JP2000141920A - Thermal transfer image receiving sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form an image of high quality even under printing conditions of a high speed and a low energy with a low cost by providing a layer containing hollow particles of specific volume hollowness rate without contact with a dye acceptive layer in a cast coated layer. SOLUTION: The thermal transfer image receiving sheet has a structure in which a paper base material 10 containing a base sheet 11 and a cast coated layer 12, and a dye acceptive layer 20 are sequentially laminated. In the material 10, a long halftone multilayer watermarking base sheet is used as the sheet 11, and the layer 12 is formed of a multilayer constitution of two or above layers. The layer 12 is, for example, a multilayer structure obtained by laminating a cast coat surface layer 12b and a hollow particle-containing layer 12a as an undercoating layer. A volume hollowness rate of the particles in the layer 12a is 40% or above or preferably 80% or above. Thus, sufficient cushionability and heat insulation effect are obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer image receiving sheet for thermally transferring an ink containing a heat sublimable dye using a thermal head or the like.

[0002]

2. Description of the Related Art In recent years, sublimation transfer recording has advantages such as good gradation expression as a method of hard copying from a color image of a television, video, or digital camera, or a color image of computer graphics. The method is widely used.

In the sublimation transfer recording method, an ink layer provided on a ribbon substrate and containing a thermosublimable dye is opposed to a receptor layer provided on the substrate and capable of receiving the sublimable dye. By contacting the thermal head to the ribbon substrate side and heating according to the image information, the ink containing the heat sublimable dye is transferred to the dye receiving layer of the thermal transfer image receiving sheet, and the high gradation Is formed.

As a base material of a thermal transfer image receiving sheet used in such a sublimation transfer recording method, a plastic sheet, a laminated sheet of a plastic sheet and a paper sheet, a synthetic paper, and the like are widely used. In recent years, as the sublimation transfer recording method has become widespread, there has been a strong demand for image formation at low cost. Relatively low-cost substrates include plain paper such as coated paper, art paper, cast-coated paper,
PC paper and the like are mentioned, and these are partially put to practical use.

When such a plain paper is used as a paper base, the dye receiving layer is required to have a certain cushioning property so that the thermal head can be uniformly contacted with the dye receiving layer on the surface. You. Further, in order to secure a desired high level of image density under relatively low energy printing conditions, it is necessary to effectively suppress the diffusion of thermal energy applied from the thermal head to the dye receiving layer to the substrate. For this purpose, a heat insulating layer formed by dispersing thermally expandable hollow particles (referred to as microballoons) in which a low-boiling-point liquefied gas is encapsulated in microcapsules made of a thermoplastic resin is dispersed in a binder. Attempts have been made to provide between layers.

However, in the thermal transfer image receiving sheet using such micro balloons, under high energy printing conditions in high speed printing, thermal energy applied from a thermal head causes the hollow particles to foam and further burst, causing There is a problem that a hole-like white spot occurs, color unevenness occurs in a printed matter, and color unevenness occurs due to unevenness in paper making. For this reason, the resolution of a printed matter obtained by a conventional thermal transfer image receiving sheet using microballoons was insufficient.

As described above, when plain paper is used as the paper base material, it is possible to reduce the cost of the thermal transfer image receiving sheet to some extent, but there is a disadvantage that the image quality is greatly reduced, and the image quality is reduced. At present, it has not been sufficiently achieved to reduce the manufacturing cost of the thermal transfer image-receiving sheet.

[0008]

SUMMARY OF THE INVENTION The present invention is to solve the above-mentioned problems of the prior art, and its object is to
Low cost, excellent cushioning properties, no white spots and uneven gloss in high-speed printing, no unevenness in base paper formation, unevenness in papermaking, and uneven coloring due to lack of cushioning properties. An object of the present invention is to provide a thermal transfer image receiving sheet capable of forming a high quality thermal transfer image even under energy printing conditions.

[0009]

The thermal transfer image-receiving sheet of the present invention is a paper base material comprising a fourdrinier multi-layer base paper made mainly of pulp and a multi-layer cast coat treatment layer provided on the base paper. And a thermal transfer image-receiving sheet having a dye-receiving layer formed on the cast-coating layer, wherein the cast-coating layer contains hollow particles that are not in contact with the dye-receiving layer and have a volume hollow ratio of 40% or more. It is characterized by including a layer to be formed.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The thermal transfer image-receiving sheet of the present invention is substantially composed of a fourdrinier multi-layer base paper made mainly of pulp, and a multi-layer cast coat treatment layer provided on the base paper. A paper substrate, and a dye receiving layer formed on the cast coating layer of the paper substrate, wherein the cast coating layer is a cast coat surface layer in contact with the dye receiving layer, and the paper substrate surface A hollow particle-containing layer is provided between the layer and the base paper and contains hollow particles having a volume hollow ratio of 40% or more.

The cast coat treated layer used in the present invention is formed at least in a cast coat surface layer and a hollow particle-containing layer. As in the conventional case, when the hollow particle-containing layer is a single layer, it is impossible to add a large amount of hollow particles in order to impart sufficient smoothness and prevent image deterioration due to rupture of the hollow particles. On the other hand, if the amount of the hollow particles added is insufficient, there is a problem that good cushioning properties cannot be obtained. On the other hand, according to the present invention, the cast coat surface layer can be designed to impart high gloss, sufficient smoothness to obtain a high-quality thermal transfer receiving sheet, and the hollow particle-containing layer is Suppresses heat diffusion from the heating recording means so that a desired high level of image density can be sufficiently obtained under low energy printing conditions, and has sufficient cushioning property to make uniform contact between the heating recording means and the dye receiving layer. It can be designed to have

As described above, when the present invention is used, a thermal transfer image-receiving sheet which is excellent in cushioning property and high-speed printability and can form a high-density and high-quality image under low-energy printing conditions can be obtained.

Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a sectional view of a thermal transfer image-receiving sheet according to a preferred embodiment of the present invention. This thermal transfer image-receiving sheet has a structure in which a base paper 11, a paper base 10 composed of a cast coat treatment layer 12, and a dye receiving layer 20 are sequentially laminated.

In the present invention, as the base paper 11 in the paper base material 10, a long net multi-layer base paper having two or more long nets is used. The reason for this is that, other than the four-layer multi-layer base paper, the short net single-layer base paper, the short net multi-layer base paper, the round net single-layer base paper, the round net multi-layer base paper, or the four-wire single-layer base paper This is because, when the base paper is used, uneven color formation occurs due to uneven formation, which causes deterioration in image quality.

Although there is no particular limitation on the upper limit of the fourdrinier multi-layer making, it is preferable to make two to four layers from the viewpoint of production cost and the like.

The pulp constituting the base paper 11 is not particularly limited, and beaten pulp such as softwood kraft pulp (NBKP) and hardwood kraft pulp (LBKP) can be used alone or in combination as appropriate. In addition, additives such as fillers, sizing agents, and paper strength agents may be added to the base paper 11 as necessary.

It is preferable that the surface of the base paper 11 on which the cast coat treatment layer is formed is subjected to a surface treatment for stabilizing the base paper surface and improving strength.

Further, in the present invention, the cast coat treatment layer 12 in the paper substrate 10 has a multilayer structure of two or more layers.

As shown in the figure, for example, the cast coat treatment layer 12 has a multilayer structure in which a cast coat surface layer 12b and a hollow particle-containing layer 12a as an undercoat layer are laminated. The cast coat treatment layer 12 is applied as an undercoat layer with an intermediate particle-containing layer coating liquid containing 40% or more of hollow particles by volume and a binder as a main component, and dried or semi-dried. And a top coat composition containing a binder as a main component, and press-contact with a cast drum having a mirror surface in a wet state to perform a cast coating treatment.

The pigment used in each layer of the cast coat treatment layer includes, for example, kaolin, aluminum hydroxide,
Calcium carbonate, titanium oxide, plastic pigment, and the like.

As the binder used for each of these layers, a synthetic rubber latex, starch, a protein such as casein, a synthetic resin adhesive, or the like can be used alone or in combination. In addition, if necessary, defoaming agents, release agents,
Additives such as coloring agents are appropriately used.

The undercoat layer may be formed by a known coating method such as a blade coater, an air knife coater, a roll coater,
One or two or more layers are coated on the base paper by an on-machine or off-machine coater using an apparatus such as a cast coater or a bar coater. It is desirable to do.

The volume hollow ratio of the hollow particles is 40% or more, preferably 40 to 95% from the viewpoint of acquisition cost. Further, it is more preferable to contain hollow particles having a volume hollow ratio of 80% or more. If the volume hollow ratio of the hollow particles is less than 40% by volume, sufficient cushioning properties and heat insulating effects cannot be obtained, and the object of the present invention cannot be achieved.

The hollow particles used in the present invention have an average particle diameter of 5 μm from the viewpoint of the process or the color stability.
m or less, it is preferably non-foamable or fully foamed.

The hollow particles used in the present invention can be composed of a synthetic resin. As the synthetic resin, various resins can be used, and acrylic resin, acrylic copolymer resin, vinylidene chloride resin, and vinylidene chloride copolymer resin are preferably exemplified from the viewpoint of heat resistance and acquisition cost. .

If the content of the hollow particles in the cast coat treatment layer 12 is too small, it is difficult to obtain sufficient cushioning and heat insulating effects, and if the content is too large, the gloss is reduced. It is preferably 3 to 60% by weight, more preferably 5 to 40% by weight, based on the total pigment content of the layer.

The thickness of each layer and the total thickness of the cast coat treatment layer 12 is not particularly limited, but is generally 5 to 50 g / g in total thickness.
m ² is preferred.

It is preferable to use a base paper 11 having a formation index value of 100 or more measured by, for example, a 3D sheet analyzer (manufactured by M / K Systems). Thereby, the image quality of the thermal transfer image receiving sheet can be improved. The formation index value is a numerical value indicating the degree of formation.

It is preferable that the Beck smoothness of the surface of the cast coat treatment layer 12 of the paper base material 10 is 600 seconds or more. Thereby, the image quality of the thermal transfer image receiving sheet can be further improved.

The thickness of the paper substrate 10 is not particularly limited.
In consideration of the transportability of the printer, 25 to 25
300 g / m ^2, preferably 75~200g / m ^2.

The dye receiving layer 20 is a layer on which an image is formed by receiving a heat sublimable dye of the ink layer of the thermal transfer recording medium, and has the same structure as the dye receiving layer of a conventional general thermal transfer image receiving sheet. can do.

The material of the dye receiving layer 20 is a resin having dye-dyeing properties, such as butyral, polyethylene, polyurethane, polypropylene, polyvinyl chloride, polybutadiene, polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, ethylene-acetic acid. Thermoplastic resins such as vinyl copolymers, polyamides, polyesters, polycaprolactone, polyvinyl acetal, epoxy resins, ketone resins, or modified resins thereof, cross-linked products of these with a cross-linking agent such as isocyanate, polyethylene wax, paraffin Waxes such as wax, carnauba wax, candelilla wax, ester wax, oxidized wax, rice wax, petroleum resin wax and the like.
These may be used alone or in combination of two or more. Further, known additives can be added as needed.

The thickness of the dye receiving layer 20 can be appropriately determined according to the form of use and the conditions of use.
0 g / m ² .

The dye-receiving layer 20 is prepared by dissolving the resin having dye-dyeing properties in a solvent to prepare a coating solution for forming a dye-receiving layer, and applying the coating solution on the cast coat surface layer 12c of the paper substrate 10. And dried.

This thermal transfer image-receiving sheet can be manufactured by a conventional method. For example, a coating liquid for forming a hollow particle-containing layer and a coating liquid for forming a cast coat treatment layer are coated and dried on a base paper 11 multi-layered by a fourdrinier multi-layer paper machine according to a known coating method. The obtained coating layer is cast-coated to form a cast-coating layer 12, and a coating solution for forming a dye-receiving layer is further coated thereon with a gravure coat, a Meyer bar, a roll coat, a blade coat, a knife coat, and the like. The dye receiving layer 20 is formed by coating and drying by the method described above.

The thermal transfer image-receiving sheet of the present invention described above is excellent in the cushioning property of the dye receiving layer, and forms a high-density and high-resolution image under high-speed printing conditions or relatively low energy conditions in sublimation thermal transfer recording. can do.

[0038]

The present invention will be described more specifically below with reference to examples.

Example 1 The following stock 1 was made in two layers by a fourdrinier multi-layer paper machine.

Paper Material 1 Component Weight parts Softwood bleached kraft pulp (NBKP) Freeness 390cc 15.0 Hardwood bleached kraft pulp (LBKP) Freeness 390cc 85.0 Silica (Tokusil GU-N, manufactured by Tokuyama Corp.) Pulp 2 1.0 Talc (YDK, manufactured by Kamitark Co., Ltd.) vs. pulp 12.5 Sizing agent (AL-120, manufactured by Nippon PMC Co., Ltd.) vs. pulp 0.5 Cationic starch (GEMCAT 200, manufactured by Manildora Co.) vs. pulp 0 Polyacrylamide (Harmide C-10, manufactured by Harima Chemicals, Inc.) vs. pulp 2.5 Sulfuric acid band (aluminum sulfate, manufactured by Nittetsu Mining Co., Ltd.) vs. pulp 0.1 The following size press coating solution 1 was applied as a surface treatment for stabilizing the base paper surface and improving the strength. Size Press Coating Solution 1 Component Weight parts Oxidized starch (MS # 3800, manufactured by Nippon Shokuhin Kako Co., Ltd.) 4.0 Polyvinyl alcohol (UF-170G, manufactured by Unitika Ltd.) 1.0 Water 95.0 Result , Basis weight 142 g / m ² , Beck smoothness 65 seconds,
A base paper having a formation index value of 96 was obtained.

Next, a coating liquid A for forming a cast coat treatment layer containing the hollow particles described below was coated on one surface of the formed base paper by a blade coater so as to have a dry thickness of 13 g / m ^2. And dried.

Coating solution A for forming a cast coat layer A component Weight parts Acrylic non-foamable hollow particles (HP-91, manufactured by Rohm & Haas Co.) 40 parts (volume hollow ratio 50%, average particle size 1.0 μm) ) Kaolin (Alpha Coat, ECC) 30 parts Calcium carbonate (FMT-90, manufactured by Fimatec Corporation) 30 parts Casein (manufactured by SCERMA) 10 parts Styrene butadiene latex 15 parts (Polylac, Mitsui Chemicals, Inc.) )) Calcium stearate (C-104, manufactured by San Nopco Co., Ltd.) 1 part Polyethylene wax (manufactured by San Nopco Co., Ltd.) 1 part Dispersant (Aron T-40, manufactured by Toagosei Co., Ltd.) Trace amount defoamer (SN Defoamer, manufactured by San Nopco Co.) trace solid content of 45% then, 12 g / m ² of the following cast-coated treatment layer forming coating solution B at a dry thickness The obtained coated surface is brought into contact with a coagulating liquid comprising a 1% aqueous solution of calcium formate to cause gelation, and the gelled surface is passed through a press roll with a cast drum having a surface temperature of 105 ° C. Linear pressure 100
It was pressed and dried at kg / cm to form a cast coat treated layer having a total thickness of 25 g / m ² consisting of a hollow particle-containing layer and a cast coat surface layer.

As a result, a paper base material having a basis weight of 167 g / m ² and a Beck smoothness of 490 seconds was obtained.

Coating solution B for forming a cast coat treatment layer B Component Weight part Kaolin (Alpha Coat, ECC Co., Ltd.) 70 parts Calcium carbonate (FMT-90, manufactured by Fimatec Co., Ltd.) 30 parts Casein (manufactured by SCERMA) 10 parts Styrene-butadiene latex 15 parts (Polylac, manufactured by Mitsui Chemicals, Inc.) Calcium stearate (C-104, manufactured by San Nopco Co., Ltd.) 1 part Polyethylene wax (manufactured by San Nopco Co., Ltd.) 1 part Dispersant (Aron T -40, manufactured by Toa Gosei Co., Ltd. Trace amount antifoaming agent (SN Deformer, manufactured by San Nopco Ltd.) Trace amount of paint solids 45% Next, the following dyes are received on the surface layer of the cast coat of the obtained paper base material. The coating liquid for forming a layer was applied so as to have a dry thickness of 4 μm, and dried to form a dye receiving layer. Thus, a thermal transfer image-receiving sheet of the present invention was obtained.

Coating solution for forming dye receiving layer Component Weight parts Vinyl chloride-vinyl acetate copolymer 25.0 (VMCC, manufactured by Union Carbide) Amino-modified silicone (KF-393, manufactured by Shin-Etsu Chemical Co., Ltd.) 1.0 Toluene 24.0 Methyl ethyl ketone 50.0 Evaluation of thermal transfer image-receiving sheet A 6 μm-thick polyethylene terephthalate sheet (K230S, manufactured by Diafoil Co., Ltd.) having the following ink layer forming coating liquid subjected to heat-resistant lubrication treatment on one side. Was coated so as to have a dry thickness of 1 μm and dried to form an ink layer, thereby producing a thermal transfer recording medium.

Coating solution for forming ink layer Component Weight part Disperse dye (Solvent Blue 63, manufactured by Arimoto Chemical Co., Ltd.) 4.0 Petial resin (6000EP, manufactured by Denki Kagaku Kogyo Co., Ltd.) 5.0 Toluene 31 0.0 methyl ethyl ketone 30.0 tetrahydrofuran 30.0 The ink layer of the obtained thermal transfer recording medium was superimposed on the dye receiving layer of the thermal transfer image receiving sheet, and printed with 16 gradations using a thermal simulator (output = 0.2 W / dot: pulse). Width = 6 msec .: Dot width = 8 dots / mm (about 200
dpi)). The heat transfer image-receiving sheets were visually evaluated for unevenness in paper making, glossiness, unevenness in color development, image omission, and image quality. The image quality was comprehensively evaluated based on each evaluation result. Table 1 shows the results. In the table, double circles indicate very good, ○ indicates good, and Δ indicates poor.

Example 2 In the same manner as in Example 1, papermaking was performed using a fourdrinier layer, and the same base paper was obtained by applying a size press coating solution.

Next, on one side of the base paper thus formed, a coating liquid C containing a hollow particle containing the following cast coat layer was formed by an on-machine cast bar coater so as to have a dry thickness of 13 g / m ^2. Coated.

Coating solution C for forming cast coating layer C component weight part vinylidene chloride hollow particles (F-04E, manufactured by Matsumoto Yushi Pharmaceutical Co., Ltd.) 30 parts (volume hollow ratio 90%, average particle size 4.0 μm) ) Kaolin (Alpha Coat, ECC) 40 parts Calcium carbonate (FMT-90, manufactured by Fimatec Corporation) 30 parts Casein (manufactured by SCERMA) 10 parts Styrene butadiene latex 15 parts (Polylac, Mitsui Chemicals, Inc.) )) Calcium stearate (C-104, manufactured by San Nopco Co., Ltd.) 1 part Polyethylene wax (manufactured by San Nopco Co., Ltd.) 1 part Dispersant (Aron T-40, manufactured by Toagosei Co., Ltd.) Trace amount defoamer (SN Deformer, manufactured by San Nopco Co.) Trace amount of paint solid content 45% In a semi-dried state, the cast coat treatment was further carried out in the same manner as in Example 1. Coating of the coating liquid B for forming the physical layer, gelling of the coated surface, pressure drying with a cast drum, and a cast coating treatment of a total thickness of 25 g / m ² consisting of a hollow particle-containing layer and a cast coat surface layer. A layer was formed. Thus, a paper substrate having a basis weight of 167 g / m ² and a Beck smoothness of 490 seconds was obtained.

Next, a dye receiving layer was formed on the cast coat surface layer of the obtained paper base in the same manner as in Example 1.
A thermal transfer image-receiving sheet of the present invention was obtained.

Using the obtained thermal transfer image-receiving sheet, evaluation was performed in the same manner as in Example 1. The results are shown in Table 1 below.
Shown in

Example 3 A basis weight of 142 g / m ² was obtained in the same manner as in Example 1 except that the paper material 1 was used to make a three-layer paper using a fourdrinier multilayer paper machine.
A base paper having a Beck smoothness of 66 seconds and a formation index value of 102 was obtained.

Next, the coating liquid A for forming a cast coat treatment layer was coated on one surface of the formed base paper in the same manner as in Example 1 with a blade coater to a dry thickness of 13 g / m ^2. Worked dry.

Thereafter, in the same manner as in Example 1, the coating liquid B for forming the cast coat treatment layer was applied, the coating surface was gelled, and the coating drum was pressed and dried to obtain a hollow particle-containing layer and a cast coat surface layer. Total thickness 25 consisting of two layers of
g / m ² of the cast coat treated layer was formed. Thus, a paper substrate having a basis weight of 167 g / m ² and a Beck smoothness of 490 seconds was obtained.

Next, a dye-receiving layer was formed on the cast coat surface layer of the obtained paper base in the same manner as in Example 1.
A thermal transfer image-receiving sheet of the present invention was obtained.

Evaluation was performed in the same manner as in Example 1 using the obtained thermal transfer image-receiving sheet. The results are shown in Table 1 below.
Shown in

Example 4 The same base paper was obtained in the same manner as in Example 1 by making a fourdrinier layer and applying a size press coating solution.

Next, the coating liquid A for forming a cast coat treatment layer was applied on one side of
g / m ² and dried by coating with a blade coater.

Thereafter, in the same manner as in Example 1, the coating liquid B for forming the cast coat treatment layer was applied and the coated surface was gelled, and the linear pressure was set to 150 kg / cm. Similarly, a cast coat treated layer having a total thickness of 25 g / m ² , which was composed of two layers, a hollow particle-containing layer and a cast coat surface layer, was formed. Thereby, the basis weight 167 g /
A paper substrate having m ² and a Bekk smoothness of 650 seconds was obtained.

Next, a dye receiving layer was formed on the cast coat surface layer of the obtained paper base in the same manner as in Example 1.
A thermal transfer image-receiving sheet of the present invention was obtained.

Evaluation was performed in the same manner as in Example 1 using the obtained thermal transfer image-receiving sheet. The results are shown in Table 1 below.
Shown in

COMPARATIVE EXAMPLE 1 A paper stock 1 was used to make paper with a fourdrinier single-layer paper machine instead of a fourdrinier multi-layer paper machine. The basis weight was 142 g / m ² , and the Beck smoothness was 65.
In seconds, a base paper having a formation index value of 32 was obtained.

Next, on one side of the obtained base paper, a cast coat treatment layer composed of two layers, a hollow particle-containing layer and a cast coat surface layer, was formed in the same manner as in Example 1.
Thereby, the basis weight is 167 g / m ² , and the Beck smoothness is 490.
Second paper base was obtained.

Next, a dye receiving layer was formed on the cast coat surface layer of the obtained paper substrate in the same manner as in Example 1.
A thermal transfer image-receiving sheet for comparison was obtained.

Using the obtained thermal transfer image-receiving sheet, evaluation was performed in the same manner as in Example 1. The results are shown in Table 1 below.
Shown in

COMPARATIVE EXAMPLE 2 Paper material 1 was made in a four-layer paper making machine instead of a fourdrinier multi-layer paper machine using the stock material 1, and the same size press coating solution was applied. A base paper having m ² , Beck smoothness of 65 seconds and a formation index value of 50 was obtained.

Next, on one side of the obtained base paper, in the same manner as in Example 1, a cast coat treatment layer comprising a hollow particle-containing layer and a cast coat surface layer was formed.
Thereby, the basis weight is 167 g / m ² , and the Beck smoothness is 490.
Second paper base was obtained.

Thereafter, in the same manner as in Example 1, the coating liquid B for forming a cast coat treatment layer was applied, the coated surface was gelled, and the coating drum was pressed and dried using a cast drum. Total thickness 25 consisting of two layers of
g / m ² of the cast coat treated layer was formed. Thus, a paper substrate having a basis weight of 167 g / m ² and a Beck smoothness of 490 seconds was obtained.

Next, a dye receiving layer was formed on the cast coat surface layer of the obtained paper substrate in the same manner as in Example 1.
A thermal transfer image-receiving sheet of the present invention was obtained.

Evaluation was performed in the same manner as in Example 1 using the obtained thermal transfer image-receiving sheet. The results are shown in Table 1 below.
Shown in

Comparative Example 3 Paper material 1 was made in two layers by a fourdrinier multi-layer paper machine, and the same size press coating solution was applied to obtain a base paper similar to that in Example 1.

Next, a coating solution A for forming a cast coat layer was applied on one side of the obtained base paper in the same manner as in Example 1.
Was applied to a dry thickness of 25 g / m ^2, and then the coating surface was gelled in the same manner and pressed and dried with a cast drum to form a cast coat treatment layer composed of a single layer containing hollow particles. As a result, a paper base material having a basis weight of 167 g / m ² and a Beck smoothness of 220 seconds was obtained.

Next, on the cast coat surface layer of the obtained paper base material, a dye receiving layer was formed in the same manner as in Example 1.
A thermal transfer image-receiving sheet for comparison was obtained.

Using the obtained thermal transfer image-receiving sheet, evaluation was performed in the same manner as in Example 1. The results are shown in Table 1 below.
Shown in

Comparative Example 4 Paper stock 1 was made in two layers by a fourdrinier multi-layer paper machine, and the same size press coating solution was applied to obtain a base paper similar to that in Example 1.

Next, a coating solution B for forming a cast coat layer was applied on one side of the obtained base paper in the same manner as in Example 1.
Was applied in a dry thickness of 25 g / m ^2, and then the coating surface was gelled in the same manner and pressed and dried with a cast drum to form a single layer of a cast coat treatment layer containing no hollow particles. Thus, a paper substrate having a basis weight of 167 g / m ² and a Beck smoothness of 490 seconds was obtained.

Next, a dye receiving layer was formed on the cast coat surface layer of the obtained paper base in the same manner as in Example 1.
A thermal transfer image-receiving sheet for comparison was obtained.

Using the obtained thermal transfer image-receiving sheet, evaluation was performed in the same manner as in Example 1. The results are shown in Table 1 below.
Shown in

Comparative Example 5 Paper stock 1 was made in two layers by a fourdrinier multi-layer paper machine, and the same size press coating solution was applied to obtain a base paper similar to that in Example 1.

Next, on one side of the obtained base paper, the following coating liquid D for forming a cast coat treatment layer was dried at a dry thickness of 13 g /
It was coated with an on-machine cast bar coater so as to obtain m ² .

Coating Solution D for Cast Coat Processing Layer Component Component Parts by weight Silica-based hollow particles (prototype in-house) 10 parts (volume hollow ratio 10%, average particle size 1.6 μm) Kaolin (Alpha Coat, Inc.) ECC) 60 parts Calcium carbonate (FMT-90, manufactured by Fimatec Corporation) 30 parts Casein (manufactured by SCERMA) 10 parts Styrene-butadiene latex 15 parts (Polylac, manufactured by Mitsui Chemicals, Inc.) Calcium stearate (C-104) 1 part Polyethylene wax (manufactured by San Nopco Co., Ltd.) 1 part Dispersant (Aron T-40, manufactured by Toa Gosei Co., Ltd.) Trace amount Antifoaming agent (SN Deformer, manufactured by San Nopco Ltd.) Trace amount The solid content of the coating is 45%. Thereafter, the semiconductor coating is dried, and the coating liquid B for forming a cast coat layer is further dried on the semiconductor in a dry thickness of 12 g. m ²
In the same manner as in Example 1, the coated surface was gelled and dried by pressure welding with a cast drum to form a cast coat-treated layer having a total thickness of 25 g / m ² consisting of two layers. Thus, a paper substrate having a basis weight of 167 g / m ² and a Beck smoothness of 490 seconds was obtained.

Next, a dye-receiving layer was formed on the cast coat surface layer of the obtained paper base in the same manner as in Example 1.
A thermal transfer image-receiving sheet for comparison was obtained.

Evaluation was performed in the same manner as in Example 1 using the obtained thermal transfer image-receiving sheet. The results are shown in Table 1 below.
Shown in

[0084]

[Table 1]

As is clear from Table 1, when the thermal transfer image-receiving sheets according to Examples 1 to 4 were used, even when printing was performed under the low-energy printing conditions and high-speed printing conditions described in each of the examples, unevenness in paper making, It was found that a high-quality image with high density and excellent glossiness can be obtained without causing uneven coloring and image omission.

In particular, it was found that when hollow particles having a volume hollow ratio of about 80% or more were used as in Example 2, high-sensitivity and high-quality images could be obtained.

Further, when a base paper having a formation index of 100 or more is used as in Example 3, the low color-developing area becomes particularly high in quality. Degree 600
It was found that when a paper base material of seconds or longer was used, the overall quality was high and the glossiness was particularly high.

On the other hand, as in Comparative Examples 1 and 2, when the fourdrinier multi-layer base paper was not used, uneven formation and non-uniform formation occurred. Further, when a single layer of the cast coat treatment layer containing no hollow particles was formed as the cast coat treatment layer as in Comparative Example 3, image omission occurred, and uneven color formation was observed, particularly in a low color formation region. occured. When a hollow particle-containing layer single layer was formed as in Comparative Example 4,
When the hollow volume ratio of the hollow particles used is lower than 40% as in Comparative Example 5, cushioning properties are insufficient, and uneven color formation occurs, particularly in a low color-developing region.

[0089]

The thermal transfer image-receiving sheet of the present invention is inexpensive and has excellent cushioning properties. Therefore, when the thermal transfer image-receiving sheet of the present invention is used, white spots and gloss unevenness do not occur in high-speed printing. It is possible to form a high-quality thermal transfer image even under low energy printing conditions, without causing unevenness in formation of base paper, unevenness in paper making, and uneven coloring due to insufficient cushioning properties.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view illustrating an example of a thermal transfer image receiving sheet of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Paper base material 11 ... Base paper 12 ... Cast coat treatment layer 12a ... Hollow particle containing layer 12b ... Cast coat surface layer 20 ... Dye receiving layer

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[Procedure amendment]

[Submission date] November 27, 1998 (1998.11.
27)

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Fig. 1

[Correction method] Change

[Correction contents]

FIG.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Kenjiro Kuroda 1-5-1, Taito, Taito-ku, Tokyo Inside Toppan Printing Co., Ltd. (72) Inventor Koji Murata 1-15-1 Taito, Taito-ku, Tokyo Letterpress Inside Printing Co., Ltd. (72) Katsuhiro Katayama, 451-1 Harada, Fuji City, Shizuoka Prefecture Inside Gojo Paper Co., Ltd. (72) Inventor Mitsutaka Arai 451-1 Harada, Fuji City, Shizuoka Prefecture Gojo Paper Company F-term (reference) 2H111 AA01 AA14 AA27 CA03 CA04 CA12 CA13 CA14 CA23 CA33 CA41 CA45 4L055 AG11 AG12 AG27 AG54 AG63 AG67 AG71 AG76 AG94 AG97 AH02 AH37 AJ04 AJ08 BD16 BE08 BE09 CD01 CD27 EA06 EA12 EA18 FA15 FA16 GA13 GA20

Claims (4)

[Claims] 1. A fourdrinier multi-layer base paper made mainly of pulp, a paper base material including a multi-layer cast coat treatment layer provided on the base paper, and a paper base formed on the cast coat treatment layer A thermal transfer image-receiving sheet having a dye-receiving layer, wherein the cast coat-treated layer comprises a layer that does not contact the dye-receiving layer and contains hollow particles having a volume hollow ratio of 40% or more. . 2. The thermal transfer image-receiving sheet according to claim 1, wherein the hollow particles have a volume hollow ratio of 80% or more. 3. The thermal transfer image-receiving sheet according to claim 1, wherein the base paper has a formation index value of 100 or more. 4. The thermal transfer image-receiving sheet according to claim 1, wherein the Beck smoothness of the surface of the cast coat treatment layer is 600 seconds or more.