JPH0692038A - Laminated substrate for sublimation type thermal transfer image receiving sheet - Google Patents

Abstract

PURPOSE:To provide the laminated substrate reduced in the curl quantity generated by the heat at the time of the recording of an image due to a thermal head and enhanced in the dot reproducibility in a low density part. CONSTITUTION:In a laminated substrate 6 for a sublimation type thermal transfer image receiving sheet wherein films 4, 5 are bonded to both surfaces of a sheet like support 1 through adhesive layers 4, 5 and at least the surface adhesive layer 4 is composed of a self-adhesive or an elastic adhesive, at least the film 2 on the surface side of the substrate 6 has a heat shrinkage factor according to JISC-2318 of 6% or less in both longitudinal and lateral directions of the substrate and contains fine air bubbles.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a laminated substrate for a sublimation type thermal transfer image receiving sheet.

[0002]

2. Description of the Related Art An image receiving sheet used in a sublimation type thermal transfer recording system has an image receiving layer composed of a thermoplastic polyester resin having a strong dyeing property to a heat sublimable dye and a releasing agent. The one formed above is used. However, an image receiving sheet using a single-layered body of synthetic paper or a plastic film as a substrate is apt to curl due to heat at the time of transfer by a thermal head, and its running property in a thermal transfer recording apparatus is insufficient. there were. As an improvement, a laminated substrate of synthetic paper / cellulose fiber paper / synthetic paper (JP-A-62-198497)
However, although the curl is less than that of the conventional substrate such as synthetic paper, the curl improving effect in the high density (high applied energy) part is not sufficiently exhibited. Further, the present applicant has previously proposed a substrate in which two films are laminated via a pressure-sensitive adhesive layer or an elastic adhesive layer,
Although the curl is less than that of a conventional substrate such as synthetic paper, the curl improvement in the high density (high applied energy) part is still insufficient. Further, a thermal transfer image receiving medium is formed by adhering films on both front and back surfaces of a sheet-like support through adhesive layers, and the adhesive layer on the surface side on which the image receiving layer is formed is a pressure sensitive adhesive or an elastic adhesive. Although a laminated substrate for a sheet was also proposed earlier, when the heat shrinkage rate of the film to be adhered is large (synthetic paper, expanded polypropylene, etc.), the curl improvement in the high density (high applied energy) part is not yet sufficient.
Furthermore, when the heat-shrinkage rate of the adhered film is small (transparent or white PET film, etc.), the curl in the high-concentration (high applied energy) part is good, but the cushioning property of the adhered film is poor, so that the curl is low. Insufficient sensitivity and white spots occur in the density (low applied energy) part.

[0003]

SUMMARY OF THE INVENTION The present invention solves the drawbacks of the prior art, significantly reduces the curl generated by heat during image recording by a thermal head, and further improves the image quality in the low-density portion with good dot reproducibility. An object is to provide an improved sublimation-type laminated substrate for a thermal transfer image-receiving sheet.

[0004]

According to the present invention, a film is adhered to both front and back surfaces of a sheet-like support through an adhesive layer, and at least the surface side where an image receiving layer is formed is adhered. In a laminated substrate for a thermal transfer image receiving sheet, the agent layer of which comprises an adhesive or an elastic adhesive, the film on at least the surface side on which the image receiving layer is formed is JIS C
There is provided a laminated substrate for a thermal transfer image-receiving sheet, which is a film containing fine bubbles having a heat shrinkage ratio according to -2318 of 6% or less in both the longitudinal and transverse directions. Further, at least the film on the surface side on which the image receiving layer is formed is a foamed film having a heat shrinkage ratio of 2.5% or less in both the longitudinal and transverse directions according to JIS C-2318. A laminated substrate for the sublimation type thermal transfer image receiving sheet is provided. Further, the laminated substrate for the sublimation type thermal transfer image receiving sheet is provided, wherein the film on the front surface side is a polyethylene terephthalate film.

Since the laminated substrate for sublimation type thermal transfer image receiving sheet of the present invention has the above-mentioned constitution, it has the following operational effects. 1) Films are adhered to both front and back surfaces of a sheet-like support constituting the substrate via adhesive layers, and at least the adhesive layer on the surface side where the image receiving layer is formed is a pressure-sensitive adhesive or elastic adhesive. The image receiving layer at the time of printing by being composed of the agent,
The heat shrinkage of the film on the surface side can be absorbed by the stress relaxation of the pressure-sensitive adhesive or the elastic adhesive to reduce the curl amount. Further, at least the film on the surface side on which the receptive layer is formed has a heat shrinkage ratio according to JIS C-2318 of 6% or less in both the vertical and horizontal directions, so that the high density (high applied energy) part It is possible to reduce the heat shrinkage rate of the film itself on the front surface side, and consequently reduce the curl amount of the entire receiving paper. Further, when at least the surface side film on which the image receiving layer is formed is a foamed film, the cushioning property is improved, the adhesion between the ink layer and the image receiving layer is improved, and the dots in the low density (low applied energy) part The reproducibility can be improved, and as a result, insufficient sensitivity and occurrence of blank areas can be prevented. 2) By setting the heat shrinkage rate of at least the surface side film on which the receptor layer is formed to 2.5% or less in both the longitudinal and lateral directions according to JIS C-2318,
It is possible to reduce the heat shrinkage of the film itself on the surface side in the high density (high applied energy) portion, and as a result, further reduce the curl amount of the entire receiving paper. 3) The one using foamed PET as the surface side film is low in cost and at the same time excellent in heat shrinkage of the film itself, and also excellent in whiteness as a substrate, so that heat shrinkage reduction treatment or It does not require a step of adding a fluorescent whitening agent or a white pigment for adjusting whiteness.

Next, the present invention will be described in more detail with reference to the drawings. FIG. 1 shows a laminated substrate 6 according to the present invention, in which a front-side foamed film 2 is laminated and adhered on the surface of a support 1 via an adhesive layer 4, and on the back surface of the support 1. Is a backside film 3 laminated and adhered via an adhesive layer 5. FIG. 2 is an image receiving sheet in which the image receiving layer 7 is formed on the surface side film 2 of the laminated substrate 6 according to the present invention.

The image receiving layer 7 may have a single-layer structure or a multi-layer structure. Further, a layer (heat fusion preventing layer) for preventing heat fusion with an image transfer medium (ink sheet) (not shown) may be provided on the image receiving layer 7 or the image receiving layer 7 An intermediate layer may be provided between the surface-side film 2 and the surface film 2 for the purpose of improving adhesion, or a layer may be provided on the image-receiving layer 7 or the thermal transfer prevention layer for antistatic purposes. A back coat layer may be provided on the back side film 3 for blocking prevention and double feed prevention.

Examples of the sheet-like support 1 used in the laminated substrate of the present invention include paper such as high-quality paper, medium-quality paper, Japanese paper, thin paper and coated paper (including lightly coated paper, art paper, etc.). , Polyester, polyvinyl chloride, polyolefin,
A synthetic resin film such as nylon or cellophane can be used. The sheet-shaped support 1 used in the laminated substrate of the present invention preferably has a thickness of 20 to 300 μm. When the thickness is less than 20 μm, the obtained image-receiving sheet becomes weak in stiffness, and it becomes impossible to sufficiently prevent curling that occurs during image recording. On the other hand, if the thickness exceeds 300 μm, the thickness of the obtained image receiving sheet becomes excessively large, the running property of the image receiving sheet in the printer is deteriorated, and the number of stored sheets is reduced, which is not preferable. The sheet-shaped support 1 preferably has a heat shrinkage rate according to JIS C-2318 of 3% or less in both the vertical and horizontal directions.

As the film used for the back side film 3 of the laminated substrate of the present invention, a polyethylene film, a polypropylene film, a polyvinyl chloride film, a polyvinylidene chloride film, which has no voids or has voids inside, Polyvinyl alcohol film,
Polyethylene terephthalate film, polycarbonate film, nylon film, polystyrene film, ethylene-vinyl acetate copolymer film, ethylene-vinyl alcohol copolymer film, polyethylene naphthalate film, fluorinated ethylene propylene film, aromatic polyamide film, polyarylate film , A polyether sulfone film, a polyether imide film, a polyimide film, an acrylic resin film, a plastic film such as an ionomer.

Further, the foamed film used for the surface side film 2 of the laminated substrate and having a heat shrinkage ratio according to JIS C-2318 of 6% or less in both the longitudinal and transverse directions has the above-mentioned voids. Examples thereof include a film or a film having voids that has been subjected to a heat shrinkage reduction treatment, for example, a heating (heat setting) treatment. Examples of the heat shrinkage reduction treatment include a method of heating an untreated film by bringing it into contact with a hot roll. By performing the treatment, the stress held in the film during stretching can be relaxed and the heat shrinkage rate can be reduced. The materials of the front surface side film 2 and the back surface side film 3 may be the same or different.

The film having voids can be obtained by a method of forming a film by extruding a resin together with a foaming agent through an orifice, a method of generating voids by adding fine particles to the resin and stretching. Examples of the film having voids obtained by adding fine particles to a resin and stretching the film include a biaxially stretched multi-layer structure film containing a mixture of a polyolefin and an inorganic pigment as a main component. The polyolefin resin constituting such a stretched multilayer structure film is generally selected from polyethylene resin and polypropylene resin, and the inorganic pigment is selected from titanium dioxide, calcium carbonate and the like. The appropriate content of the inorganic pigment in the film is about 3 to 80% by weight. The structure of this stretched film is composed of a base material layer made of an inorganic pigment-containing polyolefin resin and a paper-like layer made of a uniaxially or biaxially stretched inorganic pigment-containing polyolefin resin film attached to both front and back surfaces thereof. It may be a three-layer structure or a layered structure having four or more layers such as a four-layer structure including the above-mentioned base material layer, paper-like layer, and other layers such as a surface layer with improved whiteness. Absent.

Film (stretched film) in the present invention
In Nos. 2 and 3, when the heat shrinkage rate according to JIS C-2318 is 2.5% or less in both the vertical and horizontal directions, the curl generated during the printing operation of the high energy part by the thermal transfer method is further reduced. It is particularly preferable because it can be performed. Further, specifically, the foamed PET is low in cost, and at the same time, is excellent in heat shrinkage of the film itself,
Further, it is particularly preferable because it is excellent in whiteness as a substrate, and steps such as heat shrinkage reduction treatment and addition of a fluorescent whitening agent or a white pigment for adjusting whiteness are not required. The thickness of the front surface side film 2 and the back surface side film 3 is both 4 to 250 μm, preferably 9 to 150 μm.
It is about m.

In the laminated substrate of the present invention, the sheet-like support 1 and the front surface side film 2 are laminated and adhered via an adhesive 4. The adhesive layer 4 here is formed by coating an adhesive or an elastic adhesive by a known method. The "adhesive" is one of the adhesives, and this adhesive, together with the "elastic adhesive", has a lower cohesive force and absorbs and relaxes stress more quickly than other adhesives. Therefore, in the image-receiving sheet using the laminated substrate of the present invention, the shrinkage stress of the image-receiving layer 7 and the surface side film 2 which is generated by the heat at the time of image recording by the thermal head is reduced by the pressure-sensitive adhesive layer or the elastic adhesive. Is absorbed by the sheet-shaped support 1
It is possible to make the curl of the image receiving sheet very small by utilizing the rigidity of the back side film 3.

As the pressure-sensitive adhesive forming the adhesive layer 4, any conventionally known pressure-sensitive adhesive can be used. Since the adhesive has viscoelastic behavior, it is basically based on a polymer. The blending ratio actually differs depending on the application, but basically it has a two-component structure of a polymer elastic material and a tackifier as the skeleton, and in order to impart various resistances, a tackifier, an adhesion improver, and other additives are added. Used.

Examples of the polymer used as the elastic polymer include natural rubber, styrene-butadiene copolymer, isoprene copolymer, chloroprene copolymer, acrylic ester copolymer, vinyl-ether copolymer, Examples include EVA resin, polyisobutylene, polyurethane, and siloxane cross-linking type polymer.

Examples of tackifiers include rosin, dammar,
Tackifying resin such as copar, water point rosin, coumarone indene resin, polyterpene, phenol resin, alkyd resin, petroleum hydrocarbon resin, xylene resin, epoxy resin; phthalate ester, phosphate ester, chlorinated paraffin and other plasticizers Softeners such as animal and vegetable oils and fats and mineral oils; and low polymerized products of the above polymers. In addition, an antiaging agent, a stabilizer, a colorant and the like are used as additives as required.

On the other hand, as the elastic adhesive forming the adhesive layer 4, any known elastic adhesive can be used. In particular, the Young's modulus of the adhesive layer formed of the elastic adhesive is 1 to
It is preferably 2,000 kg / cm ² . The elastic adhesive has a polymer elastic body as a main component, and in order to impart various heat resistances, an adhesion improver, an antioxidant and a stabilizer are used as necessary. Of the above elastic adhesives, an elastic adhesive containing a synthetic rubber or a siloxane cross-linking polymer as a main component is particularly preferable because it has a large ability to absorb stress.
Examples of the elastic adhesive containing a siloxane cross-linking polymer as a main component include, for example, a liquid polymer containing an amino group capable of reacting with epoxy, a main chain structure of which is polyoxypropylene, and a moisture-curable silyl group, and an epoxy resin. Examples of the composition include and.

To the pressure-sensitive adhesive or elastic adhesive, water or an organic solvent is added to the above-mentioned one as needed to adjust the viscosity, and the adhesive layer 4 is formed by a conventional method such as a coating method or a hot melt coating method. It is formed on the sheet-shaped support 1. The thickness of the adhesive layer 4 is about 1 to 60 μm, preferably 5
μm to 50 μm. If it is thinner than 1 μm, the curl preventing effect is poor, and if it is thicker than 60 μm, problems such as sticking out of the adhesive or elastic adhesive from the laminated substrate may occur.

As the adhesive forming the adhesive layer 5, any conventionally known adhesive or pressure-sensitive adhesive can be used. Specifically, urea resin, melamine resin, phenol resin, epoxy resin, vinyl acetate resin is used. , Vinyl acetate / acrylic copolymer resin, EVA meter resin, acrylic resin, polyvinyl ether resin, vinyl chloride / acetic acid copolymer resin, polystyrene resin, polyester resin, polyurethane resin, polyamide resin, poly Chlorinated polyolefin resin, polyvinyl butyral resin, acrylic ester resin, methacrylic ester copolymer,
Any adhesive such as a natural rubber-based adhesive, a cyanoacrylate-based adhesive, or a silicone-based adhesive, or an adhesive obtained by adding an appropriate tackifier to these adhesives can be used. If necessary, a plasticizer, a filler, an antiaging agent, etc. may be added to the adhesive layer 5.

Therefore, the adhesive layer 5 is adjusted by adding water or an organic solvent to the above-mentioned adhesive components, if necessary, to adjust the viscosity, and coating the same on a sheet-like support by a conventional method.
And the backside film 3 are laminated and adhered via the adhesive layer 5. A suitable thickness of the adhesive layer 5 is about 1 to 40 μm.

[0021]

EXAMPLES Next, the present invention will be described more specifically by way of examples. Parts herein are by weight.

Example 1 As the front side film and the back side film, a heat-shrinkage reduction-treated expanded polypropylene film (trade name: YP56,
Thickness: about 48 μm, heat shrinkage ratio: length, width about 5%, manufactured by Toray).
A sheet-like support made of a T film (trade name E20, manufactured by Toray Industries, Inc.) was laminated and adhered on both sides by a dry lamination method to prepare a laminated substrate for an image receiving sheet of the present invention. An acrylic pressure-sensitive adhesive (trade name: Polythic 370-S; manufactured by Sanyo Kasei Co., Ltd.) was used for sticking the support on the front surface side to the film, and the thickness of the pressure-sensitive adhesive layer was about 3 μm, and the support on the back surface side A polyester adhesive (trade name S-3911; manufactured by Toagosei Kagaku) was used for adhesion between the body and the film, and the thickness of the adhesive layer was about 3 μm.

Example 2 As the front side film and the back side film, a heat-shrinkage-reduced expanded polypropylene film (trade name: YP56,
Thickness: Approximately 48 μm, Thermal shrinkage: 2.6% vertical, 2.8 horizontal
%, Manufactured by Toray Industries, Inc.)
m of a white PET film (trade name E20; manufactured by Toray Industries, Inc.) was laminated and adhered on both sides by a dry lamination method to prepare a laminated substrate for an image receiving sheet of the present invention. An acrylic pressure-sensitive adhesive (trade name: Polythic 370-S; manufactured by Sanyo Kasei Co., Ltd.) was used for sticking the support on the front surface side to the film, and the thickness of the pressure-sensitive adhesive layer was about 3 μm, and the support on the back surface side A polyester adhesive (trade name S-3911; manufactured by Toagosei Kagaku) was used for adhesion between the body and the film, and the thickness of the adhesive layer was about 3 μm.

Example 3 Foamed polyethylene terephthalate film (trade name: E60, thickness: about 50) was used as the front and back films.
μm, heat shrinkage ratio: 1.0% length, 1.8% width, manufactured by Toray)
This film was laminated on both sides of a sheet-like support made of a white PET film (trade name E20; manufactured by Toray Industries, Inc.) having a thickness of about 100 μm to prepare a laminated substrate for an image receiving sheet of the present invention. . Acrylic ester copolymer-based adhesive (trade name Olivine BPS 5454; manufactured by Toyo Ink Co., Ltd.) was used for sticking the support on both front and back sides to the film, and the thickness of each adhesive layer was about 3 μm. .

Comparative Example 1 A foamed polypropylene film (trade name: YP56, thickness: about 48 μm, heat shrinkage: length 6.6%, width 7.0%, manufactured by Toray Industries, Inc.) was used as the front and back films. This film was laminated and adhered on both sides of a sheet-like support made of a white PET film (trade name E20; manufactured by Toray Co., Ltd.) having a thickness of about 100 μm by a dry lamination method to obtain a laminate for an image receiving sheet of the present invention. A substrate was prepared. An acrylic pressure-sensitive adhesive (trade name: Polythic 370-S; manufactured by Sanyo Kasei Co., Ltd.) was used for sticking the support on the front surface side to the film, and the thickness of the pressure-sensitive adhesive layer was about 3 μm, and the support on the back surface side A polyester adhesive (trade name S-391) is used for adhesion between the body and the film.
1; manufactured by Toagosei Kagaku Co., Ltd.), and the thickness of the adhesive layer was about 3 μm.

Comparative Example 2 White polyethylene terephthalate film (trade name: E20, thickness: about 50 μm) was used as the front and back films.
m, heat shrinkage ratio: length 1.4%, width 0.4%, manufactured by Toray Co., Ltd.), and this film is a sheet-like support made of a white PET film (trade name E20; manufactured by Toray Co., Ltd.) having a thickness of about 100 μm. The laminated base material for an image receiving sheet of the present invention was prepared by laminating and adhering it to both surfaces of the body. Acrylic ester copolymer-based adhesive (trade name Olivine BPS 5454; manufactured by Toyo Ink Co., Ltd.) was used for sticking the support on both front and back sides to the film, and the thickness of each adhesive layer was about 3 μm. .

Subsequently, the following image-receptive layer coating liquid was applied onto this laminated substrate with a wire bar, dried at a drying temperature of 80 ° C. for 1 minute, and then aged at 60 ° C. for 2 hours to give a thickness of about An image receiving sheet was prepared by laminating a 3 μm image receiving layer. (Solution for receiving layer) Saturated copolyester resin (trade name: Byron 200; manufactured by Toyobo Co., Ltd.) 100 (trade name: AY42-125; manufactured by Toray Dow Corning Silicone Co., Ltd.) 5 Solvent Toluene 300 Methyl ethyl ketone 300 On the other hand, a silicone resin heat-resistant layer A 6 μm-thick PET film having a thickness of 1 μm was coated with the following ink layer coating liquid to a thickness of 2.0 μm using a wire bar and dried to prepare a sublimation transfer recording material. (Coating liquid for yellow ink layer) Polyvinyl butyral resin (Brand name BX-1, manufactured by Sekisui Chemical Co., Ltd.) 10 Sublimation dye for yellow (Brand name Yellow VP; manufactured by Mitsui Toatsu Dye company) 4 Solvent Toluene 95 Methyl ethyl ketone 95 (Magenta ink) Layer coating liquid) Polyvinyl butyral resin (Brand name BX-1; manufactured by Sekisui Chemical Co., Ltd.) 10 Sublimation dye for magenta (Brand name Magenta VP; manufactured by Mitsui Toatsu Dye company) 10 Solvent Toluene 95 Methyl ethyl ketone 95 (Coating for cyan ink layer) Liquid) Polyvinyl butyral resin (trade name BX-1, manufactured by Sekisui Chemical Co., Ltd.) 10 Cyan sublimation dye (trade name cyan VP; manufactured by Mitsui Toatsu Dye Co., Ltd.) 10 Solvent Toluene 95 Methyl ethyl ketone 95 Obtained sublimation transfer recording material and image The receiving sheet is used as the ink layer of the sublimation transfer recording medium and the image receiving layer of the image receiving sheet. Superposed as facing, yellow by changing the heating energy in the thermal head from the back of the sublimation recording medium, magenta, performs superimposed sequentially recording cyan, to obtain a black solid image. The recording density of the thermal head is 12 dots / m.
m, and the applied energy was 0.64 mj / dot. The degree of curling of the image receiving sheet after image recording was examined, and the results are summarized in Table 1.

[0028]

[Table 1] (Note) The image receiving sheet (A4 size) after recording was placed on a flat desk with the recording surface facing upward, and the height from the flat surface to the recording surface was measured, and the maximum value was shown.

[0029]

The laminated substrate for sublimation type thermal transfer image-receiving sheet of the present invention comprises a sheet-like support constituting the substrate, and a film adhered to the front and back surfaces of the substrate via adhesive layers. By forming at least the surface-side adhesive layer from a pressure-sensitive adhesive or an elastic adhesive, the image-receiving layer at the time of printing, heat shrinkage of the film on the surface side is absorbed by stress relaxation of the pressure-sensitive adhesive or elastic adhesive, and curls. The amount can be reduced. Further, by setting the heat shrinkage rate according to JIS C-2318 of the film on which at least the receiving layer is formed to be 6% or less in both the longitudinal and lateral directions, the film in the high density (high applied energy) part can be obtained. The heat shrinkage rate of the film itself on the front surface side can be reduced, and as a result, the curl amount of the entire receiving paper can be reduced. Further, by setting the heat shrinkage rate to 2.5% or less in both the vertical and horizontal directions, the heat shrinkage rate of the film itself on the surface side in the high concentration (high applied energy) part is further reduced, and the result Therefore, the curl amount of the entire receiving paper can be further reduced. Further, since the film on at least the surface side on which the image receiving layer is formed is a foamed film, the cushioning property is improved to improve the adhesion between the ink layer and the image receiving layer, and the low density (low applied energy) It is possible to improve the dot reproducibility in the area and consequently prevent the lack of sensitivity and the occurrence of white spots. Furthermore, when foamed PET is used as the foamed film, the cost of the foamed PET is low, and at the same time, the heat shrinkage of the film itself is excellent, and the whiteness of the substrate is also excellent. It does not require steps such as reduction treatment and addition of a fluorescent whitening agent or white pigment for adjusting whiteness.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a laminated substrate for a sublimation type thermal transfer image receiving sheet of the present invention.

FIG. 2 is a schematic cross-sectional view of a sublimation type thermal transfer image receiving sheet in which an image receiving layer is formed on the surface side film of the laminated substrate of the present invention.

[Explanation of symbols]

 1 sheet-like support 2 front side film 3 back side film 4 adhesive layer (adhesive layer or elastic adhesive layer) 5 adhesive layer 6 laminated substrate 7 image receiving layer

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Hiroki Kuboyama 1-3-6 Nakamagome, Ota-ku, Tokyo Stock company Ricoh Co., Ltd. (72) Inventor Yutaka Ariga 1-3-3 Nakamagome, Ota-ku, Tokyo Stock Company Ricoh

Claims (3)

[Claims] 1. A sheet-like support having a front surface and a back surface each having a film adhered thereto via an adhesive layer, and at least the adhesive layer on the front surface side on which the image receiving layer is formed is made of a pressure-sensitive adhesive or an elastic adhesive. In the laminated substrate for a thermal transfer image-receiving sheet, the film having at least the surface side on which the image-receiving layer is formed has a longitudinal heat shrinkage ratio according to JIS C-2318,
A laminated substrate for a sublimation type thermal transfer image-receiving sheet, which is a film containing 6% or less of fine bubbles in any of the transverse directions. 2. A film on at least the surface side on which the image-receiving layer is formed is a foamed film having a heat shrinkage ratio according to JIS C-2318 of 2.5% or less in both the longitudinal and transverse directions. The laminated substrate for a sublimation type thermal transfer image receiving sheet according to claim 1. 3. The laminated substrate for a sublimation type thermal transfer image-receiving sheet according to claim 1, wherein the film on the front surface side is a polyethylene terephthalate film.