JP2002321462A - Recording medium for thermal transfer recording - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a receptive sheet which shows satisfactory dye receptivity and ink receptivity and obtains high image density and further, prevents a curl and a crease due to heat from being generated. SOLUTION: This recording medium for thermal transfer recording has a multi-layered laminate comprising a polyester resin layer containing a non- crystalline polyester resin and a polycarbonate resin layer. In addition, the multi-layered laminate is structured of 10 to 10,000 layers, each layer being 1 to 0.001 μm thick as a thermal transfer receptive layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording medium for thermal transfer recording which is widely used as an information recording medium such as a printer paper or a card for printing characters and images. The present invention relates to a recording medium for thermal transfer recording using a composite film as a receiving layer.

[0002]

2. Description of the Related Art A recording medium of the present invention is more suitable for a sublimation transfer recording method among thermal transfer recording methods. Hereinafter, a recording medium for sublimation transfer recording will be described as an example. In the present specification, for simplification, a recording medium for sublimation transfer recording is referred to as a “receiving sheet”, and a sublimation transfer receiving layer is referred to as a “receiving layer”. Therefore, here, "receiving sheet"
Is a concept including a sheet, a film, and a solid.

In the sublimation transfer recording system, a sublimable dye is transferred onto a dye receiving layer in contact with the thermal transfer sheet by heating a thermal transfer sheet coated with a sublimable disperse dye with a thermal head or the like, thereby obtaining a printed image. Things. Examples of the receiving sheet include JP-A-57-107885, JP-A-60-64899, and JP-A-61-25879.
As disclosed in Japanese Patent Application Laid-Open No. 0-206, etc., there is known one in which a saturated polyester resin layer is formed on a support.

If the polyester resin itself can be used as a support and a receiving layer for such a coating type receiving sheet, an inexpensive receiving sheet can be produced without taking a new step of coating. In particular, a film that is a paper substitute made of synthetic resin as a main material is more water-resistant, moisture-absorbing, dimensional stability, surface stability, gloss and sharpness of printed matter than paper made of natural pulp as a main material, Since it is excellent in mechanical strength and the like, various uses have been developed in recent years by utilizing its characteristics.

[0005] The main raw materials of the film include polyolefin resins such as polyethylene and polypropylene, and polyester resins. Of these, polyester resins represented by polyethylene terephthalate heat the film to a high temperature with a printing heating head. This is an important characteristic required as a film having high heat resistance and strong stiffness required for sublimation transfer recording.

When a saturated polyester resin is coated on a support, the crystallinity of the saturated polyester is low and there is room for the sublimation dye to sufficiently diffuse. Crystallinity occurs. For this reason, when a polyester film is used directly as a sublimation transfer recording medium, it is difficult to obtain a high image density because the crystallinity in the film is high and the sublimation diffusion of the printing dye does not sufficiently occur in the recording medium. As described above, at present, only a film or a sheet mainly composed of a stretched polyester resin lacks characteristics as a sublimation transfer recording medium.

Therefore, it is considered that a non-crystalline polyester resin having reduced crystallinity or having no crystallinity can prevent a decrease in recording density. A layer made of a polyester resin-based resin containing these amorphous polyester resins is excellent in sublimation transferability and can be directly recorded on the surface after film formation, but since it contains an amorphous polyester resin, recording of sublimation transfer is possible. It tends to contract due to heat generated when recording for a long time like a head. Since it is amorphous, it does not show a clear melting point and molecular motion starts from the low temperature region, so heat and heat generated by the thermal head causes shrinkage and elongation from the low temperature region, and the surface becomes uneven depending on the image Failure occurs.

To avoid this, it is conceivable to use a mixture with a crystalline polyester resin having high heat resistance. However, it cannot be avoided that the recording density decreases as the amount of the crystalline polyester resin mixed with the non-elevating polyester increases, and the amount of the crystalline polyester resin relative to the amorphous polyester resin must be limited. It is not possible at present. In addition, amorphous polyester and high heat-resistant polycarbonate resin are mixed to form a sea-island structure polymer alloy, or they are made to behave like one resin by compatibilizing using these two resins. Although this is a conventional technique, as in the case of crystalline polyester, there were cases where the recording density of sublimation transfer was not sufficient, or only characteristics with incomplete heat resistance were obtained.

[0009]

SUMMARY OF THE INVENTION The present invention relates to a thermal transfer receiving sheet which, when used as a receiving layer on a support, shows good dye receptivity and ink receptivity and provides a high image density. An object of the present invention is to provide a receiving sheet in which curling and wrinkling of the sheet due to heat are prevented.
Another object of the present invention is to provide a receiving sheet which itself serves both as a support and a receiving layer, exhibits good receptivity, and prevents curling and wrinkling due to heat.

[0010]

In order to solve the above problems, the present invention employs the following constitution. That is, the first of the present invention is "a multilayer laminate in which a polyester-based resin layer containing an amorphous polyester resin and a polycarbonate-based resin layer are laminated, and each layer comprises a layer of 1 to 0.001 μm per layer, In addition, the present invention is a "recording body for thermal transfer recording having a multilayer laminate in which they are laminated in 10 to 10000 layers as a thermal transfer receiving layer".

According to a second aspect of the present invention, in the first aspect,
A recording medium for thermal transfer recording, wherein the receiving layer has a thickness of 1 to 100 μm.

According to a third aspect of the present invention, in the first or second aspect, the receiving layer is formed on a support of any of paper, laminated paper, plastic film, and plastic sheet. The recording medium for thermal transfer recording described above.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The receiving sheet of the present invention has a polyester-based resin receiving layer, and does not impair the inherent properties of the polyester-based resin film, that is, the conventional polyester-based resin without impairing its rigidity and heat resistance. The present invention has found a sublimation transfer receiving material capable of obtaining a high recording density not found in a film.

The receiving sheet of the present invention has a polyester-based resin layer containing an amorphous polyester and a polycarbonate-based resin layer, and the polyester-based resin layer and the polycarbonate-based resin layer are composed of many layers in the thickness direction. A receiving sheet having a receiving layer.

The polyester resin containing the amorphous polyester can effectively accept the sublimation dye.
On the other hand, since polycarbonate resin has excellent heat resistance, it is possible to prevent thermal shrinkage of an amorphous polyester resin. However, there is a limit in preventing the thermal shrinkage of the surface of the receiving layer if the two are polymer blended to form the receiving layer. Therefore, the present inventors have conducted intensive studies and found that the polyester resin layer containing the amorphous polyester resin and the polycarbonate resin layer are formed into an ultra-multilayer structure composed of a large number of ultra-thin layers to form an amorphous polyester resin. The present inventors have found that a receiving layer having both the good dye receptivity of the resin and the heat resistance of the polycarbonate resin can be obtained, and have reached the present invention.

As described above, according to the present invention, the layer containing the amorphous polyester and the layer containing the polycarbonate resin are each formed as a single layer, and are formed into a super-multi-layer structure composed of a large number of layers. It can be handled as one receiving layer while completely retaining the properties of the layer.
In the receiving layer of the present invention, the thickness per layer is 1 to 0.001.
μm, preferably 0.1 to 0.01 μm, and has an ultra-multilayer structure of 10 to 10,000 layers, preferably 20 to 3000 layers. The receiving layer having such an ultra-multilayer structure has a pseudo structure as if two resins which are originally incompatible with each other are compatible. In the receiving layer having such an ultra-multilayer structure, the role of the polycarbonate-based resin layer receiving heat resistance and the role of the amorphous polyester-containing layer to play a major role in diffusion of the sublimable dye can be achieved.

In the present invention, the thickness of the entire receiving layer is from 1 μm to 100 μm. Preferably it is 3 μm to 50 μm. If it is less than 1 μm, all of the transferred sublimation dye cannot be received, so that a high recording density cannot be obtained. 1
When the thickness exceeds 00 μm, not only is it economically disadvantageous, but also the diffusion of the transferred dye spreads over a wide range, so that a reduction in the recording density cannot be avoided. Further, the purpose can be achieved by forming the receiving layer into a multilayer structure of ten or more layers composed of a polyester resin and a polycarbonate resin. If the number of layers is less than 10, the number of layers in the thickness direction is small, so that the thickness of each layer is large, and the shrinkage of the surface layer due to heat is delicate. Therefore, the number of layers is preferably 20 or more, and more preferably 300 or more. A configuration exceeding 10,000 layers is not preferable because the thickness of the single layer becomes too thin to form a uniform layer and the film breaks. The thickness of each of the polyester resin layer and the polycarbonate resin layer is 1 to 0.0 as described above.
01 μm, especially the thickness of the polycarbonate layer,
0.1-0.001 μm to facilitate diffusion of dye
It is preferred that

In a film having a very small film thickness per layer as in the present invention, the dye that has reached the surface layer is easily diffused and fixed because it has several ultra-thin surface layers. For this reason, it is possible to obtain a recording density that cannot be obtained by ordinary mixing. Furthermore, since the polycarbonate layer is independently present as a single film in the film, and the number thereof is extremely large, the film also shows good heat resistance.

As described above, in the present invention, by forming the two resin layers in a multilayer structure in the thickness direction and increasing the number of the layers, the characteristics of each resin can be independently maximized. . Of course, an adhesive layer may be provided between these two resin layers to improve the adhesiveness.
When recording is to be performed directly on the multilayer film configured as described above, a higher recording density can be obtained by forming the amorphous polyester resin on the outermost layer. Further, the sublimation transfer receiving layer having such an ultra-multilayer structure may be formed on a support as a laminated layer having a thickness of 1 to 30 μm. As the support used,
Examples include paper, paperboard, laminated paper obtained by laminating polyethylene or polyester film on these papers, films such as polyester film, and plastic sheets. Among them, a foaming or cavity-containing film having a cavity inside is particularly preferable because of its excellent heat insulating property. Hereinafter, these components will be sequentially described.

First, in the present invention, the polyester constituting the polyester resin includes aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid and naphthalenedicarboxylic acid or esters thereof, ethylene glycol, diethylene glycol, 1,4-butanediol, and the like. Polyesters obtained by polycondensation of glycols such as neopentyl glycol.These polyesters can be obtained by directly reacting an aromatic dicarboxylic acid and a glycol, or by esterifying an alkyl ester of an aromatic dicarboxylic acid with a glycol. It can also be produced by polycondensation after an exchange reaction, or by polycondensation of a diglycol ester of an aromatic dicarboxylic acid.

Representative examples of such polyesters include polyethylene terephthalate, polyethylene butylene terephthalate, and polyethylene-2,6-naphthalate. These polyesters may be homopolymers or copolymers obtained by copolymerizing the third component. Of course, in the present invention, the ethylene terephthalate unit and the butylene terephthalate unit are used. Alternatively, a polyester in which the ratio of ethylene-2,6-naphthalate units occupies 70 mol% or more, more preferably 80 mol% or more, and further preferably 90 mol% or more is preferable.

Next, the amorphous polyester resin used in the present invention is a 10 ° C.
Of heat of crystallization when the temperature is lowered at a rate of 5 cal / g
The following polyesters are preferred. Specifically 1,4
-Cyclohexane dimethanol derivative copolymerized polyester, amorphous polyethylene terephthalate, amorphous polyethylene naphthalate, polyethylene terephthalate copolymer, and the like. Among them, a polyester composed of a dicarboxylic acid unit mainly composed of a terephthalic acid unit and a glycol unit mainly composed of an ethylene glycol unit (I) and a 1,4-cyclohexanedimethanol unit (II) is more preferable. I)
And 1,4-cyclohexanedimethanol unit (II)
Has a molar ratio (I) / (II) of 1 or more, more preferably 90
/ 10-60 / 40 is preferred.

The method for producing the amorphous polyester is not particularly limited. For example, terephthalic acid or its lower alkyl ester and 1,4-cyclohexane may be used in the presence or absence of a catalyst such as an organotitanium compound. And a method obtained by polycondensing dimethanol and ethylene glycol. As the polymerization conditions, for example, the conditions described in U.S. Pat. No. 2,901,466 can be applied.

The amorphous polyester preferably used as a material of the multilayer sheet of the present invention contains an acid in a range that does not impair the effects of the present invention, usually 20 mol% or less, preferably 10 mol% or less. As components, isophthalic acid, orthophthalic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, methyl terephthalic acid, 4,4′-biphenyldicarboxylic acid, 2,2 ′ -Biphenyldicarboxylic acid, 1,2'-bis (4-carboxyphenoxy)-
Other dicarboxylic acids such as ethane, succinic acid, adipic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, octadecanedicarboxylic acid, dimer acid, and 1,4-cyclohexanedicarboxylic acid, and propylene as a glycol component Glycol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, 1,3-
Those obtained by copolymerizing other glycols such as cyclohexanedimethanol, 1,2-cyclohexanedimethanol, and 2,2-bis (2′-hydroxyethoxyphenyl) propane can also be used.

In such an amorphous polyester, the movement between molecules is not restricted as compared with the crystalline polyester, so that the sublimable dye easily diffuses and penetrates into the inside, so that a high image density can be obtained.

The preferred compounding amount of the amorphous polyester resin in the polyester resin varies depending on the recording density of the sublimation transfer recording required for the finally obtained film. It is selected from the range of not less than 20% by weight, more preferably not less than 50% by weight. If the content is less than 20% by weight, it is difficult to obtain satisfactory recording density, gradation, drawing properties, and the like.

The polycarbonate resin referred to in the present invention is:
By reacting an aromatic dihydroxy compound such as bishydroxyphenylpropane (commonly known as bisphenol S or bisphenol F) or an alicyclic dihydroxy compound such as cyclohexane dimethanol or cyclixenediol with a compound such as phosgene or dialkyl carbonate by an arbitrary method. The resulting resin can be mentioned. This resin preferably has an average molecular weight of 1,000 to 200,000 and a glass transition point of 90 ° C or higher. Aromatic polycarbonate is 2,2'-bis (4-hydroxyphenyl)
Preferable examples include those using at least one selected from propane (commonly known as bisphenol A), 4,4'-dihydroxydiphenylalkane, 4,4'-dihydroxydiphenylsulfone, and 4,4'-dihydroxydiphenylether as a main raw material. However, those produced using bisphenol A as a main raw material are preferred. Specifically, polycarbonate obtained by using the above bisphenol A as a dihydroxy component and by a transesterification method or a phosgene method is preferable. Further, bisphenol A in which a part, preferably 10 mol% or less, is substituted with 4,4'-dihydroxydiphenylalkane, 4,4'-dihydroxydiphenylsulfone, 4,4'-dihydroxydiphenylether or the like is also preferable.

What is generally called a multilayer film is made by a method using a usual feed block, and the number of layers is 5
At most, the number of layers is about 7 layers, and at most about 9 layers are laminated with another film on this multilayer film. The present inventors have conducted intensive studies in order to solve these limitations, and as a result, have found that a method that can be called an ultra-multilayer may be used.

A general multilayer film is manufactured as follows. That is, first, a polyester resin and a polycarbonate resin are separately put into an extruder, and each is made into a two-part three-layer resin structure by a feed block, or an adhesive resin is added to the two resins to make a three-layer five-layer resin. Configure. The cross-section of the layered feed block has a rectangular shape. Next, it is a usual method to simply introduce the molten resin of this shape into a T-die, stretch it in the lateral (XY axis) direction, draw it out, cool it, and then directly or stretch it to form a film.

On the other hand, the super multilayer film of the present invention is
The thickness of the rectangular resin formed by the feed block (Z
Axis) direction but not in the flow path (XY axis) direction,
Obtain resin blocks, each of which is a multilayer. The obtained resin blocks are overlapped in the vertical direction while passing through a new flow path, that is, the XY plane of each block is overlapped in the Z-axis direction to form a new multilayer resin block.

For example, a three-layer, five-layer film can be formed by a usual method using the first feed block, and the resulting film can be divided into four parts and superposed to form a twenty-layer multilayer film.
When this resin block is further divided into four parts and overlapped, a film having a multi-layer structure of 80 layers can be formed, and by repeating the same process, a 320-layer film can be formed. Such a super multilayer film can be further stretched or extruded and laminated on a support to obtain a sublimation transfer recording material.

As a method of stretching an unstretched film,
Although it is not particularly limited, it is necessary to stretch at least uniaxially, and the method is a roll stretching method (2 different circumferential speeds).
Stretching method in the running direction of the film between two or more rolls), long gap stretching method, tenter stretching method (stretching method in which the film is held and spread by clips), tubular stretching method, inflation stretching method (by air pressure) It is possible to use any method such as
The film is stretched in one predetermined direction (main stretching direction) by these known stretching methods. In either method, stretching is performed by sequential biaxial stretching, simultaneous biaxial stretching, uniaxial stretching, or a combination thereof. When biaxial stretching is used, stretching in the vertical and horizontal directions may be performed simultaneously, but in order to obtain a better stretching effect, a sequential biaxial stretching method in which one of them is stretched first is recommended. . In this case, the stretching order in the vertical and horizontal directions may be performed in any order. However, in consideration of mechanical properties, the film is first stretched in the longitudinal direction corresponding to the film flow direction, and then sequentially stretched in the transverse direction. It is preferable to use an axial stretching method.

Here, in the conventional method of successively biaxial stretching, the unstretched sheet is first roll-stretched in the longitudinal direction, and then tenter-stretched in the width direction.
This is a method of performing heat treatment at 0 ° C. or higher (Japanese Patent Laid-Open No. 63-168).
441, JP-A-63-193938, JP-A-2-80247, JP-A-2-284929, JP-A-3-114817, JP-A-4-202
540, etc.).

From the viewpoint of the preferable heat shrinkage required for the multilayer film thus obtained,
The heat shrinkage at 0 ° C. is preferably less than 2%. The thickness ratio of the polyester-based resin layer and the polycarbonate-based resin layer is determined by the relationship between the wrinkles and unevenness of the recording medium and the recording density. The ratio of the polyester-based resin layer to the polycarbonate-based resin layer is 0.01 to 1%. Is preferred. If it is less than 0.01, wrinkles and unevenness are likely to occur, and if it exceeds 1, a decrease in recording density is inevitable. Of course, since the decrease in recording density depends on the thickness of the polycarbonate resin layer, the thickness is 1 μm or less, preferably 0.1 μm or less.
It is 1 μm or less, more preferably 0.01 μm or less.

Further, a layer of a saturated polyester resin, a polycarbonate resin, a vinyl chloride resin, or the like can be formed as a recording receiving layer on the multilayer film for the purpose of further improving the performance.

It is also effective to form a coating layer on one or both surfaces of the polyester resin film of the present invention obtained as described above to improve the wettability and adhesion with ink or the like, if necessary. is there. As a main component of the coating layer, a polyester resin having a good affinity for the film is preferable, but in addition, a polyurethane resin, a polyester / urethane resin, an acrylic resin, and the like, with respect to a normal polyester resin film. A resin used for improving the adhesiveness or the like is appropriately selected and used.

As a method for forming the coating layer, known methods such as a gravure coating method, a kiss coating method, a dip coating method, a spray coating method, a curtain coating method, an air knife coating method, a blade coating method, a reverse roll coating method, and the like. All are applicable. As for the timing of application, before the stretching of the film (that is, a method of applying the polymer mixture to the surface of the polymer mixture before the stretching treatment), after the stretching (that is, after applying the film to the surface of the cavity-containing film stretched in the uniaxial direction, The stretching may be performed at any point after the stretching in the perpendicular direction) or after the relaxation treatment (that is, the method of coating the surface of the void-containing film after the stretching treatment).

The film of the present invention contains the above-mentioned constituents as essential components, but contains inorganic or organic fine particles for the purpose of imparting a hiding property (non-permeability or whiteness) to the film. Is also effective. Such fine particles include silica, kaolin, talc, calcium carbonate, zeolite, alumina, barium sulfate,
Examples thereof include inorganic fine powders such as carbon black, zinc oxide, and titanium oxide; and organic fine powders such as a crosslinked polymer and an organic white pigment. If necessary, an appropriate amount of other components such as an antistatic agent, an ultraviolet absorber, a plasticizer, and a coloring agent can be contained.

In the present invention, resins other than the above-mentioned resins used in the present invention can be mixed as long as the performance is not impaired. Examples of the resin to be mixed include a polyvinyl resin, a polyacrylic resin, a polymethacrylic resin, a polyolefin resin, a cellulose derivative resin, a polyether resin, a polyester resin, and a polycarbonate resin.

The resin of the present invention can be thermoset or crosslinked for the purpose of improving image durability.
Examples of thermosetting resins used in combination with a crosslinking agent include silicone resins, melamine resins, phenol formaldehyde resins,
Epoxy resins and isocyanate resins are mentioned. Further, examples of the crosslinking include ionic crosslinking and radiation crosslinking.

Various slip agents can be blended in the thermal transfer sheet for the purpose of improving the releasability. Examples of the lubricant include a fluorine resin, a silicone resin, and a surfactant such as an organic sulfonate compound, an organic phosphate compound, and an organic carboxylate compound.

Further, an ultraviolet absorber, an antioxidant and the like may be blended as a light fastness improving agent for the image.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the following Examples do not limit the present invention, and all changes and implementations without departing from the spirit of the present invention will be described. Within the technical scope of

[0044]

EXAMPLES The measuring and evaluating methods employed in the following examples are as follows. In the following description, “parts” represents “parts by weight”, and “%” represents “% by weight”. (1) Curls and Wrinkles Curls and wrinkles due to the heat of the printer are color hard copies [D-SCAN, manufactured by Seiko Denshi Kogyo Co., Ltd.]
CH-5504], the image from the video was actually output. The case where no curl or wrinkle was generated in the output printed matter was evaluated as ○, the case where it was slightly generated was evaluated as △, and the case where it was completely generated was evaluated as x. (2) Sublimation transfer recording density Color hard copy [Seiko Electronics Co., Ltd., D-
[SCAN CH-5504], the image from the video was actually output. The recording density was measured with a Macbeth densitometer.

<Example 1> A raw material (A,
B) was put into a screw extruder, and through a normal feed block, a resin block having a layer configuration of two and three layers (ABA) was immediately introduced into the super multilayer division block. Vertical (Z-axis) of two types and three layers of resin blocks in a super multilayer block
After dividing the resin block into four in the direction, each resin block is overlapped with a flow path, and a resin block having one of 12 layers is obtained. This resin block is further introduced into the next similar super-multilayer divided block to form a 12 × 4. The same operation as a 48-layer super-multi-layer was repeated, and finally a 192-layer resin block was melt-extruded from a T-die at 290 ° C., and then electrostatically adhered and solidified on a cooling rotating roll to obtain a resin block of about 110.
An unstretched sheet of 0 μm was obtained. Next, the unstretched sheet was stretched 3.1 times at 80 ° C. by a roll stretching machine, and then transversely stretched 2.6 times at 125 ° C. with a test tenter. 1.4 at 220 ° C
Laterally stretched twice. Thereafter, the polyester resin film of the present invention was obtained by performing a relaxation heat treatment of 4% at 235 ° C. (thickness: about 70 μm). Composition : Resin A to be a surface layer: Amorphous polyethylene terephthalate resin (manufactured by Eastman Chemical Company, PET-
G) Resin in the middle layer B: polycarbonate resin A: B: A = 3: 1: 3 (thickness ratio of first ABA block) The results obtained by measuring the above evaluation items for the film obtained in this manner are as follows. It is shown in Table 1. Table 1 also shows the results obtained in the following Examples and Comparative Examples.

<Example 2> In Example 1, an ultra-multi-layer film of 762 layers was formed by further passing through the divided blocks.

<Embodiment 3> In Embodiment 2, a super-multi-layer film of 3048 layers was prepared by further passing through a divided block.

<Example 4> In Example 1, the molten resin block which had been drawn out of the T-die without being stretched was extruded and laminated on a 70 μm void-containing polyester film, and was then subjected to 20 μm.
m of the receiving layer.

<Comparative Example 1> Amorphous polyethylene terephthalate resin and polycarbonate resin were kneaded at a ratio of 3: 1 with a twin screw extruder, pelletized, extruded on a sheet with a T die, and stretched to form a film. .

<Comparative Example 2> As in Example 1, only amorphous polystyrene terephthalate resin having a thickness of 1100 μm was used.
m unstretched sheet having a thickness of 70 μm as in Example 1.
Was prepared.

<Comparative Example 3> An unstretched sheet having a thickness of 1100 µm was obtained in the same manner as in Example 1 using only the polycarbonate resin, and a biaxially stretched film having a thickness of 70 µm was formed in the same manner as in Example 1.

<Comparative Example 4> The thickness of the polystyrene terephthalate resin (crystalline) alone was 110 in the same manner as in Example 1.
An unstretched sheet having a thickness of 0 μm was obtained.
A μm biaxially stretched film was prepared.

[0053]

[Table 1]

From Table 1, the following can be considered. The films of Examples 1 to 4 of the present invention showed no curl or wrinkle due to heat and had a high image density. On the other hand, wrinkles are observed only by melt-kneading the amorphous polyester and the polycarbonate of Comparative Example 1, and the recording density is not satisfactory or the recording density is low in Comparative Example 2 in which the recording density is not satisfactory. Comparative Examples 3 and 4 have no wrinkles, but have a low recording density.

[0055]

Since the film of the present invention is constructed as described above, it is possible to obtain a drawing property which cannot be obtained by the conventional polyester resin alone, and to reduce curl by heat compared with these conventional films. It is hard for me to enter. Therefore, the film of the present invention is most suitable as a recording medium for sublimation transfer recording. Further, it can be used for a thermal transfer recording material.

Claims (3)

[Claims] 1. A multilayer laminate comprising a polyester resin layer containing an amorphous polyester resin and a polycarbonate resin layer, wherein each layer has a thickness of 1 to 0.00 per layer.
Consist of 1 μm layers and they are 10-1000
A recording medium for thermal transfer recording, comprising a multi-layer laminate laminated in 0 layers as a thermal transfer receiving layer. 2. The recording medium for thermal transfer recording according to claim 1, wherein said receiving layer has a thickness of 1 to 100 μm. 3. The receiving layer according to claim 1, wherein the receiving layer is formed on a support selected from the group consisting of paper, laminated paper, plastic film, and plastic sheet. Recording medium for thermal transfer recording.