JPH08282105A - Reversible thermal recording sheet - Google Patents

Abstract

PURPOSE: To provide a rewritable reversible thermal recording sheet using a leuco dye being a color forming dye material and a coupling/erasing agent reacting with the leuco dye at a time of heating to form and erase a color, imparting high printing intensity, having good erasing properties, extended in repeated use life and having high capacity. CONSTITUTION: A reversible thermal recording sheet is obtained by providing a protective layer based on a polyolefin resin having a cyclic structure with a glass transition temp. of 140 deg.C or higher on a reversible thermal recording layer using a leuco dye and a coupling/erasing agent and characterized by that fatty acid amide with an m.p. of 100 deg.C or lower is added to the protective layer in an amt. of 0.5-30% by wt. of the polyolefin resin. By this constitution, the high capacity rewritable reversible thermal recording sheet imparting high printing density, having good erasing properties and extended in repeated use life can be realized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reversible heat-sensitive recording sheet, and more particularly to a heat-sensitive recording sheet that reversibly colors and decolors an image by the difference in heat energy.

[0002]

2. Description of the Related Art Conventionally, thermal recording paper has been used for facsimile,
It has been widely used for labels, word processors, plotters, thermal printers, etc. In recent years, research on reversible thermosensitive recording materials capable of reversibly recording and erasing images such as characters and pictures has been conducted due to problems such as waste disposal and promotion of resource saving. . The prior art relating to such a reversible thermosensitive recording material has hitherto been (1) JP-A-63-39377, (2) JP-A-63-41186, and (3) JP-A-2-566. (4) Japanese Patent Application Laid-Open No. 2-1363, (5)
JP-A-2-80289, (6) JP-A-2-81
672, (7) Japanese Patent Application Laid-Open No. 2-86491.
(8) JP-A-58-191190, (9) JP-A-60-193691, and (10) JP-A-62-25
5482, (11) JP-A-4-14482, (12) International Publication w090 / 118888,
(13) JP-A-4-46986, (14) JP-A-4-50289, (15) JP-A-4-502290
Japanese Patent Laid-Open Publication No. Hei 5-92661 (16). In the conventional techniques described in (1) to (7) above, an organic low molecular weight substance is dispersed in an organic polymer binder, and crystallization and polycrystallization of this organic low molecular weight substance are performed by thermal energy. It is characterized by being reversibly performed in a binder. However, the method of forming an image by utilizing the white turbidity phenomenon due to such polycrystallization is generally insufficient in terms of contrast, and has a drawback that it is difficult to visually determine. Further, the conventional techniques described in (8) to (10) above are composed of a color former, a developer, an organic polymer binder, etc., of course, printing can be done by heat, Steam is required. The conventional technique described in the above (11) naturally erases a printed image, and it is difficult to control printing and erasing. Further, the conventional techniques described in the above (12) to (16) include a leuco dye, a decolorizing agent that thermally reacts with the leuco dye to develop and decolor, an organic polymer binder, and the like. It consists of In general, such a heat-sensitive composition has a high contrast and is easy to visually identify, but it is recognized that the printability and the erasability are deteriorated by repeating the printing and erasing, and the repeated use life is improved. It was strongly desired from the viewpoint of practical application.

[0003]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention The above-mentioned conventional techniques, particularly the leuco dyes described in (12) to (16), and a decolorizing agent exhibiting a color-developing and decoloring action when thermally reacted with the leuco dye. In the prior art consisting of an organic polymer binder, etc., such a heat-sensitive composition has a high contrast,
Although it is easy to visually identify, there is a problem that repeated use of printing and erasing deteriorates printability and erasability, and shortens the service life of the reversible thermosensitive recording sheet.

An object of the present invention is to solve the above-mentioned problems in the prior art. It has a high print density, good erasability, little deterioration even after repeated use, and a rewritable reversible medium having a long service life. To provide a heat-sensitive recording sheet.

[0005]

In order to achieve the above-mentioned object of the present invention, the present inventors have conducted various studies, and as a result, provided a protective layer on a reversible thermosensitive recording layer, and as the composition of the protective layer,
It has been found that a fatty acid amide whose main component is a polyolefin resin having a cyclic structure having a glass transition temperature of 140 ° C or higher and a melting point of 100 ° C or lower is added in an amount of 0.5 to 30% by weight based on the polyolefin resin. The object of the present invention is achieved by adopting the configuration described in the claims. That is, the present invention provides a reversible thermosensitive recording sheet comprising a color-forming dye material and a color-developing and decoloring agent exhibiting a color-developing and decoloring effect when heated, as described in claim 1. Includes at least a supporting substrate, a reversible thermosensitive recording layer, and a protective layer, and the protective layer has a composition containing a polyolefin resin having a cyclic structure as a main component and a fatty acid amide. Further, the present invention, as described in claim 2, in claim 1, the addition amount of the fatty acid amide added to the protective layer is 0.5 to 0.5% by weight with respect to the polyolefin resin having a cyclic structure. 30% is included. Further, according to the present invention, as described in claim 3,
In Claim 1 or 2, a fatty acid amide having a melting point of 100 ° C. or lower is used. Further, according to the present invention, as described in claim 4, in claim 1 or 2, the polyolefin resin having a cyclic structure having a glass transition temperature of 140 ° C. or higher is used. In addition, the present invention, as described in claim 5,
The color-forming dye material used in the reversible thermosensitive recording layer according to any one of claims 1 to 4 comprises a leuco dye. The leuco dye can develop various colors such as black, red, and blue, and as such a leuco dye, those shown below are used. Crystal violet lactone, 2- (2-chloroanilino) -6-
Diethylaminofluorane, 2-anilino-3-methyl-6-dibutylaminofluorane, 2- (2-chloroanilino) -6-dibutylaminofluorane, 1,3-dimethyl-6-diethylaminofluorane, 1,3- Diethyl-6-diethylaminofluorane, 2-N, N-dibenzylaminodiethylaminofluorane, 3-indolino-3- (p-dimethylaminophenyl) -6-dimethylaminophthalide, 3-diethylamino-7-chlorofluor Oran, 2- (2-fluorophenylamino) -6
-Diethylaminofluorane, 2- (2-fluorophenylamino) -6-di-n-butylaminofluorane,
3-diethylamino-7-cyclohexylaminofluorane, 3-diethylamino-6-methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7-
(1,4-Dimethylanilino) fluorane 3-diethylamino-6-methyl-7-p-butylanilinofluorane, 3-cyclohexylamino-6-chlorofluorane, 2-anilino-3-methyl-6- ( N-
Ethyl-P-toluidino) -fluorane, 3-pyrrolidino-6-methyl-7-anilinofluorane, 3-pyrrolidino-7-cyclohexylaminofluorane 3-N-methylcyclohexylamino-6-methyl-7
-Anilinofluorane, 3-N-ethylpentylamino-6-methyl-7-anilinofluorane, 3-cyclohexylmethylamino-6-methyl-7-anilinofluorane, 3-ethylisobutylamino-6- Methyl-7
-Anilinofluorane, 3-propylmethylamino-6
-Methyl-7-anilinofluorane and the like. Further, according to the present invention, as described in claim 6, in any one of claims 1 to 4, phenol is used as a developer / color-reducing agent having a color-developing and decoloring effect for the reversible thermosensitive recording layer. A complex composed of a carboxylic acid having a hydroxyl group and an aliphatic amine is used. Usually, such a complex is synthesized from a carboxylic acid and an amine as shown below. As the carboxylic acid having a phenolic hydroxyl group, gallic acid,
Salicylic acid, m-hydroxybenzoic acid, p-
Hydroxybenzoic acid, 2,3-dihydroxybenzoic acid, 2,4-dihydroxybenzoic acid, 2,6
-Dihydroxybenzoic acid, 3,5-hydroxybenzoic acid,
2,4,6-trihydroxybenzoic acid, 3,5
Dihydroxybenzoic acid, hydroxy-m-toluic acid, hydroxy-o-toluic acid, hydroxy-p-
Toluic acid, 3,5-di-butylphthalic acid, 3,
5-di-t-aminosalicylic acid, hydroxyisophthalic acid, hydroxyphthalic acid, 4-chlorosalicylic acid, 4-bromo-α-resorcinic acid, 5
-Methoxysalicylic acid, caffeic acid,
Umberic acid, hydroxyphenylacetic acid, 2,2-bis (4-hydroxyphenyl) acetic acid 3- (hydroxyphenyl 9-propionic acid, hydroferulic acid, 2,2-bis (4-hydroxyphenyl) ethanoic acid, 2,2- Bis (4-hydroxyphenyl) propionic acid, 3,3-bis (4-hydroxyphenyl) propionic acid, 4,4-bis (4-hydroxyphenyl) butanoic acid, 4,4-bis (4-hydroxyphenyl) heptane Acid, 5,5-bis (4-hydroxyphenyl) hexanoic acid, 6,6-bis (4-hydroxyphenyl) heptanoic acid, 7,7-bis (4-hydroxyphenyl) heptanoic acid, 7,7-bis ( 4-hydroxyphenyl) octanoic acid, 8,8-bis (4-hydroxyphenyl) octanoic acid, and the like. Examples of the aliphatic amine compound is reacted with carbon acid, hexylamine, octylamine, Noniaruamin, decylamine, undecylamine, dodecylamine, tridecylamine, tetradecylamine, pentadecylamine amine,
Hexadecylamine, heptadecylamine, octadecylamine, dimethylamine, diethylamine, dipropylamine, diisopropylamine, dibutylamine, diamylamine, trimethylamine, triethylamine, tripropylamine, tributylamine, triallylamine, allylamine, diallylamine, triallylamine, cyclo Propylamine, cyclobutylamine, cyclopentylamine, cyclohexylamine, benzylamine, dibenzylamine, tribenzylamine, 3-methoxypropylamine, 3-ethoxypropylamine, 3-propoxypropylamine, 3-butyloxypropylamine, 3 -Pentyloxypropylamine, 3-hexyloxypropylamine, 3-heptyloxypropyl Amine,
3-octyloxypropylamine, 3-nonyloxypropylamine, 3-decyloxypropylamine, 3-didecyloxypropylamine, 3-
Undecyloxypropylamine, 3-dodecyloxypropylamine, 3-tridecyloxypropylamine, 3-tetradecyloxypropylamine, 3
-Pentadecyloxypropylamine, 3-hexadecyloxypropylamine, 3-heptadecyloxypropylamine, 3-octadecyloxypropylamine,
3-nanodecyloxypropylamine, 3-eicosyloxypropylamine, 3- (2-ethylhexyloxy) propylamine, ethylenediamine, diaminopropane, N-hexylpropanediamine, N-heptylpropanediamine, N-octylpropanediamine, Tetramethylenediamine,
Hexamethylenediamine, N-ethylmethylenediamine, N, N-diethylhexamethylenediamine, 2,
2,4-trimethylhexamethylenediamine and the like can be mentioned. Further, according to the present invention, as in claim 7, in any one of claims 1 to 4, the reversible thermosensitive recording layer contains an organic polymer binder.
Organic polymer binders used in the reversible thermosensitive recording layer include polyacrylic acid ester, polymethacrylic acid ester, polyurethane, polyvinyl acetate, polyvinyl chloride, polynorbornene,
One or a mixture of two or more selected from organic polymers such as polystyrene, polyester, polyvinyl butyral, and copolymers of two or more of these is used. Further, according to the present invention, as described in claim 8,
In any one of claims 1 to 4, the reversible thermosensitive recording layer contains a heat-fusible substance.
As the heat-fusible substance, arnava wax,
Paraffin wax, polyethylene wax, polypropylene wax, stearic acid amide,
Oleic acid amide, palmitic acid amide, lauric acid amide, N-laurylbenzamide, N-stearylbenzamide N, N-distearylbenzamide,
N, N-dilaurylbenzamide, N, N-distearyl terephthalic acid amide, ethylenebisstearic acid amide, ethylenebispalmitic acid amide, benzenesulfonamide, toluenesulfonamide, ethylbenzenesulfonamide, octylbenzenesulfonamide, laurylbenzenesulfonamide Examples thereof include amide and stearylbenzenesulfonamide. Further, according to the present invention, as described in claim 9, in any one of claims 1 to 4, the reversible thermosensitive recording layer contains at least one of an ultraviolet absorber and a white pigment. It is a thing. As the ultraviolet absorber, a generally used ultraviolet absorber can be used, and as the white pigment, calcium carbonate or the like which is usually used can be mentioned.

[0006]

It is considered as follows that the principle of repeating coloring / decoloring of the present invention and the improvement of erasability and the life characteristics, that is, the repetitive service life of the reversible thermosensitive recording sheet can be improved. When the leuco dye is heated with an acidic substance called a developer, both or the developers melt and react, the leuco dye is affected by the acidity of the developer, and the lactone ring in the molecule opens. What was initially colorless develops various colors such as black, red, and blue. On the contrary, when a basic substance is brought into contact with the colored leuco dye, the opened lactone ring is closed to return to a colorless state. Therefore, the lactone ring can be opened or closed by using a compound having both acidic and basic groups in the molecule, that is, a color-developing agent.
For example, when a complex composed of a carboxylic acid having a phenolic hydroxyl group and an aliphatic amine is mixed with a leuco dye, the acidity of the carboxylic acid acts when instantaneous heating is performed as in printing with a thermal printer. Color develops, and when heated slowly and slowly, the basicity of the amine works to erase the color. In principle, this process of coloring and erasing can be repeated, but in general, the repeated use causes loss of sharpness of the printed image, and sufficient erasing is not possible, so That improvement was strongly desired. The reversible thermosensitive recording sheet according to the present invention is the reversible thermosensitive recording sheet comprising a color-forming dye material and a color-developing and decoloring agent exhibiting a coloring and decoloring effect upon heating as described in claim 1. Heat-sensitive recording sheet comprises at least a supporting substrate, a reversible heat-sensitive recording layer, and a protective layer, and the protective layer contains a polyolefin resin having a heat-resistant cyclic structure as a main component,
Since the reversible thermosensitive recording layer is configured to contain a fatty acid amide having a low melting point, the protective layer can effectively suppress abrasion due to repeated use of coloring and decoloring, and thus the number of times of repeated use increases. In addition, the service life is remarkably improved, and the low melting point fatty acid amide added to the protective layer is dissolved at the interface with the reversible thermosensitive recording layer during decolorization.
Since the dye and the color-developing / reducing agent in the heat-sensitive recording layer are dissolved, the decoloring property at the interface is further improved. Further, in the reversible thermosensitive recording sheet of the present invention, as described in claim 2, the amount of the fatty acid amide added to the protective layer is 0.1% by weight with respect to the polyolefin resin having a cyclic structure. 5-
By adding 30%, the slipperiness of the protective layer is improved and the decoloring property at the interface of the reversible thermosensitive recording layer is further improved. Further, in the reversible thermosensitive recording sheet of the present invention, as described in claim 3, the fatty acid amide has a melting point of 100 ° C.
Since the following is used, the slipperiness of the protective layer is improved, and the dye and the color-developing / reducing agent are easily dissolved at the interface of the reversible thermosensitive recording layer to improve the decoloring property. Further, the reversible thermosensitive recording sheet of the present invention has a glass transition temperature of 140 ° C. as a main component of the protective layer as described in claim 4.
Since the polyolefin resin having the above cyclic structure is used, the reversible thermosensitive recording layer is protected by the heat-resistant and abrasion-resistant protective layer, and the life of repeated use is further extended. Further, in the reversible thermosensitive recording sheet of the present invention, as described in claim 5, since a leuco dye is used in the reversible thermosensitive recording layer, various colors such as black, red and blue can be developed. it can. Further, in the reversible thermosensitive recording sheet of the present invention, as described in claim 6, the developer / color-reducing agent used for the reversible thermosensitive recording layer, which exhibits coloring and decoloring actions, is
A carboxylic acid having a phenolic hydroxyl group and a complex synthesized from an aliphatic amine are used. For example, when instantaneous heating such as printing with a thermal printer is performed, the acidity of the above-mentioned carboxylic acid is increased. Reversible thermosensitive recording and reproduction in which various colors such as black, red, and blue are developed by acting on the leuco dye, and when heated gradually, the basicity of the amine acts on the leuco dye to erase the color. It can be done effectively. Further, in the reversible thermosensitive recording sheet of the present invention, since an organic polymer binder is used in the reversible thermosensitive recording layer as described in claim 7, a leuco dye and a color-developing / reducing agent contained in the reversible thermosensitive recording layer. And the like can be uniformly dispersed and held, and the durability of the reversible thermosensitive recording sheet can be improved. Further, in the reversible thermosensitive recording sheet of the present invention, as described in claim 8, since the reversible thermosensitive recording layer contains a heat-fusible substance, the coloring or decoloring reaction is accelerated. Further, in the reversible thermosensitive recording sheet of the present invention, as described in claim 9, the reversible thermosensitive recording layer contains at least one of an ultraviolet absorber and a white pigment. The layer can suppress the influence from ultraviolet rays.

[0007]

EXAMPLES The present invention will be described in more detail below with reference to examples. The technical scope of the present invention is not limited to the examples shown below. The reversible thermosensitive recording layer was prepared as follows. In addition,% described in the examples
All represent weight percentages. First, as a reversible thermosensitive recording layer (hereinafter referred to as a thermosensitive layer) A, the following (composition 1)
After applying the heat-sensitive layer material of No. 2 to a ball mill for 20 hours, the heat-sensitive layer A was obtained by coating the void-containing polyester film with a wire bar and drying at 60 ° C. for 30 minutes. Further, as the heat-sensitive layer B, the heat-sensitive layer material of the following (composition 2),
A heat sensitive layer B was prepared in the same manner as in the case of the heat sensitive layer A. As the heat-sensitive layer C, the heat-sensitive layer C having the following (composition 3) was prepared in the same manner as in the case of the heat-sensitive layer A. Also,
As the heat-sensitive layer D, the heat-sensitive layer D having the following (composition 4) was prepared in the same manner as in the case of the heat-sensitive layer A. (Composition 1) 2- (2-chloroanilino) -6-diethylaminofluorane ...... 4% 2,2-bis (4-hydroxyphenyl) ethanoic acid and tetradecylamine complex ...... 8% benzenesulfonamide ...... 5% Calcium carbonate: 10% Polyacrylic acid ester: 8% Methyl ethyl ketone: 30% Toluene: 35% (Composition 2) 3-Diethylamino-6-methyl-7-anilinofluorane: 5% Gallic acid and penta Decylamine complex: 10% Lauryl amide: 5% Polymethacrylic acid ester: 5% 2- (2'-Hydroxy-5'-tert-octylphenyl) benzotriazole: 5% Calcium carbonate: 15% Toluene 55% (composition 3) 3-diethylamino-6-methyl-7- (1,4-dimethylacetate Nilino) Fluoran: 5% 2,2-bis (4-hydroxyphenyl) acetic acid and octadecylamine complex: 15% Stearamide: 5% Polyvinyl acetate: 10% Ethyl acetate: 15% Toluene: 50% (composition 4) 1,3-diethyl-6-diethylaminofluorane ...... 7% 3,5-dihydroxybenzoic acid and 3-decyloxypropylamine complex ...... 10% ethylenebisstearic acid amide ...... 3% bis (5-benzoyl-4-hydroxy-2-methoxyphenyl) methane 5% calcium carbonate 15% polyvinyl butyral 10% ethyl acetate 30% methyl ethyl ketone 20% <Example 1> The above procedure On the heat-sensitive layer A prepared in 1., a protective layer coating liquid consisting of the following (composition 5) is applied with a wire bar. , And dried for 10 minutes at 100 ° C., to form a protective layer having a thickness of about 1 [mu] m. (Composition 5) Polyolefin resin (ZEONEX 480: manufactured by Nippon Zeon Co., Ltd.) ...... 9.5% Stearamide ...... 0.5% Toluene ...... 90.0% Reversible thermosensitive recording sheet prepared in this manner As a result of repeating printing and erasing of characters, the optical density when printing is 0.65 or more, the optical density when erasing is 0.07 or less, and the high-performance reversible property that can be used repeatedly 50 times or more. A heat-sensitive recording sheet was obtained.

Example 2 A coating solution for a protective layer comprising the following (composition 6) was applied onto the heat-sensitive layer B produced by the above procedure with a wire bar and dried at 100 ° C. for 10 minutes to give a thick film. A protective layer having a thickness of about 1 μm was formed. (Composition 6) Polyolefin resin (Arton I: manufactured by Nippon Synthetic Rubber Co., Ltd.) …… 8.0% Erucamide amide …… 2.0% Ethyl acetate …… 50.0% Toluene …… 40.0% The reversible thermosensitive recording sheet prepared as above was subjected to repeated printing and erasing of characters. As a result, the optical density during printing was 0.67 or more, and the optical density during erasing was 0.07 or less and the repeating characteristics were 50 or less. A high-performance reversible thermosensitive recording sheet that can be used more than once was obtained.

Example 3 On the heat-sensitive layer C produced by the above procedure, a protective layer coating solution comprising the following (composition 7) was applied with a wire bar and dried at 100 ° C. for 10 minutes to obtain a thick film. A protective layer having a thickness of about 1 μm was formed. (Composition 7) Polyolefin resin (Arton F: manufactured by Nippon Synthetic Rubber Co., Ltd.) …… 8.5% Oleic acid amide …… 1.5% Toluene …… 90.0% Reversible thermosensitive recording prepared in this manner As a result of repeatedly printing and erasing characters, the sheet has an optical density of 0.66 or more when printed, an optical density of 0.06 or less when erased, and a high-performance reversible property that can be used repeatedly 50 times or more. A heat-sensitive recording sheet was obtained.

<Examples 4 to 9> A toluene solution having a protective layer composition shown in Table 1 was coated on the heat-sensitive layer D produced by the above procedure with a wire bar and dried at 100 ° C for 10 minutes. A protective layer having a thickness of about 1 μm was formed. The solid content concentration of the protective layer coating liquid was adjusted to 10%, and toluene was used as the solvent. Table 1 shows the composition (% by weight) of the protective layer and the optical densities during printing and erasing.

[0011]

[Table 1]

The reversible thermosensitive recording sheet thus prepared was repeatedly printed with characters and was erased. As a result, the optical density during printing was 0.60 or more, and the optical density during erasing was 0.60. A high-performance reversible thermosensitive recording sheet having a repeating property of not more than 08 and capable of being used 50 times or more was obtained.

Comparative Example 1 On the heat-sensitive layer A produced by the above procedure, a protective layer coating solution comprising the following (composition 8) was applied with a wire bar and dried at 100 ° C. for 10 minutes. A protective layer having a thickness of about 1 μm was formed. (Composition 8) Polyolefin resin (Atone G: manufactured by Nippon Synthetic Rubber Co., Ltd.) …… 8.0% Methyl stearate …… 2.0% Toluene …… 90.0% Reversible feeling produced in this way As a result of repeated printing and erasing of characters, the thermal recording sheet had an optical density of 0.60 when printed, but the optical density when erasing was 0.17 and the erasability was a little poor. Over 40 times, the reversible thermosensitive recording sheet was abraded, resulting in poor erasability and repetitive durability.

Comparative Example 2 On the heat-sensitive layer B produced by the above procedure, a protective layer coating solution comprising the following (composition 9) was applied with a wire bar and dried at 100 ° C. for 10 minutes. A protective layer having a thickness of about 1 μm was formed. (Composition 9) Polyester resin (Polyester: manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) ... 8.5% Stearamide ...... 1.5% Toluene ...... 50.0% Methyl ethyl ketone ...... 40.0% The reversible thermosensitive recording sheet prepared by the above-mentioned method has a result that after printing and erasing characters repeatedly, the optical density at the time of printing is 0.65 and the optical density at the time of erasing is 0.07. However, when the number of times of repeated use exceeds 10, the reversible thermosensitive recording sheet is abraded, which is not practical.

Comparative Example 3 A coating solution for protective layer consisting of the following (composition 10) was coated on the heat-sensitive layer C produced by the above procedure with a wire bar and dried at 100 ° C. for 10 minutes. A protective layer having a thickness of about 1 μm was formed. (Composition 10) Polyolefin resin (ZEONEX 480: manufactured by Nippon Zeon Co., Ltd.) ... 6.5% Oleic acid amide ... 3.5% Toluene ... 90.0% Reversible thermosensitive recording sheet prepared in this manner As a result of repeating the printing and erasing of characters, -G has an optical density of 0.45 when printed, and an optical density of 0.05 when erasing, which is excellent in erasability, but the printing density is low. When it was used repeatedly for several times, the reversible thermosensitive recording sheet was abraded, which was not practical.

<Comparative Example 4> On the heat-sensitive layer D produced by the above procedure, the coating solution for protective layer having the following (composition 11) was applied to the wire.
It was applied with a bar and dried at 100 ° C. for 10 minutes to form a protective layer having a thickness of about 1 μm. (Composition 11) Polyolefin resin (Atone G: manufactured by Nippon Synthetic Rubber Co., Ltd.) ... 9.0% Bis-stearic acid amide ... 1.0% Toluene ... 90.0% Reversible thus prepared As a result of repeated printing and erasing of characters, the heat-sensitive recording sheet had an optical density of 0.58 when printed, but the optical density when erasing was 0.22, which was inferior in erasability. When it was used more than 30 times, the reversible thermosensitive recording sheet was abraded, resulting in poor erasability and durability after repeated use.

[0017]

As described above in detail, the protective layer containing, as a main component, a polyolefin resin having a cyclic structure and having a glass transition temperature of 140 ° C. or higher is provided on the heat-sensitive recording layer of the reversible heat-sensitive recording sheet of the present invention. In addition, a fatty acid amide having a melting point of 100 ° C. or lower was added to the above polyolefin resin in an amount of 0.1.
By adding 5 to 30% by weight, it is possible to provide a high performance rewritable reversible thermosensitive recording sheet having a high print density, a good erasability and a long repeated use life.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location B41M 5/18 111 (72) Inventor Soichi Hasegawa 3819 Noborito, Tama-ku, Kawasaki-shi, Kanagawa Prefecture Sliontech Co., Ltd. (72) Inventor Hiroshi Uchiyama 3819 Noborito, Tama-ku, Kawasaki-shi, Kanagawa Sliontech Co., Ltd. (72) Inventor Kazuyoshi Yatsuka 3819 Noborito, Tama-ku, Kawasaki-shi, Kanagawa (72) Inventor Sato Akiko 3819 Noborito, Tama-ku, Kawasaki City, Kanagawa Prefecture Sliontech Co., Ltd.

Claims (9)

[Claims] 1. A reversible heat-sensitive recording sheet using a color-forming dye material and a color-developing and decoloring agent exhibiting a color-developing and decoloring effect when heated, wherein the reversible heat-sensitive recording sheet comprises at least a support substrate and a reversible material. A reversible thermosensitive recording sheet comprising a thermosensitive recording layer and a protective layer, the protective layer comprising a polyolefin resin having a cyclic structure as a main component and a fatty acid amide. 2. The protective layer according to claim 1, wherein the fatty acid amide is added in an amount of 0.5 to 30% by weight based on the weight of the polyolefin resin having a cyclic structure. Reversible thermosensitive recording sheet. 3. A reversible thermosensitive recording sheet according to claim 1, wherein the fatty acid amide has a melting point of 100 ° C. or lower. 4. The glass transition temperature of the polyolefin resin having a cyclic structure according to claim 1 or 2,
A reversible thermosensitive recording sheet having a temperature of 0 ° C. or higher. 5. A reversible thermosensitive recording sheet according to any one of claims 1 to 4, wherein the color-forming dye material used in the reversible thermosensitive recording layer comprises a leuco dye. 6. The color-developing agent used in the reversible thermosensitive recording layer according to claim 1, which is a complex composed of a carboxylic acid having a phenolic hydroxyl group and an aliphatic amine. A reversible thermosensitive recording sheet. 7. A reversible thermosensitive recording sheet according to any one of claims 1 to 4, wherein the reversible thermosensitive recording layer contains an organic polymer binder. 8. A reversible thermosensitive recording sheet according to any one of claims 1 to 4, wherein the reversible thermosensitive recording layer contains a heat-fusible substance. 9. The reversible thermosensitive recording layer according to claim 1, wherein the reversible thermosensitive recording layer contains at least one of an ultraviolet absorber and a white pigment. Thermal recording sheet.