JP2000272259A - Heat transfer receiving sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat transfer receiving sheet which has a high sensitivity and provides a picture of high quality and clarity at a low cost. SOLUTION: In the heat transfer receiving sheet wherein a sheet-like cellulose core material layer, a porous resin layer formed on at least one side of the cellulose core material layer, a thermoplastic resin laminate layer, and a dye receptive layer are successively stacked, the laminate layer is formed by an extruding laminate method, and the clarity of a surface of the dye receptive layer according to JIS K7105 C(2.0)=10% or more.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer receiving sheet. More specifically, the present invention is suitable for a thermal printer, particularly a dye thermal transfer printer, has a good image quality, can obtain a clear and high-resolution image similar to a silver halide photograph, has almost no curl, and has a low cost. The present invention also relates to a heat transfer receiving sheet (hereinafter simply referred to as a receiving sheet) which is also advantageous.

[0002]

2. Description of the Related Art In recent years, a thermal printer, particularly a dye thermal transfer printer capable of printing a clear full-color image, has attracted attention. Dye thermal transfer printers superimpose a receiving layer containing a dye-dyeable resin of a receiving sheet on a dye ink sheet, and apply heat at a required concentration of the dye layer on the receiving layer by heat supplied from a thermal head or the like. To form an image. The ink sheet is composed of three colors of yellow, magenta and cyan, or four colors of black and black. A full-color image is obtained by repeatedly transferring the dyes of each color of the ink sheet to the receiving sheet in order.

In such a printer with a thermal head, a dye-dyeable resin is used as a main component on a sheet such as a uniaxially or biaxially stretched film or a multilayer structure film (synthetic paper) in order to obtain good printed images. In many cases, a receiving sheet having an image receiving layer containing the same is used. The sheet as described above has advantages such as uniform thickness, flexibility, and low thermal conductivity as compared with paper made of cellulose fiber, so that a uniform and high-density transfer image can be obtained. There is an advantage that it can be. In particular, in the case of a stretched film, a receiving sheet having good surface gloss can be obtained by adjusting the stretching ratio.

However, when thermal transfer recording is performed on a receiving sheet using the above-described film or synthetic paper as a sheet-like substrate, the stretching stress of the film is released by heat, and the film contracts due to heat. The curl (print curl) becomes large, making it difficult to run through the printer, and also has the disadvantage that the commercial value of the obtained print is significantly reduced. So, to suppress print curl,
A substrate obtained by laminating the above-mentioned film or synthetic paper on both sides of the paper is often used, but the process is complicated and the cost increases.

[0005]

SUMMARY OF THE INVENTION The present invention uses a paper substrate and is capable of forming a clear image with high sensitivity, high image quality and excellent surface gloss on various thermal printers. An object of the present invention is to provide a low-cost thermal transfer receiving sheet having good curl.

[0006]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors have conducted intensive studies mainly on the structure of the receiving sheet. As a result, a porous resin layer was formed on one surface of the cellulose core material layer. A receiving sheet in which a laminate layer of a thermoplastic resin and a dye-dyeing receiving layer are sequentially laminated, the density of the porous resin layer is defined, the method of forming the laminate is limited, and the image of the surface of the receiving layer is sharp. It has been found that by setting the degree to a specific value, a thermal transfer receiving sheet having high sensitivity, high image quality, excellent image clarity, and low cost can be obtained. In the first invention, a sheet-like cellulose core material layer, a resin layer having porosity on at least one surface of the sheet-like cellulose core material layer, a laminate layer of a thermoplastic resin, and a dye-dyeing receiving layer are sequentially laminated. In the thermal transfer receiving sheet, the density of the porous resin layer is 0.05 to
0.5 g / cm ³ , the laminate layer was formed by extrusion lamination, and the J
Image sharpness based on ISK7105 is C _(2.0) = 10
% Or more. Preferably, the laminate layer contains 1 to 20% by weight of the pigment.

In order to solve the above problems, the present inventors have made intensive studies mainly on the structure of the receiving sheet. As a result, a porous resin layer and a thermoplastic resin were formed on one surface of the cellulose core material layer. A receiving sheet in which a laminate layer and a dye-dyeing receiving layer are sequentially laminated, the density of a porous resin is defined, the method of forming the laminate layer is limited, and the value of 60 ° specular gloss of the surface of the receiving layer is defined. By specifying, high sensitivity, high image quality, excellent surface gloss,
Moreover, they have found that a low-cost thermal transfer receiving sheet can be obtained. The second invention is a sheet-like cellulose core material layer,
In a thermal transfer receiving sheet in which a porous resin layer, a thermoplastic resin laminate layer, and a dye-dyeing receiving layer are sequentially laminated on at least one surface of the sheet-shaped cellulose core material layer, the density of the porous resin layer is 0. 0.05-0.5g
/ Cm ³ , the laminate layer is formed by the extrusion lamination method, and JISZ8
74. A thermal transfer receiving sheet characterized in that the 60 ° specular gloss described in 741 is 80% or more. Preferably, the laminate layer contains 1 to 20% by weight of the pigment.

Further, the present inventors have conducted intensive studies mainly on the structure of the receiving sheet in order to provide a receiving sheet with high sensitivity and high image quality. As a result, a porous resin layer was formed on one surface of the cellulose core material layer. This is a receiving sheet in which a laminate layer of a thermoplastic resin and a dye-dyeable receiving layer are sequentially laminated, and can be achieved by forming a plurality of porous resin layers and limiting the method of forming the laminate layer. The third invention is a sheet-like cellulose core layer, and a resin layer having porosity on at least one surface of the sheet-like cellulose core layer,
In a thermal transfer receiving sheet in which a laminate layer of a thermoplastic resin and a dye-dyeable receiving layer are sequentially laminated, a porous resin layer is formed by a plurality of layers, and a resin layer having a porosity on at least the side on which the laminate layer is formed Has a particle size of 0.1
A heat transfer receiving sheet, comprising a layer containing hollow particles having a diameter of from 10 to 10 μm, wherein the laminate layer is formed by an extrusion lamination method. The density of the layer formed on the core material layer side of the plurality of porous resin layers is preferably 0.05 to 0.5 g / cm ³ . More preferably, it is 0.05 to 0.4 g / cm ³ . Further, the density of a layer containing hollow particles having a particle diameter of 0.1 to 10 μm formed on the laminate layer side in which a plurality of porous resin layers are formed may be 0.3 to 0.8 g / cm ^3. preferable.

[0009] Of the first, second, and third inventions, a configuration that satisfies two is more preferable, and a configuration that satisfies all three is particularly preferable. That is, if the first invention and the second invention are satisfied, a receiving sheet having excellent image clarity and surface glossiness is obtained, and if the first invention and the third invention are satisfied, the image clarity is excellent. And high concentration,
A receiving sheet of high image quality. If the second and third inventions are satisfied, the receiving sheet has excellent surface gloss and high density and high image quality. If all are satisfied, clearness and surface gloss of the image are excellent. In addition, the receiving sheet can provide high density and high image quality.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The thermal transfer receiving sheet of the present invention comprises a porous resin layer (hereinafter also referred to as a porous resin layer), a thermoplastic resin laminate layer, and a dye dye on one surface of a cellulose core material layer. This is a layer configuration in which an adhesion receiving layer is sequentially laminated.

As the cellulose core layer constituting the present invention, a paper base material containing wood pulp as a main component is preferably used because it has moderate heat insulating properties and cushioning properties and is advantageous in terms of cost. Can be For example, hardwood pulp, softwood pulp, wood pulp such as hardwood softwood mixed pulp, and kraft pulp, sulfite pulp, soda pulp, etc. Paper having improved surface smoothness by applying and compressing is preferred. The grammage is
50 to 250 g / m ² is preferred. If necessary, a coating layer containing a pigment may be provided. Specifically, high-quality paper,
Examples include art paper, coated paper, matte paper, impregnated paper, paperboard, and the like. Further, those subjected to calendering for high smoothness are preferred. Further, the back side or both sides of the paper substrate may be coated with a water-resistant, thermoplastic resin, such as a polyolefin resin. The polyolefin resin is selected from homopolymers of ethylene, α-olefins, for example, propylene, and at least two copolymers of the olefin, and two or more of these various polymers can be used in combination. is there.

[0012] The paper base is made of various ordinary paper additives,
For example, a dry paper strength agent (cationized starch, cationized polyacrylamide, etc.), a sizing agent (fatty acid salt, rosin,
Maleated rosin, cationized sizing agent, reactive sizing agent, etc.), filler (clay, kaolin, titanium, etc.), wet paper strength enhancer (melamine resin, epoxidized polyamide resin, etc.), fixing agent (aluminum sulfate, cationized) It may contain one or more kinds such as starch and the like, and a pH regulator (caustic soda, sodium carbonate and the like). The base paper is made of water-soluble polymer additives, sizing agents, inorganic electrolytes, hygroscopic substances, pigments,
It may be tab-sized or size-pressed with a treatment liquid containing one or more dyes, pH adjusters, and the like.

According to the present invention, the apparent density of at least the surface of the cellulose core material layer on which the receiving layer is formed is 0.3.
By adopting a configuration in which a porous resin layer having a thickness of from 0.5 to 0.5 g / cm ³ and a laminate layer of a thermoplastic resin formed by an extrusion lamination method are employed, the recording sensitivity and the recording density are further improved. It is considered that the reason is that the porous resin layer and the laminate layer have high heat insulating properties. In order to obtain high recording sensitivity and recording density, it is necessary to control the apparent density of the porous resin layer in the range of 0.05 to 0.5 g / cm ³ , and 0.07 to 0.45
The range of g / cm ³ is particularly preferred. The lower the density of the porous resin layer is, the better the heat insulating property is. However, if the apparent density is less than 0.05 g / cm ³ , the strength of the porous resin layer is insufficient and the smoothness of the surface of the receiving layer is low. And recording quality tends to deteriorate. On the other hand, if the apparent density exceeds 0.5 g / cm ³ , a sufficient effect of improving the recording sensitivity and the recording density cannot be obtained. When the thickness of the porous resin layer is less than 2 μm, the heat insulating property is not effective, and the recording density tends to decrease. As the thickness of the porous resin layer is increased, the recording sensitivity is improved and the image quality is also improved. However, when the thickness exceeds 60 μm, the effect is saturated and the economic disadvantage is caused.

Further, according to the present invention, by providing such a porous resin layer and a laminate layer, white spots at the time of printing are reduced, and the recording image quality is improved. One of the reasons is that the unevenness of the cellulose sheet is leveled by providing the porous resin layer, and the surface of the laminate layer is kept smooth. Furthermore, the porous resin layer and the laminate layer have a cushioning property. This is considered to have high adhesion to the thermal head during printing. In order to obtain high recording image quality, it is preferable to use a thermoplastic resin having a glass transition temperature of -10 to 70 ° C for the porous resin layer, and it is preferable to control the thickness of the porous resin layer in the range of 2 to 60 µm. When the glass transition temperature is lower than −10 ° C., the porous resin layer is melted by contact with a molten resin exceeding 200 ° C. in the extrusion laminating step of forming a laminate layer, and the voids are crushed, so that the heat insulating property is reduced. And the recording sensitivity decreases. When the glass transition temperature is higher than 70 ° C., since there is no cushioning property, the adhesion to the ink ribbon is deteriorated, and the image quality is reduced.

As the porous resin layer constituting the present invention,
This is a layer containing a resin and, if necessary, a pigment as a main component. For example, a method of blending and applying a microcapsule-like resin containing a swelling agent that is gasified by heating to a coating liquid and applying the resulting mixture, and foaming by heating, is formed by applying the microcapsules after expanding them in advance. Method, a method of applying a coating liquid containing a hollow spherical plastic pigment, a method of mixing the anionic resin particles and the cationic resin particles in the coating liquid to create voids by aggregation, a resin, or a resin and a pigment. A method of mechanically agitating a liquid containing the mixture to form and disperse a large number of fine air bubbles, and applying and drying the air-containing resin liquid to form a liquid, can be exemplified, but not limited thereto. Further, the porous resin layer can be formed by laminating a plurality of layers.

Examples of usable resins include polyvinyl alcohol having various molecular weights and degrees of saponification and derivatives thereof, starch, derivatives of starch (for example, various modified starches such as oxidized starch and cationized starch), methoxycellulose, Carboxymethylcellulose, methylcellulose, cellulose derivatives such as ethylcellulose, sodium polyacrylate, polyvinylpyrrolidone, acrylamide-acrylate copolymer,
Acrylic acid amide-acrylic acid ester-methacrylic acid ester copolymer, styrene-maleic anhydride copolymer alkali salt, polyacrylamide and derivatives thereof,
Water-soluble resin such as polyethylene glycol, and polyvinyl acetate, polyurethane, styrene-butadiene copolymer (SBR latex), acrylonitrile-butadiene copolymer (NBR latex), polyacrylate, vinyl chloride-vinyl acetate copolymer Resin such as coalesce, polybutyl methacrylate, ethylene-vinyl acetate copolymer, styrene-butadiene-acrylic copolymer, polyvinylidene chloride, and further, glue, casein, soy protein, gelatin, sodium alginate and the like can be used. However, the present invention is not limited to these. These resins can be used alone or as a mixture of two or more, if necessary.

Examples of pigments that can be used in combination include inorganic pigments such as zinc oxide, titanium oxide, calcium carbonate, silicic acid, silicate, clay, talc, mica, calcined clay, aluminum hydroxide, barium sulfate, lithopone, and colloidal silica. Use of organic pigments such as polystyrene, polyethylene, polypropylene, epoxy resin, styrene-acrylic copolymer, etc., spherical or hollow, or plastic pigments of a type processed into various shapes, starch powder, cellulose powder, etc. However, the present invention is not limited to these. These pigments can be used alone or in combination of two or more, if necessary.

The laminated layer of the thermoplastic resin constituting the present invention is limited to the extrusion lamination method. In the extrusion lamination method, when the thermoplastic resin is pressed against the cooling roll, the surface of the cooling roll is transferred to the surface of the resin layer. For this reason, the surface of the resin layer can be finished to a very smooth surface, and a high-quality receiving layer can be obtained. The thermoplastic resin that can be used is not particularly limited as long as it is a thermoplastic resin, for example, high-density polyethylene, medium-density polyethylene, low-density polyethylene, polypropylene,
Polyolefin resins such as polybutene and polypentene are good.

A pigment can be contained in the laminate layer. For example, zinc oxide, titanium oxide, calcium carbonate, silicic acid, silicate, clay, talc, mica, calcined clay, aluminum hydroxide, barium sulfate, lithopone, inorganic pigments such as colloidal silica, epoxy resin, styrene-acrylic copolymer, etc. Organic pigments, starch powders, cellulose powders, etc., referred to as plastic pigments of a true sphere, hollow, or processed into various shapes can be used, but are not limited thereto. These pigments can be used alone or in combination of two or more, if necessary.

In the constitution of the receiving sheet of the present invention, a dye-dyeable receiving layer for receiving the dye of the ink ribbon is formed on the laminate layer. The receiving layer contains a resin having a high dye-dyeing property as an essential component, and is appropriately blended with a crosslinking agent, an anti-fusing agent, an ultraviolet absorber and the like. As the resin having a high dye-dyeing property, a cellulose resin, an acetate butyrate resin, a polyester resin, or the like is used. Also, isocyanate compounds, epoxy compounds, etc. for the cross-linking agent, benzotriazole-based, benzophenone-based, phenyl salicylate-based, cyanoacrylate-based compounds, etc. for the ultraviolet absorber, acrylic silicone-based resin, etc. for the anti-fusion agent,
Further, a lubricant, a release agent and the like are used. It is desirable that these receiving layer components cause a crosslinking reaction via a crosslinking agent. The coating amount of the receiving layer is preferably in the range of 0.1 to 20.0 g / m ² .

The first invention relates to such a cellulose core material.
Layer, porous resin layer, laminate layer, dye-dyeing receiving layer and
In addition to the layer structure described above, the dye
Image clarity (dimensions of optical combs) based on ISK7105
Is 2.0 mm), but C _(2.0)= 10% or more
It is not only high sensitivity and high image quality that
In addition, an image having excellent resolution can be obtained. JI
The image sharpness based on the description of SK7105 is C_(2.0)= 10%
By doing the above, halation (behind the image forming layer)
Side), and a clear image can be obtained.
You.

As the receiving sheet that satisfies such conditions, the conditions for lamination, the resin used, and the like may be appropriately selected. Preferably, the laminate layer is mainly composed of polyolefin, and the pigment is 1 to 20% by weight of the laminate layer.
It is good to mix so as to occupy. By the way, when the content of the pigment is less than 1% by weight, the incident light enters the laminate layer, causing halation in the laminate layer,
The result is a blurred image. If the pigment content exceeds 20% by weight, the pigment is exposed on the surface of the smooth resin layer or bubbles are generated, so that the glossiness of the surface is impaired and a clear image cannot be obtained.

The second invention adopts such a layer structure as a cellulose core material layer, a porous resin layer, a laminate layer, and a dye-dyeing receiving layer, and further comprises a J
By requiring that the 60-degree specular gloss described in ISZ8741 be 80% or more, a receiving sheet having not only high sensitivity and high image quality but also excellent surface gloss can be obtained. By the way,
If the 60-degree specular gloss is less than 80%, the surface gloss will be low. As the receiving sheet that satisfies such conditions, the conditions for lamination, the resin used, and the like may be appropriately selected. Preferably, during the lamination, by using a mirror-finished smooth cooling roll, the laminate layer surface can be finished to a very smooth surface, and a receiving sheet having a very high surface gloss can be obtained. It is preferable that the laminate layer contains 1 to 20% by weight of a pigment because a clear image can be obtained.

The third invention adopts such a layer structure as a cellulose core material layer, a porous resin layer, a laminate layer, and a dye-dyeing accepting layer, and the porous resin layer comprises a plurality of layers. By forming a layer containing hollow particles having a particle diameter of 0.1 to 10 μm at least on the porous resin layer on which the laminate layer is formed, higher recording image quality and higher recording density can be obtained. . Above all, the porous resin layer on the core material layer side (hereinafter also referred to as porous resin layer A) is preferably a thermoplastic resin layer having a density of 0.05 to 0.4 g / cm ³ , and the porous resin layer on the laminate layer side is preferable. The porous resin layer (hereinafter also referred to as porous resin layer B) has a density of 0.3 to
0.8 g / cm ³ and a particle diameter of 0.1 to 10 μm
It is preferable that the resin layer contains hollow particles of m.
In particular, the porous resin layer A has a density of 0.05 to 0.5 g / cm.
^{3 is} a thermoplastic resin layer, and the porous resin layer B has a density of 0.3.
³ to 0.8 g / cm ³ and a particle size of 0.1 to 1
A configuration in which two resin layers each including hollow particles having a diameter of 0 μm are laminated is particularly preferable.

When the density of the resin layer (porous resin layer A) on the side of the core material layer exceeds 0.5 g / cm ³ , the cushioning property tends to decrease and the image quality tends to decrease, and the heat insulating property becomes insufficient. There is also a tendency that a high recording density cannot be obtained. Density 0.0
If it is less than 5 g / cm ^3, the strength of the porous resin layer will be insufficient, and the recording image quality tends to decrease. Preferably from 0.05 to 0.4 g / cm ^3. Further, when the particle diameter of the hollow particles in the resin layer (porous resin layer B) on the laminate layer side is 10 μm or more, irregularities appear on the surface of the receiving layer, poor ink transfer occurs, and the image quality deteriorates. Easy to cause. Particle size is 10 μm or less and density is 0.3 g / cm
If it is less than ³ , it is considered that the cushioning property and the smoothness are excellent and the image quality is good, but it is difficult in manufacturing. On the other hand, if the density exceeds 0.8 g / cm ³ , the cushioning property tends to decrease and the image quality tends to decrease, and the heat insulating property tends to be insufficient and a high recording density tends not to be obtained.

When the thickness of the porous resin layer is less than 5 μm in total, the heat insulating property is not effective, and the recording density is reduced. As the thickness of the porous resin layer is increased, the recording sensitivity is improved and the image quality is also improved. However, when the thickness exceeds 60 μm, the effect is saturated and the economic disadvantage is caused. In order to obtain high recording sensitivity, it is necessary that the receiving sheet has a high heat insulating property, and the heat insulating property from the side of the receiving layer to 50 μm greatly affects the sensitivity. The smaller the density of the porous resin layer, the better the heat insulating property. The apparent density at 40 μm from the receiving layer side is 0.05 to 0.5.
By controlling the density within the range of g / cm ³ , the recording sensitivity or the recording density is extremely improved.

In the third invention, the porous resin layer (resin layer A) formed on the cellulose core layer contains a resin and, if necessary, a pigment as main components. For example, it is formed by blending and applying a microcapsule-like resin containing a swelling agent that is gasified by heating to a coating liquid, and foaming by heating, or by coating after microexpanding the microcapsules in advance. A method of applying a coating liquid containing a hollow spherical plastic pigment,
A method in which anionic resin particles and cationic resin particles are mixed in a coating liquid to form voids by aggregation, and a liquid containing a resin or a mixture of a resin and a pigment is subjected to mechanical stirring to form a large number of fine bubbles. A method of forming and dispersing, applying and drying the bubble-containing resin liquid, and forming the same can be exemplified.
This is not the case. The porous resin layer (resin layer B) on the laminate layer side can be formed by applying a coating liquid containing a hollow spherical plastic pigment.

In addition, a cellulose core material layer, a porous resin layer,
The thickness of the laminated support composed of a laminated layer of a thermoplastic resin is preferably in the range of 20 to 300 μm. When the thickness of the support is less than 20 μm, not only the mechanical strength of the receiving sheet obtained is insufficient, but also the hardness and the repulsive force against deformation become insufficient, and the receiving sheet generated at the time of printing is insufficient. In some cases, the curl cannot be sufficiently prevented. If the thickness exceeds 300 μm, the thickness of the obtained receiving sheet may be excessive. In a printer having a predetermined capacity, the receiving sheet storage capacity is limited, and an increase in the thickness of the receiving sheet naturally causes a decrease in the number of receiving sheets stored in the printer. In this case, in order to accommodate a predetermined number of receiving sheets, the volume of the printer must be increased, and it is difficult to make the printer compact.

In the receiving sheet of the present invention, on the back surface (opposite to the receiving layer), the running properties are improved, static electricity is prevented, the receiving layer is prevented from being damaged due to mutual rubbing between the receiving sheets, and further, the printed receiving sheet is used. A back cover layer may be formed for the purpose of preventing the transfer of the dye from the receiving layer to the back surface of the receiving sheet in contact with and adjacent to the receiving layer. The back cover layer contains a resin effective as an adhesive, and this resin is also effective for the running property of the receiving sheet and for preventing the receiving layer surface from being damaged. As such a resin, an acrylic resin, an epoxy resin, a polyester resin, a phenol resin, an alkyd resin, a urethane resin, a melamine resin, and the like, and a reaction cured product of these resins can be used.

Various conductive agents can be added to the back cover layer for antistatic treatment. It is desirable to use a cationic polymer as the conductive agent. As the cationic polymer, generally, polyethyleneimine, an acrylic polymer containing a cationic monomer, a cation-modified acrylamide polymer, a cationic starch and the like can be used. The coating amount of the back coating layer is 0.3
It is desirably in the range of １５15 g / m ² . 0.3
If it is less than g / m ² , it may not be possible to sufficiently prevent the receiving layer from being damaged when the receiving layer rubs against the back surface. If it exceeds 15 g / m ² , the effect is saturated and uneconomical.

Each coating layer in the present invention can be formed by applying and drying using a known coater such as a blade coater, an air knife coater, and a gate roll coater.

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which, of course, are not intended to limit the present invention. In the examples, "parts" and "%" all indicate "parts by weight" and "% by weight".

Example 1 (Formation of porous resin layer)
5 g / m ² high quality paper was used. A resin mixture having the following composition is applied on the surface of high-quality paper using a Meyer bar so that the coating amount (dry matter amount) is 8 g / m ^2, and is dried by heating to form a porous resin layer. did. The apparent density of the porous resin layer was 0.4 g / m ³ , and the thickness was 20 μm. "Resin mixture composition"-100 parts of heat-expandable resin (trademark: F-30, manufactured by Matsumoto Yushi)-30 parts of PVA (trademark: K-117, manufactured by Kuraray Co., Ltd.)

(Formation of Laminated Layer) Next, the following components were extruded and laminated to a thickness of 10 μm on the porous resin layer to form a laminated layer. A medium-density polyethylene (trade name: Neozex 40150C, manufactured by Mitsui Petrochemical, density 0.94 g / cm ³ ) having a thickness of 15 μm is formed on the back side of the high-quality paper (the side on which the porous resin layer is not formed). Extrusion lamination was performed to obtain a sheet having a laminate layer on both sides. "Laminate layer component" ・ 100 parts of low density polyethylene (trade name: Mirason P-11, manufactured by Mitsui Petrochemical) ・ Titanium oxide (manufactured by Sakai Chemical) 20 parts

(Formation of Receiving Sheet) On the back side of the obtained sheet, the following coating solution for back coating was applied at a solid content of 3 g / m 2.
² and dried to form a back coating layer. Then, the following coating liquid for a receiving layer was coated on the front side of the sheet so that the solid coating amount was 8 g / m ^2. , Drying (120
C. for 1 minute) to form a receiving layer. Further, ten sheets were stacked, and crosslinking of isocyanate was advanced in an oven at 60 ° C. to obtain a thermal transfer receiving sheet.

"Coating solution for receptor layer" 100 parts of polyester resin (trademark: Byron 200, manufactured by Toyobo Co., Ltd.) 3 parts of silicone oil (trademark: KF393, manufactured by Shin-Etsu Silicon Co., Ltd.) 3 isocyanate (trademark: Takenate D-140N, 5 parts ・ Toluene 300 parts

"Coating liquid for back surface coating layer"-Acrylic ester copolymer-(trademark: Primal WL-81, manufactured by Rohm and Haas) 100 parts-Epoxy resin (trademark: Epocoat DX-225, Shell Chemical Co., Ltd.) 5 parts-Conductive agent (trade name: Saftomer ST1000, manufactured by Mitsubishi Yuka) 50 parts-Denatured ethanol 1420 parts

Example 2 In forming a porous resin layer, the following composition was used and 2 g / m ²
A receiving sheet was obtained in the same manner as in Example 1 except that the coating was performed so as to be as follows. The apparent density of the porous layer is 0.08 g / m ³ ,
The thickness was 25 μm. "Resin mixture composition" 100 parts thermal expansion resin (trademark: F-30, manufactured by Matsumoto Yushi) 10 parts PVA (trademark: K-117, manufactured by Kuraray Co., Ltd.)

Example 3 A receiving sheet was obtained in the same manner as in Example 1 except that the following composition was extruded and laminated on the porous resin layer in forming the laminate layer. "Laminate layer component" ・ Low density polyethylene (trade name: Mirason P-11, manufactured by Mitsui Petrochemical) 100 parts ・ Titanium oxide (made by Sakai Chemical Co.) 2 parts

Example 4 (Formation of a porous resin layer) A resin mixed solution having the following composition was coated on a surface of a high-quality paper of 75 g / m ² of rice with a Meyer bar to a coating amount (dry matter) of 5 g. / M ² and dried by heating to form a porous resin layer. The apparent density of the porous resin layer is 0.3 g / m ³ and the thickness is 17 μm
Met. "Resin mixture composition" 100 hollow particles (trademark: HP-91, manufactured by Rohm and Haas)-30 parts SBR (trademark: PT-1004, manufactured by Asahi Kasei Corporation)

(Formation of Laminate Layer) Next, the following composition was extruded and laminated to a thickness of 10 μm on the porous resin layer to form a laminate layer. "Laminate layer component" ・ Polypropylene (trade name: Hypol LA-211; manufactured by Mitsui Petrochemical) 100 parts ・ Titanium oxide (made by Sakai Chemical Co.) 20 parts

(Preparation of Receptive Sheet) On the back side of high quality paper,
Medium density polyethylene (Trade name: Neozex 40150)
C, manufactured by Mitsui Petrochemical, density 0.94 g / cm ³ )
The sheet was extruded and laminated to a thickness of μm to obtain a sheet having a laminated layer on both sides. A receiving sheet was obtained in the same manner as in Example 1 except that this sheet was used.

Example 5 (Formation of a porous resin layer) A resin mixture (solid content: 35%) having the following composition was mixed with a stirrer (trade name: Kenmix Iiko PRO, manufactured by Aikosha Seisakusho). The foaming treatment was performed by stirring at a stirring speed of 490 rpm for 6 minutes. The expansion ratio was 3.0 times. Immediately after the foaming treatment, a coating amount (dry matter) of 10 g / m ² is applied on the surface of a high quality paper of 75 g / m ² of rice using an applicator bar, and the porous resin is dried. A layer was formed. The apparent density of the porous resin layer is 0.25 g / m ³ , and the thickness is 40 μm
Met.

"Resin mixture composition" 100 parts water-dispersed resin polyacrylate (trade name: AA-52, manufactured by Kanebo NSC, glass transition temperature: -7 ° C) 100 parts paraffin wax (trade name: Hydrin D-336, Chukyo Yushi) 5 parts ・ Fatty acid ammonium salt anionic surfactant (trademark: DC-100A, manufactured by San Nopco) 10 parts ・ Thickener: sodium carboxymethylcellulose (trademark: AG gum, manufactured by Daiichi Kogyo Seiyaku) 5 parts

(Formation of Laminated Layer) Next, the following composition was extruded and laminated to a thickness of 10 μm on the porous resin layer to form a laminated layer. "Laminate layer component"-Medium density polyethylene (Trade name: Neozex 40150C, manufactured by Mitsui Petrochemical) 100 parts-Titanium oxide (Sakai Chemical Co., Ltd.) 20 parts In addition, medium density polyethylene (trademark:
Neozex 40150C, manufactured by Mitsui Petrochemical, density 0.
94 g / cm ³ ) was extruded and laminated to a thickness of 20 μm to obtain a sheet having laminated layers on both sides. A receiving sheet was obtained in the same manner as in Example 1 except that this sheet was used.

Reference Example 1 A receiving sheet was obtained in the same manner as in Example 1, except that low density polyethylene (trade name: Mirason P-11, manufactured by Mitsui Petrochemical) was extruded and laminated in forming a laminate layer.

Comparative Example 1 A receiving sheet was obtained in the same manner as in Example 1 except that the following composition was extruded and laminated in forming a laminate layer. "Laminate layer component"-100 parts of low density polyethylene (trade name: Mirason P-11, manufactured by Mitsui Petrochemical)-34 parts of titanium oxide (manufactured by Sakai Chemical Co., Ltd.)

Comparative Example 2 Example 1 was repeated except that a resin mixture having the following composition was applied so as to be 1 g / m ^{2 in} forming the porous resin layer.
A receiving sheet was obtained in the same manner as described above. The apparent density of the porous resin layer was 0.04 g / m ³ , and the thickness was 25 μm. "Composition of resin mixture"-100 parts of thermal expansion resin (trademark: F-30, manufactured by Matsumoto Yushi)-3 parts of PVA (trademark: K-117, manufactured by Kuraray Co., Ltd.)

Comparative Example 3 A receiving sheet was obtained in the same manner as in Example 1, except that a resin mixture having the following composition was applied so as to be 10 g / m ^{2 in} forming a porous resin layer. The apparent density of the porous layer was 0.6 g / m ³ , and the thickness was 17 μm. "Composition of resin mixture"-100 parts of thermal expansion resin (trademark: F-30, manufactured by Matsumoto Yushi)-200 parts of PVA (trademark: K-117, manufactured by Kuraray Co., Ltd.)

Example 6 (Formation of Porous Resin Layer A) A resin mixture (solid content: 35%) having the following composition was mixed using a stirrer (trade name: Kenmix Iko PRO, manufactured by Aikosha Seisakusho). The mixture was stirred at a stirring speed of 490 rpm for 6 minutes to perform a foaming treatment.
The expansion ratio was 3.0 times. Immediately after the foaming treatment, a coating amount (dry matter) of 10 g / m ² is applied on the surface of a high quality paper of 75 g / m ² of rice using an applicator bar, and the porous resin is dried. A layer was formed. The apparent density of the porous resin layer is 0.35 g / m ³ and the thickness is 40 μm.
m.

[Resin mixed liquid composition] 100 parts of water-dispersed resin polyacrylate (trademark: AA-52, manufactured by Kanebo NSC) 5 parts of paraffin wax (trademark: Hydrin D-336, Chukyo Yushi) 5 fatty acid ammonium Salt anionic surfactant (trademark: DC-100A, manufactured by San Nopco) 10 parts ・ Thickener: sodium carboxymethyl cellulose (trademark: AG gum, manufactured by Daiichi Kogyo Seiyaku) 5 parts

(Formation of Porous Resin Layer B) Next, on the porous resin layer A, a resin mixed solution having the following composition was applied using a Mayer bar to a coating amount (dry matter amount) of 2 g / m ^2. And dried by heating to form a porous resin layer B. The apparent density of the porous resin layer B is 0.4 g / cm ³
Met. “Resin mixture composition” 100 hollow particles (trademark: HP-91, particle diameter 1 μm, manufactured by Rohm and Haas) 30 parts of PVA (trademark: K-117, manufactured by Kuraray Co., Ltd.)

(Laminate Layer) On the porous resin layer B,
The following composition was extruded and laminated to a thickness of 10 μm to form a laminate layer. In addition, medium-density polyethylene (trade name: Neozex 40150C, manufactured by Mitsui Petrochemical Co., Ltd.)
A density of 0.94 g / cm ³ ) was extruded and laminated to a thickness of 15 μm to obtain a sheet having laminated layers on both sides. "Laminate layer component" ・ 100 parts of low density polyethylene (trade name: Mirason P-11, manufactured by Mitsui Petrochemical) ・ Titanium oxide (manufactured by Sakai Chemical) 20 parts

(Preparation of Receptive Sheet) On the back side of the obtained sheet, the following coating liquid for back coating was applied at a solid content of 3 g / m 2.
² and dried to form a back coating layer. Then, the following coating liquid for a receiving layer was coated on the front side of the sheet so that the solid coating amount was 8 g / m ^2. , Drying (120
C. for 1 minute) to form a receiving layer. Further, ten sheets were stacked, and crosslinking of isocyanate was advanced in an oven at 60 ° C. to obtain a thermal transfer receiving sheet.

"Coating solution for receptor layer" 100 parts of polyester resin (trademark: Byron 200, manufactured by Toyobo Co., Ltd.) 3 parts of silicone oil (trademark: KF393, manufactured by Shin-Etsu Silicon Co., Ltd.) 3 isocyanate (trademark: Takenate D-140N, 5 parts ・ Toluene 300 parts

"Coating liquid for back surface coating layer" 100 parts of acrylate copolymer (trademark: Primal WL-81, manufactured by Rohm and Haas)-Epoxy resin (trademark: Epocoat DX-225, manufactured by Shell Chemical Company) 5 parts-Conductive agent (trademark: Saftomer ST1000, manufactured by Mitsubishi Yuka) 50 parts-Denatured ethanol 1420 parts

Example 7 In the formation of the porous resin layer A, the stirring speed was 490 rpm.
, And a receiving sheet was obtained in the same manner as in Example 6, except that the foam was applied at a foaming ratio of 5.0.
The apparent density of the porous resin layer A was 0.1 g / m ³ .

Example 8 In the formation of the porous resin layer B, the following composition was used and 2 g /
A receiving sheet was obtained in the same manner as in Example 6, except that coating was performed so as to obtain m ² . The apparent density of the porous resin layer B is 0.3 g.
/ M ³ . "Resin mixture composition"-100 parts of hollow particles (trademark: MA-1004, manufactured by Nippon Shokubai)-30 parts of PVA (trademark: K-117, manufactured by Kuraray Co., Ltd.)

Example 9 In forming the porous resin layer B, the following composition was used and 2 g /
A receiving sheet was obtained in the same manner as in Example 6, except that coating was performed so as to obtain m ² . The apparent density of the porous resin layer B is 0.8 g
/ M ³ . "Resin mixture composition" 100 parts of hollow particles (trademark: 0P-84J, particle diameter 0.5 μm, manufactured by Rohm and Haas) 100 parts of PVA (trademark: K-117, manufactured by Kuraray Co., Ltd.)

Example 10 Example 6 was repeated except that the porous resin layer A was formed by the following method.
A receiving sheet was obtained in the same manner as described above. A resin mixture having the following composition is coated on a surface of a high quality paper of 75 g / m ² of rice tsubo using a Meyer bar so that the coating amount (dry matter) is 5 g / m ^2, and is heated and dried. Thus, a porous resin layer A was formed. The apparent density of the porous resin layer A was 0.2 g / m ³ . "Resin mixture composition"-100 parts of heat-expandable resin (trademark: F-30, manufactured by Matsumoto Yushi)-30 parts of PVA (trademark: K-117, manufactured by Kuraray Co., Ltd.)

Example 11 In the formation of the porous resin layer B, the stirring speed was 490 rpm
, And a receiving sheet was obtained in the same manner as in Example 6, except that the foam was applied at a foaming ratio of 1.5. The apparent density of the porous resin layer A was 0.5 g / m ³ .

Reference Example 2 In the formation of the porous resin layer B, the following composition was used and 2 g /
A receiving sheet was obtained in the same manner as in Example 6, except that coating was performed so as to obtain m ² . The apparent density of the porous resin layer B is 0.9 g.
/ M ³ . “Resin mixture composition” 100 hollow particles (trademark: M-610, particle diameter 10 μm, manufactured by Matsumoto Yushi) 100 parts PVA (trademark: K-117, manufactured by Kuraray Co., Ltd.) 30 parts

Comparative Example 4 In the formation of the porous resin layer B, the following composition was used and 2 g /
A receiving sheet was obtained in the same manner as in Example 6, except that coating was performed so as to obtain m ² . The apparent density of the porous resin layer B is 0.4 g.
/ M ³ . "Resin mixture composition" 100 hollow particles (trademark: 80-GCA, particle diameter 20 m, manufactured by Matsumoto Yushi) 100 parts PVA (trademark: K-117, manufactured by Kuraray Co., Ltd.) 30 parts

Evaluation The receiving sheets obtained as described above were measured by the following methods, and the results obtained are shown in Tables 1 and 2.

[Image sharpness] Image sharpness was measured in accordance with JIS K7105. Optical comb size is 2.0mm
And

[Specular gloss at 60 degrees] The specular gloss at 60 degrees was measured in accordance with JIS Z8741.

[Printability] A yellow, magenta, and cyan ink sheet provided with an ink layer containing a sublimable dye and a binder on a polyester film having a thickness of 6 μm was brought into contact with a receptor sheet, and commercially available thermal transfer was performed. Using a video printer (trademark: VY-50, manufactured by Hitachi, Ltd.), a predetermined image is thermally transferred to the receiving sheet by stepwise heating with a thermal head, and a halftone single color and color superimposed image of each color is printed. did.

[Image Density] The recorded image transferred on this receiving sheet was measured with a Macbeth reflection densitometer RD-91.
4 (: trademark), the reflection density was measured for each applied energy. The density of the low gradation part with low applied energy was evaluated.

[Image Uniformity] Further, with respect to the uniformity of the recorded image in the gradation portion where the optical density (black) is equal to 1.0, the presence or absence of unevenness in density and the presence or absence of white spots are visually observed. It was evaluated comprehensively. In the above, the evaluation results were rated 5 for excellent, 4 for good, 3 for normal, 2 for slightly defective, and 1 for markedly defective.

"Clearness" The sharpness was visually observed and evaluated. Excellent was evaluated as O, slightly poor as Δ, and poor as X.

[Surface Gloss] The surface gloss of the receiving sheet was visually observed and evaluated. Excellent: ◎, excellent: ○, slightly poor: △, poor: ×
And

[0072]

[Table 1]

[0073]

[Table 2]

As is clear from Tables 1 and 2, the density of the porous resin layer is in the range of 0.05 to 0.5 g / cm ³ , and when a laminate layer by extrusion lamination is formed thereon, It can be seen that the density of the image is sufficient and the uniformity of the image is excellent. Comparative Examples 2 and 3 are examples in which the density of the porous resin layer is out of the range.

When Examples 1 to 5 are compared with Reference Example 1 and Comparative Example 1, or when Examples 6, 7, 9 to 11 and Example 8,
Comparing Reference Example 2 and Comparative Example 4, it can be seen that a clear image can be obtained when the receiving layer is formed so that the image definition becomes 10% or more even with the above-described layer configuration. Also, comparing Examples 1, 3, Reference Example 1, and Comparative Example 1,
It is understood that the image sharpness can be appropriately adjusted by adjusting the content of the pigment in the laminate layer. It can also be seen that the preferred compounding amount is 1 to 20% by weight in the laminate layer.

Examples 3 to 5, Reference Example 1, and Examples 1 to
2. Comparing Comparative Examples 1 to 3, or Examples 6 to 11
Comparing Reference Example 2 and Comparative Example 4, it can be seen that when the receiving layer is formed so that the 60-degree specular gloss is 80% or more, the surface gloss is excellent. Further, when Examples 3 to 5 and Reference Example 1 are compared, it can be seen that the uniformity and sharpness of the image are excellent by forming the laminate layer containing the pigment.

From the examples in Table 2, it can be seen that when two porous resin layers are laminated, the image density and the image uniformity are further improved. However, as in Comparative Example 4, the porous resin layer B
When a material having a particle diameter of 20 μm is used, the uniformity of an image is deteriorated. When the density of the porous resin layer B exceeds 0.8 as in Reference Example 2, the uniformity of the image tends to be poor.
It can be seen that the range of about 0.8 g / cm ³ is preferable. Further, in Example 11, the density of the porous resin layer A was 0.5 g /
is an example of cm ^3, it can be seen that the inferior image density than the other examples. As the porous resin layer A, 0.05 to
It is understood that 0.5 g / cm ³ is preferable.

As in Examples 6, 7, 9, and 10,
A receiving sheet having a plurality of porous resin layers, an image sharpness of 10% or more, and a 60-degree specular gloss of 80% is a particularly preferred receiving sheet, but the present invention is not limited thereto.

[0079]

According to the present invention, thermal printing can be performed with a high printing density, excellent image uniformity, a clear image, good surface gloss, and low cost for various thermal printers. It provides a receiving sheet and greatly contributes to the industry.

Continued on the front page F-term (reference) 2H111 AA01 AA14 AA27 CA03 CA04 CA11 CA12 CA13 CA23 CA25 CA30 CA31 CA33 CA41 CA43 CA45 DA00 4F100 AA21C AA21H AJ04A AK01B AK01C AK01E AK06C AK41D AK52BA10 BA04 BA05 BA04 BA05 BA04 BA04 DJ01E EH23C GB90 JA13B JA13E JB16C JD14D JN21D JN30 YY00 YY00B YY00C YY00D YY00E YY00H

Claims (7)

[Claims] 1. A thermal transfer receiver comprising a sheet-like cellulose core layer, a resin layer having porosity on at least one surface of the sheet-like cellulose core layer, a laminate layer of a thermoplastic resin, and a dye-dyeing receiving layer. In the sheet, the density of the porous resin layer is 0.05 to 0.5 g / cm ³ , the laminate layer is formed by extrusion lamination, and the image sharpness of the surface of the dye-dyeing receiving layer is based on JIS K7105. Is C _(2.0) = 10% or more. 2. The thermal transfer receiving sheet according to claim 1, wherein the laminate layer contains 1 to 20% by weight of a pigment. 3. A thermal transfer receiver comprising a sheet-like cellulose core layer, a resin layer having porosity on at least one surface of the sheet-like cellulose core layer, a laminate layer of a thermoplastic resin, and a dye-dyeing receptor layer. In the sheet, the density of the porous resin layer is 0.05 to 0.5 g / cm ³ , the laminate layer is formed by extrusion lamination, and the 60-degree specular gloss described in JIS Z8741 on the surface of the dye-dyeing receiving layer. Is not less than 80%. 4. The heat transfer receiving sheet according to claim 3, wherein the laminate layer contains 1 to 20% by weight of a pigment. 5. A thermal transfer receiver comprising a sheet-like cellulose core layer, a porous resin layer on at least one surface of the sheet-like cellulose core layer, a thermoplastic resin laminate layer, and a dye-dyeing receptor layer. In the sheet, the porous resin layer is formed of a plurality of layers, and at least the porous resin layer on the side on which the laminate layer is formed is a layer containing hollow particles having a particle size of 0.1 to 10 μm. A heat transfer receiving sheet, wherein the laminate layer is formed by an extrusion lamination method. 6. The density of a layer formed on a core material layer side of a plurality of porous resin layers is 0.05 to 0.5 g / cm ^3.
The heat transfer receiving sheet according to claim 5, wherein 7. The method according to claim 7, wherein the plurality of porous resin layers are lamine.
The particle diameter formed on the side of the coating layer is 0.1 to 10 μm.
The density of the layer containing empty particles is 0.3 to 0.8 g / cm. ^ThreeIn
The heat transfer receiving sheet according to claim 5 or 6, wherein