JPS60101087A - Thermal transfer sheet - Google Patents

Abstract

PURPOSE:To obtain a high density color image having continuous gradation and having high thermal sensitivity, by laminating a thermal transfer layer comprising a binder resin containing a dye to be thermally transferred to a support and containing a specific polyvinyl butyral resin in said binder resin in a specific ratio. CONSTITUTION:As the binder resin of thermal tranfer layer 3, a polyvinyl butyral resin having a M.W. of 60,000-200,000 and a glass transition temp. of 60-110 deg.C is used. Further, the vinyl alcohol part is 10-40wt% of the polyvinyl butyral resin. In this case, a resin for enhancing dring property in forming the thermal tranfer layer by coating can be substituted in an amount of up to 10wt% of the binder resin. The thermal transfer layer 3 is formed by providing an ink composition for forming the thermal transfer layer prepared by dissolving a dye and the binder resin along with a solvent on a base material 2 by a printing or coating method.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermal transfer sheet, and more specifically, to a thermal transfer sheet that performs thermal printing according to image information using a thermal head or a laser. The present invention relates to a thermal transfer sheet particularly suitable for obtaining a thermal transfer sheet.

4 Inventions - Hungry Friends - Shikin (Kiruru Engagement - Zhuo) In order to obtain an image according to the image information using a thermal head or a laser, thermosensitive coloring paper has been mainly used in the United States. In thermal color development (4), a colorless or light-colored leuco dye provided on a base paper at room temperature and a color developer are brought into contact with each other by heating to obtain a color image. Such color developers include phenol, Commonly used compounds include salicylic acid, lead stopper, and rosin.

However, what about heat-sensitive color paper like the one above? There is a fatal drawback that the colored image produced by 4J will fade if stored for a long period of time, and color printing is limited to one color, making it impossible to obtain a color image with continuous gradation.

On the other hand, thermal transfer paper in which a heat-melting wax layer in which a pigment is dispersed is provided on base paper-F has recently begun to be used. When this thermal transfer paper and the transfer paper ξ- are superimposed and thermal printing is performed from the back side of the thermal transfer paper, the wax layer containing the face 1 is transferred onto the transfer paper to obtain an image. According to this printing method, a durable image can be obtained, and a multicolor image can be obtained by printing multiple times using thermal transfer paper containing pigments of the three primary colors, but essentially It is not possible to obtain photographic images with continuous gradations.

By the way, in recent years, there has been an increasing demand for producing images such as color photographs directly from electrical signals, and various attempts have been made.One such attempt is to project images directly onto a CRT. However, if the silver halide film is an instant film, the running cost increases, and if the silver halide film is 3S film, there is no processing required after photography. However, the former has the disadvantage of poor image quality, while the latter requires image processing. The drawback is that it is difficult to easily obtain photographic images.

In order to solve these drawbacks, a thermal transfer sheet provided with a sublimable disperse dye layer having the property of transferring when heated is used in combination with a thermal transfer sheet, and the sublimable disperse dye is not controlled and then transferred onto the thermal transfer sheet. A method has been proposed to obtain a photograph-like image with gradations by shifting the image to gradation (Image' Journal of the Institute of Electronics, Vol. 72, No. 1 (/9gJ)).

This method is attracting attention because an image having continuous gradation can be obtained from a television signal through simple processing, and the equipment used therein is not complicated. Seven conventional techniques similar to this method include the dry transfer printing method for polyester fibers, and this dry transfer printing method is
A dye such as a sublimable disperse dye is dispersed or dissolved in a synthetic resin solution to make a paint, and this paint is applied in a pattern onto thin paper and dried to make a thermal transfer sheet, and this thermal transfer sheet is used as a thermal transfer sheet of polyester. In this method, polyester fibers are overlapped with polyester fibers and heated in a dense layer, and a disperse dye is dyed onto the polyester fibers to obtain an image. However, it is difficult to obtain a high-density colored image even if the thermal transfer sheet fx conventionally used in the dry transfer printing method for polyester fibers is used as is and thermal printing is performed with a thermal head or the like. Reasons for this are, number 7, that the thermal sensitivity of the thermal transfer sheet is not high and that the thermal transfer sheet has a low ability to absorb dyes. Among these defects, those originating from the thermal transfer sheet side have a glass transition temperature of -100 to 20 degrees Celsius, and are destructive groups. Thermal transfer sheet has a thermal transfer layer formed in the shape of a sea island, consisting of mutually independent island portions made of a synthetic resin having a glass transition temperature of 1IO°C or higher and a sea portion made of a synthetic resin having a glass transition temperature of 1IO°C or higher (Patent application No. 5G-7,
351, No. 27), but the problem caused by the thermal transfer sheet side has not yet been solved. This is because in conventional printing methods for textiles, dye transfer and dyeing are achieved by heating at 20θ℃ for 1 minute, whereas heating with a thermal head is performed at approximately θ℃. This is because it is short, about a few m5ec.

The inventor of the present invention applied the above-mentioned patent application No. 3G-/3 to a thermal transfer sheet and the spine in order to obtain a photo-like image by thermal printing using a thermal head or the like. As a result of various efforts to obtain a thermal transfer sheet suitable for use in combination with the thermal transfer sheet of No. tλ7, the following facts were discovered.

Conventionally, generally used thermal transfer sheets (in this case, disperse dyes are dispersed in granular form in a binder), and in order to heat the dye molecules in such a state (to make them bloom), High energy is required because it is necessary to break the interaction within the crystal and give the dye molecules more thermal energy than the interaction with the binder, allowing them to sublimate and dye onto the thermal transfer sheet. In order to obtain a high-density colored image, if the dye is contained in a high ratio to the binder resin, a certain high-density image can be obtained, but the bonding in the thermal transfer layer of the thermal transfer sheet is poor. Because the strength is weak, if you overlap it with the thermal transfer sheet and peel it off after printing with a thermal head, etc., the resin will be removed.
The phenomenon of being removed by the thermal transfer sheet is unlikely to occur.

Furthermore, dyes are extremely expensive, and from the standpoint of OA equipment and home use, it is economically disadvantageous to use more dye than necessary. .

On the other hand, if it is possible to hold the dye in a binder in a molecularly dispersed form rather than in a granular form, it is possible to transfer the dye in a practical manner even if there is no intracrystalline interaction that occurs when the dye is dispersed in a granular form. You can't get paper. In other words, the molecular weight of the dye molecules is 1'l'J smaller than that of 750 to 900,
It is very moving and interesting in Banh Ku. Therefore, for example, if a binder with a low glass transition temperature (Tg) is used, it will aggregate over time and cause combined 1-filter development, eventually resulting in a state in which the dye is dispersed in χV particles as described above. or it may bleed onto the optical surface of the thermal transfer layer.
During recording, the pressure between the thermal head and the platen causes the dye to build up around the heated area, causing background smudges and significantly degrading the image quality.

Moreover, even if the binder has a high glass transition temperature (Tg),
If the molecular weight of the binder is not large enough, it cannot hold the dye molecules.
Even if dye molecules are allowed to form in a binder with a high Tg) and a relatively large molecular weight, a state with stability over time can be achieved due to the affinity between the dye molecules and the binder. I feel safe about sex.

The present inventors have studied history based on these experimental facts, and have found that by using the thermal transfer sheet described in the claims, the shortcomings of the prior art can be solved at once. It is.

Purpose and summary of "Hikari" The present invention attempts to solve the drawbacks associated with the prior art, and it is an object of the present invention to solve the drawbacks associated with the prior art. By using ink in combination, we aim to achieve the following objectives.

(a) Obtaining a colored image 147 by dyeing t1 having continuous gradation like a silver halide photograph directly from an electric signal.

(b) Obtaining high-density colored images with high thermal sensitivity.

(c) The thermal transfer sheet does not change over time even when stored for a long period of time (and maintains the performance of (al) and (bl) above.

In order to achieve the above objectives, from a technical perspective, it is safe to satisfy the conditions described below.

(a) Apply the ink prepared by dissolving dye molecules and binder resin onto the base sheet. There is an affinity for 7) things.

(In addition, even if this thermal transfer sheet is stored for a long period of time, the dye molecules will not aggregate or precipitate over time. In other words, there is an affinity between the dye molecules and the binder resin, and
The glass transition temperature (Tg) of the binder is a quotient (,
Molecule) company is also big.

(By heating with a Cl thermal head, etc., the dye molecules are sufficiently elevated and bonded. In other words, the dye molecules and the binder tree 11i
The affinity with ff is not excessively affected (and the glass transition 6
1. The temperature (Tg) must be at an appropriate value.

The thermal transfer sheet that the present inventors have studied and obtained from the above viewpoints is made of polyvinyl butyler/L"a' binder, has a molecular weight of 60,000 to 20,000, and has a glass transition θ1A degree (T
g) is from 60°C to /10'c, the weight percent of the vinyl alcohol moiety contained is from /S% to 110%, and preferably the dye is a disperse dye and is bathed in the binder. It is a feature.

Detailed Description of the Invention The present invention will be described in detail below using drawings.
-Ru.

As shown in FIG.
It is constructed by providing a thermal transfer layer 3 on a base body.

Papers or films such as condenser paper, polyester film, polystyrene film, polysulfonate film, polyimide film, polyvinyl alcohol film, cellophane, etc. are used as the base material, and the thickness thereof is J to S O/j7+1. Preferably,
It is 3 to 15μ7n.

Among these papers and films, condenser paper is used when price and heat resistance in an untreated state are important. When it is important that the film does not break when running and has a smooth surface, a polyester film is preferably used.

The thermal transfer layer 3 consists of a sublimable dye and a binder,
The thickness of J-3 is 0.5 to N, θμ7+1°, preferably o, S-2,0μnt6 degrees.

The dye contained in the thermal transfer layer 3 is more preferably a disperse dye, and is a small molecule #i of about 750 to 000 g:
It is selected by taking into consideration heat sublimation temperature, hue, durability, solubility in ink and binder tree J market, etc. Specifically, the following five are exemplified.

The proportion of the dye contained in the thermal transfer layer is determined by the sublimation temperature of the dye and the covering power in a colored state (depending on the size of the color rendering property, but usually S to 70, preferably 70 to 6).
It is about 0%.

Polyvinyl butyral 4tJJll is used as the binding resin for the thermal transfer layer 3 of the thermal transfer sheet/of the present invention, and its molecular weight is 60,000 or more in order to produce cohesive strength as a binder, and the viscosity at the time of coating is suitable. In view of the necessary costs, it is preferable to set it to 200,000 yen or less. In addition, the glass transition temperature (Tg) is 60°C or higher, more preferably 70°C or higher, in order to prevent dye aggregation and precipitation during thermal transfer I9!3, and facilitate sublimation of the dye. The viewpoint power is less than //θ'C. Furthermore, the vinyl alcohol moiety has good affinity with dyes due to hydrogen bonding, etc.! I
L,:ti% is 10 to q in polyvinyl butyral resin
O ratio, preferably 75 to 30%. If the weight percent of the vinyl alcohol portion is less than 10%, the thermal transfer layer will not have sufficient stability over time, resulting in dye aggregation, precipitation, or bleeding to the surface; if it exceeds 1I-0%, there will be too much affinity portion. Therefore, during printing using a thermal head or the like, the dye is not released from the thermal transfer layer, resulting in a low print density.

The binder resin contains a cellulose-based material to improve drying properties when forming a thermal transfer layer.
Up to 10% of the weight of II
f I') Sign.

In order to form the thermal transfer layer 3 on the base material, a dye and a binder are used as an ink composition for forming the thermal transfer layer.
It may be provided on the base material by any method. Incidentally, if necessary, optional additive No. 4 may be added to the ink composition for forming a thermal transfer layer.

The basic structure of the thermal transfer sheet is as described above,
When directly heating the surface of the base sheet using a contact type heating means such as a thermal head, as shown in FIG. By providing a slippery layer containing a lubricant or a mold release agent, it is possible to prevent melting between the heating means such as a thermal head and the base sheet, and to improve sliding.

The thermal transfer sheet may be in the form of sheets cut into required dimensions (or may be continuous or rolled (or may be in the form of a narrow tube).

When providing the thermal transfer layer 3 on the substrate sheet, a coating composition for the thermal transfer layer 3 containing the same coloring material may be applied to the entire surface of the substrate sheet, but in some cases,
Even if a number of ink compositions for thermal transfer layers containing different coloring materials are formed on different areas of the surface of the notebook, it is possible. For example, as shown in FIG. 3, there is a thermal transfer sheet in which a black thermal transfer layer S and a red thermal transfer layer 6 are laminated in parallel on a base sheet λ, or a yellow thermal transfer sheet as shown in FIG. A thermal transfer sheet is used in which a thermal transfer layer 7, a red thermal transfer layer g, a blue thermal transfer layer t, and a black thermal transfer layer lθ are repeatedly provided on a base body. By using such a thermal transfer sheet provided with a plurality of thermal transfer sheets having different hues, there is an advantage that one multicolor image can be obtained with one thermal transfer sheet.

It is also possible to facilitate use by forming perforations on the thermal transfer sheet or providing register marks for pointing out the positions of areas of different hues.

The thermal transfer sheet and the thermal transfer sheet prepared as described above are, for example, as shown in FIG.
The thermal transfer layer 3 and the receptor layer /3 on the base sheet /2 of the thermal transfer sheet are stacked facing each other in contact with each other, and thermal energy according to the information is applied to the interface between the thermal transfer layer and the receptor layer. ? : Transfer the dye in the thermal transfer layer to the receiving layer by giving:

Thermal head/thermal head is the heat source that provides thermal energy.
In addition to 41, well-known devices such as laser light, infrared flash, and thermal pens can be used.

Thermal energy can be applied not only from the thermal transfer sheet side, but also from the side of the heated sheet, or from both It(II) sides, but from the viewpoint of effective use of thermal energy, It is better to do this from the thermal transfer sheet side.However, it is better to apply heat energy from the thermal transfer sheet side to control the applied thermal energy and express the gradation of light and shade of the image, or to apply the color material. is preferable in the sense that it promotes Mj expansion on the thermal transfer sheet and ensures the continuous tone expression of the image, and the method of applying thermal energy from both sides enjoys the advantages of both methods at the same time. can.

When a thermal head is used as a heat source for providing thermal energy, the applied thermal energy can be varied continuously or in multiple steps by modulating the voltage or pulse width applied to the thermal head.

When laser light is used as a heat source for providing heat energy, the heat energy provided can be changed by changing the amount of laser light and the irradiation area.

If a dontogenerator with a built-in acousto-optic element is used, thermal energy can be applied depending on the size of the halftone dot.

In addition, when using a laser beam, there is no overlap with the thermal transfer sheet.
It is best to do this by sufficiently increasing the amount of the sheet and the Lj sheet.
Additionally, the surface to be irradiated with the laser beam should be painted, for example, black or blue, to absorb the laser light.

Alternatively, non-4. By adding a substance that absorbs the colored laser light and converts it into heat, heat transfer to the dye will be more efficient and the resolution will be higher.

Apply thermal energy When using an infrared flash lamp as a heat source, it is best to use it in the same way as when using a laser beam, or use Baku-7 or a halftone dot pattern that continuously expresses the light and shade of the image H, such as black. These patterns may be carried out either by using a colored layer, such as black, or by using a colored layer such as black on the surface and corresponding to the negative of the above pattern.
It is also possible to use a combination of negative patterns.

Is there thermal energy at the interface between the thermal transfer layer and the receiving 1g? When the dye is applied, the dye in the thermal transfer layer is thermally applied to the receiving layer 13 in an amount corresponding to the applied thermal energy.

In the above thermal transfer recording, dyes corresponding to the thermal energy are thermally transferred to the receiving layer, and an image in seven colors can be recorded. By sequentially replacing the indigo and, if necessary, black thermal transfer sheets and performing thermal transfer according to each color, it is also possible to obtain a color photographic color image that is a combination of each color. Instead of using thermal transfer sheets for each color, as shown in Figure 7, a thermal transfer sheet Y is used that has areas pre-painted in each color, and the yellow area is used to thermally transfer the yellow separated color image, and then Apply to the red area of the thermal transfer sheet, and then repeat sequentially to create yellow, red,
Adopting a method of thermally transferring the indigo blue and, if necessary, black color-separated images has the advantage that there is no need to replace the thermal transfer sheet.

In addition, the size of the heat source used to provide thermal energy,
The quality of the image obtained can be improved by appropriately adjusting the adhesion between the thermal transfer sheet and the thermal transfer sheet and the thermal energy.

The thermal transfer sheet according to the present invention can be used in combination with a thermal transfer sheet to perform printing using various thermal printing printers, facsimiles, or (making photo prints using a direct recording method, making prints from a television screen, etc.). It can be used for etc.

For example, if a received television screen is recorded on a storage medium such as a magnetic tape or magnetic disk, yellow, red,
Write down the signals for each color separation pattern of indigo and, if necessary, black, and output the signals of each stored color separation pattern. The above-mentioned heat from the head etc. imparts an imprint to the combined body of the thermal transfer sheet and the sheet to be thermally transferred,
If you perform legal heat transfer for each color, you can reproduce it as a print on a television screen. When a thermal transfer sheet and a thermal transfer sheet according to the present invention are used as a combination body for printing out a television screen like this, the thermal transfer sheet is usually white in color. Is it something with a colorless and transparent receptor layer lined with a base material such as paper, or something with a backing made of white receptor paper? When used, it is convenient to obtain a single reflection image.

Note that the same thing as in Section 2 can be done by computer operation.
Combinations of characters, figures, symbols, colors, etc. formed on the RT screen, graphic patterns can also be used as original images, and if the original image is a painting, photograph,
When the image is a fixed image such as a stamp, or an actual object such as a person, still life, or landscape, the same method as described above can be performed by using an appropriate means such as a video camera as a medium. Furthermore, an electronic plate making machine (color scanner) used for photolithography for printing may be used to obtain the exact image of each color separation pattern from the original image.

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

Example / Corona treatment on one side as a support? Applied thickness q INr
PET film (manufactured by Toyobo Co., Ltd., 5-PET) is coated with one of the following ink compositions for a thermal transfer layer. Apply and dry the wire bar coating so that the dry coating weight is /, 0 ~, then apply one drop of silicone oil (X-Dangu 00.3A, manufactured by Shin-Etsu Silicone) on the back surface with a dropper, and then cover the entire surface. It was spread out and processed on the back side to make a thermal transfer sheet.

Ink Composition for Thermal Transfer Layer Toru/G θ〆l Methyl Ethyl Ketone 1lQtt Isobutanol 10 〃 Here, polyvinyl butyral (BX-/) has a molecular weight of about 100,000, a Tg of g3℃, and a vinyl alcohol part squared [
11% is approximately 2θ%. The resulting thermal transfer layer was transparent, and no particles were observed when observed under a microscope (
Magnification 1Ioo).

Next, as a general manager, isoμmn thick synthetic paper (YUI made by Tamago Yuka) O-FPG/SO)'a? use,
A thermal transfer sheet was prepared by coating an ink composition for a receptor layer having the following composition using a wire bar coating so that the dry thickness was S~. After temporary drying with a dryer, drying was performed in an oven at 100'C for 7 hours to sufficiently volatilize the solvent.

Toluene / Riθ〃 Methyl ethyl ketone 10〃 Cyclohexanone θ Depending on the head, the output of the thermal head; tW//dot; pulse width; 0. J
-'l, 5 m5ec, dot density +i;, y dot/
As a result of recording under my conditions, the pulse was 11 meters and 5 meters.
The reflection density of the highly colored part of gec is /, 65,
Also, the part (Rus width 0.3m5ecσ) is 0.76,
A record with gradation depending on the applied energy was obtained (measuring device: Macbeth density, 4'IRD -9/g). Also, after printing with a thermal head, heat transfer 'J5. When the sheet and the temporary thermal transfer sheet were peeled off, no transfer of the lateral bending of the thermal transfer layer was observed, and no background staining occurred in the non-heated areas.

In addition, even if the same thermal transfer film was exposed in a rolled state in an oven at θ°C for 1 day for 30 days, no apparent changes or deterioration of recording performance were observed. It showed practicality.

All of the thermal transfer layer ink compositions in Example 1 and 2 were used except that Polyvinyl Butyral 7JBX-/Denka Butyral SOθ0-AK manufactured by Denki Kagaku Co., Ltd. (Thermal transfer sheets were prepared using ink with the same composition. ! ; 000-A has a molecular weight of about / J million, Tg of about 7 g “C
, Vinyl Alcohol HB σ) Stop 11
(% is approximately 16%.

The resulting thermal transfer layer was also transparent and no particulate matter was observed. Example 1 of this thermal transfer sheet
When recording was performed under the same conditions in combination with a thermal transfer sheet, the pulse +l] was generated. The reflection density of the Sm5ecO) portion is /, 70. o,,7m5ec part was 0°17. Further, there was no occurrence of scumming in the non-heated portions or transfer of resin when both sheets were peeled off. Furthermore, implementation 19+
When accelerated heating test (Y) was carried out under the same conditions as 1/, no change was observed.

Example 3 A thermal transfer sheet) Y was obtained in exactly the same manner as in the thermal transfer layer ink composition of Example, except that the polyvinyl butyral was changed to Denka Butyral boooo-c manufactured by Denki Kagaku Co., Ltd. This polyvinyl butyral resin has a molecular weight of about 153,000, a Tg of about qo''c, and a vinyl alcohol content of 16% by weight. When the obtained thermal transfer sheet was used and recorded in the same manner as in Example 1, The color density is /,
6θ and olo (9.5 m5ec during pulse, respectively)
0.3 m5ec), the results of the red time acceleration test were also the same.

Example 1 Example/BX- among the thermal transfer layer ink compositions
The chemical composition was changed to Denka Butyralda 000-/, which had a similar composition, but the Tg was about 0°C and the amount of vinyl alcohol was about 20%.

When recording was performed using this thermal transfer sheet and the thermal transfer sheet, the pulse was '1'. The reflection density of the Sm5ec part is /, qO, 0.3 msec c (1) iB
I got exactly the same results except that the minute was Q10. Furthermore,
The results of the accelerated heating test were also good.

Example S An ink composition for a thermal transfer layer having the following composition was prepared, and Example S/
It was applied to the same film as above so that the dry weight was /, 0%.

Ink composition for thermal transfer layer: ethyl heptylulose (manufactured by Percules, ECN-/1I)
0,3/1 toluene lθ 〃 methyl ethyl ketone 〃 isobutanol /Qll When recording was performed on the thermal transfer sheet obtained from this composition in the same manner as in Example 1, the recording was exactly the same as in Example 1. Performance was obtained, and there were no problems at all with aging (Q:).

Comparative Example: An ink composition for a thermal transfer layer having the following Anl composition was prepared, and the dry coating amount was 7.0% on 5-PET with a thickness of 9 μIn (
A film was formed on R.

Ink composition for thermal transfer layer Polyvinyl butyral 17,3// (Shimiki Chemical Co., Ltd., 5-LECBM-2) Toluene lIO// Methyl ethyl ketone qθ overlapped part Inbutanol /Qtt Here, 5-LE'CBM-2 has a molecular weight of Approximately 30,000 Tg
is approximately 62°C, and the weight percent of the vinyl anoneol portion is approximately 27°C.
% of this heat transfer sheet at room temperature.
After leaving it for an hour, some precipitation of dye was observed on the surface of the thermal transfer layer, and when the thermal head was used to print on the thermal transfer layer, a clear record of color development (aJ and I+-6) was obtained, but at the same time there was no background smudge. This occurred and could not be put to practical use.

Comparative Example An ink composition for a thermal transfer layer was prepared having the same composition as in Comparative Example 1 except that Denka Butyral JOOO-K (manufactured by Denki Kagaku Kogyo) was used instead of the binder gBM-co.

Here, Denka Butyral 3θDO- is polyvinyl butyral having a molecular weight of about J70,000, a Tg of about 0°C, and a vinyl alcohol content σ) of 9%. This ink composition was applied on a film similar to Example 1.

Dry face Alr using wire bar coating method
A thermal transfer sheet weighing 7 g//I was obtained. Seven printings were made in the same manner using this sheet and a receiving sheet, and a high-density recording of qoq was obtained in the color density of the pulse 1 m8ee portion. However, when this thermal transfer sheet was left open for 20 hours at 60°C to accelerate aging, dye precipitation occurred on the surface of the thermal transfer layer, and when printing was performed using the thermal transfer sheet in the precipitated state, Background smearing was observed in the non-recorded areas, and the thermal transfer sheet was unsatisfactory for practical use.

Comparative Example 3 The binder 7 of Comparative Shio 11/ was mixed with 5-LECBL-/(
An ink composition for a thermal transfer layer was prepared using exactly the same composition except that the ink composition was changed to "Act (manufactured by Suikagaku)". This ink? When the dye was applied onto the same film as in Example 1, curdling of the dye occurred upon drying with a dryer. This phenomenon could not be prevented even if the bath agent in the ink was changed to dioxane or nclohexanone, which has a high dye bath decomposition property and a high boiling point. Polyvinyl butyral 5-L used here
ECBL-/ has a molecular weight of approximately 76,000 and a Tg of approximately 5g℃
, the weight lf% of the vinyl alcohol portion is about 25%.

Comparative example q An ink composition for a thermal transfer layer having the following composition was prepared.

Ink composition for thermal transfer layer Toluene 1/-Q// Methyl ethyl ketone 11Q// Dioxane 7Ol/ This ink was coated on a film similar to that in Example/ by the wire bar coating method. /, 0 return σ thermal transfer sheet? Created. When this was printed using a thermal head in the same manner as in Example 1, 11. Sm5ec, each pulse 11 of 0.3m5eC]
The reflection density of each part is 1. g! ;, O1/7. In order to determine the stability of this transfer sheet over time, we conducted an accelerated test by placing it in an open oven at 0°C.
Prints printed using this method may have background smudges,
Stability was insufficient.

Example 6 An ink for a thermal transfer layer having the following composition was prepared and coated onto the same film as in Example 1 by a wire bar coating method so that the dry coating amount was 0.6 or more. When this thermal transfer sheet was printed under the same conditions as in Example 1, reflection densities of /, SII, o, and og were obtained at the pulse width % of 5 m5ec, θ, and Jmsec, respectively.

Ink composition for thermal transfer layer Disperse dye (manufactured by Mitsubishi Kasei, PTY-Taco) 1.2 parts by weight Toluene 1lQt/Methyl ethyl ketone 1lQtt Isobutanol /Q// When this thermal transfer sheet was observed under a microscope, no particulate matter was found. was not observed, and the dye was in a dissolved state (magnification: 00). Further, when an accelerated test was performed by placing the sample in an oven at 6θ°C, no abnormality was observed even after 2 months had passed.

Example 7 A thermal transfer layered ink composition having the following composition was prepared and used in Example 1.
4F was coated on the same film as above so that the amount of fabric produced when dried was /, θ~.

Ink composition for thermal transfer layer Toluene 11011 Methyl ethyl ketone 11Qtt Microhexanone 10 // When printing was performed using this thermal transfer sheet under the same conditions as in Example, pulse 1] lI-05msec, θ
: The reflection a degree of the JmSec part is 7.60 degrees each.
A record of 1/2 was obtained. No graininess was observed in this thermal transfer sheet when observed under a microscope.
No abnormality occurred even when an accelerated aging test was performed by leaving the product open for 2 months at ℃.

[Brief explanation of drawings]

Figures 1 to 2 show examples of the thermal transfer sheet of the present invention, Figures 1 and 2 are cross-sectional views, Figures 3 and 3 are perspective views, and Figure 5 A is a diagram of the present invention. thermal transfer sheet tt
FIG. ／・・・・・・・・・・・・Thermal transfer sheet λ・・・・・・
...Base sheet 3...Thermal transfer layer// ...Thermal transfer sheet/, 2.
・・・・・・・・・Base sheet/3・・・・・・・・・・
・・・Reception layer//I-・・・・・・11・・Pot・Thermal head/311・e11*IIth・ee・Grate/Roll procedure amendment (voluntary) 1 middle if'l nokku Small + 1/i sum” Q17 l, 'l request ko θ Waguta left
2. Name of the invention Thermal transfer sheet 3. Mijl: Relationship with the name 'IGf'l 11r J'l Applicant 11 Location East I: Town 2-1 Shuku-ku Ichigaya Kaga-cho-1-January 2 Name 44;' (2891 people Uhon Printing Co., Ltd. Hiroshi Kitajima Yoshitoshi 4, Agent 1iIili 〒1 (] 2 Higashi Jrj Pli City Ward Ichigaya Kaga-cho - No. 1112 Showa - Year - Month) l] - (Shipping l-i: Showa year month 1) 5ゝ6, Supplementary 1 Number of inventions increased by 1 None 6, '7.Sho i-+1's S-j elephant + 1.l Specification of the invention of the nail Detailed explanation column 7″8, Xi
Tonouchi'rF (1) The following is exemplified in the first page of the specification, line 1g. ” should be corrected as shown in “”4 below.
). ``Give me an example of the following;

Claims (1)

[Scope of Claims] (]) A thermal transfer layer made of baingoo resin containing a dye that is transferred by heating and transferred to the transfer material is laminated on the base sheet, and the binder resin is (a1 molecular weight 6 10,000~λ
A thermal transfer sheet characterized in that it is a polyvinyl butyral resin having a glass transition temperature of 60°C to 10°C (c) and a vinyl alcohol portion of 10% to 10% by weight and containing θ% by weight or more. (2) The thermal transfer sheet according to claim UU, characterized in that the dye is a heat-rising disperse dye. (31 The disperse dye is dissolved in the binder resin) A thermal transfer sheet according to claim (2).