JP2018062083A - Heat-sensitive recording material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat-sensitive recording material with excellent storage stability of a chromogenic recording part.SOLUTION: The heat-sensitive recording material employs a phenolic color developing compound and a compound represented by the general formula (1) in the figure as color developing compounds. (In the formula (1), Rto Reach independently represent a hydrogen atom, halogen atom, nitro group, amino group, alkyl group, alkoxy group, aryloxy group, alkylcarbonyloxy group, alkylcarbonylamino group, arylcarbonylamino group, alkylsulfonylamino group, arylsulfonylamino group, monoalkylamino group, dialkylamino group, or arylamino group.)SELECTED DRAWING: None

Description

  The present invention relates to a heat-sensitive recording material excellent in storage stability of a color recording part.

  In general, heat-sensitive recording materials are obtained by dispersing a leuco dye and a developer such as a phenolic compound separately into fine particles, and then mixing both of them together, such as a binder, a sensitizer, a filler, and a lubricant. A coating solution obtained by adding additives is applied to paper, film, synthetic paper, etc., and develops color by chemical reaction that occurs when one or both of leuco dye and developer are melted and contacted by heating. It is for recording. For the color development of such a heat-sensitive recording material, a thermal printer or the like with a built-in thermal head is used. Compared with other recording methods, this thermal recording method is (1) no noise during recording, (2) no need for development and fixing, (3) maintenance-free, (4) machine is relatively Due to its low cost, it is widely used in the facsimile field, the output of computers, the field of printers such as calculators, the field of recorders for medical measurement, the field of automatic ticket machines, the field of thermal recording labels, and the like.

  In recent years, the use of heat-sensitive recording materials has expanded, and the use of labels, train tickets, coupon tickets, etc. has increased with the establishment of POS systems in retail stores and supermarkets and the automation systems for transportation facilities. In these applications, storage stability such as water resistance and alcohol resistance of a color recording portion (indicating printing, images, patterns, etc.) against water, alcohol, etc. is important. In addition, the demand for high-speed recording has further increased in order to improve productivity, and development of a heat-sensitive recording material that can sufficiently cope with high-speed recording is strongly desired. In this case, a developer with a low melting point and a low heat of fusion is required, but this property is likely to cause deterioration of the non-colored recording area (background fogging) of the heat-sensitive recording material during production, use or storage. In addition to high whiteness, improvement in storage stability of the non-colored recording area (background) is also strongly desired.

  In general, a developer having a phenolic hydroxyl group has a high developing ability. Among them, a bisphenol developer has a high color density, and therefore, for example, 2,2-bis (4-hydroxyphenylpropane) disclosed in Patent Document 1 is used. Many reports have been reported, including (bisphenol A) and 4,4′-dihydroxydiphenylsulfone (bisphenol S) disclosed in Patent Document 2. However, they are inferior in water resistance and have drawbacks such as deterioration of the background (background fogging).

  Therefore, Patent Document 3 discloses a heat-sensitive recording material using a specific color developing compound that is excellent in water resistance and has a high background stability against heat, but is included in a plastic sheet or an eraser. Improvement in plasticizer resistance is strongly desired because the storage stability (plasticizer resistance) of the color recording part (background) with respect to the plasticizer is poor.

US Pat. No. 3,539,375 Japanese Patent Laid-Open No. 57-11088 Japanese Patent Application No. 2015-254099

  SUMMARY OF THE INVENTION An object of the present invention is to provide a heat-sensitive recording material having excellent storage stability of a color recording part for the purpose of solving the drawbacks of the prior art.

  The inventor of the present invention has completed the present invention as a result of intensive studies to achieve the above object.

That is, the present invention
[1] A heat-sensitive recording material using a compound represented by the following general formula (1) and a phenol-based developer compound,

（式（１）中、Ｒ^１〜Ｒ^５はそれぞれ独立に水素原子、ハロゲン原子、ニトロ基、アミノ基、アルキル基、アルコキシ基、アリールオキシ基、アルキルカルボニルオキシ基、アルキルカルボニルアミノ基、アリールカルボニルアミノ基、アルキルスルホニルアミノ基、アリールスルホニルアミノ基、モノアルキルアミノ基、ジアルキルアミノ基、アリールアミノ基を表す。）
［２］フェノール系顕色性化合物が、４，４’−ジヒドロキシジフェニルスルホンであることを特徴とする［１］に記載の感熱記録材料、
［３］一般式（１）が下記式（２）で表される化合物であることを特徴とする［１］または［２］に記載の感熱記録材料、

(In the formula (1), R ^{1 to} R ⁵ are each independently a hydrogen atom, a halogen atom, a nitro group, an amino group, an alkyl group, an alkoxy group, an aryloxy group, an alkylcarbonyloxy group, an alkylcarbonylamino group, an arylcarbonyl group. (Amino group, alkylsulfonylamino group, arylsulfonylamino group, monoalkylamino group, dialkylamino group, arylamino group are represented.)
[2] The heat-sensitive recording material according to [1], wherein the phenol-based color developing compound is 4,4′-dihydroxydiphenylsulfone,
[3] The heat-sensitive recording material according to [1] or [2], wherein the general formula (1) is a compound represented by the following formula (2):

（式（２）中、Ｒ^３は前記と同義である）
［４］式（１）において、Ｒ^３がメチル基であることを特徴とする［１］乃至［３］のいずれか一項に記載の感熱記録材料、
［５］［１］乃至［４］のいずれか一項に記載の感熱記録材料を含む感熱記録層、
［６］［１］乃至［５］のいずれか一項に記載の感熱記録材料または感熱記録層を含む感熱記録紙、
に関する。

(In formula (2), R ³ is as defined above)
[4] The heat-sensitive recording material according to any one of [1] to [3], wherein in formula (1), R ³ is a methyl group,
[5] A heat-sensitive recording layer comprising the heat-sensitive recording material according to any one of [1] to [4],
[6] A heat-sensitive recording paper comprising the heat-sensitive recording material or heat-sensitive recording layer according to any one of [1] to [5],
About.

  The present invention provides a heat-sensitive recording material in which the color recording portion exhibits high stability with respect to a plasticizer by using the compound represented by the general formula (1) and a phenol-based color developing compound as the color developing compound. I was able to.

The present invention will be described in detail.
The present invention usually includes a colorless or light-color developing compound, a compound represented by the above general formula (1) as a developing compound and a phenol developing compound, and if necessary, other developing properties. The present invention relates to a heat-sensitive recording material containing a compound, a sensitizer, a storage stability improver, and the binder and filler described below, and other additives.

  The phenolic color developing compound used in the present invention means a compound having a hydroxy group directly bonded to a benzene ring in the molecule, and a compound known per se can be used. Specific examples thereof include α-naphthol, β-naphthol, p-octylphenol, 4-t-octylphenol, pt-butylphenol, p-phenylphenol, 1,1-bis (p-hydroxyphenyl) propane, 2, 2-bis (p-hydroxyphenyl) propane (also known as bisphenol A or BPA), 2,2-bis (p-hydroxyphenyl) butane, 1,1-bis (p-hydroxyphenyl) cyclohexane, 4,4′- Thiobisphenol, 4,4′-cyclo-hexylidene diphenol, 2,2′-bis (2,5-dibromo-4-hydroxyphenyl) propane, 4,4′-isopropylidenebis (2-t-butylphenol) 2,2′-methylenebis (4-chlorophenol), 4,4′-dihydroxydiphenyl Sulfone, 4-hydroxy-4′-methoxydiphenylsulfone, 2,4′-dihydroxydiphenylsulfone, 4-hydroxy-4′-isopropoxydiphenylsulfone, 4-hydroxy-4′-ethoxydiphenylsulfone, 4-hydroxy-4 '-Propoxydiphenylsulfone, 4-hydroxy-4'-vinyloxydiphenylsulfone, 4-hydroxy-4'-butoxydiphenylsulfone, 4-hydroxy-4'-benzyloxydiphenylsulfone, methyl bis (4-hydroxyphenyl) acetate Butyl bis (4-hydroxyphenyl) acetate, benzyl bis (4-hydroxyphenyl) acetate, 2,4-dihydroxy-2′-methoxybenzanilide and the like.

  Among these phenol-based color developing compounds, 2,2-bis (p-hydroxyphenyl) propane, 4,4′-dihydroxydiphenylsulfone, 2,4′-dihydroxydiphenylsulfone, 4-hydroxy-4′- Isopropoxy diphenyl sulfone, 4-hydroxy-4′-propoxy diphenyl sulfone, and 4-hydroxy-4′-vinyloxydiphenyl sulfone are preferable, and 4,4′-dihydroxydiphenyl sulfone is particularly preferable.

As a halogen atom in R < ¹ > -R < ⁵ > of General formula (1), a fluorine atom, a chlorine atom, and a bromine atom are mentioned, A fluorine atom or a chlorine atom is preferable.

Examples of the alkyl group in R ^{1 to} R ⁵ of the general formula (1) include a linear, branched, or cyclic alkyl group. Of these, a linear or branched chain is preferable, and a linear is more preferable. The range of the carbon number is usually C1 to C12, preferably C1 to C8, more preferably C1 to C6, and still more preferably C1 to C4. Specific examples thereof include linear chains such as methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, n-undecyl and n-dodecyl. Alkyl groups; branched chain alkyl groups such as isopropyl, isobutyl, sec-butyl, t-butyl, isopentyl, isohexyl, and isooctyl; cyclic alkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl;

Examples of the alkoxy group in R ^{1 to} R ⁵ of the general formula (1) include a linear, branched, or cyclic alkoxy group. Among them, a linear or branched chain is preferable, and a linear is more preferable. The range of the carbon number is usually C1 to C12, preferably C1 to C8, more preferably C1 to C6, and still more preferably C1 to C4. Specific examples thereof include linear ones such as methoxy, ethoxy, n-propoxy, n-butoxy, n-pentoxy, n-hexyloxy, n-heptoxy, n-octyloxy, n-nonyloxy, n-decyloxy; isopropoxy , Isobutoxy, sec-butoxy, t-butoxy, isoamyloxy, t-amyloxy, isohexyloxy, t-hexyloxy, isoheptoxy, t-heptoxy, isooctyloxy, t-octyloxy, 2-ethylhexyloxy, isononyloxy, isodecyloxy, etc. Are C3-C10); cyclic (preferably C3-C7) such as cyclopropoxy, cyclobutoxy, cyclopentoxy, cyclohexyloxy, cycloheptoxy; preferably linear or branched alkoxy groups.

The aryloxy group in R ^{1 to} R ⁵ of the general formula (1) is preferably a C6-C12 aryloxy group, and specific examples thereof include phenoxy, naphthyloxy, biphenyloxy and the like.

Examples of the alkylcarbonyloxy group in R ^{1 to} R ⁵ of the general formula (1) include a linear, branched or cyclic alkylcarbonyloxy group, and a C1 to C10 alkylcarbonyloxy group is preferable, and specific examples thereof are as follows. Methylcarbonyloxy, ethylcarbonyloxy, n-propylcarbonyloxy, n-butylcarbonyloxy, n-pentylcarbonyloxy, n-hexylcarbonyloxy, n-heptylcarbonyloxy, n-octylcarbonyloxy, n-nonylcarbonyloxy , N-decylcarbonyloxy and the like; isopropylcarbonyloxy, isobutylcarbonyloxy, sec-butylcarbonyloxy, t-butylcarbonyloxy, isoamylcarbonyloxy, t-amylcarbonyloxy Si, isohexylcarbonyloxy, t-hexylcarbonyloxy, isoheptylcarbonyloxy, t-heptylcarbonyloxy, isooctylcarbonyloxy, t-octylcarbonyloxy, 2-ethylhexylcarbonyloxy, isononylcarbonyloxy, isodecylcarbonyloxy Branched chain (preferably C3 to C10) such as cyclopropylcarbonyloxy, cyclobutylcarbonyloxy, cyclopentylcarbonyloxy, cyclohexylcarbonyloxy, cycloheptylcarbonyloxy and the like (preferably C3 to C7); A linear or branched alkylcarbonyloxy group is preferable, and a linear alkylcarbonyloxy group is more preferable. An arylcarbonyloxy group, preferably a C6-C12 arylcarbonyloxy group (specific examples include phenylcarbonyloxy, naphthylcarbonyloxy, biphenylcarbonyloxy and the like).

Examples of the alkylcarbonylamino group in R ^{1 to} R ⁵ of the general formula (1) include a linear, branched or cyclic alkylcarbonylamino group, and a C1 to C10 alkylcarbonylamino group is preferable, and specific examples thereof are as follows. Methylcarbonylamino, ethylcarbonylamino, n-propylcarbonylamino, n-butylcarbonylamino, n-pentylcarbonylamino, n-hexylcarbonylamino, n-heptylcarbonylamino, n-octylcarbonylamino, n-nonylcarbonylamino , N-decylcarbonylamino and the like; isopropylcarbonylamino, isobutylcarbonylamino, sec-butylcarbonylamino, t-butylcarbonylamino, isoamylcarbonylamino, t-amylcarbonylamino , Isohexylcarbonylamino, t-hexylcarbonylamino, isoheptylcarbonylamino, t-heptylcarbonylamino, isooctylcarbonylamino, t-octylcarbonylamino, 2-ethylhexylcarbonylamino, isononylcarbonylamino, isodecylcarbonylamino A branched chain such as cyclopropylcarbonylamino, cyclobutylcarbonylamino, cyclopentylcarbonylamino, cyclohexylcarbonylamino, cycloheptylcarbonylamino, etc. (preferably C3 to C7); Includes a linear or branched alkylcarbonylamino group, more preferably a linear alkylcarbonylamino group.

The arylcarbonylamino group in R ^{1 to} R ⁵ in the general formula (1) is preferably a C6-C12 arylcarbonylamino group, and specific examples thereof include phenylcarbonylamino, naphthylcarbonylamino, biphenylcarbonylamino, and the like. .

Examples of the alkylsulfonylamino group in R ^{1 to} R ⁵ of the general formula (1) include a linear, branched or cyclic alkylsulfonylamino group, and a C1 to C10 alkylsulfonylamino group is preferable, and specific examples thereof are as follows. , Methylsulfonylamino, ethylsulfonylamino, n-propylsulfonylamino, n-butylsulfonylamino, n-pentylsulfonylamino, n-hexylsulfonylamino, n-heptylsulfonylamino, n-octylsulfonylamino, n-nonylsulfonylamino , N-decylsulfonylamino, isopropylsulfonylamino, isobutylsulfonylamino, sec-butylsulfonylamino, t-butylsulfonylamino, isoamylsulfonylamino, t-amylsulfonyl Mino, isohexylsulfonylamino, t-hexylsulfonylamino, isoheptylsulfonylamino, t-heptylsulfonylamino, isooctylsulfonylamino, t-octylsulfonylamino, 2-ethylhexylsulfonylamino, isononylsulfonylamino, isodecylsulfonylamino A branched chain such as cyclopropylsulfonylamino, cyclobutylsulfonylamino, cyclopentylsulfonylamino, cyclohexylsulfonylamino, cycloheptylsulfonylamino and the like (preferably C3-C7); preferably Is linear or branched, more preferably linear.

The arylsulfonylamino group in R ^{1 to} R ⁵ of the general formula (1) is preferably a C6-C12 arylsulfonylamino group, and specific examples thereof include phenylsulfonylamino, toluenesulfonylamino, naphthylsulfonylamino, biphenylsulfonylamino. Etc.

Examples of the monoalkylamino group in R ^{1 to} R ⁵ in the general formula (1) include a linear, branched or cyclic monoalkylamino group, and a mono C1 to C10 alkylamino group is preferable. , Methylamino, ethylamino, n-propylamino, n-butylamino, n-pentylamino, n-hexylamino, n-heptylamino, n-octylamino, n-nonylamino, n-decylamino; Isopropylamino, isobutylamino, sec-butylamino, t-butylamino, isoamylamino, t-amylamino, isohexylamino, t-hexylamino, isoheptylamino, t-heptylamino, isooctylamino, t-octylamino, 2-ethylhexylamino, isononylamino, isode Branched chain such as ruamino (preferably C3 to C10); cyclic (preferably C3 to C7) such as cyclopropylamino, cyclobutylamino, cyclopentylamino, cyclohexylamino, cycloheptylamino; preferably linear or A branched one, more preferably a straight one is mentioned.

Examples of the dialkylamino group in R ^{1 to} R ⁵ of the general formula (1) include a linear, branched or cyclic dialkylamino group, and a di-C1 to C10 alkylamino group is preferable, and specific examples thereof include dimethyl Amino, diethylamino, di-n-propylamino, di-n-butylamino, di-n-pentylamino, di-n-hexylamino, di-n-heptylamino, di-n-octylamino, di-n- Straight chain such as nonylamino, di-n-decylamino; diisopropylamino, diisobutylamino, di-sec-butylamino, di-t-butylamino, diisoamylamino, di-t-amylamino, diisohexylamino, di- t-hexylamino, diisoheptylamino, di-t-heptylamino, diisooctylamino, di-t- Branched chain such as octylamino, di- (2-ethylhexyl) amino, diisononylamino, diisodecylamino (preferably having two C3 to C10 branched chains); dicyclopropylamino, dicyclobutylamino, dicyclopentylamino , Dicyclohexylamino, dicycloheptylamino and the like (preferably having two C3-C7 cyclic groups); preferably linear or branched, more preferably linear.

Examples of the arylamino group in R ^{1 to} R ⁵ of the general formula (1) include a monoarylamino group or a diarylamino group, and a mono C6 to C12 arylamino group is preferable. Specific examples thereof include phenylamino (anilino). ), Naphthylamino, biphenylamino and the like. On the other hand, examples of the diC6-C12 arylamino group as the arylamino group include diphenylamino, dinaphthylamino, and di (biphenyl) amino.

As R < ¹ > -R < ⁵ > of General formula (1) in this invention, a methyl group or a hydrogen atom is especially preferable.

The substitution position of the partial skeleton represented by the following general formula (4) bonded to one benzene ring of the diphenylurea structure in the general formula (1) is ortho to the aminocarbonyl group on the benzene ring. Position, meta position, or para position, ortho position or meta position is preferable, and meta position is particularly preferable.

Specific examples of the compound in the present invention include the specific examples shown in Table 1 below, but are not limited thereto.

Next, a method for producing the compound of the present invention will be described.
The compound of this invention is manufactured by combining two well-known manufacturing methods shown below.
[Manufacturing process 1]

（式中、Ｒ^１〜Ｒ^５は、前記と同義である。）

(In the formula, R ^{1 to} R ⁵ are as defined above.)

  The compound of the general formula [1-2] can be produced by reacting the aminophenol of the formula [1-1] with an acid halide or acid anhydride in the presence or absence of a base.

  The usage-amount of the acid halide used for this reaction is 0.1-50 mol times normally with respect to 1 mol of aminophenols of a formula [1-1], and 1-5 mol times is preferable.

  In general, an acid halide can be produced by reacting a compound represented by the following general formula [1-4] with thionyl chloride or oxalyl chloride.

（式中、Ｒ^１〜Ｒ^５は、前記と同義である。）

(In the formula, R ^{1 to} R ⁵ are as defined above.)

  The usage-amount of the acid anhydride used for this reaction is 0.1-50 mol times normally with respect to 1 mol of aminophenols of Formula [1-1], and 1-5 mol times is preferable.

  Examples of the base optionally used in this reaction include inorganic bases such as sodium hydroxide, potassium hydroxide, sodium hydrogen carbonate, sodium carbonate, potassium hydrogen carbonate, potassium carbonate, and cesium carbonate; triethylamine, pyridine, diisopropylethylamine, and the like. Of the organic base. The usage-amount of a base is 0.1-50 mol times normally with respect to 1 mol of aminophenols of a formula [1-1], and 1-5 mol times is preferable.

  [Manufacturing process 2]

（式中、Ｒ^１〜Ｒ^５は、前記と同義である。）

(In the formula, R ^{1 to} R ⁵ are as defined above.)

  The compound of the general formula [1-3] can be produced by reacting the compound of the general formula [1-2] with phenyl isocyanate in the presence or absence of a base. The amount of phenyl isocyanate used in this reaction is usually 0.1 to 50 moles, preferably 0.1 to 5 moles per mole of the compound of the general formula [1-2].

  Examples of the base optionally used in this reaction include inorganic bases such as sodium hydroxide, potassium hydroxide, sodium hydrogen carbonate, sodium carbonate, potassium hydrogen carbonate, potassium carbonate, and cesium carbonate; organic such as triethylamine and diisopropylethylamine A base. The usage-amount of these bases is 0.1-50 mol times normally with respect to 1 mol of compounds of general formula [1-2], and 1-5 mol times is preferable.

  The solvent used in these two production steps is not particularly limited as long as it does not affect the reaction. For example, N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, etc. Amide compounds; halogenated hydrocarbon compounds such as methylene chloride and chloroform; aromatic hydrocarbon compounds such as benzene, toluene, and xylene; ethers such as dioxane, tetrahydrofuran, anisole, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, and diethylene glycol diethyl ether Compound; Nitrile compound such as acetonitrile; ketone compound such as acetone and 2-butanone; ester compound such as ethyl acetate and butyl acetate; sulfone compound such as sulfolane; Sulfoxide compounds such as methyl sulfoxide and the like, which may be used alone or in combination. In the production process 1, water may be used as necessary.

  The reaction temperature of these two production steps is usually −78 to 100 ° C., preferably 0 to 80 ° C., and the reaction time may be 10 minutes to 24 hours.

In addition to the above production method, the compound of the present invention can be synthesized by combining the following two known production methods.
[Manufacturing process 3]

上記一般式［２−１］の化合物は、塩基の存在下または不存在下、式［１−１］のアミノフェノールとイソシアン酸フェニルを反応させることにより製造することができる。この反応に用いられるイソシアン酸フェニルの使用量は、一般式［１−１］の化合物１モルに対して通常０．１〜５０モル倍であり、０．１〜５モル倍が好ましい。

The compound of the general formula [2-1] can be produced by reacting the aminophenol of the formula [1-1] with phenyl isocyanate in the presence or absence of a base. The usage-amount of the phenyl isocyanate used for this reaction is 0.1-50 mol times normally with respect to 1 mol of compounds of general formula [1-1], and 0.1-5 mol times is preferable.

  Examples of the base optionally used in this reaction include inorganic bases such as sodium hydroxide, potassium hydroxide, sodium hydrogen carbonate, sodium carbonate, potassium hydrogen carbonate, potassium carbonate, and cesium carbonate; organic such as triethylamine and diisopropylethylamine A base. The usage-amount of these bases is 0.1-50 mol times normally with respect to 1 mol of compounds of General formula [1-1], and 1-5 mol times is preferable.

（式中、Ｒ^１〜Ｒ^５は、前記と同義である。）

(In the formula, R ^{1 to} R ⁵ are as defined above.)

[Manufacturing process 4]
The compound of the general formula [1-3] can be produced by reacting the compound of the formula [2-1] with an acid halide or acid anhydride in the presence or absence of a base.

  The usage-amount of the acid halide used for this reaction is 0.1-50 mol times normally with respect to 1 mol of compounds of Formula [2-1], and 1-5 mol times is preferable.

  In general, an acid halide can be produced by reacting a compound represented by the following general formula [1-4] with thionyl chloride or oxalyl chloride.

（式中、Ｒ^１〜Ｒ^５は、前記と同義である。）

(In the formula, R ^{1 to} R ⁵ are as defined above.)

  The usage-amount of the acid anhydride used for this reaction is 0.1-50 mol times normally with respect to 1 mol of compounds of Formula [2-1], and 1-5 mol times is preferable.

  Examples of the base optionally used in this reaction include inorganic bases such as sodium hydroxide, potassium hydroxide, sodium hydrogen carbonate, sodium carbonate, potassium hydrogen carbonate, potassium carbonate, and cesium carbonate; triethylamine, pyridine, diisopropylethylamine, and the like. Of the organic base. The usage-amount of a base is 0.1-50 mol times normally with respect to 1 mol of compounds of Formula [2-1], and 1-5 mol times is preferable.

  The solvent used in these two production steps is not particularly limited as long as it does not affect the reaction. For example, N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, etc. Amide compounds; halogenated hydrocarbon compounds such as methylene chloride and chloroform; aromatic hydrocarbon compounds such as benzene, toluene, and xylene; ethers such as dioxane, tetrahydrofuran, anisole, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, and diethylene glycol diethyl ether Compound; Nitrile compound such as acetonitrile; ketone compound such as acetone and 2-butanone; ester compound such as ethyl acetate and butyl acetate; sulfone compound such as sulfolane; Sulfoxide compounds such as methyl sulfoxide and the like, which may be used alone or in combination. In the production process 4, water may be used as necessary.

  The reaction temperature of these two production steps is usually −78 to 100 ° C., preferably 0 to 80 ° C., and the reaction time may be 10 minutes to 24 hours.

  In forming the heat-sensitive recording material in the present invention, the color developing compound is usually 1 to 50% by mass, preferably 5 to 30% by mass, and the compound represented by the above general formula (1) as a color developing compound and a phenolic compound. The total amount of the color compound is usually 1 to 50% by mass, preferably 5 to 30% by mass, the sensitizer is 1 to 80% by mass, the preservability improver is usually 0 to 30% by mass, and the binder is usually 1 to 90% by mass, filler is usually 0-80% by mass, and other lubricants, surfactants, antifoaming agents, and UV absorbers are each used in an arbitrary ratio, for example, usually 0-30% by mass each (mass%) Is the mass ratio of each component in the thermosensitive coloring layer). In a more preferred embodiment, the mass ratio of the compound represented by the general formula (1) and the phenolic color developing compound in the above composition is preferably 9: 1 to 1: 9, and 7: 3 to 2: 8. Is particularly preferred. In the heat-sensitive recording material of the present invention, a known color developing compound, sensitizer or other additive may be used in combination other than the above components.

  The color-forming compound used in the present invention is not particularly limited as long as it is generally used for pressure-sensitive recording paper and heat-sensitive recording paper. Examples of the chromogenic compound used include fluoran compounds, triarylmethane compounds, spiro compounds, diphenylmethane compounds, thiazine compounds, lactam compounds, and fluorene compounds, with fluorane compounds being preferred.

  Specific examples of the fluorane compound include 3-diethylamino-6-methyl-7-anilinofluorane, 3-dibutylamino-6-methyl-7-anilinofluorane, 3- (N-methyl-N- Cyclohexylamino) -6-methyl-7-anilinofluorane, 3- (N-ethyl-N-isopentylamino) -6-methyl-7-anilinofluorane, 3- (N-ethyl-N-isobutyl) Amino) -6-methyl-7-anilinofluorane, 3- [N-ethyl-N- (3-ethoxypropyl) amino] -6-methyl-7-anilinofluorane, 3- (N-ethyl- N-hexylamino) -6-methyl-7-anilinofluorane, 3-dipentylamino-6-methyl-7-anilinofluorane, 3- (N-methyl-N-propylamino) -6-me Ru-7-anilinofluorane, 3- (N-ethyl-N-tetrahydrofurylamino) -6-methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7- (p-chloroanilino) fluorane 3-diethylamino-6-methyl-7- (p-fluoroanilino) fluorane, 3- [N-ethyl-N- (p-tolyl) amino] -6-methyl-7-anilinofluorane, 3- Diethylamino-6-methyl-7- (p-toluidino) fluorane, 3-diethylamino-7- (o-chloroanilino) fluorane, 3-dibutylamino-7- (o-chloroanilino) fluorane, 3-diethylamino-7- (o -Fluoroanilino) fluorane, 3-dibutylamino-7- (o-fluoroanilino) fluorane, 3-diethylamino-7- 3,4-dichloroanilino) fluorane, 3-pyrrolidino-6-methyl-7-anilinofluorane, 3-diethylamino-6-chloro-7-ethoxyethylaminofluorane, 3-diethylamino-6-chloro-7 -Anilinofluorane, 3-diethylamino-7-chlorofluorane, 3-diethylamino-7-methylfluorane, 3-diethylamino-7-octylfluorane, 3- [N-ethyl-N- (p-tolyl) Amino] -6-methyl-7-phenethylfluorane and the like, and 3-dibutylamino-6-methyl-7-anilinofluorane is preferred.

  Specific examples of triarylmethane compounds include, for example, 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide (also known as crystal violet lactone or CVL), 3,3-bis (p-dimethyl). Aminophenyl) phthalide, 3- (p-dimethylaminophenyl) -3- (1,2-dimethylaminoindol-3-yl) phthalide, 3- (p-dimethylaminophenyl) -3- (2-methylindole- 3-yl) phthalide, 3- (p-dimethylaminophenyl) -3- (2-phenylindol-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-ethylcarbazol-3-yl) -5-dimethylaminophthalide, 3,3- (2-phenylindol-3-yl) -5-dimethylaminophthalide, 3-p-dimethylaminophenyl-3- ( 1-methylpyrrol-2-yl) -6-dimethylaminophthalide and the like.

  Specific examples of the spiro compound include, for example, 3-methylspirodinaphthopyran, 3-ethylspirodinaphthopyran, 3,3′-dichlorospirodinaphthopyran, 3-benzylspirodinaphthopyran, 3-propylspirobenzo. Pyran, 3-methylnaphtho- (3-methoxybenzo) spiropyran, 1,3,3-trimethyl-6-nitro-8′-methoxyspiro (indoline-2,2′-benzopyran), etc .; specific examples of diphenylmethane compounds Are, for example, N-halophenyl-leucooramine, 4,4-bis-dimethylaminophenylbenzhydrylbenzyl ether, N-2,4,5-trichlorophenylleucooramine, and the like. Specific examples of thiazine compounds include For example, benzoylleucomethylene blue, p-nitrobenzoylleucome Specific examples of lactam compounds include, for example, rhodamine B anilinolactam, rhodamine Bp-chloroanilinolactam, etc .; specific examples of fluorene compounds include, for example, 3,6-bis (dimethylamino) fluorene Spiro (9,3 ′)-6′-dimethylaminophthalide, 3,6-bis (dimethylamino) fluorene spiro (9,3 ′)-6′-pyrrolidinophthalide, 3-dimethylamino-6-diethylamino Fluorene spiro (9,3 ′)-6′-pyrrolidinophthalide and the like. These color forming compounds are used alone or in combination.

  The color developing compound that can be used together in the present invention is not particularly limited, and examples thereof include benzotriazole derivatives, saccharin derivatives, sulfonamide derivatives, malonamide derivatives, thiourea derivatives, sulfonylurea derivatives, diphenylsulfone derivatives substituted with amino groups, Examples include aromatic carboxylic acid derivatives.

  The benzotriazole derivative is not particularly limited, and specific examples thereof include benzotriazole, 5-methyl-1H-benzotriazole, 4-methyl-1H-benzotriazole, phenyl-6benzotriazole, and phenyl-5. Examples include benzotriazole, chloro-5 benzotriazole, chloro-5 methylbenzotriazole, chloro-5 isopropyl-7 methyl-4 benzotriazole, bromo-5 benzotriazole, and the like.

  The saccharin derivative is not particularly limited, and specific examples thereof include saccharin, 1-bromosaccharin, 1-nitrosaccharin, 1-aminosaccharin and the like.

  The sulfonamide derivative is not particularly limited, and specific examples thereof include methanylanilide, N-phenyl-4-aminobenzenesulfonamide, neourilone, N-phenyl-3-nitrobenzenesulfonamide, N- (4- Methyl-2-nitrophenyl) benzenesulfonamide, N- (2-methoxyphenyl) -p-ruenesulfonamide, N- (4-toxylphenyl) -p-toluenesulfonamide, N- (2-chlorophenyl) -p -Toluenesulfonamide, N- (4-methylphenyl) -4-methylbenzenesulfonamide, N- (2-methylphenyl) -p-toluenesulfonamide, N-phenylbenzenesulfonamide, 4-bromo-4'- Methylbenzenesulfonanilide, N- (4-bromophenyl) ben Sulfonamide, N- (3-nitrophenyl) benzenesulfonamide, N- (4-nitrophenyl) -4-methylbenzenesulfonamide, N- (4-methylphenyl) benzenesulfonamide, N-phenyl-p- Toluenesulfonamide, N-phenylbenzenesulfonamide and the like can be mentioned.

  The malonamide derivative is not particularly limited, but specific examples thereof include N, N′-bis (2-hydroxy-5-phenyl) phenyl-malonamide, N, N′-diphenylmalonamide, N, N '-Bis (2,4,6-tribromophenyl) malonamide, N, N'-bis (2-aminophenyl) malonamide, N, N'-bis (m-trifluoromethylphenyl) malonamide, N, N' -Bis (m-trifluoromethylphenyl) α, α-dichloromalonamide, diethylmalondianilide and the like.

  The thiourea derivative is not particularly limited, and specific examples thereof include 1,3-bis (4-methylphenyl) thiourea, 1,3-bisphenylthiourea, 1,3-bis (4 -Chlorophenyl) thiourea, 1,3-bis (4-methoxyphenyl) thiourea, N, N'-bis (3-chlorophenyl) thiourea, 1,3-bis (3-methoxyphenyl) thiourea, 3-bis (3-methylphenyl) thiourea, 1,3-bis (4-benzylphenyl) thiourea, 1,3-bis (4-bromophenyl) thiourea, 1-phenyl-3-butylthiourea, 1 -Phenyl-3-ethylthiourea and the like.

  The sulfonylurea derivative is not particularly limited, and specific examples thereof include N- (p-toluenesulfonyl) -N ′-(3-n-butylaminosulfonylphenyl) urea, N- (p-toluenesulfonyl). ) -N '-(4-trimethylacetophenyl) urea, N- (benzenesulfonyl) -N'-(3-p-toluenesulfonyloxyphenyl) urea, N- (p-toluenesulfonyl) -N '-(3 -P-toluenesulfonylphenyl) urea, N- (p-toluenesulfonyl) -N '-(3-phenylsulfonyloxyphenyl) urea, tolbutamide, chloropropamide and the like.

  The diphenylsulfone derivative substituted with an amino group is not particularly limited, and specific examples thereof include 2-aminodiphenylsulfone, 2,2′-diaminodiphenylsulfone, 3,3′-diaminodiphenylsulfone, 4,4′-diaminodiphenyl sulfone and the like can be mentioned.

  The aromatic carboxylic acid derivative is not particularly limited, and specific examples thereof include benzyl p-hydroxybenzoate, ethyl p-hydroxybenzoate, dibenzyl 4-hydroxyphthalate, dimethyl 4-hydroxyphthalate, Examples include ethyl 5-hydroxyisophthalate, 3,5-di-t-butylsalicylic acid, 3,5-di-α-methylbenzylsalicylic acid, aromatic carboxylic acid or a polyvalent metal salt thereof.

  Specific examples of the sensitizer (thermofusible compound) used in the present invention include waxes such as animal and vegetable waxes and synthetic waxes, higher fatty acids, higher fatty acid amides, higher fatty acid anilides, naphthalene derivatives, aromatic ethers. , Aromatic carboxylic acid derivatives, aromatic sulfonic acid ester derivatives, carbonic acid or oxalic acid diester derivatives, biphenyl derivatives, terphenyl derivatives, sulfone derivatives, etc. Among them, those which are solid at room temperature and have a melting point of 60 ° C. or higher are preferable. used.

  Specific examples of waxes include, for example, wood wax, carnauba wax, shellac, paraffin, montan wax, oxidized paraffin, polyethylene wax, polyethylene oxide, etc .; higher fatty acids such as stearic acid, behenic acid, etc .; higher fatty acid amides For example, stearic acid amide, oleic acid amide, N-methyl stearic acid amide, erucic acid amide, methylol behenic acid amide, methylene bis stearic acid amide, ethylene bis stearic acid amide, etc .; Examples of naphthalene derivatives include 1-benzyloxynaphthalene, 2-benzyloxynaphthalene, 1-hydroxynaphthoic acid phenyl ester, 2,6-diisopropylnaphthalene and the like; Examples of the group ether include 1,2-diphenoxyethane, 1,4-diphenoxybutane, 1,2-bis (3-methylphenoxy) ethane, 1,2-bis (4-methoxyphenoxy) ethane, 1, 2-bis (3,4-dimethylphenyl) ethane, 1-phenoxy-2- (4-chlorophenoxy) ethane, 1-phenoxy-2- (4-methoxyphenoxy) ethane, 1,2-diphenoxymethylbenzene, Diphenyl glycol and the like; examples of the aromatic carboxylic acid derivative include p-hydroxybenzoic acid benzyl ester, p-benzyloxybenzoic acid benzyl ester and terephthalic acid dibenzyl ester; and the aromatic sulfonic acid ester derivative such as p-toluene. Sulfonic acid phenyl ester, phenyl mesitylene sulfonate, 4- Examples of carbonic acid or oxalic acid diester derivatives include diphenyl carbonate, oxalic acid dibenzyl ester, oxalic acid di (4-chlorobenzyl) ester, oxalic acid di (4- Methylbenzyl) esters; biphenyl derivatives such as p-benzylbiphenyl and p-allyloxybiphenyl; terphenyl derivatives such as m-terphenyl and the like; sulfone derivatives such as p-toluenesulfonamide and benzene Sulfonanilide, p-toluenesulfonanilide, 4,4′-diallyloxydiphenylsulfone, diphenylsulfone and the like; Examples of aromatic ketone derivatives include 4,4′-dimethylbenzophenone and dibenzoylmethane; Examples of the group hydrocarbon compound include p-acetotoluidine.

  Specific examples of the storage stability improver used in the present invention include, for example, 2,2′-methylenebis (4-methyl-6-tert-butylphenol), 2,2′-methylenebis (4-ethyl-6-tert-butylphenol). ), 2,2′-ethylidenebis (4,6-di-t-butylphenol), 4,4′-thiobis (2-methyl-6-t-butylphenol), 4,4′-butylidenebis (6-t-) Butyl-m-cresol), 1- [α-methyl-α- (4′-hydroxyphenyl) ethyl] -4- [α ′, α′-bis (4′-hydroxyphenyl) ethyl] benzene, 1,1 , 3-tris (2-methyl-4-hydroxy-5-cyclohexylphenyl) butane, 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, tris (2, -Dimethyl-4-t-butyl-3-hydroxybenzyl) isocyanurate, 4,4'-thiobis (3-methylphenol), 4,4'-dihydroxy-3,3 ', 5,5'-tetrabromodiphenyl Sulfone, 4,4′-dihydroxy-3,3 ′, 5,5′-tetramethyldiphenylsulfone, 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, 2,2-bis (4 Hindered phenol compounds such as -hydroxy-3,5-dichlorophenyl) propane and 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 1,4-diglycidyloxybenzene, 4,4'- Diglycidyloxydiphenylsulfone, 4-benzyloxy-4 '-(2-methylglycidyloxy) diphenylsulfone, terephthalic acid Epoxy compounds such as diglycidyl, cresol novolac type epoxy resin, phenol novolac type epoxy resin, bisphenol A type epoxy resin, N, N′-di-2-naphthyl-p-phenylenediamine, 2,2′-methylenebis (4,6 -Di-t-butylphenyl) phosphate sodium or polyvalent metal salt, bis (4-ethyleneiminocarbonylaminophenyl) methane and the like. For example, 2,2′-methylenebis (4-methyl-6-tert-butylphenol), 2,2′-methylenebis (4-ethyl-6-tert-butylphenol), 2,2′-ethylidenebis (4,6-dioxy) -T-butylphenol), 4,4'-thiobis (2-methyl-6-t-butylphenol), 4,4'-butylidenebis (6-t-butyl-m-cresol), 1- [α-methyl-α -(4'-hydroxyphenyl) ethyl] -4- [α ', α'-bis (4'-hydroxyphenyl) ethyl] benzene, 1,1,3-tris (2-methyl-4-hydroxy-5- Cyclohexylphenyl) butane, 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, tris (2,6-dimethyl-4-tert-butyl-3-hydroxyben) L) Isocyanurate, 4,4′-thiobis (3-methylphenol), 4,4′-dihydroxy-3,3 ′, 5,5′-tetrabromodiphenylsulfone, 4,4′-dihydroxy-3,3 ', 5,5'-tetramethyldiphenylsulfone, 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, 2,2-bis (4-hydroxy-3,5-dichlorophenyl) propane, 2 Hindered phenol compounds such as 1,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 1,4-diglycidyloxybenzene, 4,4′-diglycidyloxydiphenylsulfone, 4-benzyloxy-4 '-(2-Methylglycidyloxy) diphenylsulfone, diglycidyl terephthalate, cresol novolac type epoxy resin , Epoxy compounds such as phenol novolac type epoxy resin and bisphenol A type epoxy resin, N, N′-di-2-naphthyl-p-phenylenediamine, 2,2′-methylenebis (4,6-di-t-butylphenyl) ) Phosphate sodium or polyvalent metal salt, bis (4-ethyleneiminocarbonylaminophenyl) methane, and the like.

  Specific examples of the binder used in the present invention include, for example, methyl cellulose, methoxy cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, sodium carboxymethyl cellulose, cellulose, polyvinyl alcohol (PVA), carboxyl group-modified polyvinyl alcohol, sulfonic acid group-modified polyvinyl alcohol, Silyl group-modified polyvinyl alcohol, polyvinyl pyrrolidone, polyacrylamide, polyacrylic acid, starch and derivatives thereof, casein, gelatin, water-soluble isoprene rubber, alkali salt of styrene / maleic anhydride copolymer, iso (or diiso) butylene / anhydrous Water-soluble maleic acid copolymer such as alkali salt, (meth) acrylic acid ester copolymer, styrene / (meth) acrylic acid ester copolymer , Polyurethane, polyester polyurethane, polyether polyurethane, polyvinyl acetate, ethylene / vinyl acetate copolymer, polyvinyl chloride, vinyl chloride / vinyl acetate copolymer, polyvinylidene chloride, polystyrene, styrene / butadiene (SB) Polymer, carboxylated styrene / butadiene (SB) copolymer, styrene / butadiene / acrylic acid copolymer, acrylonitrile / butadiene (NB) copolymer, carboxylated acrylonitrile / butadiene (NB) copolymer, colloidal silica And hydrophobic polymer emulsions such as composite particles of (meth) acrylic resin.

  Specific examples of the filler used in the present invention include, for example, calcium carbonate, magnesium carbonate, magnesium oxide, silica, white carbon, talc, clay, alumina, magnesium hydroxide, aluminum hydroxide, aluminum oxide, barium sulfate, polystyrene resin. And urea-formalin resin.

  Furthermore, various additives other than those described above can be used in the present invention. For example, higher fatty acid metal salts such as zinc stearate and calcium stearate for the purpose of preventing thermal head wear and sticking, and preventing oxidation or aging. Examples thereof include ultraviolet absorbers such as phenol derivatives, benzophenone compounds, and benzotriazole compounds for imparting effects, various surfactants, and antifoaming agents.

Next, a method for producing the heat-sensitive recording material of the present invention will be described. A color-forming compound, a compound represented by the general formula (1), and a phenol-based color developing compound used in the present invention, each separately, together with a binder or other additives as necessary, a ball mill, an attritor, After pulverizing and dispersing with a disperser such as a sand mill to form a dispersion (usually, water is used as a medium when pulverization or dispersion is performed in a wet manner), the dispersion is mixed to prepare a thermal recording layer coating liquid, It is applied by a bar coater, blade coater, etc. on a support such as paper (plain paper, fine paper, coated paper, etc.), plastic sheet, synthetic paper, etc., so that the dry mass is usually 1 to 20 g / m ² . It is dried to produce the heat-sensitive recording material of the present invention.

If necessary, an intermediate layer may be provided between the heat-sensitive recording layer and the support, or an overcoat layer (protective layer) may be provided on the heat-sensitive recording layer. The intermediate layer and the overcoat layer (protective layer) are crushed and dispersed as necessary in the same manner as in the preparation of the thermal recording layer coating solution, for example, together with the above-mentioned binder or other additives as necessary. After the layer coating liquid or the overcoat layer (protective layer) coating liquid is applied, the coating is applied so that the mass during drying is usually about 0.1 to 10 g / m ² and dried.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited at all by the following examples. In the examples, “parts” are parts by mass, and “%” in the description of the solution is mass%.

[Synthesis Example 1] Synthesis of Compound No. 2 in Table 1 [Step 1]

In 52.8 parts of a 25% aqueous sodium hydroxide solution, 30.0 parts of 3-aminophenol (Tokyo Kasei Kogyo) was added and stirred, and the temperature was raised to 65 ° C. Next, 52.9 parts of p-toluenesulfonyl chloride (Tokyo Kasei Kogyo) was added and stirred for 1 hour at the same temperature. Then, the precipitate was filtered off, and the filtrate was washed with water and dried, whereby the above compound [ 1-2] was obtained as a tan solid (34.1 parts).
MS (ESI): [M + H] ⁺ : cal. : 264.1, found: 264.1.
[Step 2]

5.0 parts of the above compound [1-2] was added to 25 parts of DMF and stirred, and then 2.3 parts of phenyl isocyanate (Tokyo Chemical Industry) was added dropwise at room temperature. After stirring at the same temperature for 1 hour, the reaction solution was dropped into 250 parts of water to precipitate crystals. The precipitate was washed successively with dichloromethane and water and dried to obtain 4.1 parts of Compound No. 2 in Table 1 as a white solid.
MS (ESI): [M−H] ⁻ : cal. : 381.1, found: 381.1.

[Example 1] Production of thermosensitive recording material The above compound [1-3] was measured by a sand grinder with the following composition, and the median particle size was measured by a laser diffraction / scattering particle size distribution measuring apparatus LA-950 (Horiba, Ltd.). Dispersion liquid [A] was prepared by pulverizing and dispersing to 1 μm.

[A] Solution: 25.0 parts of Compound No. 2 described in Table 1
25% PVA aqueous solution 20.0 parts
55.0 parts of water

A mixture of the following composition was pulverized and dispersed using a sand grinder so that the median particle diameter was 1 μm or less to prepare a color developing compound dispersion [B].
[B] Liquid: 35.0 parts of 3-dibutylamino-6-methyl-7-anilinofluorane
40.0 parts of 15% PVA aqueous solution
25.0 parts of water

A dispersion [C] was prepared by pulverizing and dispersing 4,4′-dihydroxydiphenylsulfone used in combination in the present invention with a sand grinder having the following composition so that the median particle diameter was 1 μm or less.
[C] Solution: 4,4′-dihydroxydiphenylsulfone (Tokyo Chemical Industry) 25.0 parts
25% PVA aqueous solution 20.0 parts
55.0 parts of water

Next, the above-mentioned [A] liquid, [B] liquid, and [C] liquid are mixed with the following composition to prepare a thermal recording layer coating liquid, and the mass upon drying is on a fine paper having a basis weight of 50 g / m ^2. The heat-sensitive recording material of the present invention was produced by applying and drying so as to be 5 g / m ² .
[A] Liquid 16.8 parts [B] Liquid 8.6 parts [C] Liquid 7.2 parts 67% calcium carbonate aqueous dispersion 9.0 parts 48% modified styrene / butadiene copolymer latex 6.3 parts Water 52.1 copies

(Formation of protective layer)
Next, a protective layer coating solution having the following composition was applied onto the heat-sensitive recording layer so that the mass upon drying was 2 g / m ² and dried to prepare a heat-sensitive recording material with a protective layer.
40% styrene / acrylic ester copolymer emulsion 115.0 parts 5% bentonite aqueous dispersion 17.0 parts 45% styrene / acrylic copolymer aqueous emulsion 44.0 parts 39% aqueous zinc stearate dispersion 103.0 Part 67% calcium carbonate aqueous dispersion 15.0 parts

[Example 2]
Next, the above-mentioned [A] liquid, [B] liquid, and [C] liquid are mixed with the following composition to prepare a thermal recording layer coating liquid, and the mass upon drying is on a fine paper having a basis weight of 50 g / m ^2. The heat-sensitive recording material of the present invention was produced by applying and drying so as to be 5 g / m ² .
[A] Liquid 14.4 parts [B] Liquid 8.6 parts [C] Liquid 9.6 parts 67% calcium carbonate aqueous dispersion 9.0 parts 48% Modified styrene / butadiene copolymer latex 6.3 parts Water 52.1 copies

[Example 3]
Next, the above-mentioned [A] liquid, [B] liquid, and [C] liquid are mixed with the following composition to prepare a thermal recording layer coating liquid, and the mass upon drying is on a fine paper having a basis weight of 50 g / m ^2. The heat-sensitive recording material of the present invention was produced by applying and drying so as to be 5 g / m ² .
[A] Liquid 12.0 parts [B] Liquid 8.6 parts [C] Liquid 12.0 parts 67% calcium carbonate aqueous dispersion 9.0 parts 48% modified styrene / butadiene copolymer latex 6.3 parts Water 52.1 copies

[Example 4]
Next, the above-mentioned [A] liquid, [B] liquid, and [C] liquid are mixed with the following composition to prepare a thermal recording layer coating liquid, and the mass upon drying is on a fine paper having a basis weight of 50 g / m ^2. The heat-sensitive recording material of the present invention was produced by applying and drying so as to be 5 g / m ² .
[A] Liquid 9.6 parts [B] Liquid 8.6 parts [C] Liquid 14.4 parts 67% calcium carbonate aqueous dispersion 9.0 parts 48% Modified styrene / butadiene copolymer latex 6.3 parts Water 52.1 copies

[Example 5]
Next, the above-mentioned [A] liquid, [B] liquid, and [C] liquid are mixed with the following composition to prepare a thermal recording layer coating liquid, and the mass upon drying is on a fine paper having a basis weight of 50 g / m ^2. The heat-sensitive recording material of the present invention was produced by applying and drying so as to be 5 g / m ² .
[A] liquid 7.2 parts [B] liquid 8.6 parts [C] liquid 16.8 parts 67% calcium carbonate aqueous dispersion 9.0 parts 48% modified styrene / butadiene copolymer latex 6.3 parts water 52.1 copies

[Example 6]
Next, the above-mentioned [A] liquid, [B] liquid, and [C] liquid are mixed with the following composition to prepare a thermal recording layer coating liquid, and the mass upon drying is on a fine paper having a basis weight of 50 g / m ^2. The heat-sensitive recording material of the present invention was produced by applying and drying so as to be 5 g / m ² .
[A] Liquid 4.8 parts [B] Liquid 8.6 parts [C] Liquid 19.2 parts 67% calcium carbonate aqueous dispersion 9.0 parts 48% Modified styrene / butadiene copolymer latex 6.3 parts Water 52.1 copies

[Example 7]
Next, the above-mentioned [A] liquid, [B] liquid, and [C] liquid are mixed with the following composition to prepare a thermal recording layer coating liquid, and the mass upon drying is on a fine paper having a basis weight of 50 g / m ^2. The heat-sensitive recording material of the present invention was produced by applying and drying so as to be 5 g / m ² .
[A] Liquid 2.4 parts [B] Liquid 8.6 parts [C] Liquid 21.6 parts 67% calcium carbonate aqueous dispersion 9.0 parts 48% modified styrene / butadiene copolymer latex 6.3 parts Water 52.1 copies

[Comparative Example 1]
A comparative heat-sensitive recording material was obtained by applying and drying in the same manner as in Example 1 except that the above [A] liquid and [B] liquid were mixed in the following composition ratio.
[A] Liquid 24.0 parts [B] Liquid 8.6 parts 67% calcium carbonate aqueous dispersion 9.0 parts 48% modified styrene-butadiene copolymer latex 6.3 parts Water 52.1 parts

[Comparative Example 2]
A comparative heat-sensitive recording material was obtained by applying and drying in the same manner as in Example 1 except that the above [C] liquid and [B] liquid were mixed in the following composition ratio.
[C] Liquid 24.0 parts [B] Liquid 8.6 parts 67% calcium carbonate aqueous dispersion 9.0 parts 48% modified styrene-butadiene copolymer latex 6.3 parts Water 52.1 parts

[Storage stability test (plasticizer resistance test)]
A vinyl chloride wrap film (containing a plasticizer) is wrapped around a glass plate in a single layer, and a pulse width of 1.4 msec is applied on it using a thermal printer (TH-M2 / PP) manufactured by Okura Engineering Co., Ltd. The heat-sensitive recording materials obtained in Examples 1 to 7 and Comparative Examples 1 and 2 printed (colored) were attached. Further, the same vinyl chloride wrap film was wound on it in a single layer and allowed to stand at 45 ° C. for 24 hours. The Macbeth reflection density of the color recording part of the heat-sensitive recording material before and after the test was measured using a colorimeter manufactured by GRETAG-MACBETH, trade name “SpectroEye”. Colorimetry was performed under the conditions of Illuminant C as the light source, ANSI A as the density standard, and a viewing angle of 2 degrees. The results are shown in Table 2 below. It can be seen that the higher the residual ratio, the better the plasticizer resistance. The residual rate was determined by the following calculation formula (I).
Residual rate (%) = (Macbeth reflection density of color recording portion of heat-sensitive recording material after test) / (Macbeth reflection density of color recording portion of heat-sensitive recording material before test) × 100 (I)

As is clear from Table 2, the heat-sensitive recording material of the present invention using the compound represented by the general formula (1) and the phenolic color developing compound as the color developing compound is a comparative example in which each compound is used alone. Compared with 1 or 2, the residual ratio after the test is high, and the color recording part is excellent in plasticizer resistance.

Claims (6)

A heat-sensitive recording material comprising a compound represented by the following general formula (1) and a phenol-based color developing compound.

(In the formula (1), R ^{1 to} R ⁵ are each independently a hydrogen atom, a halogen atom, a nitro group, an amino group, an alkyl group, an alkoxy group, an aryloxy group, an alkylcarbonyloxy group, an alkylcarbonylamino group, an arylcarbonyl group. (Amino group, alkylsulfonylamino group, arylsulfonylamino group, monoalkylamino group, dialkylamino group, arylamino group are represented.) The heat-sensitive recording material according to claim 1, wherein the phenol-based color developing compound is 4,4'-dihydroxydiphenyl sulfone. The heat-sensitive recording material according to claim 1 or 2, wherein the general formula (1) is a compound represented by the following formula (2).

(In formula (2), R ³ has the same meaning as described above.) The thermosensitive recording material according to any one of claims 1 to ³ , wherein in the formula (1), R ³ is a methyl group. A heat-sensitive recording layer comprising the heat-sensitive recording material according to claim 1. A heat-sensitive recording paper comprising the heat-sensitive recording material or the heat-sensitive recording layer according to claim 1.