JPS6127290A - Thermal transfer sheet - Google Patents

Abstract

PURPOSE:To enable images with high density and continuous gradation to be obtained while preventing a thermal transfer layer of a thermal transfer sheet from sticking to and being transferred to a receiving layer of a thermal transfer recording sheet, by incorporating a dye-permeable releasing agent into the receiving layer for a dye transferred from the thermal transfer sheet. CONSTITUTION:The thermal transfer recording sheet 1 comprises the receiving layer 3 provided on a base 2, with a dye-permeable releasing agent incorporated in the layer 3. By this, the receiving layer of the thermal transfer recording sheet and the thermal transfer layer of the thermal transfer sheet are prevented from being welded to each other at the time of thermal transfer. Accordingly, it is possible to obtain a thermal transfer recording sheet free of the problem that the thermal transfer layer of the thermal transfer sheet sticks to and is transferred to the receiving layer of the thermal transfer recording sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a thermal transfer sheet, and more particularly, to a thermal transfer sheet used in combination with a thermal transfer sheet, in which thermal printing is performed according to image information using a thermal head or laser. The present invention relates to a thermal transfer sheet.

Technical aspects of the invention and its problems Heat-sensitive coloring paper has conventionally been mainly used to analyze images according to image information using a thermal head or laser. In this heat-sensitive coloring paper, a colorless or light-colored leuco dye provided on a base paper and a color developer are brought into contact with each other by heating to obtain a colored image. As such color developers, phenolic compounds, zinc salicylate derivatives, rosin, etc. are generally used. However, the above-mentioned heat-sensitive color paper has the fatal disadvantage that the color images obtained become overcolored when stored for a long period of time, and color printing is limited to two colors, and colors with continuous gradation cannot be used. It was not possible to obtain an image.

On the other hand, thermal transfer paper, which has a heat-melting wax layer in which pigments are dispersed on a base paper, has recently begun to be used. When the thermal transfer paper and the transfer paper are placed one on top of the other and thermal printing is performed from the back side of the thermal transfer paper, the wax layer containing the pigment is transferred onto the transfer paper to obtain an image. According to such a printing method, a durable image can be obtained, and
Multicolor images can be obtained by printing multiple times using thermal transfer paper containing pigments of the three primary colors, but it is not possible to obtain photographic images with essentially continuous gradation.

Incidentally, in recent years, there has been a growing demand for obtaining photograph-like images directly from electrical signals, and various attempts have been made to do so.

One such attempt is to project an image on a CRT and photograph it using silver halide film, but if the silver halide film is an instant film, it has the disadvantage of high running costs. , and 35m of silver halide film.
In the case of film, development processing is required after photographing, so there is a drawback that there is no immediacy. As another method, an impact ribbon method or an inkjet method has been proposed, but the former has the disadvantage of poor image quality, and the latter requires image processing, making it difficult to easily obtain photographic images. It has the disadvantage of being ugly.

In order to eliminate these drawbacks, a thermal transfer sheet with a sublimable disperse dye layer having a property of transferring when heated is used in combination with a thermal transfer sheet, and the sublimable disperse dye is transferred while being controlled. Transferred onto the thermal transfer sheet
A method has been proposed to obtain a photograph-like image with gradation. According to this method, a continuous Ni1l image can be obtained from a television signal through simple processing, and the method used in this process is not complicated, so it is attracting attention. One of the conventional techniques similar to this method is the dry transfer printing method for polyester fibers.This dry transfer printing method involves dispersing or dissolving dyes such as sublimable disperse dyes in a synthetic resin solution. This paint is applied in a pattern onto tissue paper, etc., and dried to form a thermal transfer sheet.The thermal transfer sheet is placed on a polyester fiber, which is the sheet to be thermally transferred, and heated in close contact to dye the polyester fiber with a disperse dye. This is a method of obtaining images by

However, even if a thermal transfer sheet as described above and a thermal transfer sheet made of polyester fiber are overlapped and printed by heating with a thermal head or the like, a high-density color image cannot be obtained. The reason for this may be that the surface smoothness of the polyester fiber cloth is not good, but it is thought that the main reason is as follows. In other words, in the normal dry transfer printing method or wet transfer printing method, the sublimation dye is transferred onto the polyester fiber cloth by a sufficient heating time, whereas the transfer of the sublimable dye onto the polyester fiber cloth is carried out by heating with a thermal head or the like. This is because the length is usually very short, so that the dye does not transfer sufficiently onto the fabric. Incidentally, in the dry transfer printing method, dye transfer is achieved by heating at 200°C for about 1 minute, whereas heating with a thermal head is as short as about several -5 ec at 400°C.

In order to solve these problems and obtain images with sufficient density, the receiving layer of the thermal transfer sheet 1- is made of a resin having a low glass transition point and high affinity for dyes, such as polyester resin (Vylon: Toyobo Co., Ltd.). It is being considered to form a In this case, the dye is likely to penetrate into the receiving layer even with one heating energy of the υ-nle head, and a high-density image may be obtained.

However, in the above case, after the thermal transfer sheet and the thermal transfer sheet are overlapped and heated, both sheets 1
When attempting to peel off . . . , the thermal transfer layer itself of the transfer sheet adheres to the receiving layer of the thermal transfer sheet and is peeled off, resulting in a product that is completely unusable. The reason for this is thought to be as follows.

(I) Polyethylene terephthalate (PET) is generally used as the base film of a thermal transfer sheet, but there is little transfer layer binder that firmly adheres to this base film.

(It) In order to obtain a high image mti, it is necessary to use a resin with a low glass transition point and low softening point as the receiving layer of the thermal transfer sheet, but such resins generally soften due to the energy applied by the thermal head. death,
To exhibit stickiness.

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 thermal transfer sheet having a specific configuration, and have completed the present invention. It's arrived.

The object of the present invention is to solve the drawbacks associated with the prior art by combining a thermal transfer sheet having a thermal transfer layer containing a thermally transferable dye and a thermal transfer sheet having a specific structure. By using it, we aim to achieve the following objectives.

(a) During thermal transfer, the receiving layer of the thermal transfer layer and the thermal transfer layer of the thermal transfer sheet are not thermally fused, 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 cause any damage.

(b)! Taka'amaro as shown in the photo directly from the Qi signal,
To obtain a colored image having resolution and continuous gradation.

In order to achieve the above objects, in the present invention,
A thermal transfer sheet provided with a receptor layer having the following properties is provided, and this thermal transfer sheet is used in combination with the thermal transfer sheet.

That is, the thermal transfer sheet of the first aspect of the present invention comprises a base material and a receptor layer that receives the dye that migrates from the thermal transfer sheet when heated (this receptor layer is provided on the base material). ), and is characterized in that the receptor layer contains a dye-permeable release agent.

Further, the thermal transfer sheet of the second aspect of the present invention includes a base material, a receptor layer provided on the base material that receives the dye that migrates from the thermal transfer sheet when heated, and a receptor layer provided on the base material that receives the dye that migrates from the thermal transfer sheet when heated. It is characterized by having a dye-permeable release agent layer provided on at least a portion of the layer.

DETAILED DESCRIPTION OF THE INVENTION The present invention will now be described with reference to preferred embodiments shown in the drawings.

As shown in FIG. 1, the thermal transfer sheet 1 according to the first aspect of the present invention includes a receiving layer 3 provided on a base material 2. Further, in the thermal transfer sheet 1 of the second aspect of the present invention, as shown in FIG. A chemical layer 4 is provided.

The release agent layer 4 may be provided over the entire surface of the receptor layer 3, or may be provided only on a portion of the receptor layer 3, as shown in FIG.

The base material 2 plays the role of holding the receptor layer 3, and since heat is applied during thermal transfer, it is desirable that the base material 2 has sufficient mechanical strength that there is no problem in handling it even in a heated state.

Specific examples of such a base material 2 include flexible thin-layer sheets such as condenser paper, glassine paper, parchment paper, highly sized paper, and plastic film. Among these, condenser paper and polyethylene pre-7 tallate film are often used.Condenser paper is mainly used when heat resistance is important, and polyethylene Terephthalate film is mainly used. The thickness of this base material 2 is usually 3-
50 x m , preferably 5 to 15 μl rLw*.

As mentioned above, the receptor layer 3 of the thermal transfer sheet 1 has the function of receiving and receiving the dye that migrates from the thermal transfer sheet when heated, and specifically, the following materials are used. .

(a) Materials with ester bonds: polynisder resin, polyacrylic acid ester resin, polycarbonate resin, polyvinyl acetate resin, styrene acrylate resin, vinyl toluene acrylate resin, etc.

(b) Those with urethane bonds polyurethane resin, etc.

(c) Those with an amide bond polyamide resin, etc.

(d) Those with urea bonds urea resin etc.

(e) Others having highly polar bonds, such as polycaprolactone resin, styrene-maleic anhydride resin, polyvinyl chloride resin, polyacrylonitrile resin, etc.

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

Further, the receiving layer 3 can also be formed from two types of resins having different properties. For example, a synthetic resin having a glass transition temperature of -100 to 20°C and a polar group forms the first region of the receiving layer, and a synthetic resin having a glass transition temperature of 40°C or higher forms the second region of the receiving layer. A region can be formed. Both the first region and the second region are exposed on the surface of the receptor layer, the first region occupies 15% or more of the surface, and the first region exists independently from each other in the form of an island. It is preferable that the length of each of the shaped portions in the longitudinal direction is 0.5 to 200 μm.

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

As such a mold release agent, solid waxes, fluorine-based or phosphate-based surfactants, silicone oils, etc. are used. These compounds are added in advance to the resin forming the receptive layer, and the receptive layer is obtained by coating the resulting resin mixture solution onto the base material and drying it. explain.

The solid wax is preferably dispersed as fine particles in the resin forming the receptor layer 3. Therefore, the solid wax is milled in a ball mill, 1J, before being added to the resin.
It is preferable to process using a hand mill or the like. As the solid wax, polyethylene wax, amide wax, Teflon powder, etc. are used. This solid wax is added to the resin at a concentration of 5 to 50% by weight of the resin type ω, preferably 10 to 20% by weight. Addition amount is 5
If the amount is less than % by weight, a sufficient mold release effect may not be obtained, and the thermal transfer layer may thermally adhere to the receptor layer.

If the amount added exceeds 50% by weight, the dye that migrates from the thermal transfer layer upon heating may not be sufficiently received, and therefore the resulting image may not have sufficient resolution.

A fluorine-based or phosphate-based surfactant is also added as a mold release agent to the resin forming the receptor layer.

It is thought that a part of the surfactant added to the resin appears on the surface of the receptor layer, and therefore a mold release effect is obtained. Examples of such surfactants include Plysurf A208S, phosphoric acid ester compounds,
Price Surf A210G, Price Surf DB-01 (all manufactured by Daiichi Kogyo Seiyaku), Gafac R8-410, Gaff 7 Tsuku RA-600, Gaff 1 Tsuku RE610 (all manufactured by Toho Chemical Industries), and Unidyne D as a fluorine-based surfactant.
S501, Unidyne DS502 (Daikin Industries')
, FC430, FC431 (Sumitomo 3M), etc. This surfactant is added to the resin in an amount of 0.0% by weight of the resin.
It is added in an amount of 5-10% by weight. If the amount added is less than 0.5% by weight, a sufficient mold release effect cannot be obtained.

If the amount added exceeds 10% by weight, the surface of the receptor layer becomes sticky, dirt tends to adhere to the surface, and when the transfer layer and receptor layer come into contact, heating/flashing may occur. If the dye in the transfer layer transfers to the receiving layer <r, background staining occurs.

Additionally, silicone Ayls are also added as a mold release agent to the resin forming the receptor layer. Although oily silicone oils can also be used, curable silicone oils are preferred. Examples of curable silicone oils include reaction-curing types, photo-curing types, and catalytic-curing types. Particularly preferred are hardened silicone resins.

When such curable silicone oils are used as a 1lli molding agent, the surface of the receptor layer becomes sticky or dust is attached, compared to the case of using a surfactant-based mold release agent as described above. Therefore, it can be used multiple times. The curable silicone oil contains, in the resin,
It can be added 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 mold release effect may not be obtained and the thermal transfer layer may thermally adhere to the receptor layer. Furthermore, if the amount added exceeds 30% by weight, the dye that migrates from the thermal transfer layer during heating cannot be sufficiently received.
Therefore, the resulting image may not have sufficient recording density.

The reaction-curing silicone oil is preferably one obtained by reaction-curing an amine-modified silicone oil and an epoxy-modified silicone oil. Specifically, the amino-modified silicone oil is KF-39 manufactured by Shin-Etsu Chemical Co., Ltd.
3, KF-857, KF-858, X-22-3680
, X-22-3801C, etc. are used;
As Shihentake silicone oil, KF-100TSK
F-101, X-60-164, KF-103! '
is used.

As a catalyst or photo-curable silicone oil, K8
705F-PS (Catalyst>, KS705-PS-1 (Catalyst), KS720, KS770-PL-3 (Catalyst>, K
Examples include S774-PL-3.

As described above, in the thermal transfer sheet 1 of the second aspect of the present invention, the receptor layer 3 made of the resin is provided on the base material 2, and a release agent is further applied on at least a portion of the receptor layer 3. layer 4
The mold release agent layer 4 is formed by dissolving or dispersing the above-mentioned mold release agent in a suitable solvent and applying the resulting solution or dispersion onto the receptor layer 3. It can then be formed by drying.

The film thickness of this mold release agent layer is preferably 0.01 to 5 μm.
．． It is desirable that it is 0.05 to 2 μa.

If the thickness of the release agent layer is less than 0.01 μm, a sufficient mold release effect cannot be obtained, while if it exceeds 5 μm, dye permeability will be hindered, which is not preferable.

As described above, the release agent layer 4 may be provided on the entire surface of the receiving layer H3, but may be provided only on a portion of the receiving layer 3. Generally, it is difficult to print explanatory text on the release agent layer, but it is possible to print on the receptor layer. Therefore, if it is necessary to print on a thermal transfer sheet, it is preferable to provide the release agent layer only on a portion of the receptor layer.

The thermal transfer sheet 1 as described above is used in combination with a 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 side of a support 6, and this thermal transfer sheet M7 transfers the color contained therein when heated. The material is transferred onto the thermal transfer sheet.

Examples of such coloring materials include disperse dyes, oil dyes, certain basic dyes, and intermediates that can be converted into these dyes, which have a relatively small molecular weight of about 150 to 400. They are selected and used in consideration of thermal transfer temperature, thermal transfer efficiency, hue, color rendering, weather resistance, etc.

The above coloring material is dispersed in a suitable synthetic resin binder forming a thermal transfer layer and provided on the support 6. As such a synthetic resin binder, it is usually preferable to select one that has high heat resistance and does not hinder the migration of the coloring material that occurs when heated; for example, the following are used.

(I) Cellulose resins ethyl cellulose, droxyethyl cellulose, ■pool hydroxy cellulose, hydroxypropyl cellulose, methyl cellulose, cellulose acetate, cellulose acetate butyrate, etc.

(If) Vinyl resins such as polyvinyl alcohol, polyvinyl acetate, polyvinyl butyral, polyvinylpyrrolidone, polyester, and polyacrylamide.

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

To provide the thermal transfer layer 7 on the support 6, a coloring material and a synthetic resin binder are kneaded with a groove material or a diluent to form a coating composition for the thermal transfer layer, and this is applied to the support 6 by an appropriate printing or coating method. It should be installed above. Note that optional additives may be added to the coating composition for the thermal transfer layer, if necessary.

The basic structure of the thermal transfer sheet is as described above,
When directly heating the surface of the support using a contact type heating means such as a thermal head, as shown in FIG. By providing the slippery layer 8 containing a lubricant or a mold release agent, it is possible to prevent the heating means such as a 't-mul head from fusing with the support and to improve sliding.

The thermal transfer sheet 1- and the thermal transfer sheet prepared as described above are stacked 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 according to image information to the interface between the image forming layer and the receiving layer, the coloring material in the thermal transfer layer can be transferred to the receiving layer according to the thermal energy.

EXAMPLES The present invention will be explained below with reference to Examples, but the present invention is not limited to these Examples.

<Example-1> An in-1 composition for forming a receptor layer having the following composition was prepared, and a dry coating amount of 4
．． It was coated at a concentration of 0 g/vl, and then dried to form a heat transfer sheet.

B') I), -j Resin: Vylon 200
(Toyobo) 1 parts by weight Amino-modified silicone: KF-393 (Shin-Etsu Chemical) 0.03 parts by weight Epoxy-modified silicone -N: X-22-343 (Shin-Etsu Chemical) 0.03 parts by weight methyl 1 pulketone/toluene/cyclohexanone (weight ratio 4:4:2)...・・・・・・
...9.0 Part by weight, followed by heat transfer %J of phase formation
, J layer forming layer forming layer 4, 1P E T D, was applied so that the dry coating amount was 1.0 g/lIi, and dried to obtain a thermal transfer sheet.

Disperse dye: KST-8-136 (
Nippon Gunpowder)・・・・・・・・・・・・・・・0.4 parts by weight Ethyl hydroxyedilce mud loin (Vercules)・・・・・・・・・・・・・・・
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 stacked facing each other, heated from the thermal transfer sheet side with a thermal head, printed, and then both sheets are When peeled off, the receiving layer and the transfer layer were easily peeled off, and no peeling of the transfer layer resin to the receiving layer occurred, and a recorded image with continuous gradations was obtained.

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

Polyester resin: Vylon 200 (Toyobo)
・・・・・・・・・・・・・・・1.0 heavy omega part methyl ethyl ketone/toluene (weight ratio 1:1) ・・・・・・・・・・・・9
. 0 parts by weight of a mold release agent layer forming solution having the following composition was then applied onto the polyester resin layer using Myabah #6 and dried at 100° C. for 5 minutes.

Nolumino Henkan Series'-n:'K['-393...
...... 1.0 parts by weight 1 volume modified silicone: X-22-343 1.0
Part by weight - Tanol ・・・・・・・・・・・・
・25.0 heavy chain part isobut[J-bilal]-ru...
...23.0 parts by weight The release agent layer forming solution at this time was applied so that the dry application area was about 0.15 J/foot. When this was recorded under the same printing conditions as in Example 1, no thermal fusion of the thermal transfer layer to the receiving layer occurred, and good mold releasability was exhibited.

<Example-3> A polyester solution having the same composition as in Example-2 was applied to synthetic paper Y of △5 size (148#ll1l×210tnm).
A dry coating area of 4.0 g/d) was applied to the entire surface of LJPO FPG #150 and dried to form a receptor resin layer.

Next, a release agent layer ink composition having the same composition as in Example 2 was coated on a half square area using a gravure printing method.
It was dried to form a release agent layer (release agent layer thickness: approximately 0.1
μm).

Next, sublimation transfer recording was carried out in the same manner as in the example described only on the part where the release agent layer was formed, and in this case as well, no peeling of the transfer layer occurred and good mold release properties were exhibited. Ta.

Next, thermal transfer printing using wax was performed on the remaining portion of the polynisder resin layer only using a thermal transfer printer TN5000 (Toshiba), and clear black printing was obtained, confirming the ease of addition.

<Example 4> An ink composition for forming a receptor layer having the following composition was prepared and applied to Sogetsu synthetic paper YUPO FPG #150 at 100°C.
for 10 minutes (dry coating: approx. 4.5 g/r
d).

Polyester resin: Vylon 103 (Toyobo T
O = 47°C)... 0.8 parts by weight EVA polymer plasticizer: 1 Ruballoy 741P (Mitsui Polychemical T
q=-37℃)・・・・・・・・・・・・ 0.2 type seedling part amino-modified silicone 1-in: KF857 (Shin-Etsu Chemical 1-industry) ・・・・・・・・・・・・・0.
04 parts by weight 1 part by weight Modified silicone: KF103 (Shin-Etsu Chemical Co., Ltd.) 0.04 parts by weight Medyle ble ketone/toluene/cyclohexanone (weight ratio 4: 4:2)・・・・・・・・・
...9.0 parts by weight Next, when printing was performed in the same manner as in Example 1, good releasability was exhibited, and no peeling of the transfer layer occurred.

<Example 5>) An ink composition for forming a receptor layer having the above composition was prepared, and the composition was coated onto synthetic paper YLJPOFPG #150 as a base and dried. Og/Td>.

Polyurethane elastomer (Dainippon Ink Chemical Pandex T5670 TQ=-35℃)・・・・・・・・・
...0.5 parts by weight polyvinyl butyral (Building Chemical, S-LEC BX-I TO=83℃) ...
...0.5 parts by weight methyl edyl ketone/tolu 1
/ Ethyl Cellosolve (Memory 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 applied onto the receptor layer under the same conditions and dried to form a release agent layer.

When this was printed using a thermal head in the same manner as in Example 1, the transfer layer did not thermally adhere to the receiving layer and exhibited good releasability.

[Brief explanation of drawings]

1, 2, and 3 are cross-sectional views of a thermal transfer sheet according to the present invention, and FIGS. 4 and 5 are cross-sectional views of a thermal transfer sheet used in combination with the thermal transfer sheet. 1 is a sectional view when a thermal transfer sheet and a thermal transfer sheet are used in combination. DESCRIPTION OF SYMBOLS 1... Thermal transfer sheet, 2... Base material, 3... Receptive layer, 4... Release agent layer, 5... Thermal transfer sheet, 6...
- Support sparrow, 7... Thermal transfer layer, 8... Slippery layer. 1 Figure 1 Figure 2' Figure 3, 14e Figure 5 Figure 6

Claims (1)

[Scope of Claims] 1. Comprising a base material and a receiving layer provided on the base material that receives the dye transferred from the thermal transfer sheet when heated, and the dye permeates into the receiving layer. 1. A thermal transfer sheet used in combination with a thermal transfer sheet, characterized in that it contains a releasing agent. 2. The thermal transfer sheet according to claim 1, wherein the release agent is a reaction cured product of amino-modified silicone and epoxy-modified silicone. 3. The release agent is present in the receptor layer in an amount of 0.5 to 3 of the weight of the receptor layer.
The thermal transfer sheet according to claim 1, wherein the thermal transfer sheet is present in an amount of 0% by weight. 4. A base material, a receptor layer provided on the base material that receives the dye transferred from the thermal transfer sheet when heated, and a dye permeable layer provided on at least a portion of this receptor layer. A thermal transfer sheet comprising a release agent layer. 5. The thermal transfer sheet according to claim 4, wherein the mold release agent is a reaction cured product of amino-modified silicone and epoxy-modified silicone. 6. The thermal transfer sheet according to claim 4, wherein the release agent layer has a thickness of 0.01 to 5 μm. 7. The thermal transfer sheet according to claim 4, wherein the release agent layer is provided over the entire surface of the receptor layer.