JPH07237357A - Thermal recording material - Google Patents

Abstract

PURPOSE:To obtain high sensitivity and storage stability, especially, the storage stability of a background in a thermal recording material having a thermal color forming layer containing specific fluorane as a leuco dye, specific diphenylmethane as an acidic substance, at least one kind of petroleum wax selected from specific waxes and methylolated fatty acid amide. CONSTITUTION:In a thermal recording material wherein a thermal color forming layer based on a colorless or light-colored electron donating leuco dye, an electron acceptive org. acidic substance reacting with the leuco dye under heating to allow the leuco dye to form a color and an adhesive is provided on one surface of a support, as the leuco dye, 3-di(n-butylamino)-7-(o-chloroanilino) fluorane is added and, as the acidic substance, 4,4'-bis(p- toluenesulfonylaminocarbonylamino)diphenylmethane is added and at least one kind of petroleum wax selected from paraffin wax, polyolefin wax and microcrystalline wax and methylolated fatty acid amide are added to the thermal color forming layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermosensitive recording medium having excellent sensitivity and storage stability, and in particular, tickets such as boarding tickets, pass tickets, coupons, gift cards, prepaid cards and the like. The present invention relates to a heat-sensitive recording paper suitable for use in various types and a heat-sensitive magnetic recording body capable of thermally printing a part of magnetic recording information.

[0002]

2. Description of the Related Art A thermosensitive recording medium is generally composed of paper, synthetic paper, plastic film or the like on one side of which a colorless or pale color-forming substance such as an electron-donating leuco dye and an electron-accepting phenolic substance are formed. A thermosensitive color-developing layer containing an organic acid developer such as a compound and an adhesive as main components, and a color-recorded image is obtained by reacting these color-forming dyes and the developer with thermal energy. be able to. Such a thermal recording medium has advantages such as a compact recording apparatus, low cost, and easy maintenance, and is not only used as a recording medium for a facsimile, an automatic ticket vending machine, or a scientific measuring instrument, POS label, C
It is widely used as an output medium for various printers and plotters for AD and CRT medical images. In addition, combining a magnetic recording method with a large information recording capacity and a thermal recording method,
There is used a thermosensitive magnetic recording medium capable of reading and writing information and visually readable. For example, it is used in a wide range of applications such as prepaid cards such as telephone cards and orange cards, boarding tickets, pass tickets, commuter tickets, and coupon tickets.

The heat-sensitive recording material and heat-sensitive magnetic recording material used for such various purposes have not only heat-sensitive recording characteristics, but also images such as water resistance, chemical resistance, oil resistance and plasticizer resistance. Storage stability is required. Therefore, attempts have been made to improve the storage stability by providing a protective layer having a strong barrier property on the surface of the thermosensitive recording medium. However, long-term storage stability was not yet sufficient. This is because the storage stability of the thermosensitive coloring layer itself is insufficient, and in order to improve this, an aromatic isocyanate compound and an imino compound are used as the coloring components (JP-A-58-38733 and JP-A-58-38733). -149388, JP-A-59-115888, JP-A-4-
164686, JP 4-284288, JP 4-305489
Or a salicylic acid derivative having high storage stability or a metal salt thereof is used as an organic acid developer (JP-A-4-65292, JP-A-4-19880, JP-A4-211).
No. 989) is proposed. However, there is no material having sufficient sensitivity that can enhance the storage stability of the thermosensitive coloring layer.

[0004]

DISCLOSURE OF THE INVENTION The present invention is directed to a thermosensitive recording material having a thermosensitive coloring layer provided on at least one surface of a support, and to the surface of the support on which the thermosensitive coloring layer is not provided, or to the support and thermosensitive layer. It is intended to obtain a thermosensitive magnetic recording medium having a high sensitivity and storage stability, in particular, high background storage stability, in a thermosensitive magnetic recording medium having a magnetic recording layer provided between color forming layers.

[0005]

The present invention relates to an electron-accepting organic acidic substance which reacts with a colorless or light-colored electron-donating leuco dye on at least one surface of a support to cause the leuco dye to develop color when heated. A heat-sensitive recording material provided with a color-developing heat-sensitive layer containing an adhesive as a main component, containing 3-di (n-butylamino) -7- (o-chloroanilino) fluorane as the leuco dye and using the acidic substance as the acidic substance. 4,4'-bis (p-toluenesulfonylaminocarbonylamino) diphenylmethane (hereinafter referred to as the present color developer) is contained, and paraffin wax is contained in the thermosensitive coloring layer.
A heat-sensitive recording material comprising at least one petroleum wax selected from polyolefin wax and microcrystalline wax and a methylolated fatty acid amide. The present invention also provides a magnetic recording layer containing magnetic powder and an adhesive as main components on the surface of the support on which the thermosensitive coloring layer is not provided or between the support and the thermosensitive coloring layer. Present in a thermosensitive magnetic recording medium.

By using this developer as the developer of the thermosensitive coloring layer, a thermosensitive recording material and a thermosensitive magnetic recording material having high storage stability can be obtained, but sufficient sensitivity cannot be obtained. It was It was found that high sensitivity can be obtained by combining this color developer, petroleum wax, and methylolated fatty acid amide, but regarding storage stability,
Although the printed area was excellent, the storage stability of the background, especially the resistance to temperature and humidity, and the resistance to plasticizer were insufficient. Therefore, as a result of further research on the storage stability of the background, the inclusion of 3-di (n-butylamino) -7- (o-chloroanilino) fluorane as a leuco dye has excellent sensitivity and storage stability. It has been found that a body and a thermosensitive magnetic recording body can be obtained.

The support used in the present invention includes high-quality paper, medium-quality paper, recycled paper, coated paper, as well as polyolefin resin and white inorganic pigment that are heat-kneaded, extruded from a die, and stretched in the longitudinal direction. Synthetic paper produced by laminating 1-2 layers of a film consisting of a polyolefin resin and a white inorganic pigment on both sides per one side, and making it translucent or opaque by stretching in the transverse direction, and polyethylene, polypropylene, ethylene-vinyl acetate A film obtained by biaxially stretching a thermoplastic resin such as a copolymer resin, polyvinyl chloride, polystyrene, or polyester alone or a mixture thereof, and a thermoplastic resin and a white inorganic pigment, which are kneaded by heating and biaxially. Stretched opaque or translucent films can be used.

The thermosensitive coloring layer of the present invention contains, as main components, a colorless or light-colored electron-donating leuco dye, an electron-accepting organic acidic substance that causes the leuco dye to develop a color upon heating, and an adhesive, and if necessary. It can be provided by applying a thermosensitive coloring layer coating material to which a crosslinking agent, a pigment and a heat-fusible substance are added. The coating amount of the thermosensitive coloring layer is
Generally, 3 to 10 g / m ² is preferable in terms of color density. As a coating method, an air knife method, a Meyer bar method, a blade method, a reverse roll method, a slit die method, or the like which has been conventionally used by those skilled in the art can be used. Further, by smoothing the surface of the thermosensitive coloring layer with a super calender, a gloss calender, a machine calender, etc., it is possible to enhance the recording density, the sensitivity and the uniformity of the image.

The colorless or light-colored electron-donating leuco dye used in the present invention is 3-di (n-butylamino) -7 in order to improve the storage stability of the background such as resistance to temperature and humidity and resistance to plasticizer. It contains-(o-chloroanilino) fluorane. The leuco dye of the present invention is polyvinyl alcohol,
It is mixed with a water-soluble resin such as methylcellulose or hydroxypropylated starch and pulverized with a disperser such as a ball mill, attritor, sand grinder, dynomill or ultraviscomill to an average particle diameter of 3 μm or less, preferably 1 μm or less, Distributed. The leuco dye dispersion of the present invention can be added in a proportion of 5 to 30% with respect to the solid content of the thermosensitive coloring layer.

The color developer used in the present invention is 4,4'-bis (p-toluenesulfonylaminocarbonylamino) in order to improve storage stability such as oil resistance, plasticizer resistance and water resistance of recorded images. ) Contains diphenylmethane.
However, a conventionally known developer composed of an electron-accepting organic acidic substance and 4,4′-bis (p-toluenesulfonylaminocarbonylamino) diphenylmethane can be used in combination within a range that does not impair the desired effect. Such an electron-accepting organic acidic substance is at room temperature or higher, preferably 70
It is liquefied or vaporized at a temperature of not less than ° C and reacts with the color forming dye to form a color.

Examples of the electron-accepting organic acidic substance include 4,4'-isopropylidene diphenol (bisphenol A), 4,4'-isopropylidene bis (2-chlorophenol) and 4,4'-isopropylidene bis. (2
-Methylphenol), 4,4'-isopropylidenebis (2,6-tert-butylphenol), 4,4 '
-Sec-butylidene diphenol, 4,4'-cyclohexylidene diphenol, 4-tert-butylphenol, 4-phenylphenol, 4-hydroxydiphenoxide, naphthol, β-naphthol, methyl-4
-Hydroxybenzoate, 4-hydroxy-acetophenone, anilide salicylate, novolac type phenol, halogenated novolac type phenol resin, 4,4 '
-Thiobis (3-methyl-6-tert-butylphenol), propyl P-hydroxybenzoate, isopropyl P-hydroxybenzoate, butyl P-hydroxybenzoate, benzyl P-hydroxybenzoate, methylbenzyl P-hydroxybenzoate, Aliphatic carboxylic acids such as oxalic acid, maleic acid, tartaric acid, citric acid, succinic acid, stearic acid, benzoic acid, p-tert-butylbenzoic acid, phthalic acid, gallic acid, salicylic acid, 3-isopropylsalicylic acid, 3,5 -Di-α-methylbenzyl salicylic acid, bis (4-hydroxyphenyl) sulfide,
1,7-di (4-hydroxyphenylthio) -3,5-
Dioxaheptane, p-nitrobenzoic acid, salts of these organic developers with polyvalent metals such as zinc, magnesium, aluminum, calcium, titanium, manganese, tin and nickel,

4,4'-dihydroxydiphenyl sulfone, 2,4'-dihydroxydiphenyl sulfone, 3,
3'-dihydroxydiphenyl sulfone, 3,3'-diamino-4,4'-dihydroxydiphenyl sulfone,
3,3'-diallyl-4,4'-dihydroxydiphenyl sulfone, 3,3'-dichloro-4,4'-dihydroxydiphenyl sulfone, 4-hydroxy-diphenyl sulfone, 4-hydroxy-4'-isopropyldiphenyl sulfone, 4-hydroxy-4 'isopropyloxydiphenyl sulfone, 4-hydroxy-4'-benzyloxydiphenyl sulfone, 2,4-dihydroxydiphenyl sulfone, 2,4'-dihydroxy-4'-methyldiphenyl sulfone, 3,4-dihydroxy Phenyl-p-trisulfone, N- (o-toluoyl) -p-
It is composed of at least one member selected from toluenesulfoamide, N- (p-toluenesulfonyl) -N′-phenylurea and the like.

The developer of the present invention is mixed with a water-soluble resin appropriately selected from those used for dispersing the leuco dye,
The average particle size is 3 μm or less, preferably 2 μm, using a disperser appropriately selected from the dispersers used for dispersing the leuco dye.
It is pulverized and dispersed to the following particle size. The electron-accepting acidic substance is usually used in a proportion of 1 to 5 parts by weight, preferably 1.5 to 3 parts by weight, based on 1 part by weight of the color forming dye.

The petroleum waxes used in the present invention are paraffin wax, polyolefin wax, microcrystalline wax, etc., such as paraffin wax having a melting point of 42 to 73 ° C. and microcrystalline wax having a melting point of 50 to 120 ° C. Examples of the wax include polyolefin waxes such as polyethylene wax and polypropylene wax. This polyolefin wax usually has a molecular weight of about 1,000 to 10,000, that is, is generally known as a polyolefin wax, and these polyolefin waxes are usually obtained by a high pressure and low pressure polymerization method or by thermal decomposition of a high molecular weight polyolefin. . In order to make it easier to emulsify, these petroleum waxes are oxidized to give hydroxyl groups, ester groups, carboxyl groups, aldehyde groups,
The thing which introduce | transduced the polar group, such as a peroxide group, can also be used. Further, in order to lower the softening point of waxes and improve workability, these waxes may be used in combination. Further, these petroleum waxes preferably have a melting point of room temperature or higher, preferably 40 ° C. or higher.

The petroleum wax is blended in the thermosensitive coloring layer as dispersed particles. The petroleum wax is dispersed into particles as small as possible by a pulverizer such as a ball mill, specifically, a particle diameter of several μm or less. It is desirable to grind until it becomes. The petroleum wax may be dispersed and used as described above, or may be added in the form of emulsion using an emulsifier. Further, a surfactant such as a dispersant or an antifoaming agent can be used as a grinding aid, if necessary, a filler such as talc or clay as a whitening agent, a powdery starch as an anti-tacking agent, an improvement in coating property. If necessary, a surfactant or the like can also be used.

The methylolated fatty acid amide used in the present invention is a waxy substance having a high melting point in which formaldehyde is added to the fatty acid amide and is represented by the general formula RCONHCH ₂ OH (R means a linear aliphatic hydrocarbon, 12 carbons
The above is desirable). Methylol stearamide that is commonly used as a methylolated fatty acid amide is
It is usually a mixture of C18 and C16 saturated hydrocarbons in a ratio of approximately 7: 3. In the present invention, it does not matter particularly if the carbon number is within the above-mentioned numerical value.

The blending ratio is in the range of 1 to 2 parts by weight of petroleum wax relative to 1 part by weight of methylolated fatty acid amide. The total blending amount of methylolated fatty acid amide and petroleum wax is based on the total solid content of the thermosensitive coloring layer. Good results were obtained when 5 to 15 parts by weight were compounded. At higher compounding amounts,
Greater adherence of lees to the thermal head during printing. Further, if the blending amount is less than this, the sensitizing effect is poor.

In the present invention, other materials constituting the thermosensitive coloring layer include adhesive resins, inorganic or organic pigments, waxes, metal soaps, and auxiliary additives conventionally used in thermosensitive recording media, such as dispersants. , Surface-active agents, antioxidants, UV inhibitors, coloring dyes and coloring pigments.

The adhesive resin can be combined with a generally known adhesive resin. Examples thereof include polyvinyl alcohol, carboxy group-modified polyvinyl alcohol, acetoacetyl group-modified polyvinyl alcohol, cationic group-modified polyvinyl alcohol, sulfone group-modified polyvinyl alcohol, silica-modified polyvinyl alcohol, starch and its derivatives, gum arabic, gelatin, casein, Chitosan, methyl cellulose, hydroxyethyl cellulose, hydroxymethyl cellulose, polyvinylpyrrolidone, polyacrylic acid salt, polyacrylic amide, styrene-maleic anhydride copolymer,
Methyl vinyl ether-maleic anhydride copolymer, water-soluble resin such as isopropylene-maleic anhydride copolymer,
Water-dispersible resins such as styrene-butadiene latex, vinyl acetate-acrylic acid ester copolymer emulsion, polyurethane emulsion, polyvinyl chloride emulsion, polyvinylidene chloride emulsion, methacrylic acid ester copolymer emulsion and acrylic acid ester copolymer emulsion Can be used.

In order to strengthen the water resistance of the coating film, a water-soluble and / or water-dispersible resin adhesive containing a reactive group such as an acetoacetyl group, a carboxyl group or an amide group. And a cross-linking agent are preferably used in combination. As the cross-linking agent, glyoxal, glutaraldehyde, polyhydric aldehyde compounds such as dialdehyde starch, polyamine compounds such as polyethyleneimine, epoxy compounds, polyamide resins, diglycidyl compounds such as glycerin diglycidyl ether,
A dimethylolurea compound, an inorganic compound such as ammonium persulfate, ferric chloride, magnesium chloride, or the like, boric acid, or borax can be used.

Examples of organic or inorganic pigments include clay, calcined clay, calcium carbonate, magnesium carbonate,
Inorganic fine powder such as talc, silica, diatomaceous earth, synthetic aluminum silicate, zinc oxide, titanium oxide, aluminum hydroxide, barium sulfate, surface-treated calcium carbonate and silica, and urea-formalin resin, styrene / methacryl Examples thereof include fine powders of organic resins such as acid copolymers and polystyrene resins.

Examples of auxiliary additives conventionally used in thermal recording media include di-p-methylbenzyl oxalate, di-p-chlorobenzyl oxalate, dimethyl terephthalate, dibutyl terephthalate and diterephthalate. Benzyl ester, isophthalic acid dibutyl ester, 1-hydroxynaphthoic acid phenyl ester,
1,2-di (3-methylphenoxy) ethane, 1,2-
Diphenoxyethane, 1-phenoxy-2- (4-methylphenoxy) ethane, diphenyl carbonate, diphenyl sulfone, p-benzylbiphenyl, 2,2′-methylenebis (4-methyl-6-t-butylphenol), 4,
4'-butylidene bis (6-t-butyl-3-methylphenol), 1,1,3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane, 2,2 '
-Hindered substances such as methylenebis (4-ethyl-6-t-butylphenol), 2,4-di-t-butyl-3-methylphenol, 4,4'-thiobis (3-methyl-6-t-butylphenol) Phenols, 2- (2 '
-Hydroxy-5'-methylphenyl) -benzotriazole, 2-hydroxy-4-benzyloxybenzophenone and the like can be mentioned.

Examples of the metal soap include higher fatty acid polyvalent metal salts, that is, zinc stearate, aluminum stearate, calcium stearate, zinc oleate and the like. In the heat-sensitive recording material and the heat-sensitive magnetic recording material of the present invention, one or more overcoat layers may be provided on the heat-sensitive coloring layer, if desired. The overcoat layer has a coating amount after drying of a coating material containing an ultraviolet curable resin, an electron beam curable resin or a solvent-soluble, water-soluble or water-dispersible adhesive resin, a crosslinking agent, a pigment and, if necessary, a lubricant. 0.5-7g
/ M ^2, preferably can be obtained by ² coating 1 to 4 g / m.

The resin / pigment ratio of the overcoat layer is 80 /
The range of 20 to 20/80 is good, and if the compounding ratio of the resin exceeds 80%, sticking may occur during printing. The adhesive resin, cross-linking agent, and pigment used in the overcoat layer can be the same as those used in the thermosensitive coloring layer, and the coating method can be the method used for coating the thermosensitive coloring layer. In the present invention, a magnetic recording layer can be provided on the surface of the support on which the thermosensitive coloring layer is not provided or between the support and the thermosensitive coloring layer.

When the magnetic recording layer is provided between the support and the thermosensitive coloring layer, it is naturally provided before coating the thermosensitive coloring layer even when it is provided on the surface of the support on which the thermosensitive coloring layer is not provided. It is more preferable that the whiteness of the thermosensitive coloring layer is less deteriorated. The magnetic recording layer contains magnetic powder and an adhesive as main components. As the magnetic powder, γ-iron oxide, cobalt-modified γ-iron oxide, barium ferrite, chrome oxide or the like can be used. The magnetic powder is preferably blended in an amount of 50 to 90% by weight based on the solid content of the magnetic recording layer. As the adhesive, a water-resistant resin and / or a water-dispersible resin used in the thermosensitive coloring layer may be mixed with a water-proofing agent to impart water resistance, or a polyurethane resin, a vinyl chloride resin, or a vinyl chloride-vinyl acetate Water resistance can be imparted by using an organic solvent-soluble resin such as a polymer resin or a polyester resin. As the organic solvent, a solvent such as toluene, xylene, ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone or the like can be used.

The magnetic recording layer of the present invention is coated on a support by a roll coater, bar coater, air knife coater, slit die coater or the like so that the coating amount after drying is 25 to 35 g / m ^2. . After coating the magnetic recording layer,
Alternatively, it is desirable to carry out smoothing treatment with a super calender, gloss calender, machine calender or the like after coating the thermosensitive coloring layer.

[0027]

The present invention will be described in more detail with reference to the following examples, but the scope of the present invention is not limited to these examples. In each example, “part” means “part by weight”. Example 1 Canadian Standard Freeness (CFS) 480
To 100 parts of hardwood bleached kraft pulp beaten to ml,
A papermaking raw material prepared by adding 10 parts of talc, 0.3 part of a petroleum resin-based sizing agent, and 0.5 part of a sulfuric acid band, and having a basis weight of 15
4 g / m ² paper was made. A 2% solution of polyvinyl alcohol was applied to this base paper with a size press. The coating amount was 0.8 g / m ² . Smoothing treatment was carried out with a machine calender so that the Oken type smoothness (J. TAPPI No. 5) was 50 seconds to obtain a heat-sensitive recording support. The thermosensitive coloring layer coating shown below was applied on one side of this support so that the coating amount after drying was 6.0 g / m ^2, and then supercalendering was applied to the surface of the thermosensitive coloring layer. Smoothness is 8
A heat sensitive recording material of 00 seconds was obtained.

(1) Preparation of coating for thermosensitive coloring layer Liquid A (thermosensitive coloring dye dispersion) 3-di (n-butylamino) -7- (o-chloroanilino) fluorane 40 parts Polyvinyl alcohol 10% aqueous solution 40 parts (Brand name: L3266, manufactured by Nippon Gohsei Co., Ltd.) Water 20 parts Liquid B (developing agent dispersion) 4,4′-bis (p-toluenesulfonylaminocarbonylamino) diphenylmethane 40 parts Polyvinyl alcohol 10% aqueous solution 40 parts (Product Name: L3266, manufactured by Nippon Gosei Kagaku Co., Ltd. Water 20 parts C liquid (thermofusible substance dispersion liquid) Oxalic acid-di-p-methylbenzyl ester 40 parts Polyvinyl alcohol 10% aqueous solution 40 parts (Brand name: L3266, Nihon Gosei) Chemical 40) Water 40 parts A liquid, B liquid, C liquid separately for each Ultra Visco Mill (IMEX sand grinder ) In a distributed and pulverized, the average particle size was adjusted to 1μm or less.

Liquid D (pigment dispersion liquid) Clay 60 parts (trade name: HG Clay, manufactured by Huber) Polycarboxylic acid type polymer activator 0.1 part (trade name: Caribbon L400, manufactured by Sanyo Kasei) Water 40 parts This liquid D was dispersed and pulverized with an Ultra Viscomill and adjusted to have an average particle size of 2.5 μm. Liquid A 25 parts, B
Liquid 40 parts, liquid C 50 parts, liquid D 40 parts, zinc stearate 30% dispersion liquid 10 parts, 20% vinyl acetate grafted starch (Petrocoat C8, manufactured by Nitto Kagaku) as an adhesive 25
Parts, acrylic emulsion (Aron A-104, solid content 40%, manufactured by Toagosei Kagaku) 15 parts, methylol stearic acid amide as methylol fatty acid amide, and paraffin wax as petroleum wax at 5 parts by dry weight respectively. And used as a thermosensitive coloring layer paint.

Example 2 A thermosensitive recording medium was obtained in the same manner as in Example 1 except that the paraffin wax used in Example 1 was changed to polyethylene wax. Example 3 A thermosensitive recording medium was obtained in the same manner as in Example 1 except that the paraffin wax used in Example 1 was changed to microcrystalline wax.

Example 4 On one surface of the support of Example 1, the following magnetic recording layer coating material was applied such that the coating amount after drying was 30 g / m ² . (1) ChoNaru barium ferrite magnetic recording layer coating material (BaO-6Fe ₂ O ₃ coercivity: 3000 Oe, an average particle diameter of 0.6 .mu.m) 100 parts vinyl chloride - vinyl acetate copolymer 15 parts Polyurethane 25 parts lecithin 2 parts Toluene / MEK (1: 1) 330 parts On this surface of the support on which the magnetic recording layer is not provided,
The thermosensitive coloring layer of Example 1 was provided to obtain a thermosensitive magnetic recording material.

[0032]

Comparative Example 1 A thermosensitive recording medium was obtained in the same manner as in Example 1 except that the solution A in Example 1 was changed to the following solution E. Liquid E (thermosensitive dye dispersion) 3-pyrrolidino-6-methyl-7-anilinofluorane 40 parts Polyvinyl alcohol 10% aqueous solution 40 parts (trade name: L3266 manufactured by Nippon Synthetic Chemical Industry) Water 20 parts This E liquid It was dispersed and pulverized with an Ultra Viscomill and adjusted so that the average particle diameter was 1 μm or less.

Comparative Example 2 A thermosensitive recording medium was obtained in the same manner as in Example 1 except that the solution A in Example 1 was changed to the solution F shown below. Liquid F (thermosensitive dye dispersion) 3- (N-ethyl-N-isoamylamino) -6-methyl-7-anilinofluorane 40 parts Polyvinyl alcohol 10% aqueous solution 40 parts (trade name: L3266 Nippon Synthetic Chemical Industry) Water) 20 parts This F liquid was dispersed and pulverized with an Ultra Viscomill, and adjusted so that the average particle size was 1 μm or less.

Comparative Example 3 A thermosensitive recording medium was obtained in the same manner as in Example 1 except that the solution A in Example 1 was changed to the solution G shown below. Liquid G (thermosensitive dye dispersion liquid) 3-di (n-butylamino) -6-methyl-7-anilinofluorane 40 parts Polyvinyl alcohol 10% aqueous solution 40 parts (trade name: L3266 manufactured by Nippon Synthetic Chemical Industry) Water 20 parts This G liquid was dispersed and pulverized with an Ultra Viscomill, and adjusted so that the average particle diameter was 1 μm or less.

Comparative Example 4 A thermosensitive recording medium was obtained in the same manner as in Example 1 except that the paraffin wax in Example 1 was removed and the same amount of methylol stearamide was added. Comparative Example 5 A thermosensitive recording medium was obtained in the same manner as in Example 1 except that the methylolated stearamide in Example 1 was removed and the same amount of paraffin wax was added.

Comparative Example 6 A thermosensitive recording medium was obtained in the same manner as in Example 1 except that the solution B in Example 1 was changed to the solution H shown below. H liquid (developer dispersion liquid) 4,4′-isopropylidenediphenol 40 parts Polyvinyl alcohol 10% aqueous solution 40 parts (Product name: L3266 manufactured by Nippon Synthetic Chemical Industry) Water 20 parts This H liquid is dispersed with Ultra Viscomil, It was crushed and adjusted so that the average particle diameter was 1 μm or less.

Solid black recording was carried out by a card printer tester having a thick film type thermal head on each of the thermosensitive recording bodies and the thermosensitive magnetic recording bodies obtained in Examples 1 to 4 and Comparative Examples 1 to 6. The color density and the density of the white paper portion thus obtained were measured with a Macbeth reflection densitometer (RD-914). A solid black record and a white paper test piece were prepared, and a storage stability test such as water resistance, plasticizer resistance, oil resistance, temperature and humidity resistance, and chemical resistance was performed as shown below.

Water resistance test method The test piece was immersed in water at 20 ° C. for 7 hours and then dried,
The density of the printed area and the blank area is measured and evaluated. -Plasticizer resistance test method Under the conditions of 20 ° C and 65% RH, 200 g of plastic eraser (Dragonfly Mono PE) is attached to the recording surface side of the test piece.
After pressure bonding at a pressure of cm ² for 48 hours, the densities of the recording part and the blank part are measured and evaluated.・ Oil resistance test method Under the conditions of 20 ° C. and 65% RH, apply cotton seed oil (reagent) to the recording surface side of the test piece, wipe it off after 10 seconds, leave it for 24 hours, and measure the density of the recording area and the blank area. ,evaluate.

Test method for temperature and humidity resistance After leaving the test piece for 24 hours in an atmosphere of 40 ° C. and 90% RH,
The density of the printed area and the blank area is measured and evaluated.・ Chemical resistance test method 50% on the recording surface side of the test piece under the condition of 20 ° C. and 65% RH.
% Ethanol solution is dropped, and after 10 seconds, it is wiped off, and the densities of the recording part and the blank part are measured and evaluated. -Evaluation criteria As a result of the storage stability test, from the decrease in the density of the solid black recording area, ◯: 0.2 or less, Δ: 0.2 to 0.5, ×: 0.5
It was evaluated as above. From the density after the test, the color of the white paper part is ◯: 0.2 or less, Δ: 0.2 to 0.3, ×: 0.3
It was evaluated as above. The test results of each test are shown in Table 1.

[0040]

[Table 1]

[0041]

According to the present invention, high sensitivity and storage stability,
It was possible to provide a heat-sensitive recording material and a heat-sensitive magnetic recording material having particularly high background storage stability.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location B42D 15/10 551 Z B41M 5/18 101 C 108

Claims (2)

[Claims] 1. A main component comprising, on at least one surface of a support, a colorless or light-colored electron-donating leuco dye, an electron-accepting organic acidic substance that reacts under heating to develop a color of the leuco dye, and an adhesive. A thermosensitive recording medium having a thermosensitive coloring layer contains 3-di (n-butylamino) -7- (o-chloroanilino) fluorane as the leuco dye and 4,4'-bis (p -Toluenesulfonylaminocarbonylamino) diphenylmethane, wherein the thermosensitive coloring layer contains at least one petroleum wax selected from paraffin wax, polyolefin wax and microcrystalline wax and a methylolated fatty acid amide. Record body. 2. A magnetic recording layer containing magnetic powder and an adhesive as main components is provided on the surface of the support on which the thermosensitive coloring layer is not provided or between the support and the thermosensitive coloring layer. The thermosensitive recording medium according to claim 1, wherein