JPH02227282A - Thermally sensitive recording medium - Google Patents

Abstract

PURPOSE:To obtain a thermally sensitive recording medium which is highly plasticizer- resistant by adding a specific compound to at least any of a recording layer, an intermediate layer between a support and the recording layer or a protecting layer provided on the recording layer. CONSTITUTION:A compound expressed by formula (I) is added to at least any of a recording layer, an intermediate layer between a support and the recording layer or a protecting layer provided on the recording layer. The compound shown by the formula, (I) should preferably be a compound with 'l' being an integer of 1 to 5, and the recommendable number of carbons of the alkyl group and alkoxy group of substituted groups R<1>, R<2>, R<3> ana R<4> is 1 to 4. Furthermore, the recommendable mixture ratio of the compound is 0.1 to 500 pts.wt. for 100 pts.wt. of coloring agent, Especially the coloring agent should preferably be contained in the recording layer. The basic dyes which make up the recording layer are triallylmethane dye and diphenylmethane dye. The inorganic or organic acid materials which color in contact with the basic dye are active clay, attapulgite, phenol compound, aromatic carboxylic acid. The recommendable mixture ratio of the acid material is 1 to 50 pts. wt. for 1 pt.wt. of the basic dye. The coating liquid for the thermally sensitive recording layer is prepared with water as a dispersant.

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial Application Field" The present invention relates to a heat-sensitive recording medium, and more particularly to a heat-sensitive recording medium with excellent storage stability of recorded images.

``Prior art'' Heat-sensitive recording materials that utilize a color reaction between a colorless or light-colored basic dye and an organic or inorganic coloring agent to obtain a recorded image by bringing a recoloring substance into contact with heat are often used. Are known.

Such heat-sensitive recording media are relatively inexpensive, and because the equipment described above is compact and easy to maintain, they are used not only as recording media for facsimiles and various computers, but also in a wide range of fields.

For example, one of the fields of use is P.O.
With the expansion of S (point of 5ales) systemization, the number of cases in which they are used as heat-sensitive recording labels is increasing.

However, when a POS system is introduced in a supermarket or the like, the labels often come into contact with water, lamp films, oil, etc., and as a result, the recorded image (print) on the heat-sensitive label becomes defective due to fading.

In order to improve such defects, methods have been proposed in which various storage improvers are added to the heat-sensitive recording layer.

For example, JP-A-62-164579 proposes a method in which a diphenylsulfone derivative having a glycidyl group is added to the recording layer. However, although the use of such diphenylsulfone derivatives improves the storage stability of recorded images against temperature and humidity, it is difficult to resist plasticization when in contact with wrap films for a long time and is strongly affected by the plasticizer contained in the wrap films. The agent properties are not improved satisfactorily, and as a result, the recorded barcodes smear, resulting in so-called thickening of the barcodes, resulting in misreading by POS systems.

``Problems to be Solved by the Invention'' An object of the present invention is to provide a heat-sensitive recording material with extremely excellent plasticizer resistance, in which a recorded image does not smear even when in contact with a plasticizer for a long time.

``Means for Solving the Problems'' The present invention provides a heat-sensitive recording layer comprising a support and a heat-sensitive recording layer containing a colorless or light-colored basic dye and a coloring agent capable of forming a color upon contact with the dye. The recording layer, the intermediate layer provided between the support and the recording layer, or the protective layer provided on the recording layer contains a compound represented by the following general formula (1). This is a heat-sensitive recording medium.

[In the formula, R1 and R1 each represent a halogen atom, an alkyl group, or an alkoxyl group; shows.

In addition, l represents an integer from 1 to 10, and m and n are each 0.
or an integer from 1 to 4.] "Action" Specific examples of the compound represented by the above general formula [I] include the following.

[In each formula, l represents an integer of 1 to 10. 〕Such. Of course,
The compounds are not limited to these, and two or more types of compounds can be used in combination if necessary.

Among the compounds represented by the above general formula (I), l is 1 to
Compounds having an integer of 5 are preferable because a thermosensitive recording material with better plasticizer resistance can be obtained.

Further, the number of carbon atoms in the alkyl group and alkoxyl group of the substituents R1, R1, R3 and R4 is preferably 1 to 4.

It is also possible to use a compound in which l in the general formula [I] is O, such as 4,4'-diglycidyloxydiphenyl sulfone, as long as the effects of the present invention are not impaired.

The amount of these compounds used is not particularly limited, but is generally 0.1 parts by weight per 100 parts by weight of the coloring agent.
It is desirable to adjust the amount within the range of 500 parts by weight, preferably 1 to 200 parts by weight.

As described above, in the present invention, the compound represented by the above general formula [I] is contained in at least one of the recording layer, intermediate layer, or protective layer. It is desirable to include it in a layer, especially a recording layer.

In the present invention, various known colorless or light-colored basic dyes can be used as the basic dye constituting the recording layer, and examples thereof include the following.

3.3-bis(p-dimethylaminophenyl)-6-dimethylaminophthalide, 3.3-bis(p-dimethylaminophenyl)phthalide, 3-(p-dimethylaminophenyl)-3-(1,2 -dimethylindol-3-yl)phthalide, 3-(p-dimethylaminophenyl)-
3-(2-methylindol-3-yl)phthalide, 3
,3-bis(1,2-dimethylindol-3-yl)
-5-dimethylaminophthalide, 3,3-bis(1゜2
-dimethylindol-3-yl)-6-dimethylaminophthalide, 3,3-bis(9-ethylcarbazole-
3-yl)-6-dimethylaminophthalide, 3.3-bis(2-phenylindol-3-yl)-6-dimethylaminophthalide, 3-p-dimethylaminophenyl-
Triallylmethane dyes such as 3-(1-methylpyrrol-3-yl)-6-dimethylaminophthalide, 4,4'
and sudimethylaminobenzhydrylbenzyl ether, N-halophenyl-leucoolamine, N-2,4,
5-) Diphenylmethane dyes such as dichlorophenyl leuco auramine, benzoyl leucomethylene blue, p
- Thiazine dyes such as nitrobenzoylleucomethylene blue, 3-methyl-spiro-dinaphthopyran, 3-ethyl-spiro-dinaphthopyran, 3-phenyl-spiro-dinaphthopyran, 3-benzyl-spiro-dinaphthopyran, 3-methyl-naphtho (6 ′-methoxybenzo)
Spiro dyes such as spiropyran, 3-propyl-spiro-dibenzobilane, lactam dyes such as rhodamine-B-anilinolactam, rhodamine (p-nitroanilino) lactam, rhodamine (0-chloroanilino) lactam, 3-dimethylamino- 7-methoxyfluorane, 3
-diethylamino-6-methoxyfluorane, 3-diethylamino-7-methoxyfluorane, 3-diethylamino-7-chlorofluorane, 3-diethylamino-6
-Methyl-7-chlorofluorane, 3-diethylamino-6,7-dimethylfluorane, 3-(N-ethyl-
p-)luidino)-7-methylfluorane, 3-diethylamine-7-N-acetyl-N-methylaminofluorane, 3-diethylamino-7-N-methylaminofluorane, 3-diethylamino-7-dibenzylamino Fluoran, 3-diethylamino-7-N-methyl-N-
Benzylaminofluorane, 3-diethylamino-7-
N-chloroethyl-N-methylaminofluorane, 3-
Diethylamino-7-diethylaminofluorane, 3-
(N-Ethyl-p-toluidino)-6-methyl-7-phenylaminofluorane, 3-(N-ethyl-p-toluidino)-6-methyl-7-(p-)luidino)fluorane, 3-diethylamino -6-methyl-7-phenylaminofluorane, 3-dibutylamino-6-methyl-
7-phenylaminofluorane, 3-diethylamino-
7-(2-carbomethoxy-phenylamino)fluorane, 3-(N-cyclohexyl-N-methylamino)-
6-methyl-7-phenylaminofluorane, 3-pyrrolidino-6-methyl-7-phenylaminofluorane,
3-Piperidino-6-methyl-7-phenylaminofluorane, 3-diethylamino-6-methyl-7-xylidinofluorane, 3-diethylamino-7-(0-chlorophenylamino)fluorane, 3-dibutylamino-
7-(o-chlorophenylamino)fluoran, 3-pyrrolidino-6-methyl-7-p-butylphenylaminofluoran, 3-diethylamino-7-(o-fluorophenylamino)fluoran, 3-dibutylamino-7
-(0-fluorophenylamino)fluorane, 3-(
N-methyl-N-n-amyl)amino-6-methyl-7
-phenylaminofluorane, 3-(N-ethyl-N-
n-amyl)amino-6-methyl-7-phenylaminofluorane, 3-(N-ethyl-N-isoamyl)amino-6-methyl-7-phenylaminofluorane, 3-
(N-methyl-N-n-hexyl)amino-6-methyl-7-phenylaminofluorane, 3-(N-ethyl-
Fluoran dyes such as N-n-hexyl)amino-6-methyl-7-phenylaminofluorane, 3-(N-ethyl-N-β-ethylhexyl)amino-6-methyl-7-phenylaminofluorane, etc. Two or more types of these basic dyes can be used in combination, if necessary.

Various types of inorganic or organic acidic substances that develop color upon contact with the above-mentioned basic dyes are known, and examples include the following.

Activated clay, attapulgite, colloidal silica, inorganic acidic substances such as aluminum silicate, 4-tert-butylphenol, 4-hydroxydiphenoxide, α-naphthol, β-naphthol, 4-hydroxyacetophenone, 4-tert-octylcatechol, 4. 4'
-5ec-butylidene diphenol, 4-phenylphenol, 2.2'-dihydroxydiphenyl, 4.4'
-isopropylidene bis(2-tert-butylphenol), 4.4'-isopropylidene diphenol, 2
．． 2-bis(4-hydroxyphenyl)-4-methylpentane, 4,4'-cyclohexylidene diphenol,
2.2'methylenebis(4-chlorophenol), hydroquinone, hydroquinone monobenzyl ether, 4-
Hydroxybenzophenone, 2.4-dihydroxybenzophenone, 2.4.4'-trihydroxybenzophenone, 2.2',4.4'-tetrahydroxybenzophenone, bis(3-tert-butyl-4-hydroxy-6-methyl phenyl) sulfide, bis(2-methyl-4-hydroxy-6-tert-7'tylphenyl) sulfide, 4,4'-dihydroxydiphenyl sulfide, 4,4'-dihydroxydiphenyl sulfone, 4-hydroxy-4'-methyl diphenyl sulfone,
4-hydroxy-47-methyldiphenylsulfone, 4
-Hydroxy-4'-isopropoxydiphenylsulfone, 4-hydroxy-3'4'-tetramethyldiphenylsulfone, bis(3-allyl-4-hydroxyphenyl)sulfone, 3゜4-dihydroxydiphenylsulfone, 3.4- Dihydroxy-4'-methyldiphenylsulfone, di(4-hydroxyphenylthioethoxy)
Methane, 1,5-di(4-hydroxyphenylthio)-
3-oxapencune, bis(4-hydroxyphenyl)
Vinegar M7'Tyl Ester, 1,3'; (2-(4
-hydroxyphenyl)-2-propyl]benzene, 1
．． 4-di(2-(4-hydroxyphenyl)-2-propyl)benzene, dimethyl 4-hydroxyphthalate, 4
-Methyl hydroxybenzoate, ethyl 4-hydroxybenzoate, propyl 4-hydroxybenzoate, -5ee-butyl 4-hydroxybenzoate, pentyl 4-hydroxybenzoate, phenyl 4-hydroxybenzoate, benzyl 4-hydroxybenzoate , tolyl 4-hydroxybenzoate, chlorophenyl 4-hydroxybenzoate, phenylpropyl 4-hydroxybenzoate, phenethyl 4-hydroxybenzoate, 4-hydroxybenzoate III -
Phenolic compounds such as p-chlorobenzyl, p-methoxybenzyl 4-hydroxybenzoate, novolac type phenolic resin, phenol polymer, benzoic acid, p-
tert-butylbenzoic acid, trichlorobenzoic acid, terephthalic acid, 3-sec-butyl-4-hydroxybenzoic acid, 3cyclohexyl-4-hydroxybenzoic acid, 3゜5-dimethyl-4-hydroxybenzoic acid, salicylic acid,
3-isopropylsalicylic acid, 3-tert-butylsalicylic acid, 3,5-di-tert-butylsalicylic acid, 3-benzylsalicylic acid, 3-(α-methylbenzyl)salicylic acid, 3-chloro-5(α-methylbenzyl)salicylic acid, Aromatic carboxylic acids such as 3-phenyl-5-(α,α-dimethylbenzyl)salicylic acid and 3,5-di-α-methylbenzylsalicylic acid, and these phenolic compounds, and aromatic carboxylic acids such as zinc, magnesium, Salts with polyvalent metals such as aluminum, calcium, titanium, manganese, tin, nickel, and even 1
．． thiourea derivatives such as 3-dichlorophenylthiourea,
Antipyrine complex of zinc thiocyanate, etc.

The ratio of the basic dye to the coloring agent is appropriately selected depending on the type of basic dye and coloring agent used, and is not particularly limited. The coloring agent is used in an amount of about 1 to 50 parts by weight, preferably about 2 to 10 parts by weight.

A coating solution for a heat-sensitive recording layer containing a basic dye, a coloring agent, and a compound represented by the general formula (1) is generally prepared by using water as a dispersion medium and stirring and milling using a ball mill, attritor, sand mill, etc.
It is prepared by dispersing it using a crusher.

Such coating liquids usually contain starches and binders as binders.
Hydroxyethylcellulose, methylcellulose, carboxymethylcellulose, gelatin, casein, gum arabic, polyvinyl alcohol, carboxyl group-modified polyvinyl alcohol, acetoacetyl group-modified polyvinyl alcohol, diisobutylene/maleic anhydride copolymer salt, styrene/maleic anhydride copolymer salt, ethylene,
Acrylic acid copolymer salt, styrene/acrylic acid copolymer salt, styrene/butadiene copolymer emulsion, urea resin, melamine resin, amide resin, etc. in an amount of 1 to 50% by weight based on the total solid content of the coating liquid. It is set up.

Furthermore, various auxiliaries can be added to the coating liquid as necessary, such as sodium dioctyl sulfosuccinate, sodium dodecylbenzenesulfonate, sodium lauryl alcohol sulfate, fatty acid metal salts, etc. Dispersants, UV absorbers such as benzophenone,
Other foaming agents, fluorescent dyes, coloring dyes, etc. may be added as appropriate.

In addition, as necessary, waxes such as zinc stearate, calcium stearate, polyethylene wax, carnauba wax, paraffin wax, and ester wax, kaolin, clay, talc, calcium carbonate, calcined kaolin, titanium oxide, diatomaceous earth, fine particulate anhydrous silica, It is also possible to add inorganic pigments such as activated clay, and a sensitizer can also be used in combination depending on the purpose. Specific examples of the sensitizer include fatty acid amides such as stearic acid amide, stearic acid methylene bisamide, oleic acid amide, palmitic acid amide, coconut fatty acid amide, 2.2'-
Methylenebis(4-methyl-5-tert-butylphenol), 4,4'-butylidenebis(6-tert-
butyl-3-methylphenol), 2,2'-methylenebis(4-ethyl-6-jerk-butylphenol)
, hindered phenols such as 2,4-di-tert-7'thyl-3-methylphenol, 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2
-Hydroxy-4-benzyloxybenzophenone, 1
．． 2-di(3-methylphenoxy)ethane, 1゜2-diphenoxyethane, 1-phenoxy-2-(4-methylphenoxy)ethane, l-phenoxy-2-(4-methoxyphenoxy)ethane, 1-phenoxy -2-(4-
chlorophenoxy)ethane, p-benzylbiphenyl,
Naphthyl benzyl ether, benzyl-4-methylthiophenyl ether, dimethyl terephthalate, diptyl terephthalate, dibenzyl terephthalate, diptyl isophthalate, phenyl 1-hydroxynaphthoate, and various known thermofusible substances, etc. can be mentioned. Among these sensitizers, 1
, 2-di(3-methylphenoxy)ethane, 1,2-diphenoxyethane, 1-phenoxy-2-(4-methylphenoxy)ethane, 1-phenoxy-2-(4-methoxyphenoxy)ethane, l- Phenoxy-2-(4-
Particularly preferred is chlorophenoxy)ethane.

The amount of sensitizer used is not particularly limited, but generally color former 1
It is desirable to adjust the amount within a range of about 4 parts by weight or less.

The method of forming the recording layer is not particularly limited, and for example, the recording layer coating liquid may be applied to the support by an appropriate coating method such as air knife coating, varibur blade coating, pure blade coating, short dwell coating, etc. and dried. Formed in a way. The amount of coating liquid applied is also not particularly limited, and is usually 2 to 12 g/r dry weight.
rr, preferably in the range of about 3 to 10 glrd.

In addition, when the compound represented by the general formula (I) is contained in the intermediate layer, the compound is dispersed in a coating liquid for the intermediate layer containing the binders as described above, and the compound is dispersed by a known coating method. The intermediate layer may be formed by coating and drying on a support.

Kaolin, clay,
Talc, calcium carbonate, calcined kaolin, titanium oxide,
Inorganic pigments such as diatomaceous earth, particulate anhydrous silica, activated clay, and various known auxiliaries can also be added. The amount of pigment used is not particularly limited, but generally binder 1! ! It is desirable to adjust the amount within a range of about 1 to 20 parts by weight per 1 part by weight. Moreover, there is no particular limitation on the amount of coating of the intermediate layer, but -i is 1 to 2.
It is adjusted within a range of about 0g/rd.

Incidentally, the coating liquid for the intermediate layer is generally prepared using water as a dispersion medium.

Furthermore, when the compound represented by the general formula (1) is to be contained in the protective layer, the specific compound is added to the coating liquid for the protective layer containing the various binders as described above, and an appropriate amount of the compound is added. It is coated onto the recording layer using a suitable coating device, dried and kept.
It is sufficient to form an i-layer.

Among the binders, acetoacetyl group-modified polyvinyl alcohol and carboxyl group-modified polyvinyl alcohol are particularly preferably used because they exhibit excellent effects when combined with the specific substance of the present invention.

Pigments can be added to the protective layer as necessary to further improve printability and sticking. Specific examples include calcium carbonate, zinc oxide, aluminum oxide, titanium dioxide, and silicon dioxide. , inorganic pigments such as aluminum hydroxide, barium sulfate, zinc sulfate, talc, kaolin, clay-calcined kaolin, colloidal silica, and organic pigments such as styrene microspheres, nylon powder, polyethylene powder, urea/formalin resin filler, raw starch particles, etc. can be mentioned.

The amount used is generally 5 to 100 parts by weight of the resin component.
It is desirable to adjust the amount within a range of about 500 parts by weight.

Furthermore, in the coating solution forming the protective layer, lubricants such as zinc stearate, calcium stearate, polyethylene wax, carnauba wax, paraffin wax, and ester wax, surfactants (dispersants, etc.) such as sodium dioctyl sulfosuccinate, etc. Various auxiliary agents such as a wetting agent) and an antifoaming agent may also be added as appropriate. Further, in order to further improve water resistance, a curing agent such as glyoxal, boric acid, dialdehyde starch, or epoxy compound may be added.

Incidentally, the coating liquid forming the protective layer is generally prepared using water as a dispersion medium.

The coating liquid for the protective layer thus prepared is applied onto the heat-sensitive recording layer using a suitable coating device, but if the coating amount exceeds 20 g/rrl in terms of dry weight, the recording sensitivity of the heat-sensitive recording medium may be significantly reduced. Generally 0.1 to 20 g
/rd, preferably within a range of about 0.5 to 10 g/d.

In the present invention, since a specific compound is added to at least one layer of the intermediate layer, recording layer, or protective layer, it is extremely plasticizer resistant and does not cause bleeding in the recorded image even if it comes into contact with the plasticizer for a long time. Although a heat-sensitive recording material with excellent properties can be obtained, it is also possible to further improve the storage stability by incorporating a specific compound into the intermediate layer or recording layer and further providing a protective layer on the recording layer. .

Furthermore, if necessary, a protective layer may be provided on the back side of the heat-sensitive recording material to further improve storage stability, an undercoat layer that does not contain a specific compound may be provided on the support, or an adhesive treatment may be applied to the back surface of the recording material. It is possible to add various known techniques in the field of heat-sensitive recording material manufacturing, such as processing it into an adhesive label.

Note that paper, plastic film, synthetic paper, etc. can be used as the support, but paper is most preferably used in terms of cost, coating suitability, etc.

"Example" The present invention will be described in more detail with reference to Examples below, but it is of course not limited to these.

Note that "parts" and "%" in the examples indicate "parts by weight J" and "% by weight", respectively, unless otherwise specified.

Example 1 ■ Preparation of liquid A 3-(N-ethyl-N-isoamyl)amino-6-methyl-7-phenylaminofluorane 10 parts Methyl cellulose 5% aqueous solution 5 parts water
40 parts of this composition was ground in a sand mill until the average particle size was 3 μm.

■ Preparation of Solution B 4-Hydroxy-4'-isopropoxydiphenylsulfone 30 parts Methylcellulose 5% aqueous solution 5 parts water
80 parts of this composition was ground in a sand mill until the average particle size was 3 μm.

■ 20 parts of 1.2-di(3-methylphenoxy)ethane manufactured by C Liquid 5% methylcellulose aqueous solution 5 parts of water
55 parts of this composition was ground in a sand mill until the average particle size was 3 μm.

■ In Di preparation liquid product, υ (however, 1″=, 2) 20 parts methylcellulose 5% 7kJ liquid 5 parts water
55 parts of this composition was ground in a sand mill until the average particle size was 3 μm.

■ Formation of recording layer A coating liquid obtained by mixing and stirring 50 parts of liquid A, 140 parts of liquid B, 180 parts of liquid C, 36 parts of liquid D, 160 parts of a 10% polyvinyl alcohol aqueous solution, and 35 parts of calcium carbonate was mixed at 50 g/nf.
A heat-sensitive recording material was obtained by coating and drying the mixture on base paper so that the coating amount after drying was 6 g/n.

Example 2 A thermosensitive recording material was obtained in the same manner as in Example 1 except that 20 parts of (!ζ2) was used instead of 20 parts of f' and 2.

Example 3 A thermosensitive recording material was obtained in the same manner as in Example 1 except that in the preparation of liquid D, 20 parts of (1=5) was used instead of 20 parts of (E''q2).

Example 4 In preparing Solution B, 30 parts of 2,2-bis(4-hydroxyphenyl)-4-methylpentane was used instead of 30 parts of 4-hydroxy-4'-isopropoxydiphenylsulfone.
A thermosensitive recording material was obtained in the same manner as in Example 1, except that

Example 5 In preparing Solution B, except that 30 parts of 4,4'-cyclohexylidene diphenol was used instead of 30 parts of 4-hydroxy-4'-isopropoxydiphenylsulfone.
A thermosensitive recording material was obtained in the same manner as in Example 1.

Example 6 3-(N-ethyl-N
-isoamyl)amino-6-methyl-7-phenylaminofluorane instead of 10 parts of 3-di-n-butylamino-6-methyl-7-phenylaminofluorane.
A thermosensitive recording material was obtained in the same manner as in Example 1, except that

Example 7 In preparing Solution A, 3-di-n-butylamino-7-(O
A thermosensitive recording material was obtained in the same manner as in Example 1 except that 15 parts of -chlorophenylamino)fluorane was used.

Example 8 In preparing Solution A, 3-diethylulamino-7-(0-
A thermosensitive recording material was obtained in the same manner as in Example 1 except that 15 parts of chlorophenylamino)fluorane was used.

Example 9 In preparing Solution A, 3-(N-ethyl-p-)luidino)- was used instead of 10 parts of 3-(N-ethyl-N-isoamyl)amino-6-methyl-7-phenylaminofluorane. A thermosensitive recording material was obtained in the same manner as in Example 1 except that 15 parts of 6-methyl-7-phenylaminofluorane was used.

Example 10 In preparing Solution A, 3-(N-ethyl-p-)luidino)- was used instead of 10 parts of 3-(N-ethyl-N-isoamyl)amino-6-methyl-7-phenylaminofluorane. 6-Methyl-7-(p-toluidino)fluorane 1
A thermosensitive recording material was obtained in the same manner as in Example 1 except that 5 parts were used.

Example 11 ■ Formation of intermediate layer 100 parts of fired clay (trade name: Ansilex, manufactured by EMC, oil absorption: 110 m1/100 g), 100 parts of a 10% polyvinyl alcohol aqueous solution, and 200 parts of water were mixed and stirred to form a dispersion. I got it. 90 parts of the obtained dispersion and 10 parts of Solution D prepared in the same manner as in Example 1 were mixed and stirred to obtain a coating liquid for the intermediate layer. 50 g of this intermediate layer coating liquid
An intermediate layer was formed by coating and drying the mixture on a base paper of 7 g/m to a coating weight of 7 g/rd after drying.

■ Formation of recording layer 50 parts of liquid A, 140 parts of liquid B, 180 parts of liquid C, 160 parts of 10% polyvinyl alcohol aqueous solution, 35 parts of calcium carbonate.
The components were mixed and stirred to obtain a coating liquid for a recording layer. The obtained recording layer coating liquid was applied onto the intermediate layer in an amount of 6 g/dry after drying.
A heat-sensitive recording material was obtained by coating and drying so as to obtain RD.

Comparative Example 1 A thermosensitive recording material was obtained in the same manner as in Example 1 except that liquid D was not used in forming the recording layer.

Comparative Example 2 A thermosensitive recording material was prepared in the same manner as in Example 1, except that 20 parts of 4,4'-diglycidyloxydiphenylsulfone was used instead of 20 parts of υ (1#2) in the preparation of liquid D. I got it.

Comparative Example 3 In the preparation of solution D, 4,4'-diglycidyloxy-3 was added instead of 20 parts (l#2).
,3',5.5'-tetramethyldiphenylsulfone 2
A thermosensitive recording material was obtained in the same manner as in Example 1 except that 0 part was used.

The following evaluation tests were conducted on the 14 types of heat-sensitive recording bodies thus obtained, and the results are listed in Table 1.

[Color density]

Thermal printer (Texas Instruments, PC)
The color density of the recorded image obtained by printing with a Macbeth densitometer (manufactured by Macbeth Co., Ltd., model RD-100R) was measured.

[Plasticizer resistance]

Wrap vinyl dichloride wrap film (manufactured by Mitsui Toatsu Chemical Co., Ltd.) three times over a polypropylene pipe (40nφ pipe).
On top of that is a barcode printer (manufactured by Chick, H-96).
06) The heat-sensitive recording material on which the barcode was printed and colored was sandwiched so that the printed colored side was facing outward, and then a vinyl chloride wrap film was wrapped three times over it and left at 20°C for 5 days. The printed barcode was read 10 times using a hand scanner (Nippon Denso Co., Ltd., BHT-1), and the plasticizer resistance was evaluated based on the number of times it could be read.

Table 1 Example 12 ■ Formation of recording layer A thermosensitive recording material was obtained in the same manner as in Example 1.

(2) Formation of protective layer 200 parts of a 10% aqueous solution of acetoacetyl group-modified polyvinyl alcohol, 60 parts of kaolin, and 140 parts of water were mixed and stirred to obtain a coating liquid for a protective layer. The obtained coating liquid was applied onto the recording layer of the above heat-sensitive recording material so that the coating amount after drying was 6 g/rd, and was dried to obtain a heat-sensitive recording material having a protective layer.

Example 13 ■ Formation of recording layer A thermosensitive recording material was obtained in the same manner as in Example 1.

■ Formation of a protective layer A coating liquid for H1IJi obtained by mixing and stirring 200 parts of a 10% aqueous solution of carboxyl group-modified polyvinyl alcohol, 60 parts of calcium carbonate, and 140 parts of water was dried on the recording layer of the heat-sensitive recording material. The coating was coated and dried so that the subsequent coating amount was 6 glrd to obtain a heat-sensitive recording material having a protective layer.

Comparative Example 4 A thermosensitive recording material having a protective layer was obtained in the same manner as in Example 12 except that a thermosensitive recording material prepared in the same manner as in Comparative Example 1 was used.

Comparative Example 5 A thermosensitive recording material having a protective layer was obtained in the same manner as in Example 12 except that a thermosensitive recording material prepared in the same manner as in Comparative Example 2 was used.

The color density of the four types of heat-sensitive recording materials thus obtained was evaluated in the same manner as described above, and the plasticizer resistance was further evaluated in the following manner, and the results are listed in Table 2.

[Plasticizer resistance]

A vinyl chloride lamp film (manufactured by Mitsui Toatsu Chemical Co., Ltd.) is wrapped three times around a polypropylene pipe (40 mmφ pipe), and a barcode printer (manufactured by Chic Co., Ltd., H-9) is placed on top of it.
606), the heat-sensitive recording material on which the barcode was printed and colored was sandwiched so that the colored side of the print was on the outside, and a vinyl chloride wrap film was wrapped three times over it, and the material was left at 40°C for 5 days. The printed barcode was read 10 times using a hand scanner (Nippon Denso Co., Ltd., BHT-1), and the plasticizer resistance was evaluated based on the number of times it could be read.

Table 2 "Effects" As is clear from the results in Tables 1 and 2, the heat-sensitive recording materials of the present invention are all excellent heat-sensitive recording materials with extremely excellent plasticizer resistance and good color development. there were.

Claims (1)

[Scope of Claims] A heat-sensitive recording material in which a heat-sensitive recording layer containing a colorless or light-colored basic dye and a coloring agent capable of coloring upon contact with the dye is provided on a support, the recording layer, the support 1. A heat-sensitive recording material, characterized in that at least one of the intermediate layer provided between the body and the recording layer or the protective layer provided on the recording layer contains a compound represented by the following general formula [I]. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [I] [In the formula, R^1 and R^2 each represent a halogen atom, an alkyl group, or an alkoxyl group, and X is ▲There are mathematical formulas, chemical formulas, tables, etc.▼ show. However, R^3 and R^4 each represent a halogen atom, an alkyl group, or an alkoxyl group, and p and q are each 0.
or an integer from 1 to 4. In addition, l represents an integer from 1 to 10, and m and n are each 0.
or an integer from 1 to 4. ]