: Elvalloy 741P (Mitsui Polychemical Tg = -37 ℃) …… 0.2 parts by weight Amino-modified silicone: KF857 (Shin-Etsu) Chemical industry) ………… 0.04 parts by weight Epoxy-modified silicone: KF103 (Shin-Etsu Chemical Co., Ltd.) ………… 0.04 parts by weight Methyl ethyl ketone / toluene / cyclohexanone (weight ratio 4: 4: 2) ………… 9.0 parts by weight When printing was carried out in the same manner as in Example-1, good releasability was exhibited and no peeling of the transfer layer occurred.

The <Example -5> receptor layer forming ink composition having the following composition was prepared and coated and dried synthetic paper YUPO FPG ^# 0.99 as a base (dry coating amount of 4.0g / m ^2).

Polyurethane Elastomer (Dainippon Ink and Chemicals Pandex T5670 Tg = -35 ° C) 0.5 parts by weight Polyvinyl butyral (Sekisui Chemical, S-REC BX-1 Tg)
= 83 ° C) ………… 0.5 parts by weight Methyl ethyl ketone / toluene / ethyl cellosolve (weight ratio 4: 4: 2) ………… 9.0 parts by weight Next, a release agent layer forming solution having the same composition as in Example-2. Was coated on the receiving layer under the same conditions and dried to form a release agent layer.

When this was printed with a thermal head in the same manner as in Example-1, the transfer layer did not heat-bond to the receiving layer and showed good peelability.

[Brief description of drawings]

1, 2, and 3 are cross-sectional views of the heat transfer sheet according to the present invention, and FIGS. 4 and 5 are cross-sectional views of the heat transfer sheet used in combination with the heat transfer sheet. , FIG. 6 is a cross-sectional view when a heat transfer sheet and a heat transfer sheet are used in combination. 1 ... Thermal transfer sheet, 2 ... Base material, 3 ... Receptive layer, 4
...... Release agent layer, 5 ...... Thermal transfer sheet, 6 ...... Support, 7
...... Heat transfer layer, 8 …… Slippery layer.

 ─────────────────────────────────────────────────── ─── Continuation of front page (56) Reference JP-A-56-89983 (JP, A) JP-A-60-212394 (JP, A) JP-A-59-165688 (JP, A)

Claims (4)

[Claims] 1. A curable silicone oil is used for producing a thermal transfer recording sheet for sublimation transfer recording in which a receiving layer for receiving a dye transferred from the thermal transfer sheet when heated is provided on a substrate. The receiving layer-forming resin composition containing is applied onto the substrate and dried to form a receiving layer containing a dye-permeable release agent composed of a cured product of a curable silicone oil. Characterized by that
A method for producing a thermal transfer sheet for sublimation transfer recording. 2. The method according to claim 1, wherein the reaction-curable silicone oil is selected from reaction-curable silicone oil, photo-curable silicone oil or catalyst-curable silicone oil. 3. A cured product of the curable silicone oil,
The method according to claim 1, comprising a reaction-cured product of an amino-modified silicone and an epoxy-modified silicone. 4. The release agent is contained in the receiving layer in an amount of 0.
A method according to claim 1, which is present in an amount of 5 to 30% by weight.