JPS6253875A - Thermal recording material - Google Patents

Abstract

PURPOSE:To obtain a sufficient developed color density while maintaining the function of a protective layer, by subjecting a protective layer to a heat treatment in a specified temperature range after coating and drying, in a thermal recording material wherein a protective layer comprising a polymer as a main constituent is laminated on a thermal color forming layer. CONSTITUTION:A thermal recording material comprises a thermal color forming layer comprising a colorless or light-colored electron-donative dye precursor and an electron-acceptive compound for developing the color of the dye precursor by reacting therewith, and a protective layer laminated thereon which comprises a polymer as a main constituent. The protective layer is subjected to a heat treatment after coating and drying. The heat treatment is preferably carried out by passing the recording material through a pressing device comprising the combination of a metallic roll heated to 50-80 deg.C and an elastic roll so that the protective layer side is brought into contact with the metallic roll. The elastic roll is preferably formed from a material having a Shore hardness of 70-90 deg.. The dye precursor may be a compound based on triarylmethane, diphenylmethane, xanthene, thiazine, spiropyran or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Application of the Invention) The present invention relates to a heat-sensitive recording material C2, and more particularly, to coloration of a normally colorless or light-colored electron-donating dye precursor and an electron-accepting compound. Thermosensitive recording material ε using reaction
Two matters.

(Prior Art) So-called two-component heat-sensitive recording materials that utilize a color reaction between a colorless or light-colored electron-donating dye precursor and an electron-accepting compound are disclosed in Japanese Patent Publication No. Sho gj-/ll0J and No. Sho 9tJ-1.
7≦O, etc. Two-component color-forming heat-sensitive recording materials are produced by dispersing a colorless or light-colored electron-donating dye precursor and an electron-accepting compound in the form of fine particles, and then mixing these two kinds of heat-reactive compounds with a binder. One or both of them are heated to melt and come into contact with each other, and the coloring reaction that occurs is used to obtain a record.

These two-component color-forming heat-sensitive recording materials are: (1) - Full color development and no development required; (0) Paper quality is close to 52 ordinary paper; (2) Easy handling; (2) High color density; (4) Various color hues; Heat-sensitive recording materials have the advantage of being easy to use (2) and have great utility value.For this reason, they are most commonly used as heat-sensitive recording materials.Especially in the fields of facsimile, recording needles, and printers, the use of heat-sensitive recording materials has increased in recent years. As the use of facsimile has spread, the recording speed has been increased, but even heat-sensitive recording materials have a short e-lust, that is, low energy C. There has been a strong demand for improvements in gender.

On the other hand, these heat-sensitive recording materials have the disadvantage that not only the primary color is generated by heat, but also the reaction between the child-toxic dye precursor and the electron-accepting compound due to stains caused by solvents, etc. There is.

This is because all of these heat-sensitive recording materials are organic substances.
This is because the solubility in the solvent ζ2 is high, and therefore a reaction occurs in the solvent. Therefore, if you touch stationery that contains solvents, such as water-based ink pens, oil-based ink pens, fluorescent pens, or diazo developers, or adhesives and glues, the white background of the heat-sensitive recording material may develop color or the printed area may become discolored. This resulted in a significant loss of product value.

In contrast to this 952, the conventional V thermosensitive coloring layer C2, special public show V:
9t-22♂♂0, Tokukai Shoda! Efforts have been made to provide a solvent-resistant protective layer, as disclosed in Japanese Patent Application Laid-open No. -3θμ32, Japanese Patent Publication No. 2003-110011, and Japanese Patent Application Laid-open No. 2003-32302. Therefore, there is a tendency for the color density to be lower than that of the one without retention, and the current situation is that heat-sensitive recording materials having a retention layer do not necessarily have sufficient color density.

(Object of the invention) In the heat-sensitive recording material with the above-mentioned adhesive:
It is an object of the present invention to obtain a heat-sensitive recording material which can obtain sufficient color density without impairing the function of the protective layer.

(Structure of the Invention) The object of the present invention is to provide a heat-sensitive coloring layer containing a colorless or light-colored electron-donating dye precursor and an electron-accepting compound that develops a color by reacting with the electron-donating dye precursor, and a polymer. A heat-sensitive recording material characterized in that, in a heat-sensitive recording material formed by laminating a protective layer consisting mainly of It was done.

Application of protective layer and heat treatment after drying are j00c~♂t)
0ct=It is preferable to pass the sheet through a pressure device that combines a heated metal roll and an elastic roll so that the protective layer surface of the metal roll C is in contact with the pressurizing device. SamokoThe elastic roll used in the present invention has a Shore hardness of 20~? A material having a θ degree is preferable, and the material 52 is preferably a hard rubber roll.

Examples of the colorless to light-colored electron-donating dye precursor used in the heat-sensitive coloring layer of the present invention include triarylmethane compounds, diphenylmethane compounds, xanthine compounds, thiazine compounds, and spiropyran compounds. . As a specific example) 11#5M Akira is 27-! 3
Examples include those that are written in the same name as the name. Some examples of these are triarylmethane compounds, 1
．． 3,3-bis(p-dimethylavanophenyl)-6-
dimethyl abanophthalide (i.e. crystal violet lactone), J, J-bis(p-dimethylaminophenyl) phthalide, j-(p-dimethylaminophenyl)-
J-<i, 3-dimethylindol-3-yl)phthalide, 3-(p-dimethylaminophenyl ν) -3-(
J-methylindol-3-yl) phthalide, etc., and diphenylmethane compounds include g,9t'-bis-dimethylaminobenzhydrin benzyl ether,
N-halophenyl-leucoauramine, N-J,g,!
-)lichlorophenylleucoaurine, etc., and xanthine compounds include rhodamine-B-anilinolactam, rhodamine(p-nitrino)lactam, J-(
dibenzylamino)fluoran, cophenylamino 6-ethylaminofluoran%'(0-chloroanilino)-g-diethylaminofluorane 1,2-(J,
sc-dichloroanilino)-6-diethylaminofluorane, 2-anilino-3-methyl-6-piperidinofluorane, cophenyl-6-diethylaminofluorane, etc. are f-1 di-, spiro-based compounds. 3-methyl-
Spiro-dinaphthopyran, 3-ethyl-spiro-dinaphthopyran, 3,3'-cyclospirodinaphthopyran, 3-benzylspiro-dinaphthopyran, 3-methyl-nando-(3-methoxy-benzo)-spiropyran,
Examples include 3-propyl-spiro-dibenzobilane. These may be used alone or in combination. In terms of width, electron-donating dye precursors such as triarylmethane compounds (eg, crystal violet lactone) and xanthine compounds are preferred because they cause less fog and provide high color density. More preferably, the following general formula (
Examples include xanthine compounds represented by II).

(In the formula, R1 and R2 are alkyl groups or cycloalkyl groups having carbon number/-10, R3 is an aryl group, and X is carbon number/-10.
-10 alkyl group or halogen atom. ) In the general formula (n) t=, the alkyl groups represented by R1 and R2 may be linear or branched, and may have a further disubstituent.

The aryl group represented by R3 preferably has 6 to 0 carbon atoms, and is preferably a phenyl group or a phenyl group having a substituent. As a substituent for a phenyl group, the number of carbon atoms/-
10 alkyl groups are preferred.

Among the dye precursors represented by the general formula (II), particularly preferred ones are represented by the following general formula (III).

(In the formula, R1 and R2 are alkyl groups having carbon number/-10, R
4 represents a hydrogen atom or an alkyl group having a carbon number of 1 to t, and X represents an alkyl group having a carbon number of 1 to ♂ or a chlorine atom. ) In the above general formula (III)C, the alkyl groups represented by R1 and R2 may form a ring, and may further have a C disubstituent.

In the above general formula (m), compounds in which X is a methyl group or a chlorine atom are preferred.

Examples of these colorless to light-colored electron-donating dye precursors include the following compounds, but are not limited to these compounds.

2-anilino-3-methyl-6-dimethylaknofluorane, co-anilino 3-methyl-6-N-methyl-N
-ethyl razunofluorane, co-anilino-3-methyl-4-N-methyl-N-(iso-propyl)aminofluorane, 2-anilino-3-methyl-t-N-methyl-N-pentylaminofluorane, λ -Anili, No 3
-Methyl-6-N-methyl-N-cyclohexylabanofluorane, λ-anilino-3-methyl-6-dinithylabanofluorane, 2-anilino-3-chloro-but-dimethylaminofluorane, co-anilino-3-methyl-
a-N-ethyl-N-isoamylaminofluorane, co-anilino-3-methyl-6-N-methyl-N-amylaminofluorane, no-anilino-3-chloro-6
-Diemasulaminofluorane, 2-anilino-3-chloro-6-N-methyl-N-ethylaminofluorane, -
1-anilino-3-chloro+-N-methyl-N-(is
o,-propyl) abanofluorane, co-anilino 3
-Chloro-4-N-methyl-N-6-methylabanofluorane, λ-anilino-3-chloro-N-methyl-cyclohexylaminofluorane, -1-anilino-3-methyl-6-N-dithylhopentylaminofluorane , λ-anilino 3-chloro 4-N-ethyl-N-pentylaminofluorane, -2-(p-methylanilino)-3-methyl-6-dimethylaminofluorane, 2-(p-methylanilino)-3- Methyl-6-diethylaminofluorane, -2-(p-methylanilino)-3-methyl-6-N-nonal-N-ethylaminofluorane, -1(p-methylanilino)-3-methyl-j-N-methyl -N-(iso-propyl)aminofluorane, co(p--methylanilino)-3-methyl-6-N-methyl-N-bentylazunofluorane, co(p--methylanilino)-3-methyl-4- N-,
Methyl-N-cyclohexylaminoflurane, -1(
p-methylanilino)-3-methyl-≦-N-ethyl-
(/7/Leolanino, λ
-・(p-methylanilino)-3-chloro6-dimethylaminofluorane, -1(p-methylanilino)-3
-Chloro-4-diethylaminofluorane, -1(p
-Methylanilino)-3-chloro-t-N-methyl-ethylaminofluorane, -2-(p-methylanilino)-3-chloro-≦-N-methyl-N-(jso-
Propyl)aminofluorane, -2-(p-methylanilino)-3-chloro-6-N-methyl-N-cyclohexylaminofluorane, -2-(p-methylanilino)
-3-chlorocl-j-N-methyl-Nd-ethylazunofluorane, 2-(p-methylanilino) -J -
Chloro-t-N-ethyl-N-pentylaminofluorane, 2-anilino-3-nonal-6-N-methyl-hefurylmethylaminosololane, 2-anilino-3-ethyl-4-N-methyl-N -Furylmethylaminofluorane, etc., and these may be used alone, but may be used in combination with 2.2 g or more of C2 to improve the color and prevent fading of the colored image.

As the electron-accepting compound used in the heat-sensitive coloring HE2 of the present invention, compounds represented by the following general formulas (IV) to (■) are preferred.

R+1 (In the formula, X is s, o, 802, S2, 10C+.

) represents an integer of θ to 3, 几1 and 几2 are hydrogen or an alkyl group having carbon number/-1", and R0 and R22>E
M represents a cycloalkyl group formed by combining. Further, R represents a straight chain or branched alkyl group having / -/ carbon atoms or a halogen atom. ) (wherein, Y represents hydrogen, -CI[3, -on, represents a straight chain or branched alkyl group with carbon number/~≦, m%
n is an integer from O to 3, Z is hydrogen, halogen, -CH5t-
represent. ) (In the formula, R4 is a benzyl group, a halogen atom, or the number of carbon atoms)
Represents a benzyl group substituted with a straight chain or branched alkyl group of ~♂, and a straight chain or branched 9 alkyl group having /-/ carbon atoms. ) (In the formula, R6 and R7 represent an alkyl group having /-/ carbon atoms.) (In the formula, 几8 represents an alkylene group having /-7 ether bonds.) The above general formulas (IV) to ( Specific examples of the compound represented by Vl) include -, Corbis(μ'-hydroxyphenyl)pCI A, Co, Corbis(ri'-hydroxyphenyl)hentane, Co, λ-bis(ri'-hydroxyphenyl) ',j'-dichlorophenyl)brone, /-/
- his(l'-hydroxy7enyl)cyclohexane,
J1a2-? "S(4tl-hydroxyphenyl)hexane, i,t-bis(μ'-human90xyphenyl)"
Propane, /, /-his(9tI-hydroxyphenyl)butane, l,l-bis(l-hydroxyphenyl)
Hentane, l,/-bis(l'-hydroxyphenyl)
Hexane, /, /-His (Hiro'-Hydroxyphenyl)
Hebutane, /, / -1'-bis(ri'-hydroxyphenyl)-1-methyl-pentane, l,l-bis(li'-hydroxyphenyl)-2-ethyl-hexane, l,l-bis(ri'- hydroxyphenyl)dodecane, 3,3-bis(hydroxyphenyl)pentane, l, Corbis(
μ'-hydroxyphenyl)ethane, l,l-bis(,
+-Hydroxyphenyl)sulfi)', /.

/-bis(value-hydroxyphenyl)sulfone, /, /
-His(Hiro'-hydroxyphenyl)ether, 2. Corbis(da'-hydroxy-3', tl-dichlorophenyl)butane, 2. Hiro-dihydroxybenzoic acid phenyl, 2,4t-dihydroxyly'-)f)'benzoic acid phenyl, 2. phenyl l-dihydroxy-μ'-chlorobenzoate, 2. Hiro-dihydroxy-6-methylbenzoic acid phenyl, 2. t.

Coated phenyl dihydroxybenzoate, J, %-dihydroxy≦, Hiro'-phenyl dimethylbenzoate, co, a
-dihydroxy-6-methyl-hiro'-chloroan, ll phenyl fragrant, co--hensyl dihydroxybenzoate,
2. dihydroxy-ul-methylbenzoate, co, dihydroxy-sc'-p, benzyl dihydroxy-4-methylbenzoate, 29 μm dihydroxy-4-methylbenzoate, λ.

μ, benzyl 6-dolyhydroxybenzoate, co.

Hiro-dihydroxy-4,4c'-dimethylbenzoic acid benzyl, Co, tosihydroxy-6-methyluda'-chlorobenzyl JB, Hiro-dihydroxy-6-methylda'-chlorobenzyl, Hiro-hydroxybenzoic acid ether ester, Hiro-dihydroxybenzoic acid propyl ester, Hiro-hydroxybenzoic acid isopropyl ester,
Bait-Hydroxyben-4i Ugly Hensyl Ester, Derhydroxyben Jna-J-Ethylhexyl Ester, μm
hydroxyl-chlorobenzoic acid benzyl ester,
l-Hydroxy-μ'-methylbenzoic acid benzyl ester, l-hydroxy-μ'-ethylbenzoic acid M benzyl ester, 3-hydroxy-m-7talic acid dimethe.

3-hydroxy-diethyl phthalate, methylethyl 3-hydroxy-m-7talate, 3-hydroxy-
Examples thereof include dibutyl m-7talate, dimethyl 3-human α-xy-7-talate, and diethyl 3-hydroxy-O-7talate.

Moreover, as a compound of the general formula (■), specifically, etc. can be mentioned.

Preferred examples other than the electron-accepting compounds represented by formulas (N) to (■) above include bis-human"loxycumylbenzene or bis-hydroxy-α-methylbenzylbenzene; specific examples include l.

Hiro-hisu p-hydroΦshikuzurubenzene, /.

Hiro-bis-m-hydroxycumylbenzene s'e3-bis-p-hydroxycumylbenzene, l.

3-bis-m- and dicumylbenzene in slurry, l.

μm bis-〇-hydroxycumylbene bottle, l.

Gubis-p-hydroxy-α-methylbenzylbenzene, l,3-bis-p-hydroxy-α-methylbenzylbenzene, etc., and salicylic acid complexes include 3. ! -di-alpha-methylbenzylsalicylic acid, 3. Salicylic acids such as Taj Tajaribu TΦ salicylic acid, 3-α, α-dimethylbenzyl salicylic acid, or their polyvalent gold (%4: zinc and aluminum are preferred).
Others include p-phenylphenol, 3゜! Examples include, but are not limited to, phenols such as diphenylphenol and cumylphenol.

The above electron-accepting compound is an electron-donating dye precursor,
It is preferable to use a weight ratio of 5-0 to 1000, preferably 100-! 00 weight, and 141 may be used alone or in combination of two or more types.

Invention C: When such a heat-sensitive recording material≦2, a heat-fusible substance can be contained in the heat-sensitive coloring layer l in order to improve the heat responsiveness of the heat-sensitive recording material.

As an example of a preferable thermofusible substance, the following general formula ([)n(
Examples include compounds represented by XIY).

R. R5 and R6 each represent an alkyl group with carbon number/, 2 or more - μ or less, R
, indicates hydrogen or phenyl group.

, and when the phenyl group or benzyl group represented by R1 to 84 in general formulas (W) to (cumulative) is substituted with a lower alkyl group, the number of carbon atoms is 1 or more and 1 or less, preferably 1 or more and 3 It is as follows.

In addition, when tt is substituted with a halogen, preferred is chlorine''! or fluorine.

In the formula, R8 represents a covalent group, preferably an alkylene group, an alkylene group having an ether bond, an alkylene group having a carbonyl group, an alkylene group having a halogen atom,
An alkylene group having an unsaturated bond, more preferably an alkylene group, an alkylene group having an ether bond.

Father, X, Y, Z.

Y', Y', and z' may be the same or different, and are represented by a hydrogen atom, an alkyl group, a lower alkoxy group, a lower aralkyl group, a halogen atom, an alkyloxycarbonyl group, and an aralkyloxycarbonyl group.

The compounds of the general formulas (rl) to (Xll/) preferably have a melting point of 20°C or more/zO''c or less, and more preferably a melting point of 10'C or more/700C or less.

Specifically, benzyl p-benzyloxybenzoate, β
-Naphthylbenzyl ether, niaric acid amide, palmimic acid amide, N-phenyl niaric acid azedo, N-
Stearylurea, β-naf kz spear 〒29〒7+9-u
No-1-naphthoic acid phenyl ester, β-naphthol (p-chlorobenzyl) ether, β-naphthol (p-methylbenzyl) ether, α
-naphthylbenzyl ether, t, u-phthanediol-p-menal phenyl ether, /, %-2'ropanediol-p-methylphenyl ether, /, g-
phthanediol-p-inglobyrphenyl ether,
l, Hiro-butanediol-p-t-ofnalphenyl ether, co-7enoxy/-p-tolyl-oxy-ethane, /-7enoxy-2-(Ilt-ethylphenoxy)ethane,! -7 dinoxyco(μm chlorophenoxy)ethane, l.

Examples include goubutanediol phenylneedle and the like.

The above-mentioned thermofusible substances may be used alone or in combination, and in order to obtain sufficient thermoresponsiveness, C; is 1-child-accepting 1hi@C2 or io-,2( It is preferable to use 7 parts by weight, and the more preferable amount to use is 0-1z.
oIt is weight.

In two-component heat-sensitive recording materials e2, the recorded images produced are generally affected by external conditions such as humidity and heat. It tends to fade more than C2.

In the heat-sensitive recording material g2 according to the present invention g2, in order to prevent such decoloring and solidify the generated image,
It is preferable to contain a compound that prevents decolorization.

As anti-fading agents, phenol blockers and hindered phenol compounds are effective. Examples of preferred anti-fading agents include compounds represented by the following general formulas (XV) to (Supplementary Note 1).

(In the formula, 几1 is a branched alkyl group having 3 to 1 carbon atoms, R2 is hydrogen or a branched alkyl group having 3 to t carbon atoms, R3 is hydrogen or an alkyl group having 3 to 3 carbon atoms, R4 represents hydrogen or an alkyl group having 1 to 1 carbon atoms; 5, R6, 2) hydrogen or an alkyl group having 1 to 1 carbon atoms; R8 represents hydrogen or an alkyl group having 1 to 1 carbon atoms; ) (In the formula, R1 and R3 are branched 9-alkyl groups having 3 to 1 carbon atoms, R2, 几, are carbon numbers) to 1 alkyl ai', and Is X is s, o, s02, S2 , +c+,, represents a cyclobenzene group or a cyclohexylene group, and n is O~
The integer of 3, R5 and R6 represent hydrogen or an alkyl group having 7 to 1 carbon atoms. ) (In the formula, R1 and R4 are branched alkyl groups having 3 to 1 carbon atoms, and 2, 3, B, 5, and R6 are hydrogen or alkyl groups having 1 to 1 carbon atoms.

■Also.

1 is an integer of θ to 3, and 7 and R8 represent hydrogen, an alkyl group having 1-2 carbon atoms, or a cyclic pentamethylene group formed by bonding R7 and R8. ) (In the formula, R1, R2a is a branched alkyl group having 3 to t carbon atoms, z bar N l-1-1-0(CH2) n- (where n is the !I number of /-j ), i represents an integer of / -%.However, when i = i, W represents an alkyl group with carbon number /-//, and when i = J, W represents S,
O1+C+t (where R3 and R4 are hydrogen or an alkyl group having carbon number/-J', and j is 0-rC) represents an integer. ), is*j, W represents 10-R,5 (here, R5 represents hydrogen t or an alkyl group having l-r carbon atoms).

Representative examples of the phenol derivatives represented by the above general formulas (XV) to (X■) are shown below.

(A) As the phenol derivative represented by the general formula (XV), /, /, J-)lis(2-methyl-lyhydroxy-j
-1crt-1tylphenyl)butane, /, /, J-tris(-1ethyruderhydroxy-z-tert-butylphenyl)butane, l.

/, J-tris(3, tert-butyl-U-
Hydroxyphenyl)butane, /, /, J-tris(comethylruderhydroxy-!-tcrt-butylphenyl)pro/tan, etc. are used.

(B) As the phenol derivative represented by the general formula (XV), co, -'-methylenebis(j-1art-butyl-μ
m-methylphenol), λ, -′-methylene-bis(
4-tert-butyl-Hiro-ethylphenol) and the like.

(C) As the phenol derivative represented by the general formula (xW), the phenol derivative represented by the general formula (xW) is
(3-methylphenol), g,l-thio-bis(J-methyl-4-1ert-butylphenol).

(D) Examples of the phenol derivative represented by the general formula 0■) include the following.

The amount of the phenol compound represented by the above general formulas (XV) to (XVI) is 1 to 20% relative to the electron-accepting compound.
o It is preferable to use heavy weight rice cakes, and 5: What is the preferable amount to use? ~! OjuR is me.

S2 in the recording layer of the heat-sensitive recording material of the present invention usually uses a polymer as a binder.

For these polymers, 2 g of water at 0C and t
Compounds that dissolve S or more are desirable; specifically, methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, starches, gelatin, gum arabic, casein, styrene-maleic anhydride copolymer hydrolyzate, ethylene-maleic anhydride copolymer Combined hydrolyzate, inbutylene-maleic anhydride copolymer hydrolyzate,
Examples include polyvinyl alcohol, carboxy-f polyvinyl alcohol, and polyacrylamide.

Furthermore, if necessary, pigments, water-insoluble binders, metal soaps, waxes, surfactants, etc. may be added to the recording layer of the heat-sensitive recording material of the present invention.

As the pigment, zinc oxide, barium calcilamurosulfate carbonate, titanium oxide, lithopone, talc, waxite, kaolin, albanium hydroxide, silica, amorphous silica, etc. are used.

As the water-insoluble binder, synthetic rubber latex or synthetic resin emulsion is generally used, such as styrene-butadiene rubber latex-acrylonitrile-butadiene rubber latex, methyl acrylate-butadiene rubber latex, and vinyl acetate emulsion.

As the metal soap, higher Bfl fatty acid metal salts are used, and emulsions of zinc stearate, calcium stearate, aluminum stearate, etc. are used.

As the wax, emulsions such as chisel rough-in wax, microcrystalline wax, carnauba wax, methylol stearamide, polyethylene wax, polystyrene wax, etc. are used.

As the surfactant, an alkali metal salt of sulfoconomonolylic acid, a fluorine-containing surfactant, etc. are used.

Examples of polymers used in the FI-retaining layer of the present invention include methylcellulose, carboxymethylcellulose, hydrodimethylcellulose, starches, gelatin, gum arabic, casein, styrene-maleic anhydride copolymer hydrolyzate, and styrene-maleic anhydride. Acid copolymer Hafestel hydrolyzate, isobutylene-maleic anhydride copolymer hydrolyzate, polyvinyl alcohol, silica-modified polyvinyl alcohol, carboxy-modified polyvinyl alcohol, polyacrylamide derivatives, polyvinylpyrrolidone, sodium polystyrene sulfonate, sodium alginate, etc. and water-insoluble polymers such as styrene-butadiene rubber latex, acrylonidolyl-butadiene rubber latex, acrylic methyl-butadiene rubber latex, and vinyl acetate emulsion. These polymers may be used alone or in combination of one or more.

Invention J-; Preservation@I-Medium 1: Matching property with thermal bed during printing Same as above, preservation! For the purpose of improving the water resistance of Jl, a water resistance agent such as a pigment, a metal soap, or a wax may be added.

The pigment is preferably added in an amount of 0.2 times to bait times the total weight of the polymer, preferably 9 g20, I-J, 7 times -h0 If the amount added is less than the above amount, the head matching property is improved 6 If it is added in an amount greater than the above amount, the sensitivity will be severely reduced and the commercial value will be impaired. As the pigment, zinc oxide, calcium carbonate, barium sulfate, titanium oxide, lithopone, Merck, waxite, kaolin, aluminum hydroxide, silica, amorphous silica, :Ia idal silica, etc. are used.

As metal soaps, higher fatty acid metal salts are used, including zinc stearate, calcium stearate, aluminum stearate, etc. % C nitrogen acid! ＃、Clams are favorable. The amount added is 0.0% of the total weight of the protective layer. j-J (11% are positive.

! pIil2) to 10% is preferred. Examples of waxes include paraffin wax, microcrystalline wax, carnauba wax, methylol air ahydride, stearic acid acrylate 2, and polyethylene wax.

A polymer such as polystyrene wax is used, and the weight is preferably 1 to 47%, particularly 1 to 10%, based on the total weight of the protective layer.

Also, when applying Hoichiki on the heat-sensitive coloring layer.

Surfactants may be added to obtain uniform retention #II. As the surfactant, sulfosuccinic acid-based alkali metal salts, fluorine-containing surfactants, etc. are used. Specific examples of C2 include sodium salts such as di(2-ethylhexyl)sulfosuccinic acid and di(n-hexyl)sulfosuccinic acid, or ammonium salts, but most γ-ion surfactants are effective. be.

(Examples of the Invention) Examples are shown below, but the present invention is not limited thereto.

(Example/-j) Crystal violet lactone, benzyl parahydroxybenzoate, stearamide, l.

/, J-) Squirrel
ert-butylphenyl)butane, each -0? 1oo
y no j Tivoli vinyl alcohol (Kuraray PVA10t)
It was dispersed with an aqueous solution in a ball mill overnight to obtain a volume average particle size of 11-3 μm or less.

The pigment is 70y- hexametaphosphoric acid O0! Correct solution 1℃? Each of the dispersions prepared as above was mixed with crystal violet lactone dispersion zot, benzyl hydroxybenzoate dispersion 10f, azedo stearate dispersion fti,
J-ff, /, /, J-) lis(-monomethyl-methoxy-t-tert-butylphenyl)butane dispersion J
? , pigment dispersion - mixed at a ratio of t, further t=-1i
Stearin af zinc emulsion J) of ES and aqueous solution of sodium di(coethylhexyl)-sulfosuccinate T? The coating liquid obtained by adding
It was coated on high-quality paper with a C2 wire paper so that the dry coating size was 71N, and dried in a tooC oven to obtain a heat-sensitive coloring layer.

On the thermosensitive coloring layer obtained by the above method, 52, polymers shown in Table 7! Stearin solution 1ooyt=, kaolin (Kaobrite: Georgia/Hisifik Co., Ltd.) fractional solution 1jF (dispersion liquid was prepared in the same manner as the above heat-sensitive coloring method), stearin f
! j71 zinc λ/% emulsion HP, and G (2
-ethylhexyl)sulfosuccinate) 17um of λ
The coating liquid obtained by mixing the wound solution/l is
f/m2: Apply with a wire bar, t
After drying in an OOC oven, the hard chrome plated roll was heated to the first
The sample was treated at the temperature C2 shown in Table 2 to obtain a thermosensitive recording paper.

[Comparative Examples 1 to 3] Same as in Examples - two heat-sensitive coloring layers and a protective layer were coated, dried, and then treated with a pressurizing device g2 was not performed.

[Comparative example! ]

As in the example, hard chrome plated rolls were prepared as shown in Table 1 I.
: A heat-sensitive recording material was obtained by processing at the temperature C1 shown.

The following tests were conducted on the obtained thermal recording paper.

(1) Color development test main scanning! Dot 7m% honing 3I: Recording is performed by applying energy of com 8 / dot, 20 m J / 嘗 2 at a rate of 6 dots/1 m to the recording sickle element i2, and the colored body after recording with the Macbeth density needle. The concentration was measured.

(2) Measurement of soil fertility concentration The degree of m on the white background was measured using Macbeth's density meter.

Test results′! A/Table g2 shows.

From the above, it can be seen that the heat-sensitive recording paper according to the present invention has less ground blur and exhibits high color development.

Claims (1)

[Claims] Usually, a heat-sensitive coloring layer containing a colorless or light-colored electron-donating dye precursor and an electron-accepting compound that develops color by reacting with the electron-donating dye precursor, and a protective layer mainly composed of a polymer are laminated. 1. A heat-sensitive recording material comprising a protective layer, which is coated and dried, and then subjected to heat treatment at a temperature of 50°C or more and 80°C or less.