JPS63290790A - Image receiving sheet for thermal transfer recording - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a color image receiving sheet for thermal transfer recording, particularly for use in video printers that form characters and images on a receptor using electrical signals from a thermal head, etc. The present invention relates to an image receiving sheet for thermal transfer recording used for copying.

Copies that have been thermally transferred using the image-receiving sheet for thermal transfer recording of the present invention are prevented from curling, and are printed on the surface.
Irregularities caused by printing do not remain on the back side of the support.

[Prior art]

Conventionally, a transfer sheet having a transfer layer containing a sublimable or vaporizable dye is placed on top of a receiving sheet, and the transfer sheet is heated to sublimate or vaporize the dye contained in the transfer layer and dye the receiving sheet. Thermal transfer is known to produce a dye image on a receiving sheet.

Specifically, in a transfer type thermal recording method using a heat source such as a thermal head whose printing is controlled by an electric signal, as shown in FIG. A receiving sheet 1 having a layer 11 and a support 12 is transferred to a drum 3.
and a heat source 4, and the color material of the layer 22 is transferred onto the image-receiving layer 11 in response to an electric signal, thereby obtaining a paper color copy.

The image-receiving layer 11 differs depending on the content of the coloring material used. In the case of a heat-melting type coloring material containing a pigment, the support 12 itself may be used; in the case of a sublimable basic dye-type coloring material, In the case of a sublimable disperse dye type coloring material, a coat layer of a polymeric material such as polyester is used. In conventional receptors, the surface of the image-receiving layer 11 has irregularities of 5 to 15 .mu.m and undulations of 10 to 20 pm per inch due to uneven thickness of the support or surface irregularities. This unevenness or waviness has reached its limit even with surface treatment using a supercalender, although only some improvements have been made. For this reason, the coloring material transferred from the coloring material layer 22 is not only a heat-melting coloring material, but also a sublimable material when the surface unevenness of the image-receiving layer 11 is 3 to 5 μm or more or the ridge seconds are 1/1) lo pm or more. Even the coloring materials were not transferred accurately according to the image signal, causing disturbances in image quality such as missing dots and missing dots in the image, and giving a rough feeling to the intermediate tones (Japanese Patent Laid-Open No. 59-21
No. 4696).

In addition, as the support 12, paper or inorganic fine powder can be used for
Synthetic paper made of stretched film of thermoplastic resin containing 50% by weight (Japanese Patent Publication No. 46-40794), transparent polyethylene terephthalate film or the surface of the transparent film are coated with silica or carbonic acid to increase whiteness and dyeability. Coated synthetic paper or the like whose surface is coated with an inorganic compound such as calcium together with a binder is used.

Considering the after-use of the thermally transferred receiving sheet (copying, pencil writing, storage stability, etc.), inorganic fine image receiving sheets for thermal transfer recording are preferred in terms of strength, dimensional stability, and adhesion to the print head. Synthetic paper with many microvoids inside obtained by stretching a polyolefin resin film containing powder is preferable (IR 1986-24).
No. 5593, No. 61-112693, Patent Application No. 1982-2
5OSO).

[Problems with conventional technology]

This polyolefin resin synthetic paper has a soft feel and
In order to improve adhesion to the print head and paper feeding/discharging properties, the film is stretched at a temperature lower than the melting point of the polyolefin material to form microvoids inside.

However, the melting point of polyolefin is 1% compared to polyethylene terephthalate and polyamide (240-255℃).
190-2, which is as low as 67°C or less, and the temperature of the surface of the receiving sheet is higher than the melting point when printing with the print head.
It has been pointed out that the synthetic paper shrinks due to the heat during printing on paper at temperatures close to 00°C, causing the printing on the heat-sensitive transfer receiving sheet to curl on the printed inner surface (Japanese Patent Laid-Open No. 60-2
No. 45593, No. 61-283595).

Furthermore, since the synthetic paper has a structure with microvoids inside, the unevenness stress of the printing on the front surface is directly transmitted to the back side of the synthetic paper, and the problem that unevenness appears on the back side of the image-receiving sheet rarely occurs.

[Specific measures to solve the problem]

In the present invention, a plurality of sheets of synthetic paper are used as supports for the bimodal receiving sheet, and a material sheet with higher rigidity than synthetic paper is sandwiched between the synthetic papers, thereby preventing recurling and printing stress. This prevents migration of the material to the back layer side.

That is, the present invention provides a bimodal receiving sheet for thermal transfer recording in which an image receiving layer is provided on the surface of a support, in which the support has a Young's modulus of 2 as measured by JIS P-8132.
6.00 e#/- or more rigid sheet (2) is made of a synthetic material with many fine voids inside, which is made of a drawn product of polyolefin resin containing inorganic fine powder, on the front and back surfaces.
The present invention provides a bimodal receiving sheet for thermal transfer recording, characterized in that it uses a laminate in which a and c) are bonded together.

(Synthetic paper for support) As synthetic paper for support, Japanese Patent Publication No. 46-40794,
Japanese Patent Publication No. 57-149363, Publication No. 60-36173
Synthetic paper made from a stretched film of polyolefin resin containing inorganic fine powder and synthetic paper with an antistatic polymer coating layer on its surface, which are described in the above publications, are also available. A polyolefin resin film containing a polyolefin resin film containing ~25 wtfk as a surface layer, containing a larger amount of inorganic fine powder with a specific surface area of 10.000 cd/ or more than the content of the surface layer, and containing a large number of ζ clovoids produced by stretching. A multilayer resin stretched film consisting of a core layer and a back layer made of a uniaxially stretched film of polyolefin containing 25 to 75 wt. When the longest length of protrusions is 50 microns or more, 0.1-10 pieces or less are filtered and pressed with a stress of 32#/cd on a multilayer resin stretched film (atmosphere temperature: 23°C, relative humidity). 50%) Polyolefin synthetic paper with a compression rate of 20% to 40% has no white spots, and the printing surface is
Preferable in terms of pencil writability.

(Surface Layer) The surface layer of the multilayer polyolefin resin stretched film on the side of the ink receiving layer is a uniaxial layer containing an inorganic fine powder having a specific surface area of 10.000 aj/ or more by 0 to 10% by weight, preferably 5 to 8% by weight. It is a stretched or biaxially stretched resin film. The back layer on the opposite side is a uniaxially stretched resin film of the same composition, or if pencil writability is required, a layer with a specific surface area of 10.
It is a uniaxially stretched resin film containing 25 to 70 weight of inorganic fine powder of 000 d/9 or more. The latter uniaxially stretched resin film of the back layer has a large number of fine elongated vacancies (Va<void) with inorganic fine powder as the core, and has many fine cracks on the surface.

Examples of polyolefin resins constituting the surface layer and back layer include polyethylene, polyglopylene, and ethylene-
Propylene copolymer, ethylene-vinyl acetate copolymer,
Poly(4-methylpentene-1) and the like can be used, and among these, polypropylene is preferable in terms of heat resistance, solvent resistance, and cost.

To this polyolefin, polystyrene, polyamide, polyethylene terephthalate, partial hydrolyzate of ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer and its salt, vinylidene chloride copolymer, such as vinyl chloride-vinylidene chloride copolymer, etc. may be blended.

Inorganic fine powders include calcium carbonate, calcined lei,
Examples include diatomaceous earth, talc, titanium oxide, barium sulfate, aluminum sulfate, and silica.

As mentioned above, the multilayer polyolefin resin stretched film can include a back layer in addition to the surface layer and the core layer. As an example of synthetic paper that is a support for an image-receiving sheet for thermal transfer recording, a resin sheet of a composition for forming a surface layer (119) is melt-laminated on one side of a uniaxially stretched film sheet containing a composition for forming a core layer. And on the other side, 25~25~
A resin sheet for forming a back layer containing a resin composition containing 70% by weight is melted and laminated, and this multilayer sheet is once cooled, then reheated and stretched in a direction perpendicular to the uniaxial stretching direction of the sheet (2), and then heat treated. It can be obtained by

By this stretching, the sheet of composition (4) is biaxially stretched, and a large number of voids (microvoids) are formed inside the sheet. On the other hand, the surface layer (B) and the back layer were stretched in the axial direction, and the surface had minute irregularities, and the surface smoothness (BEKK INDEX) was 500 to 15.
000 seconds.

Recirculation core layer composition (a), polypropylene 50-95 weight 70),
Resin selected from high-density polyethylene, medium-density polyethylene, low-density polyethylene, ethylene/vinyl acetate copolymer 0-30% by weight (C), inorganic fine powder 10-25% by weight.

a) Surface layer composition (a), polypropylene (35-92 wt.), polystyrene, high-density polyethylene, medium-density polystyrene, low-density polyethylene, ethylene-vinyl acetate copolymer, resin selected from 0-30 wt. (C
), inorganic fine powder 0-10 weight 5゜mouth back layer (a), polypropylene 25-75 weight 5Φ), polystyrene, high-density polyethylene, medium-density polyethylene, low-density polyethylene, ethylene/vinyl acetate copolymer 0-20 Weight (C), inorganic fine powder 25-75 weight.

The thickness of each of the surface layer, back layer, and core layer is such that the total thickness of the surface layer and back layer is 10% of the total thickness of the multilayer resin stretched film.
-40%, and preferably the thickness of the core layer is 90-60%. If the surface layer and the back layer are too thick, the compressibility of the core layer cannot be utilized, and if they are too thin, the surface smoothness will be too low and the adhesion between the head and the receiving sheet will become unstable.

This multilayer polyolefin resin stretched film has poor compressibility due to the large number of microvoids contained in the core layer (in the core layer), and can be pressed from the surface with a stress of 32#/cj in an atmosphere at a temperature of 23°C and a relative humidity of 50%. When the thickness is 2
It can be compressed to about 0 to 40%.

Due to this compressibility, when a multilayer stretched polyolefin resin film is used as an image-receiving sheet for thermal transfer recording,
The adhesion between the surface ink-receiving layer and the thermal transfer dye-containing film (thermal transfer ribbon) is improved, and even if there are 6 protrusions on the surface of the image-receiving sheet for thermal transfer recording, they are pushed inside, resulting in a transferred image. has excellent clarity.

The amount of internal microvoids in this microvoid-containing sheet is expressed as: Void rate = Density of the film before stretching - Density of the microvoid-containing resin sheet after stretching It is preferably in the range of 20-50%, more preferably 25-507o.

As the surface layer, only a polyolefin resin film containing no inorganic fine powder may be used, but if necessary, it is possible to mix inorganic fine powder.The inorganic fine powder for the surface layer may be selected appropriately depending on the surface unevenness of the core layer. be done. The content of the inorganic fine powder in the surface layer is preferably selected so that the surface smoothness (Beck index) measured according to JIS P-8120 is about 500 to 15,000 seconds.

The inorganic fine powder to be mixed into the surface layer is selected so as not to form large protrusions on the surface layer as much as possible, and preferably has a 325 mesh residue of IO ppm or less. The particle size is preferably 3 microns or less.

The number of protrusions from the surface of the surface layer (6) of the support 12 with a length of 50 microns or more should be 10 or less per 0.1 so that chipping of the thermally transferred image is not a practical problem. It's important in some respects.

Even if the average particle size of the inorganic fine powder is 3 microns or less, there may be a small amount of particles with a particle size of 15 microns or 20 microns in the powder, or agglomeration of multiple particles with a major axis of 50 microns. There are things that are as large as microns. When these giant particles are present on the surface of the support 12 of the image receiving sheet 1,
A uniform film cannot be formed on the image receiving layer 11 provided thereon, and in severe cases, pinholes and other defects occur, which causes white spots.

The height h of the protrusions protruding from the flat surface of the resin surface 13 of the support 12 (IIS) is smaller than the major axis of the inorganic fine particles. .It is preferable to reduce the number of particles to 5 or less per 1-1 from the viewpoint of preventing white spots.

The back layer C) on the opposite side of the front transferred image-receiving layer contains 25 to 75 weight of inorganic fine powder, preferably in order to provide smoothness with the roll during transfer and writability to the back layer after transfer. It is better to set the % content δ to Vi30-60w<JIS P
-Surface smoothness (Peck index) measured with -8120 is 50
It is preferable to select the time to be 2.000 seconds.

The wall thickness of the synthetic paper is 30 to 80 microns, preferably 40 microns.
~80 microns. Also, the Young's modulus of synthetic paper is 9.0
00-2 a, o o o ky/cd is preferred.

(Rigid sheet) In order to cancel the shrinkage stress of the stretched multilayer polyolefin synthetic paper due to the heat of the print head, the rigid sheet sandwiched between the synthetic papers has a Young's modulus of the synthetic paper (9° polyethylene terephthalate, boria nylon 6, nylon 6.6,
+Iron 6.10, Nylon 6.12, etc.) A thermoplastic resin sheet such as polyphenylene sulfide, polycarbonate, isotactic polystyrene, etc. is used.

These sheets may be stretched or reinforced with inorganic fine powder. Aluminum foil or pulp paper can also be used for the stones. It is preferable to use a material having a heat distortion temperature 30° C. or more higher than that of the polyolefin resin used as the material for the synthetic paper for this rigid sheet, since heat resistance can be imparted to the image-receiving sheet.

The wall thickness of the rigid sheet is 5 to 120 microns, preferably 1
It is 0 to 80 microns.

[Support]

The support is obtained by bonding the rigid sheet and synthetic paper together using a solvent-based adhesive so that the synthetic paper (a, e) is sandwiched between the rigid sheets (6).

In addition, the resin of the rigid sheet material and the above-mentioned core layer composition Q are co-extruded to form a sheet, which is then stretched in the longitudinal direction, and then the above-mentioned surface layer composition [F] is applied to the front and back layers. ) and back layer composition 0 are melt-laminated and then stretched in the transverse direction.

Examples of solvent-based adhesives include polyisocyanate adhesives,
Polyester adhesive, acrylic adhesive, ethylene/
Vinyl acetate copolymer aqueous emulsion and the like can be used.

(Image-receiving layer) As the resin forming the image-receiving layer, oligoester acrylate resin, saturated polyester resin, vinyl chloride resin, etc.
Vinyl acetate copolymer, acrylic ester-based styrene copolymer, epoxy acrylate resin, etc. are used, and these are dissolved in toluene, xylene, methyl ethyl ketone, cyclohexanone, etc., and used as a coating liquid.

This coating liquid can contain an ultraviolet absorber and/or a light stabilizer to improve light resistance. Examples of ultraviolet absorbers include 2-(2'-hydroxy-3,3'
-di-t-butylphenyl)-5-chlorobenzotriazole, 2-(2-hydroxy-3,5-t-amylphenyl)-2H-benzotriazole, 2-(2'-hydroxy-3'-t- (phthyl-5'-methylphenyl)
-5-Chlorobenzotriazole, 2-(2'-hydroxy-3-5'-t-buturphenyl)-benzotriazole, 2-(2'-hydroxy-s% sl-di-t
-amylphenyl)benzotriazole and the like. Examples of the light stabilizer include distearyl pentaerythritol diphosphite, bis(2,4-di-t-butylphenyl) pentaerythritol diphosphite,
Dinonylphenylpentae JJ thritol siphosphite, cyclic neopentanetetrayl bis(octadecylphosphite), tris(nonylphenyl)
Phosphite, 1-(2-(3-(a, s-di-t-
Butyl-4-hydroxyphenyl)globionyloxy]ethyl]-4-(3-(3,5-di-t-butyl-4
-hydroxyphenyl)propionyloxy) -2,
Examples include 2,6°6-titramedelpiperidine.

The amount of these ultraviolet absorbers and light stabilizers added is 0.05 to 0.05 to 171 parts of the resin constituting the image-receiving layer 3, respectively.
1011i parts, preferably 0.5 to 3 parts by weight.

Further, in order to improve the releasability from the thermal transfer sheet, a release agent may be contained in the trap image receiving layer. Examples of the mold release agent include solid waxes such as polyethylene wax, amide wax, and Teflon powder; fluorine-based and phosphoric acid ester-based surfactants; and silicone oil, with silicone oil being preferred.

Although an oily silicone oil can be used as the silicone oil, a hardened type is preferable.

Furthermore, in order to improve the whiteness of the image-receiving layer to further enhance the clarity of the transferred image, to provide writability to the surface of the heat-transfer sheet, and to prevent the transferred image from being re-transferred, the image-receiving layer contains White pigments can be added. As the white pigment, titanium oxide, zinc oxide, kaolin clay, etc. are used, and two or more of these can be used as a mixture.

As the titanium oxide, anatase titanium oxide or rutile titanium oxide can be used, and examples of the anatase titanium oxide include KA-10, KA-20, KA-15.
, KA-30, KA-35, KA-60, KA-a o
, KA-90 (both manufactured by Titan Kogyo ■), etc., and examples of rutile titanium oxide include KR-310, KR-
380, KR-460, KR-480 (all manufactured by Titan Kogyo ■), and the like. The amount of the white pigment added is preferably 5 to 50 parts by weight per 100 parts by weight of the resin constituting the image-receiving layer.

The thickness d of the image-receiving layer 11 is generally 0.2 to 20 microns.

(Thermal Transfer Image-Receiving Sheet) The thermal transfer image-receiving sheet of the present invention can be obtained by applying a coating solution for forming an image-receiving layer on the surface of a support and drying to scatter the solvent.

The wall thickness of this bimodal receiving sheet is 80 to 280 microns,
Taper stiffness measured by JIS P-8125 is 3~
151 F-cm is preferable in terms of curl prevention and sheet feeding/discharging properties.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Manufacturing Example of Synthetic Paper Example 1 (1) 20% by weight of calcium carbonate with an average particle size of 1.5 microns was blended with 280% by weight of polypropylene with a melt index (MI) of o, s, and the temperature was set at 270°C. The mixture was mixed in an extruder, extruded into a sheet, and cooled in a cooling device to obtain a non-stretched sheet.

This sheet was trap-heated at 140° C. and then stretched 5 times in the post-heating direction.

+21 A composition for the surface layer prepared by mixing 95% by weight of polypropylene with an MI of 4.0 and 5% by weight of calcium carbonate having an average particle size of 1.5 μm (melt and knead the odor in an extruder and extrude the sheet into 5% by weight of (1)). Laminated on one side of the double stretched sheet, (1)
Calci carbonate 9440 with an average particle size of 1.5μ is added to 60% by weight of polypropylene with an MI of 4.0 on the opposite side of the 5-fold stretched sheet.
Composition 0 for the surface layer mixed with a large amount of weight was melt-kneaded in another extruder, extrusion laminated, and then cooled to 60°C.
Heated to 2°C, stretched 7.5 times in the transverse direction with a tenter,
Annealed at 165°C, cooled to 60°C, and slit the edges to obtain 316 (B/A/C: wall thickness 1 o/
A synthetic paper with a structure of 3 o/20 microns was obtained.

The Beck index of surface B of this synthetic paper is 9 at 6,800 seconds.
, whiteness as support is 94.2%, 32#/
- The compression ratio against stress was 26%.

Also, the number of protrusions that protrude beyond the resin surface 13 of the surface layer B and have a longer diameter of SO microns or more is 0.1rI?
I was lucky with 94 pieces.

Example 2 (1) 80 tfi% polypropylene with a melt index (MI) of 0.8 is mixed with 20% calcium carbonate with an average particle size of 1.5 microns, mixed in an extruder set at 270°C, and a sheet is produced. It was extruded into a shape and cooled in a cooling device to obtain a non-stretched sheet.

This sheet was heated to 140°C and then stretched 5 times in the machine direction.

(2) MI 4. Oy/l 0 min polypropylene 97.5 weight plus barium sulfate with average particle size 0.3μ 2.
Composition (2) mixed with 53i11 was melt-kneaded in an extruder, the extruded sheet was laminated on one side of the 5x stretched sheet of (1), and the MI4.0 sheet was laminated on the other side of the 5x stretched sheet of (1). Composition C), which is a mixture of 60% by weight of polypropylene and 40% by weight of calcium carbonate having an average particle size of 1.5μ, is melt-kneaded in another extruder, extrusion laminated, and cooled to 60°C.
Heated to 162°C, stretched 7.5 times in the transverse direction with a tenter, annealed at 165°C, cooled to 60°C, and slit the edges to form a 3-layer CB/A/C: wall thickness 2G/4.
A synthetic paper with a structure of 0/20 micron) was obtained.

The Beck index of surface B of this synthetic paper is 5.700 seconds, the whiteness as a support is 96.0%, and the compressibility is 2.
It was 3%.

In addition, the number of protrusions that protrude from the resin surface 13 of the surface layer B and have a major axis 1 of SO microns or more is 0.1 rr.
? I was lucky with 7 pieces.

Example 3 Synthetic paper with the physical properties shown in Table 1 was obtained in the same manner as in Example 1, except that a mixture of 298% polypropylene and 2% Ties with an average particle size of 0.25 microns was used as the surface layer (odor composition). Ta.

Example 4 A three-layered synthetic paper having wall thicknesses of B/A/C: 40/8 G/46 microns was obtained in the same manner as in Example 1 except that the slit width of the die was changed.

Example 5 (1) Calcium carbonate 251 with an average particle size of 1.5 microns is added to a mixture of 70% by weight of polypropylene with a melt index (MI) of 0.8 and 5% by weight of high-density polyethylene.
1 wt. After heating this sheet to 140℃,
It was stretched 5 times in the machine direction.

(2) M I 4-0 (') Ho'J 7'
Hi V/C)! Calcium carbonate 50i1 (mixed composition f3) with an average particle size of 1.5 microns was melt-kneaded with 50% by weight of polypropylene of MI 4-0 in a separate extruder, and then laminated in a die. Co-extruded into a sheet, stacked so that the surface 0 of the 5 times stretched sheet of (1) is on the outside, and on the opposite side, 50% polypropylene with an MI of 4.0 and calcium carbonate with an average particle size of 1.5μ. 50 weight t%
A mixture of composition (1) was melted and mixed in another extruder and extrusion laminated, then cooled to 60°C, heated to 160°C, stretched 7.5 times in the transverse direction with a tenter, and annealed at 165C. , cooled to 60°C, slit the ears, and obtained a 4-layer structure (C/B/A/B: wall thickness 5/xo/3o/
A synthetic paper of xs micron) was obtained.

Note that the number of protrusions was measured by the following method.

(1) Shine an oblique light onto the surface of the synthetic paper sample listed in 20cWIX 2 S (!II) and visually locate and mark the protruding parts.

(2) Observe the marked protrusions with a stereomicroscope set to 25x magnification, measure on A2 scale of PEAK scale Roubaix, and count the number of protrusions with a major axis of sopm or more.

(3) Do this for two samples and calculate the total number of samples to 0.
IW? The number of protrusions per hit (diameter).

Next, the compressibility was measured by the following method.

l) A ring-shaped jig with 6aI on the surface of the support
The compression ratio was calculated by dividing the decrease in thickness when a pressure of 0 #/all was applied by the thickness before applying pressure. Measurements were made at a temperature of 23°C and a relative humidity of 50°C.

(Margins below) Table 1 Example 1: Polyethylene terephthalate 2 with a wall thickness of 50μ
Axial stretched film.

Young's modulus 47,500 kf/ai Example 2: Pulp paper. Wall thickness 50μ, basis weight 65f/m", Young's modulus 73,000kl/cd, heat resistance 300℃ or higher.

Example 3: Biaxially stretched polyphenylene sulfide film with a wall thickness of 40μ. Young's modulus 40°000 ky/d, heat resistance 220°C or higher.

Good luck! Ill Toyo Morton's solvent molded rethane adhesive @BLS was used as an adhesive on the back layer side of the synthetic paper shown in Table 2 ←) obtained in each case.
-208OA'' (resin) and BLS-2080B (curing agent) at a rate of 3 f/l/, a rigid sheet Φ shown in Table 2 was attached, and the back side of this rigid sheet was Synthetic paper (e) shown in Table 2 was coated with the adhesive.
The surface layer side of the substrate was laminated to the adhesive to obtain the support shown in Table 2.

Examples 1 to 7, Comparative Examples 1 to 2 An image-receiving layer forming composition having the following composition was coated on the surface layer side of the synthetic paper (a) of the support shown in Table 2 by wire par coating to obtain the thickness when the paper was dried. The coating was coated so that the pitch was 4 m, and dried to obtain an image-receiving sheet for thermal transfer recording having the physical properties shown in Table 2.

Byron 200 (Toyobo saturated polyester 2TK depth 67°C) 5.3 parts by weight Byron 29
0 (Toyobo saturated polyester: Tgx77°C) 5.3 parts by weight Vinyrite V
YHH (vinyl chloride-vinyl acetate copolymer manufactured by $Nion Carbide) 4.5 parts by weight Titanium oxide (KA-10 manufactured by Titan Kogyo) 1.5 parts by weight KF-3
93 (Amino-modified silicone oil manufactured by Shin-Etsu Silicone) X, X parts by weight X-2
2-343 (Epoxy-modified silicone oil manufactured by Shin-Etsu Silicone) 1.1 parts by weight Toluene 30 parts by weight Methyl ethyl ketone 30 parts by weight Cyclohexanone
22 parts by weight These thermal transfer image-receiving sheets were evaluated by the following method. The results are shown in Table 2.

(1) Image judgment method: The image-receiving sheet prepared in each example and comparative example was superimposed on the transfer film "TTF Cyan 1" (trade name) made by Mitsubishi Paper Industries, which had been coated with a sublimable dye and dried, and then placed in a thermal gradient tester. ('he-HG-100 manufactured by Toyo Seiki), heat the hot plate at 10℃ from 120℃ for 5 times to 0.5A9/csf.
A transferred image was obtained by heating for 2 seconds at a pressure of .

The density of each obtained transfer image was measured using a Macbeth densitometer and evaluated on the following five scales.

5: Very good.

4: Good.

3: There is no practical problem.

2: There are some practical problems.

1: Not practical.

Evaluation of curl: The image receiving sheets prepared in each example and comparative example were transferred using a Hitachi color video printer (vy-so) and heated at 23°C.
The average height of the four edges of the receiving sheet when it was left in a 50% atmosphere for 24 hours was determined.

Whether or not the surface stress of the transferred image transfers to the back layer of the support: Visually determine the presence or absence of unevenness on the back layer of the synthetic paper of the receiving sheet on the opposite side of the transferred image used for curl evaluation.

[Brief explanation of drawings]

FIG. 1 is a plan view of the transfer thermosensitive recording apparatus, FIG. 2 is a sectional view of the synthetic paper, and FIG. 3 is a sectional view of the support. In the figure, 1 is an image-receiving sheet for thermal transfer recording, 11 is an image-receiving layer, 12 is a support, 2 is a transfer body, and 14 is a protrusion. Human is the core material layer, B is the surface layer, C is the back layer, a is the synthetic paper,
b is a rigid sheet, and C is a synthetic paper. Patent applicant: Oji Yuka Synthetic Paper Co., Ltd. Agent: Patent attorney: Masa Hase Daido Takaya Yamamoto Figure 1 to Figure 2 Figure 3

Claims (1)

[Scope of Claims] 1) An image-receiving sheet for thermal transfer recording in which an image-receiving layer is provided on the surface of a support, wherein the support is JI
Young's modulus measured with SP-8132 is 26,000 kg
/cm^2 or more, a laminate is used in which synthetic paper made of a stretched polyolefin resin containing inorganic fine powder and having many fine voids inside is laminated on the front and back sides of a rigid sheet with a diameter of /cm^2 or more. Features: Image receiving sheet for thermal transfer recording. 2) The synthetic paper has a void ratio of 20 calculated using the following method.
The image-receiving sheet for thermal transfer recording according to claim 1, characterized in that the content of the image-receiving sheet is 50%. Void ratio = [(density of film before stretching - density of microvoid-containing resin sheet after stretching) / density of film before stretching] x 100 (%) 3) The rigid sheet of the support is the synthetic paper of the front and back layers. The image-receiving sheet for thermal transfer recording according to claim 1, having a heat distortion temperature that is 30° C. or more higher than the heat distortion temperature of . 4) The image-receiving sheet for thermal transfer recording according to claim 1, wherein the image-receiving layer has a wall thickness of 0.2 to 20 microns. 5) Young's modulus of synthetic paper is 9,000 to 26,000k
The image-receiving sheet for thermal transfer recording according to claim 1, characterized in that the image receiving sheet has a particle size of 2 g/cm^2. 6), Young's modulus of the image receiving sheet for thermal transfer recording is 17,
000~40,000kg/cm^2, JISP
- Taper stiffness measured with 8125 is 3 to 15 g-cm
An image-receiving sheet for thermal transfer recording according to claim 1, characterized in that: 7) The image receiving sheet for thermal transfer recording according to claim 1, wherein the synthetic paper has a wall thickness of 30 to 80 microns, and the rigid sheet has a wall thickness of 5 to 120 microns. 8) The thickness of the image receiving sheet for thermal transfer recording is 80 to 27.
Claim 1 characterized in that it is 0 micron.
An image-receiving sheet for thermal transfer recording as described in . 9) Claim 1, wherein the rigid sheet is a biaxially stretched sheet of polyethylene terephthalate.
An image-receiving sheet for thermal transfer recording as described in . 10) The synthetic paper has a surface layer (the side in contact with the image-receiving layer) of a polyolefin resin film containing 0 to 10 wt% of inorganic fine powder, and has a specific surface area of 10,000 cm^2/g.
Contains more inorganic fine powder than the content of the surface layer,
A core layer of a polyolefin resin film containing a large number of microvoids generated by stretching and a fine inorganic powder of 25~
A multilayer resin stretched film consisting of a back layer of a polyolefin uniaxially stretched film containing 75% by weight, the surface layer of which has a protrusion that projects from the flat surface with a longest length of 50 microns or more, is 0.1 m^ The image-receiving sheet for thermal transfer recording according to claim 1, wherein the number of sheets is 10 or less per 2, and the compression ratio of the multilayer resin stretched film under a stress of 32 kg/cm^2 is 20% to 40%. .