JPS60234883A - Thermal recording paper - Google Patents

Abstract

PURPOSE:To provide a thermal recording material free of fading of recorded images, particularly, due to moisture or heat, free of generation of ground color fogging and ensuring that images are stable even when hair treatment toiletries, oils or fats are adhered thereto, by incorporating a hydroxybenzoyloxybenzoic acid ester as a stabilizer in an amount of a specified ratio to the amount of an organic color developer. CONSTITUTION:It is known that, in general, where two or more organic color developers are used together, coloring of a coating liquid in the step of preparing the coating liquid or development of a ground color with time after coating are liable to occur. However, a hydroxybenzoyloxybenzoic acid ester of general formula ( I ), wherein R is 1-12C alkyl or cycloalkyl, used a stabilizer has none of such defects, though it has a color developing capability, and it can be used extremely effectively as a stabilizer for compensating for insufficient aspects of organic color developers. The stabilizer is added in an amount of 0.1-50wt% based on the amount of the organic color developers. If the amount of the stabilizer is less than 0.1wt%, little effect of the addition can be expected, and on the other hand, if the amount is more than 50wt%, the balance thereof with the amount of the organic color developer is lost, and a color tone peculiar to each of the color developers can not be obtained.

Description

Detailed Description of the Invention Field of the Invention The present invention relates to a thermal recording paper, and in particular to a thermal recording paper that is suitable for high-density and high-speed recording and has excellent image stability. Thermal recording paper is usually produced by grinding and dispersing a colorless or light-colored basic colorless dye and an organic color developer such as a 7-nol substance into fine particles, and then mixing the two.
A coating liquid obtained by adding fillers, sensitivity improvers, lubricants, and other auxiliaries is applied to a support such as paper or film, and a color record is obtained by an instantaneous chemical reaction caused by heating. be. In this case, various hues can be obtained by selecting the type of colorless dye.In recent years, thermal recording methods have become popular and applications have diversified, and recording speeds have increased and image quality has improved, i.e. resolution has increased to 4 degrees. Emphasis has been placed on increasing densification in order to

For this reason, the thermal energy of the thermal head of a recording device is becoming smaller and smaller, and the thermal recording paper used for this needs to have sufficient color sensitivity to obtain clear color recording even with a small amount of heat. required to hold.

In addition, the heat-sensitive record 4a cannot avoid being touched by human hands due to its function as an information recording paper, but the handler's hands and fingers may be exposed to hair products used on a daily basis or oils and fats contained in the sweat of the skin. Since thermal recording paper is often contaminated with oily substances such as However, thermal recording paper generally does not have sufficient stability against these oily substances, and the color concentration in contaminated areas may decrease or even disappear.
There is also a phenomenon in which discoloration occurs when the white background becomes contaminated.

Furthermore, when the recorded images are stored for a long period of time, light
Under the influence of external conditions such as humidity and heat, colors may fade, or so-called one-ground color Capri 1 may occur, in which white areas become unnecessarily colored.

Conventionally, as a stabilizer to improve the storage stability of recorded images, JP-A-49-45747, JP-A-54-18752, %
It is described in Japanese Patent Publication No. 57-83495 that phenolic antioxidants are effective. However, when these stabilizers are used extensively, the color development sensitivity tends to decrease due to the dilution effect.

OBJECTS OF THE INVENTION The object of the present invention is to provide a colorless basic dye and an organic color developer which, when contained in a heat-sensitive coloring layer, have a sufficient dynamic coloring density.
We use heat-sensitive recording materials that have excellent long-term preservation of recorded images, do not fade due to humidity, heat, etc., do not cause background color capri, and have stable images even when hair products or oils and fats adhere to them. It is about providing.

Structure of the Invention The above object is to provide a heat-sensitive recording paper having a heat-sensitive coloring layer containing a basic colorless dye and an organic color developer, which has the following general formula (
Hydroxybenzoyloxybenzoic acid ester represented by I) is contained as a stabilizer in a ratio of 1 to 50 times the organic color developer [wherein R is 1 to 12 carbon atoms]
(A)m(B)n(A)m(B)n (A and B are hydrogen atoms, halogen atoms,
represents a nitro group, lower alkyl group, lower alkoxy group or hydroxyl group, m and n are integers from D to 6 and 9
m = n. l is an integer from 1 to 5.

Moreover, A and B- may be the same group. ). ] The stabilizer hydroxybenzoyloxybenzoic acid ester represented by the above general formula (I) was prepared by the applicant in a patent application filed in 1973.
As described in No. 9-42130, this compound itself causes a color reaction when heated with a basic colorless dye, but the present invention focuses on its function as a stabilizer rather than its color developing ability. It is something. Generally, it is known that when two or more types of organic color developers kljF- are used, liquid coloring at the coating liquid preparation stage and background coloring over time after coating are likely to occur. Although the stabilizer of the present invention has color developing ability, it has no such drawbacks and can be used very effectively as a stabilizer to compensate for the inadequacies of organic color developers.

In the present invention, the above-mentioned stabilizer is 0% relative to the organic color developer.
．． It is characterized by being added in a range of 1 to 50% by weight.

If it is less than 0.1% by weight, it is too small and almost no effect can be expected. On the other hand, if it exceeds 50g@%, the balance with the amount of organic color developer used is lost, and each organic colorant It becomes impossible to obtain a unique color tone.

In the explanation of the general formula (I), the term "lower 1" which defines an alkyl group and an alkoxy group usually indicates a group containing 1 to 5 carbon atoms. Examples of the lower alkyl group include a methyl group,
Ethyl group, n-globyl group.

Isopropyl group, n-butyl group, 5ec-butyl group,
- Tert-butyl group is exemplified, and lower alkoxy groups include methoxy group, ethoxy group, n-propoxy group,
Illustrative examples include an in-1a-7 group, an n-butquine group, a see-butquine group, and a 1jlert-butoxy group.

In general formula (■), when R is an alkyl group, it may be linear or branched, such as a methyl group, ethyl group, rho-10vir group, inflovir group, n-butyl group, Isobutyl group, 5ec-butyl group, hexyl group, octyl group, inoctyl group.

Examples include a nonyl group and a dodecyl group, and when R is a cycloalkyl group, a nclopentyl group or a P-tert group is exemplified.
-butyrun Chlorohexyl group, 2-ethylcyclohexyl group, and cyclohexyl group are exemplified, and in the case of 0, it is a usual aralkyl group or a fluorine atom.

Nitro groups such as chlorine atoms and bromine atoms.

Mono-substitution with a lower alkyl group, lower alkoxy group, or hydroxyl group (the number of substituents is up to 5)
In the case of a 7-nyl group, the usual thumenyl group and the same substituent as the substituent described in detail in the explanation of R as an aralkyl group are exemplified, and the tunyl group containing α - In the case of a naphthyl group and β-naphthyl group, R includes the usual α-naphthyl group or β-naphthyl group, and includes the same substituents as those described in detail in the general explanation of the aralkyl group. An example is a naphthyl group.

Among the hydroxybenzoyloxybenzoic acid ester compounds represented by the above-mentioned general formula (I), the above-mentioned general formula (I) is preferable in consideration of stabilizing ability, availability of synthetic raw materials, synthesis difficulty, cost, etc. As a stabilizer represented by 0, which is a compound represented by the following general formula (n) in which an a-o-e- group and a -〇)L12 () group are both bonded to the rose position, as a stabilizer melting point range, sublimability, molecular weight,
A comprehensive review of the sensitivity (thermal responsiveness), oil resistance, etc. of thermal recording paper containing a stabilizer! , the most preferred stable agent represented by the general formula (n) is R
is a 01 to C1□ alkyl group, cyclohexyl group, benzyl group, α-naphthyl group, β-naphthyl group, or β-huunethyl group.

Typical hydroxybenzoyloxybenzoate esters used in the present invention include, but are not limited to, the following.

shu 0 0 h Examples of the organic color developer used in the present invention include pysfunol A, 4-hydroxybenzoic acid esters, 4-hydroxyphthalic acid diesters, phthalic acid monoesters,
Bis-(hydroxyphenyl) sulfides, 4-hydroxy 7-dilaryl sulfone M, 4-hydroxyphenylaryl sulfonates, 1,3-di[2-(hydroxyphenyl)-2-phylloyl]-benzene kind,
Other color developers are preferred, and specific examples of these are shown below.

Bisphenol A 4.4'-inglobylidene difunol (also known as bisphenol A) 4.4'-cyclohexylitine diphenol p+p'-
(1-methyl-n-hexylidene) diphenol 4
-Hydroxybenzoic acid esters Benzyl 4-hydroxybenzoate Butyl 4-hydroxybenzoate 10biru 4-hydroxybenzoate Isopropyl 4-hydroxybenzoate Butyl 4-hydroxybenzoate Isobutyl 4-hydroxybenzoate Methylbenzyl Dimethyl 4-hydroxyphthalate 4-Diisopropyl hydroxyphthalate 4-Dibenzyl hydroxyphthalate 4-Hytomyxyphthalate dihexyl phthalate monobenzyl ester Monocyclohexyl phthalate ester Monophenyl phthalate ester Monomethyl phthalate Monophthalate monobenzyl phthalate Ethyl phenyl ester Monoalkylbenzyl phthalate Monohalogen Benzyl phthalate Monoalkoxybenzyl phthalate ester Bis-(hydroxyphenyl) sulfides Bis-(4-hydroxy-3-tert-butyl-6-
゛Methylphenyl) sulfide bis-(4- and axy-2,5-dimethyl 7-inkyl)
Sulfide bis-(4-hydroxy-2-methyl-5-ethylphenyl) sulfide bis-(4-hydroxy-2-methyl-5-isopropylphenyl) sulfide bis-(4-hydroxy-2,3-dimethyltunyl) )
Sulfide bis-(4-hydroxy-2,5-diethyltunyl)
sulfidobis-(4-human-a-x-2,5-diisofurobirtunyl)sulfidobis-(4-hydroxy-2,3,6-drimethylphenyl)sulfidohis-(2,4,5-trihytoa Kisifu;le) sulfide bis-(4-hydroxy-2-cyclohechusilu 5)
-methylphenyl)sulfidebis-(2,3,4-)lyhydroxyphenyl)sulfidebis-(4,5-dihydroaxy-2-tert-butylph≦nyl)sulfidebis-(4-hydroxy-2,5 -diphenylphenyl)sulfide bis-(4-hydroxy-2-tert-octyl-5
,-methylphenyl) sulfide 4-hydroxy-4'-isopropoxydiphenylsulfone 4-hydroxy-4'-methyldiphenylsulfone 4-hydroxy-4'-n-butyloxydiphenylsulfone 4-hydroxyphenylbenzenesulfonate 4
-Hydroxyphenyl-p-tolylsulfonate 4-Hydroxyphenylmesitylenesulfonate 4-Hydroxyphenyl-p-chlorobenzenesulfonate 4-Hydroxyphenyl-p-tert-butylbenzenesulfonate 4-Hydroxyphenyl-p-yne 10-bodies Xybenzenesulfonate 4-hydroxyphenyl-1'-naphthalenesulfonate 4-hydroxyphenyl-2'-naphthalenesulfonate 1,6-di(2-(4-hydroxyphenyl)-2
-Propyl-to-benzene 1.3-di(2-(4-hydroxy-3-alkylthunyl)-2-7"rovil")-benzene 1.3-di(2-(2,4-dihydroxyphenyl)-
2-70biru]-benzene 1.3-di(2-(2-hydroxy-5-methylphenyl)-2-propyl-to-benzene 1.5-dihydroxy-6(α,α-dimethylbenzyl)-benzene other p -tert-butylphenol 2.4-dihydroxybenzophenone Nohoraku-type phenolic resin 4-hydroxyacetophenone p-phenylphenol benzyl-4-hydroxyphenylacetate p-benzylphenol These color-fastening agents may be used alone or in combination. Can be used in combination.

Among the organic color developers mentioned above, hensyl 4-hydroxybenzoate, 4-hydroxyphenyl-2'-naphthalene sulfonate, 1,3-di(2-(4-hydroxyphenyl)-2-propyltoobenzene, 1 .5-dihydro-6(α,α-dimethylbenzyl)-benzene and 4
It has been found that -hydroxy-4'-inopropoxydiphenyl sulfone exhibits the most remarkable effect of the stabilizer of the present invention.

The reason for this is unclear, but these 51! All of the organic color developers in i have a 4-hydroxyamyl s-formation Ho-@- similar to the stabilizer of the present invention in molecular structure;
It is thought that having this structure is somehow involved.

Furthermore, If! f was proposed in No. 56-144193-
As shown in Figure 2, when benzyl 4-hydroxybenzoate is combined with a fluoran dye, it is possible to obtain a highly sensitive thermal recording paper with excellent dynamic color development. Thermal recording paper that uses thermal recording paper has a tendency for the density of the image formed by heat application to decrease over time, for crystals to precipitate on the surface of the image, which is the so-called "powdering phenomenon", and for oiliness on both sides. There was a drawback that the stability against substances was insufficient.Hydroxybenzoyloxybenzoate is effective in improving the above-mentioned drawback, and by adding it, the stability of the image is significantly improved.

On the other hand, the basic colorless dye used in the present invention is not particularly limited, but tri7-nylmethane type, fluoran type, azaphthalide type, etc. are preferable, and specific examples of these are shown below.

Triphenylmethane leuco dye 5.3-bis(p-dimethylaminophenyl)-,6-
Cynotylaminophthalide (also known as crystal violet lactone) Fluoran leuco dye 6-diethylamino-6-methyl-anilinofluoran 3-(N-ethyl-1)-)-6-methyl-7-anilitfur Quaternary 3-(N-ethyl-N-isoamyl)amino-6-methyl-7-anilitous fluoran 3-diethylamino-6-methyl-7-(o,p-dimethylanilino)fluoran 3-pyrrolidino 6- Methyl-7-anilinofluorane 3-piperidino-6-methyl-7-anilinofluorane 3-(N-cyclohexyl-N-methylamino)-6-
Methyl-7-anilinofluoran 3-diethylamino-7-(m-)lifluoromethylanilino)fluoran 3-diptylamino-7-(o-chloroanilino)fluoran 3-diethylamino-6-methyl-chlorofluoran 3- diethylamino-6-methyl-fluorane 3-cyclohexylamino-6-chlorofluoran 6-diethylamino-7-(0-chloroanilino)fluorane 3-diethylamino-benzo(,)-fluorane 3-(
4-diethylamine-2-methoxyphenyl).

-3-(1-ethyl-2-methylindol-5-yl)-4-7zaftalide.

5-(4-diethylamino-2-ethoxypher)-
3-(1-ethyl-2-methylindol-6-yl)
-7-azaphthalide 3-i/L= ) -4-aza7thalide 3-(4-N-
cyclohexyl-N-methylamino-2-methoxyphenyl)-3-(1-ethyl-2-methylindole-3
-yl)-4-azaphthalide These dyes can also be used alone or in combination.
Can be used in combination with more than one species. In particular, in the present invention,
Basic dyes include 6-diethylamino-6-methyl-anilinofluorane, 3-(N-cyclohexyl-N
-methylamine)-6-methyl-7-anilinofluorane, 5-(N-ethyl-N-isoamyl)amino-6-
Methyl-7-anilinofluorane, 5-(4-diethyl-2-ethylphenyl)-3-(1-ethyl-
When 2-1f (ruindol-3-yl)-4-azaphthalide is used alone, a thermal recording paper with significantly lower dynamic color density can be obtained.

Also, a mixture of 3-diethylamino-6-methyl-7-anilinofluorane and 3-(N-cyclohexyl-N-methylamino)-6-methyl-7-anilinofluorane is used as a basic dye. In this case, a thermal recording paper having a significantly high dynamic color density and excellent oil resistance and storage stability can be obtained.

The above-mentioned organic color developer, basic colorless dye, and stabilizer are atomized to a particle size of several microns or less using a grinder such as a ball mill, attritor, or sand grinder, or an appropriate emulsifying device, and then pulverized depending on the purpose. A coating liquid is made by adding various additive materials. This aqueous solution usually contains polyvinyl alcohol, modified polyvinyl alcohol, hydroxyethyl cellulose, methyl cellulose, starches, styrene-maleic anhydride copolymer, vinyl acetate maleic anhydride copolymer, styrene-butadiene copolymer, etc. agents, as well as kaolin, calcined kaolin, diatomaceous earth, Merck, and titanium oxide.

Inorganic or organic fillers such as aluminum hydroxide are added, but this also includes mold release agents such as fatty acid metal salts, lubricants such as waxes, ultraviolet absorbers such as pensifunone and triazole, and waterproof agents such as glyoxal. 9 Dispersants, antifoaming agents, pressure anticapsulants (e.g. fatty acid amide, ethylene bisamide, montan wax, polyethylene wax), sensitizers (e.g. dibenzyl terephthalate, P-benzoj/oxybenzoic acid) benzyl, P-tolyl carbonate, P-benzyl vinyl)
, stabilizers (e.g. phthalate moddiester gold salts, P-
Tert-butylbenzoic acid metal salt.

Nitrobenzoic acid metal salts) etc. can all be used.

By applying this coating liquid to paper or various films, the desired heat-sensitive recording paper can be obtained.

Effect of the invention The effects of the present invention include the following points.

(1) Due to its excellent thermal responsiveness, high-density and clear recording can be obtained even in high-speed, high-density recording.

(2) The image is stable against adhesion of hair styling products and oils and fats. (Good oil resistance.) (3) Excellent storage stability of recorded images, especially no fading of recorded images due to moisture, heat, etc., and no background color fogging.

(4) There is no sublimation and no powder blowing phenomenon is observed.

EXAMPLES Next, typical examples will be described to specifically explain the present invention.

[Example 1] Solution A (dye dispersion) Solution B (color improver dispersion) Solution C (stabilizer dispersion) Each solution of the above composition was ground to a particle size of 6 microns using an attritor.

Next, mix the dispersion liquid in the following proportions to make a betting liquid. 9.1 @ 50 g of the above coating liquid on one side of 7 m" base paper, the amount applied is about 6 Og/ The sheets were coated and dried to a smoothness of 200 to 60 with a super calender.
It was processed so that it became 0 seconds.

[Examples 2 and 6] In Example 1, when preparing the coating liquid, stabilizer dispersion C
The same procedure was carried out except that the liquid was changed to 5 parts and 1.25 parts instead of 10 parts.

[Comparative Examples 1 and (G2)] Heat-sensitive recording paper was prepared in the same manner as in Example 1, except that a coating liquid containing 15 parts of stabilizer dispersion liquid C and a coating liquid containing no liquid C were used. It was created.

The thermal recording papers obtained in Examples 1 to 3 and Comparative Examples 1 to 2 above were subjected to quality performance tests on the following items, and the test results are shown in Table 1.

Note (1) Color density; Macbeth densitometer (RD-514,'
Uses an amber filter. same as below. ) Measured at 0 Note (2) Static color density;
The color was developed by pressing for 5 seconds at a pressure of g lad and measured with a Macbeth densitometer. Note (3) Dynamic color density; RO) 1 part - thermal printing tester THP 8050 using gold, pulse @ 11. [The image density recorded for 12 milliseconds and an applied voltage of 16.5 V was measured using a Macbeth densitometer.

Note (4) Blank paper shelf life: Measured with an uncolored partial tube Macbeth densitometer.

Note (5) Humidity resistance: Ground color density is 0 after being left under high humidity conditions of 40℃, 90% R)l for 24 hours □Note (6) Heat resistance: After being left under high temperature dry conditions of 60℃ for 24 hours ground color density.

Note (7) Record storage properties: Using heat-sensitive facsimile KB-4800 made by Tokyo Shibaura Electric, applied voltage 1B, 03v1
The image density recorded with a pulse width of 3.2 milliseconds was measured using a Macbeth densitometer.

Note (8) Humidity resistance: Under high humidity conditions of 40℃ and 90℃RH,
Image density after being left for 24 hours.

Note (9) Heat resistance: Image density after being left for 24 hours under high temperature drying conditions at 60°C.

Employee Oil resistance: After spreading a droplet of castor oil (0.8 mg) onto a glass plate with a syringe and spreading it over LOcrI, it was measured with the above meter using a rubber stamp of 1 crIL x 1.5 cR.

Note 1) Remaining rate of color density: Calculated from the following formula 0 As is clear from Table 1, it can be seen that addition of a stabilizer improves color density and various stability. In addition, in Comparative Example 1, in which a large amount of stabilizer (601%) was blended with the organic color developer (Bistunol A), the original line point color of Bistunol A was lost, resulting in a black with a strong greenish tinge. It became an image of.

[Example 4] Solution D (dye dispersion) Solution E (developer dispersion) I”g (stabilizer dispersion fL) Each solution of the above composition was ground with an attritor to a particle size of 3 microns. .

Next, the dispersion liquid was mixed in the following ratio to prepare a coating liquid. Using the above coating liquid, a thermosensitive recording paper was prepared in the same manner as in Example 1.

[Reliable Example 5] In Example 4, when preparing the coating liquid, the stabilizer dispersion F
The same procedure was repeated except that 2.5 parts of the liquid was used instead of 10 parts.

[Comparative Example 3] A coating liquid was prepared in the same manner as in Example 4, except that the stabilizer dispersion liquid F was not used, and a thermosensitive recording paper was produced.

[Example 6] Solution G (dye dispersion) Solution H (developer dispersion) Solution I (stabilizing agent dispersion) Six solutions of the above compositions were ground with an attritor to a particle size of 3 microns.

Next, the dispersion liquid was mixed in the following ratio to prepare a coating liquid. Using the above coating liquid, a thermal recording paper was prepared in the same manner as in Example 1.

[Actual stock example puff]

In Actual Example 6, when preparing the coating liquid, 1 part of stabilizer H liquid was added.
The same procedure was carried out except that 2.5 seconds was used instead of 0 copies.

[Comparative Example 4] A coating liquid was prepared in the same manner as in Example 6, except that stabilizer dispersion liquid (1) was not used, and heat-sensitive recording paper was prepared.

[Example 8] Solution J (dye dispersion) [3-diethylamino-6-methyl-7-ni solution (developer dispersion) Solution L (stable dispersion e, > Each Fei of the above composition, Particle size 3 with t″ attritor
Grind down to microns.

Next, the dispersion liquid was mixed in the following ratio to prepare a coating liquid. Using the above coating liquid, a thermosensitive recording paper was prepared in the same manner as in Example 1.

[Example 9] The same procedure as in Example 8 was repeated except that 2.5 parts of the stabilizer dispersion liquid was used instead of 10 parts of the stabilizer dispersion liquid when preparing the coating liquid.

[Comparative Example 5] Agent Stability (1) A coating solution was prepared in the same manner as in Example 8, except that the dispersion solution was not used, and heat-sensitive recording paper was produced.

[Example 10] Coating solution (dye dispersion) Solution N (developer dispersion) Solution 0 (stabilized dispersion with other agents) Six solutions of the above composition were ground to a particle size of 3 microns in at least 2 cycles. do.

Next, mix the dispersion liquid in the following proportions to make a coating liquid. Using the above coating liquid, proceed in the same manner as in Example 1.Thermal Recording I
Example 11 The procedure of Example 10 was repeated except that in preparing the coating liquid, the amount of the stabilizer dispersion liquid 0 was changed to 2.5 parts instead of 10 parts.

[Comparative Example 6] A coating liquid was prepared in the same manner as in Example 10, except that the stabilizer dispersion liquid O was not used, and heat-sensitive recording paper was prepared.[Example 12] P liquid (dye dispersion) Q Liquid (coloring agent dispersion feL) R liquid (stabilizing agent dispersion) 6 liquids of the above composition were ground with an attritor to a particle size of 3 microns.

Next, the dispersion liquid was mixed in the following ratio to prepare a coating liquid. Using the above coating liquid, a thermosensitive recording paper was prepared in the same manner as in Example 1.

[Example 13] A coating liquid was prepared in the same manner as in Example 12 except that the amount of stabilizer dispersion liquid R was changed to 2.5 parts instead of 10 parts.

[Comparative Example 7] The coating liquid was transformed in the same manner as in 12, and the thermal recording paper P was created. The results are summarized in Table 2.

According to Table 2 above, when each Example is compared with each Comparative Example, the addition of the stabilizer of the present invention improves the dynamic coloring density, and also improves white paper storage stability, record storage stability, and oil resistance. It can be seen that the image stability is improved. In addition, when the heat-sensitive recording paper of Comparative Example 6 was heated at room temperature for one month, the defects of the organic color developer used, benzyl 4-hydroxybenzoate, appeared, and a considerable amount of powder was blown on the surface of the recorded image. However, in the corresponding Examples 4 and 5, this defect was improved and powder blowing did not occur.

Patent applicant: Jujo Paper Co., Ltd. Yoshitomi Pharmaceutical Co., Ltd. ・　−5j

Claims (4)

[Claims] (1) In a thermosensitive recording paper having a heat-sensitive coloring layer containing a basic colorless dye that is usually colorless or light-colored and an organic color developer, hydroxybenzoyloxybenzoic acid ester represented by the following general formula (I) is used as a stabilizer. A thermosensitive recording paper characterized in that it contains 0.1 to 50% by weight of an organic color developer. [In the formula, R is an alkyl group or cycloalkyl group having 1 to 12 carbon atoms. (A)m(A)m (However, A and B are respectively hydrogen atoms, halogen atoms,
It represents a nitro group, a lower alkyl group, a lower alkoxy group, or a humanmixyl group, and A and B may be the same group. l is an integer from 1 to 5. m and n are integers of 0 to 6, and m = n. ). ] (2) As a stabilizer represented by the general formula (I), R-
The thermosensitive recording paper according to claim 1, characterized in that a compound represented by the following general formula (II) in which both the 0-C- group and the -0H group are bonded at the rose position is used. (3) As a stabilizer represented by the general formula (n),
R is a C1 to CI□ alkyl group, cyclohexyl group, benzyl group, α-naphthyl group, β-naphthyl group, or β
-Claim 2, characterized in that it uses a chemical compound which is a phunetyl group.
Thermal recording paper described in section. (4) The organic color developer is benzyl 4-hydroxybenzoate,
4-Hydroxyphenyl-2'-naphthalene sulfonate, 1,3-di[2-(4-hydroxyphenyl)-2
-70 pills]-benzene, 1,3-dihydroxy-6(
Claim 1 which is a 4-hydroxyfunyl compound selected from the group consisting of α,α-dimethylbenzyl)-benzene and 4-hydroxy-4′-(sobroboxydiphenylsulfone. The heat-sensitive recording paper described in item 5 of the item or frame.