JP3205917B2 - Thermal recording material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-sensitive recording material, and more particularly to an improvement in a heat-sensitive recording material provided with a heat-sensitive recording layer colored by heat on a support.

[0002]

2. Description of the Related Art A heat-sensitive recording material having a heat-sensitive recording layer mainly composed of a leuco dye and a compound composed of an acidic substance capable of coloring the leuco dye by heat on a support such as paper or film is known as a heat head. -A colored image can be obtained by heating with a hot pen, laser light, strobe lamp, etc. Compared with other recording materials, this type of recording material has advantages such as complicated operations and devices are unnecessary at the time of recording, recording can be performed in a short time, noise generation and environmental pollution are reduced, and costs are low. Therefore, it is used as a versatile recording material such as copying books and documents, facsimile machines, ticket vending machines, electronic calculators, recorders and labels. A thermochromic composition used for such a thermosensitive recording material is composed of a general color former and a developer which causes the color former to develop color when heated, and has a lactone, lactam or spiropyran ring as the color former. A colorless or light-colored leuco dye and an organic acid and a phenolic compound have been conventionally used as a developer. The recording material obtained by combining the color former and the developer has the advantages that the color tone of the obtained image is particularly clear, the whiteness of the background is high, and the weather resistance of the image is excellent. Have been.

However, this type of heat-sensitive recording material has a D
There are drawbacks in that the image disappears when it comes into contact with a plasticizer such as OA or DOP, a white portion is colored by a solvent such as ethanol or ethyl acetate, and image reliability is poor. To improve these, it has been proposed to provide a protective layer on the thermosensitive coloring layer (JP-A-54-128347, JP-A-54-3594). For such a protective layer, it has been proposed that a water-soluble resin, for example, polyvinyl alcohol and a modified product thereof, and starch and a modified product thereof, are effective for enhancing oil resistance and plasticizer resistance (Japanese Patent Application Laid-Open No. H11-163873). 56-1
26193, JP-A-56-13993), and water-soluble resins are mainly used. However, a protective layer using such a water-soluble resin often lacks water resistance, and a method of curing the protective layer by using a crosslinking agent together (Japanese Patent Laid-Open No.
-188392) is often used. Many cross-linking agents have been proposed, but each has unsatisfactory problems. For example, it has been proposed to use a glycidyl-based cross-linking agent (Japanese Patent Application Laid-Open No. 57-188392) to provide excellent oil resistance and matching resistance (adhesion of heat head debris). Not enough.

A protective layer using a glyoxydyl crosslinker as an amino compound (JP-A-64-61287) has a water-resistant property.
Although it has excellent chemical resistance, it generates formalin and is unsuitable for use on food labels and the like. Further, the crosslinking agent containing an amino group causes yellowing of the protective layer, the aziridine-based crosslinking agent is unstable in an aqueous solution, and the glycidylamine-based crosslinking agent has problems such as generation of formalin. . Use of an epoxy-based crosslinking agent (JP-A-49-3)
No. 6343, JP-A-60-68990), but those having an aromatic ring are inferior in plasticizer resistance and are polyether-type epoxy crosslinking agents (JP-A-49-363).
No. 43) has a molecular weight of 500 or less, and has heat resistance,
Problems such as background coloration remain. Examples of the protective layer include those formed from a casein and a crosslinking agent having a methylol group (Japanese Patent Application Laid-Open No. 60-193693), a copolymer obtained from an acrylamide-acrylonitrile-carboxyl group-containing vinyl monomer, and an epoxy group. Formed from a crosslinkable emulsion having the following formula (JP-A-61-374).
No. 67), a product obtained from polyvinyl alcohol and a 2,4-dihydroxy-1,4-dioxane derivative (JP-A-62-44494), and a product using bis (4-glycidyloxyphenyl) sulfone as a crosslinking agent (Japanese Unexamined Patent Publication No. 62-270382) has been proposed, but there is a drawback that when the water resistance is to be improved, the pot life of the coating liquid is shortened.

[0005]

DISCLOSURE OF THE INVENTION The present invention overcomes the above-mentioned problems, and is excellent in plasticizer resistance, solvent resistance, water resistance and heat resistance, hardly develops background color, and has a long pot life. An object of the present invention is to provide a heat-sensitive recording material using the same.

[0006]

According to the present invention, the following heat-sensitive recording material is provided. (1) providing a heat-sensitive recording layer colored by heat on a support,
Further, in the heat-sensitive recording material having a protective layer obtained by using a resin and a cross-linking agent as main components on the heat-sensitive recording layer, the cross-linking agent has a molecular weight represented by the following general formula (1) having two epoxy groups. A heat-sensitive recording material using a polyether of 1000 to 6000.

Embedded image (2) providing a heat-sensitive recording layer colored by heat on a support,
Further, in the heat-sensitive recording material having a protective layer obtained by using a resin and a cross-linking agent as main components on the heat-sensitive recording layer, a compound represented by the following general formula (2) or (3) was used as the cross-linking agent. A heat-sensitive recording material characterized in that:

Embedded image (In the formula, X represents an alkyl group, an alkoxy group, a polyether group which may be branched , and R ₁ represents a methylenediphenylene group .)

Embedded image (Where R ₁ Is an alkylene group or methylenediphenylene
Represents a group. )  (3) The resin forming the protective layer is polyvinyl alcohol
Or styrene-maleic anhydride copolymer.
And characterized by the above(1) or (2)Thermal recording material described
Fees.

The present inventors have conducted intensive studies on a cross-linking agent constituting a protective layer provided on the heat-sensitive recording layer and eliminating the above-mentioned disadvantages.
By using a polyether represented by the following general formula (1) having a molecular weight of 1000 to 6000 or a compound represented by the following general formula (2) or (3) , plasticizer resistance, water resistance, The present inventors have found that a heat-sensitive recording material which is excellent in solvent resistance and heat resistance, has no background coloration, and has a long pot life of a coating liquid for a protective layer can be obtained, thereby completing the present invention.

Embedded image (Where n is a number from about 15 to 98)

Embedded image (In the formula, X represents an alkyl group, an alkoxy group, a polyether group which may be branched , and R ₁ represents a methylenediphenylene group .)

Embedded image (Wherein, R ₁ is an alkylene group or methylenediphenylene
Represents a group. )

Hereinafter, the present invention will be described in more detail. The polyether crosslinking agent having two epoxy groups used in the present invention is a compound represented by the following general formula (1).

Embedded image

Specific examples of the ε-caprolactam compound crosslinking agent used in the present invention are as follows.

Embedded image (In the formula, X represents an alkyl group, an alkoxy group or a polyether group which may be branched.)

Embedded image

Embedded image

Further, in the present invention, together with the crosslinking agent of the present invention, a crosslinking agent conventionally used, for example, formalin, chromium alum, glyoxal, boric acid, an amine compound, a polyamide epichlorohydrin compound, a glycidyl compound, It can be used in combination with a methylol compound, an ethyleneimine compound, and an epoxy compound other than the crosslinking agent having an epoxy group of the present invention.

The resin used for the protective layer of the present invention includes, for example, polyvinyl alcohol, cellulose derivatives, starch and derivatives thereof, carboxyl group-modified polyvinyl alcohol, polyacrylic acid and derivatives thereof, styrene / acrylic acid copolymer and derivatives thereof , Poly (meth) acrylamide and derivatives thereof, styrene / acrylic acid / acrylamide copolymer, amino group-modified polyvinyl alcohol,
Water-soluble resin such as epoxy-modified polyvinyl alcohol, polyethyleneimine, aqueous polyester, aqueous polyurethane, maleic anhydride copolymer and its derivatives, polyester, polyurethane, acrylate (co) polymer, styrene / acrylic copolymer Aqueous emulsion resins such as coalescing, epoxy resin, polyvinyl acetate, polyvinylidene chloride, polyvinyl chloride and derivatives thereof. Among these, a water-soluble resin is preferable, and (modified) polyvinyl alcohol is particularly preferable, and among them, a completely saponified type having a polymerization degree of 1,000 or more is preferable.

In the protective layer of the present invention, the above resin,
In addition to the crosslinking agent, if necessary, auxiliary additives commonly used in this type of heat-sensitive recording material, for example, a filler, a surfactant, a heat-fusible substance (or a lubricant), and a pressure coloring inhibitor are used in combination. be able to. In this case, as the filler, for example, calcium carbonate, silica, zinc oxide, titanium oxide,
In addition to inorganic fine powders such as aluminum hydroxide, zinc hydroxide, barium sulfate, clay, talc, surface-treated calcium and silica, urea-formalin resins, styrene / methacrylic acid copolymers, and organic systems such as polystyrene resins Can be mentioned. Examples of the heat-fusible substance include higher fatty acids or esters, amides or metal salts thereof, various waxes, condensates of aromatic carboxylic acids and amines, phenyl benzoate, higher linear glycols, and the like. Those having a melting point of about 50 to 200 ° C, such as dialkyl 1,4-epoxy-hexahydrophthalate, higher ketones, p-benzylbiphenyl and other heat-fusible organic compounds.

The method of color development by heat used in the present invention includes a method utilizing a color development reaction between a leuco dye and a developer, a method utilizing a reaction between a diazo compound and a coupler, and a method utilizing a reaction between an isocyanate and an amine. There are things to do. Since the feature of the present invention resides in the protective layer of the heat-sensitive recording material, the color forming method is not particularly limited. Hereinafter, the thermal recording method using a general leuco dye will be described.

In the present invention, the leuco dye used in the thermosensitive coloring layer is applied alone or in combination of two or more.
As such leuco dyes, those applied to this type of heat-sensitive material are arbitrarily applied, and examples thereof include triphenylmethane, fluoran, phenothiazine, auramine, spiropyran, and indolinophthalide. A leuco compound of a dye is preferably used. Specific examples of such leuco dyes include, for example, those shown below.

3,3-bis (p-dimethylaminophenyl)-
Phthalide, 3,3-bis (p-dimethylaminophenyl) -6
-Dimethylaminophthalide (also known as crystal violet lactone), 3,3-bis (p-dimethylaminophenyl)
-6-diethylaminophthalide, 3,3-bis (p-dimethylaminophenyl) -6-chlorophthalide, 3,3-bis (p-
Dibutylaminophenyl) phthalide, 3-cyclohexylamino-6-chlorofluoran, 3-dimethylamino-5,
7-dimethylfluoran, 3-N-methyl-N-isobutyl-6-
Methyl-7-anilinofluoran, 3-N-ethyl-N-isoamyl-6-methyl-7-anilinofluoran, 3-diethylamino-7-chlorofluoran, 3-diethylamino-7-methylfluoran, 3-diethylamino-7,8-benzfluoran, 3-diethylamino-6-methyl-7-chlorofluoran, 3- (N-p-tolyl-N-ethylamino) -6-
Methyl-7-anilinofluoran, 3-pyrrolidino-6-
Methyl-7-anilinofluoran, 2- {N- (3'-trifluoromethylphenyl) amino} -6-diethylaminofluoran, 2- {3,6-bis (diethylamino) -9- (o-
(Chloranilino) xanthyl lactam lactam｝, 3-diethylamino-6-methyl-7- (m-trichloromethylanilino) fluoran, 3-diethylamino-7- (o-chloroanilino) fluoran, 3-dibutylamino-7- (o -Chloroanilino) fluoran, 3-N-methyl-N-amylamino-6-methyl-7-anilinofluoran, 3-N-methyl-N
-Cyclohexylamino-6-methyl-7-anilinofluoran, 3-diethylamino-6-methyl-7-anilinofluoran, 3-diethylamino-6-methyl-7- (2 ', 4'-dimethylanilino ) Fluoran, 3- (N, N-diethylamino) -5
-Methyl-7- (N, N-dibenzylamino) fluoran, benzoylleucomethylene blue, 6'-chloro-8'-methoxy-benzoindolino-spiropyran, 6'-bromo-
3'-methoxy-benzoindolino-spiropyran, 3-
(2′-hydroxy-4′-dimethylaminophenyl) -3-
(2′-methoxy-5′-chlorophenyl) phthalide, 3- (2 ′
-Hydroxy-4'-dimethylaminophenyl) -3- (2 '
-Methoxy-5'-nitrophenyl) phthalide, 3- (2'-
(Hydroxy-4'-diethylaminophenyl) -3- (2'-
Methoxy-5'-methylphenyl) phthalide, 3- (2'-methoxy-4'-dimethylaminophenyl) -3- (2'-hydroxy-4'-chloro-5'-methylphenyl) phthalide, 3
-Morpholino-7- (N-propyl-trifluoromethylanilino) fluoran, 3-pyrrolidino-7-trifluoromethylanilinofluoran, 3-diethylamino-5-chloro-7- (N-benzyl-trifluoromethyl (Anilino) fluoran, 3-pyrrolidino-7- (di-p-chlorophenyl)
Methylaminofluoran, 3-diethylamino-5-chloro-
7- (α-phenylethylamino) fluoran, 3- (N-ethyl
-p-Toluidino) -7- (α-phenylethylamino) fluoran, 3-diethylamino-7- (o-methoxycarbonylphenylamino) fluoran, 3-diethylamino-5-methyl-7-
(α-phenylethylamino) fluoran, 3-diethylamino-7-piperidinofluoran, 2-chloro-3- (N-methyltoluidino) -7- (pn-butylanilino) fluoran, 3-
(N-methyl-N-isopropylamino) -6-methyl-7-anilinofluoran, 3-dibutylamino-6-methyl-7-anilinofluoran, 3,6-bis (dimethylamino) fluorenespiro ( 9,3 ′)-6′-dimethylaminophthalide, 3- (N-benzyl-N-cyclohexylamino) -5,6-benzo-7-α
-Naphthylamino-4'-bromofluoran, 3-diethylamino-6-chloro-7-anilinofluoran, 3-N-ethyl-N
-(2-ethoxypropyl) amino-6-methyl-7-anilinofluoran, 3-N-ethyl-N-tetrahydrofurfurylamino-6-methyl-7-anilinofluoran, 3-diethylamino
-6-methyl-7-mesitidino-4 ', 5'-benzofluoran, 3-
N-ethyl-N-isobutyl-6-methyl-7-anilinofluoran and the like.

Examples of the color developing agent used in the heat-sensitive coloring layer of the present invention include various electron-accepting compounds capable of coloring the leuco dye upon contact, such as phenolic compounds, thiophenolic compounds, thiourea derivatives, and organic compounds. Acids and metal salts thereof are preferably applied, and specific examples thereof include the following.

4,4'-isopropylidenebisphenol,
4,4′-isopropylidenebis (o-methylphenol),
4,4'-secondary butylidenebisphenol 4,4'-isopropylidenebis (2-tert-butylphenol), 4,4'-cyclohexylidenediphenol, 4,4'-
Isopropylidenebis (2-chlorophenol), 2,2'-
Methylenebis (4-methyl-6-tert-butylphenol), 2,2′-methylenebis (4-ethyl-6-tert-butylphenol), 4,4′-butylidenebis (6-tert-butyl-2-methylphenol), 1 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,1,3-tris (2-methyl-4-hydroxy-
5-cyclohexylphenyl) butane, 4,4'-thiobis (6
-Tert-butyl-2-methylphenol), 4,4'-
Diphenolsulfone, 4-isopropoxy-4'-hydroxydiphenylsulfone, 4-benzyloxy-4'-hydroxydiphenylsulfone, 4,4'-diphenolsulfoxide, isopropyl P-hydroxybenzoate, benzyl P-hydroxybenzoate , Benzyl protocatechuate, stearyl gallate, lauryl gallate, octyl gallate, 1,7-bis (4-hydroxyphenylthio) -3,5-dioxaheptane, 1,5-bis (4-hydroxyphenylthio) -3-oxapentane, 1,3-bis (4-hydroxyphenylthio) -propane, 1,3-bis (4-hydroxyphenylthio) -2-hydroxypropane, N, N'-diphenylthiourea, N, N'-di (m-chlorophenyl) thiourea, salicylanilide, 5-chloro-salicylanilide, 2-hydroxy-3-naphthoic acid, 2-hydroxy-1- Futoe acid, 1-hydroxy-2-naphthoic acid, zinc hydroxynaphthoic acid, aluminum, metal salts such as calcium,
Bis- (4-hydroxyphenyl) acetic acid methyl ester, bis- (4-hydroxyphenyl) acetic acid benzyl ester, 1,3
-Bis (4-hydroxycumyl) benzene, 1,4-bis (4-
(Hydroxycumyl) benzene, 2,4′-diphenolsulfone, 3,3′-diallyl-4,4′-diphenolsulfone,
α, α-bis (4-hydroxyphenyl) -α-methyltoluene, antipyrine complex of zinc thiocyanate, tetrabromobisphenol A, tetrabromobisphenol S and the like.

In order to produce the heat-sensitive recording material of the present invention,
When the leuco dye and the developer are bound and supported on the support, various conventional binders can be appropriately used, and specific examples thereof include the following.

Polyvinyl alcohol, starch and derivatives thereof, methoxycellulose, hydroxymethyl cellulose
, Hydroxyethyl cellulose, carboxymethyl cellulose, methyl cellulose, ethyl cellulose, etc., cellulose derivatives, sodium polyacrylate, polyvinylpyrrolidone, acrylamide / acrylate copolymer, acrylamide / acryl Water-soluble polymers such as acid ester / methacrylic acid terpolymer, styrene / maleic anhydride copolymer alkali salt, isobutylene / maleic anhydride copolymer alkali salt, polyacrylamide, sodium alginate, gelatin, casein, etc. Besides, polyvinyl acetate,
Emulsions such as polyurethane, polyacrylic acid, polymethacrylate, polyacrylate, vinyl chloride / vinyl acetate copolymer, polybutyl methacrylate, ethylene / vinyl acetate copolymer, and styrene / butadiene copolymer, Latex such as styrene / butadiene / acrylic copolymer.

In the heat-sensitive coloring layer of the present invention, if necessary, auxiliary additives commonly used in this type of heat-sensitive recording material, such as fillers, surfactants, heat-sensitive materials, together with the leuco dye and the developer. A fusible substance (or lubricant), a pressure coloring inhibitor, and the like can be used in combination. In this case, specific examples of the filler and the heat-fusible substance include those similar to those exemplified in relation to the protective layer.

In the present invention, an undercoat layer containing a filler, a binder and the like can be provided between the support and the thermosensitive coloring layer. In this case, the same fillers and binders as the main components constituting the undercoat layer may be the same as those exemplified for the heat-sensitive recording layer. With such a configuration, water resistance and chemical resistance to water and chemicals leached from the back surface of the support are excellent. In the present invention, a back coat layer can be provided on the back surface of the support. In this case, it is preferable to use the same main components as those exemplified for the heat-sensitive recording layer. According to such a configuration, leaching of water and chemicals from the back surface of the support can be effectively suppressed. Further, in the present invention, it is possible to form two or more protective layers.

The heat-sensitive recording material of the present invention is used in various fields. In particular, the heat-sensitive recording type label sheet or the heat-sensitive recording sheet,
It can be advantageously used as a thermosensitive recording type magnetic ticket. In the case of a heat-sensitive recording type label sheet, a heat-sensitive coloring layer containing the leuco dye and a developer described above and the protective layer are provided on one surface of the support, and the other surface of the support is provided with an adhesive layer interposed therebetween. What is necessary is just to provide a peeling mount, and in the case of magnetic ticket paper,
A magnetic recording layer mainly composed of a ferromagnetic material and a binder may be provided instead of the release liner.

[0023]

The present invention will be described in more detail with reference to the following examples. The following parts and percentages are all based on weight.

Examples 1 and 2 and Comparative Examples 1 to 4 [Formation of heat-sensitive recording layer] A mixture having the following composition was pulverized and dispersed by a sand grinder for 2 to 4 hours, and [Liquid A] and [Liquid B] were mixed. Prepared. [Solution A] 3- (N-methyl-N-cyclohexyl) amino-6-10 parts Methyl-7-anilinofluoran 10% aqueous solution of polyvinyl alcohol 10 parts Water 80 parts [Solution B] 4-hydroxyphenyl-4 '-Isopropoxyphenyl sulfone 10 parts Calcium carbonate 10 parts 1,1,3-tris (2-methyl-4-hydroxy-5-cyclohexyl) 5 parts Phenyl) butane 10% aqueous solution of polyvinyl alcohol 20 parts Water 55 parts [Solution A] and [Solution B] were dispersed in a sand mill for 24 hours to obtain each dispersion, and the weight ratio was [Solution A]: [Solution B].
= 1: 3 to prepare a coating solution for the heat-sensitive recording layer, which was dried on a commercial high-quality paper to have a coating weight of 50 g / m ² ,
The coated paper was dried so as to have a dry weight of 5 g / m ² to obtain a paper coated with the heat-sensitive recording layer.

[Formation of protective layer] [Solution C] 10 parts of kaolin 10 parts of a 10% aqueous solution of polyvinyl alcohol 10 parts of water 80 parts [Solution C] was also dispersed in a sand mill for 15 hours to obtain a kaolin dispersion. [D1 liquid] to [D6 liquid] Carolin dispersion liquid (liquid C) 20 parts 10% aqueous solution of polyvinyl alcohol 40 parts Crosslinking agent (shown in Table 1 ) 10% aqueous solution (dispersion liquid) 1 part Water 49 parts Each of the above The coating liquid was used as the layer forming liquid shown in Table 1 so that the dry weight was 3 g / m ² on the recording layer on the paper on which the heat-sensitive recording layer was formed, on the back surface of the paper, or between the high-quality paper and the heat-sensitive recording layer. And dried to form a predetermined layer, and further subjected to surface treatment with a super calender, and Examples 1-2 and Comparative Examples 1-4
Was prepared.

[0026]

[Table 1]

The heat-sensitive recording materials of Examples 1 and 2 and Comparative Examples 1 to 4 were measured for plasticizer resistance, water resistance, and heat-resistant background color development by the methods described below.
It is shown in FIG. Plasticizer test In a heat block, apply DOA to the color developed to a density of 1.30 with a Macbeth densitometer, measure the density with a Macbeth densitometer after 16 hours at 30 ° C., and measure the degree of disappearance of the printed portion. Find out. Water resistance test (reactivity) After the sample is left at 40 ° C. for 16 hours, it is immersed in water for 16 hours, rubbed with a finger, and examined for peeling. …: No peeling…: Slight peeling…: Peeling Heat-resistant ground color test The sample measured with a Macbeth densitometer was left at 70 ° C. for 1 hour, then again measured with a Macbeth densitometer, and before and after standing. Examine the degree of color development.

[0028]

[Table 2]

Examples 3 to 6 and Comparative Examples 5 to 8 The same procedures as in Example 1 were carried out except that the following protective layer forming liquids [F1 liquid] to [F8 liquid] were used for the paper coated with the heat-sensitive recording layer obtained in Example 1. 1
A heat-sensitive recording material was prepared in the same manner as described above.

[Formation of protective layer] [Solution E] 10 parts of silica 10 parts of a 10% aqueous solution of polyvinyl alcohol 10 parts of water 80 parts [Solution E] was also dispersed in a sand mill for 15 hours to obtain a silica dispersion. [F1 solution] to [F8 solution] Silica dispersion (Solution E) 20 parts Resin 10% aqueous solution 40 parts Crosslinking agent (described in Table 3 ) 10% aqueous solution (dispersion) 1 part Water 49 parts

[0031]

[Table 3]

The heat-sensitive recording materials of Examples 3 to 6 and Comparative Examples 5 to 8 were measured for plasticizer resistance and water resistance in the same manner as in Example 1, and the results are shown in Table 4 . The liquid properties were measured by the method described below, and the results are shown in Table 4 . Liquid test After leaving the coating liquid at 30 ° C for 24 hours, the viscosity of the liquid and the
It is applied on the thermosensitive coloring layer and subjected to the same storage stability test as described above, and is compared with a sample obtained from a liquid immediately after preparation.

[0033]

[Table 4]

[0034]

According to the heat-sensitive recording material of the present invention, a protective layer mainly composed of a resin and a polyether having a molecular weight of 1,000 to 6,000 and having two or more epoxy groups as a crosslinking agent is provided on the heat-sensitive recording layer. Therefore, it has excellent solvent resistance, plasticizer resistance, and water resistance, and also has excellent heat-resistant ground coloration. In addition, since a protective layer formed mainly of a resin and a ε-caprolactam compound as a crosslinking agent as a main component is provided, the plasticizer resistance and water resistance are excellent, and the pot life of the coating liquid is long. This has the effect.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-103386 (JP, A) JP-A-60-68990 (JP, A) JP-A-4-138283 (JP, A) JP-A-5-138 309942 (JP, A) JP-A-61-66692 (JP, A) JP-A-6-24139 (JP, A) JP-A-5-221135 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41M 5/28-5/34

Claims (3)

(57) [Claims] 1. A heat-sensitive recording material comprising: a heat-sensitive recording layer which is colored by heat on a support; and a protective layer obtained by using a resin and a cross-linking agent as main components on the heat-sensitive recording layer. A heat-sensitive recording material, wherein a polyether having two epoxy groups and having a molecular weight of 1,000 to 6,000 and having a molecular weight of 1,000 and having two epoxy groups is used. Embedded image 2. A thermosensitive recording material comprising: a heat-sensitive recording layer which is colored by heat provided on a support; and a protective layer obtained by using a resin and a cross-linking agent as main components on the heat-sensitive recording layer. A heat-sensitive recording material comprising a compound represented by the following general formula (2) or (3) as an agent. Embedded image (In the formula, X represents an alkyl group, an alkoxy group, or a polyether group which may be branched , and R ₁ represents a methylenediphenylene group .) (Wherein, R ₁ is an alkylene group or methylenediphenylene
Represents a group. ) 3. The heat-sensitive recording material according to claim 1, wherein the resin forming the protective layer is polyvinyl alcohol or a styrene-maleic anhydride copolymer.