JP2019130879A - Heat-sensitive recording material - Google Patents

Abstract

To provide a heat-sensitive recording material in which a print part has excellent plasticizer resistance and alcohol resistance, and the texture has excellent storage stability in a high moisture environment and against alcohol.SOLUTION: A heat-sensitive recording material has a compound represented by general formula (1) as a color developing compound, and a 1,3-diphenyl urea as a shelf life improver. In the formula (1), R-Rindependently represent 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 arylcarbonylamino group, an alkylsulfonylamino group, an arylsulfonylamino group, a monoalkylamino group, a dialkylamino group, and an arylamino group.SELECTED DRAWING: None

Description

  The present invention relates to a heat-sensitive recording material having excellent printing section and background storage stability.

  In general, a heat-sensitive recording material is usually a colorless or light leuco dye and a developing compound such as a phenolic compound dispersed separately into fine particles, and then mixed together, and this is combined with a binder and a sensitizer. The coating liquid obtained by adding additives such as fillers and lubricants is applied to paper, film, synthetic paper, etc., and one or both of the leuco dye and the color developing compound are melted by heating. Color recording (printing) is obtained by a chemical reaction caused by contact. In order to color the heat-sensitive recording material in this way, 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 Since it has an advantage such as being inexpensive, it is widely used in the field of facsimile, 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 been expanded, and the use for labels, 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, preservability such as water resistance and alcohol resistance of a recorded image (print, image, pattern) generated by touching water, alcohol or the like is an essential condition. Further, food labels are required to have storability (plasticizer resistance) of a recorded image with respect to a plasticizer contained in a wrap film used for packaging or the like. In addition, the demand for high-speed recording has been further increased in order to improve productivity, and the development of a heat-sensitive recording material excellent in thermal responsiveness that can sufficiently cope with high-speed recording is strongly desired. In order to increase the thermal response, generally, a color developing compound having a low melting point and a low heat of fusion is required, but such a property is not printed on the thermal recording material at the time of manufacture, use or storage. Since a phenomenon called “background fogging”, in which (background) is darkened, is likely to occur, improvement of the stability of the background is desired.

  In general, a color developing compound having a phenolic hydroxyl group has a high color developing ability. Among them, bisphenol compounds have been reported in large numbers because of their high color density, and 2,2-bis (4-hydroxyphenylpropane) ( Bisphenol A) (Patent Document 1), 4,4′-dihydroxydiphenylsulfone (bisphenol S) (Patent Document 2), and the like have been proposed. However, since these have a high melting point, they are inferior in heat responsiveness, and also have the disadvantage that the printed part is inferior in water resistance. Further, the use of phenolic compounds such as bisphenol A has been pointed out as a problem due to the endocrine problem, and a non-phenolic color developing compound that does not contain a phenol structure is desired.

  In response to such a request, Patent Document 3 discloses a heat-sensitive recording material using a specific color developing compound that has excellent water resistance of a printed portion and has high background stability against heat. However, it cannot be said that the plasticizer resistance of the printed portion is sufficient, and as a color developing compound exhibiting high storage stability with respect to the plasticizer, a diphenylsulfone crosslinkable compound (Patent Document 4) and a urea urethane compound ( Patent Document 5) has been proposed, but there is a problem that the thermal response is low.

  On the other hand, a thermosensitive recording material is disclosed in which the storage stability of the printed part is improved by using a specific color developing compound in combination with the diphenylsulfone crosslinkable compound or urea urethane compound. When the compounds are combined, the endocrine problem becomes a problem, and when the urea urethane compound is combined, the background fog generated when stored in a high humidity environment is remarkable. It was a challenge to achieve both storage stability.

US Pat. No. 3,539,375 Japanese Patent Laid-Open No. 57-11088 International Publication No. 2017/111032 Japanese Patent Laid-Open No. 08-333329 JP 2000-143611 A

  An object of the present invention is to solve the above-described problems of the prior art, and more specifically, to provide a heat-sensitive recording material excellent in storage stability of a printed part and a background.

  As a result of intensive studies to achieve the above object, the inventor of the present invention, in a thermosensitive recording material containing a compound having a specific structure as a color developing compound and 1,3-diphenylurea as a preservative improver, The present invention has been completed by newly finding that the printed part has excellent plasticizer resistance and alcohol resistance, and excellent storage stability of the background in a high humidity environment and alcohol.

（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］一般式（１）で表される顕色性化合物１質量部に対し、１，３−ジフェニル尿素を０．１〜２．５質量部の固形分換算質量比で含有す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）の化合物が下記式（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、

（式（２）中、Ｒ^３は前記と同義である。）
［４］一般式（２）において、Ｒ^３がメチル基であることを特徴とする［３］に記載の感熱記録材料、
［５］発色性化合物が、フルオラン系化合物であることを特徴とする［１］乃至［４］のいずれか一つに記載の感熱記録材料、
［６］［１］乃至［５］のいずれか一つに記載の感熱記録材料を含むことを特徴とする感熱記録層、
［７］［６］に記載の感熱記録層を含むことを特徴とする感熱記録紙、
に関する。 That is, the present invention
[1] A heat-sensitive recording material comprising a support and a heat-sensitive recording layer comprising a color-forming compound and a color developing compound as main components. A compound represented by the following general formula (1) in the heat-sensitive recording layer: A heat-sensitive recording material, characterized by comprising a color developing compound and 1,3-diphenylurea as a preservability improver,

(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] It is characterized by containing 1,3-diphenylurea in a solid content equivalent mass ratio of 0.1 to 2.5 parts by mass with respect to 1 part by mass of the color developing compound represented by the general formula (1). The heat-sensitive recording material according to [1],
[3] The heat-sensitive recording material according to [1] or [2], wherein the compound of 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.)
[4] The heat-sensitive recording material according to [3], wherein in general formula (2), R ³ is a methyl group,
[5] The heat-sensitive recording material according to any one of [1] to [4], wherein the color-forming compound is a fluorane compound.
[6] A heat-sensitive recording layer comprising the heat-sensitive recording material according to any one of [1] to [5],
[7] A thermal recording paper comprising the thermal recording layer according to [6],
About.

  According to the present invention, it is possible to provide a heat-sensitive recording material in which the printing portion is excellent in plasticizer resistance and alcohol resistance, and is excellent in storage stability of the background in a high humidity environment and alcohol.

  The present invention will be described in detail based on embodiments, but is not limited to the embodiments shown below. The present invention relates to a heat-sensitive recording material containing a compound represented by the above general formula (1) as a color developing compound and 1,3-diphenylurea as a preservability improver, a heat-sensitive recording layer containing the same, and a heat-sensitive recording paper. About.

In one Embodiment of this invention, a fluorine atom, a chlorine atom, and a bromine atom are mentioned as a halogen atom in R < ¹ > -R < ⁵ > of General formula (1), A fluorine atom and a chlorine atom are preferable.

In one embodiment of the present invention, examples of the alkyl group in R ^{1 to} R ⁵ of the general formula (1) include a linear, branched, or cyclic alkyl group, and among them, a linear or branched chain is preferable. Chains are more preferred. The range of the carbon number is usually C1 to C12, preferably C1 to C8, more preferably C1 to C6, and further 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. Examples include 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.

In one embodiment of the present invention, examples of the alkoxy group represented by R ^{1 to} R ⁵ in the general formula (1) include a linear, branched, or cyclic alkoxy group, and among these, a linear or branched chain is preferable. Chains are more preferred. The range of the carbon number is usually C1 to C12, preferably C1 to C8, more preferably C1 to C6, and further 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.

In one embodiment of the present invention, 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. .

In one embodiment of the present invention, the alkylcarbonyloxy group in R ^{1 to} R ⁵ of the general formula (1) includes a linear, branched or cyclic alkylcarbonyloxy group, and a C1-C10 alkylcarbonyloxy group. Specific examples thereof include methylcarbonyloxy, ethylcarbonyloxy, n-propylcarbonyloxy, n-butylcarbonyloxy, n-pentylcarbonyloxy, n-hexylcarbonyloxy, n-heptylcarbonyloxy, n-octyl. Straight chain such as carbonyloxy, n-nonylcarbonyloxy, n-decylcarbonyloxy; isopropylcarbonyloxy, isobutylcarbonyloxy, sec-butylcarbonyloxy, t-butylcarbonyloxy, isoamylcarbonyloxy t-amylcarbonyloxy, isohexylcarbonyloxy, t-hexylcarbonyloxy, isoheptylcarbonyloxy, t-heptylcarbonyloxy, isooctylcarbonyloxy, t-octylcarbonyloxy, 2-ethylhexylcarbonyloxy, isononylcarbonyloxy, A branched chain such as isodecylcarbonyloxy (preferably C3 to C10); cyclic such as cyclopropylcarbonyloxy, cyclobutylcarbonyloxy, cyclopentylcarbonyloxy, cyclohexylcarbonyloxy, cycloheptylcarbonyloxy (preferably C3 to C7) Among them, 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.

In one embodiment of the present invention, 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-C10 alkylcarbonylamino group. Specific examples thereof include methylcarbonylamino, ethylcarbonylamino, n-propylcarbonylamino, n-butylcarbonylamino, n-pentylcarbonylamino, n-hexylcarbonylamino, n-heptylcarbonylamino, n-octyl. Straight chain such as carbonylamino, n-nonylcarbonylamino, n-decylcarbonylamino; isopropylcarbonylamino, isobutylcarbonylamino, sec-butylcarbonylamino, t-butylcarbonylamino, isoamylcarbonylamino t-amylcarbonylamino, isohexylcarbonylamino, t-hexylcarbonylamino, isoheptylcarbonylamino, t-heptylcarbonylamino, isooctylcarbonylamino, t-octylcarbonylamino, 2-ethylhexylcarbonylamino, isononylcarbonylamino, A branched chain such as isodecylcarbonylamino (preferably C3 to C10); cyclic such as cyclopropylcarbonylamino, cyclobutylcarbonylamino, cyclopentylcarbonylamino, cyclohexylcarbonylamino, cycloheptylcarbonylamino (preferably C3 to C7) Preferably a linear or branched alkylcarbonylamino group, more preferably a linear alkylcarbonylamino group.

In one embodiment of the present invention, the arylcarbonylamino group in R ^{1 to} R ⁵ of the general formula (1) is preferably a C6-C12 arylcarbonylamino group, and specific examples thereof include phenylcarbonylamino, naphthylcarbonylamino. , Biphenylcarbonylamino and the like.

In one embodiment of the present invention, 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-C10 alkylsulfonylamino group. Specific examples thereof include methylsulfonylamino, ethylsulfonylamino, n-propylsulfonylamino, n-butylsulfonylamino, n-pentylsulfonylamino, n-hexylsulfonylamino, n-heptylsulfonylamino, n-octyl. Straight chain such as sulfonylamino, n-nonylsulfonylamino, n-decylsulfonylamino; isopropylsulfonylamino, isobutylsulfonylamino, sec-butylsulfonylamino, t-butylsulfonylamino, isoamylsulfonylamino, -Amylsulfonylamino, isohexylsulfonylamino, t-hexylsulfonylamino, isoheptylsulfonylamino, t-heptylsulfonylamino, isooctylsulfonylamino, t-octylsulfonylamino, 2-ethylhexylsulfonylamino, isononylsulfonylamino, iso A branched chain such as decylsulfonylamino (preferably C3 to C10); cyclic (preferably C3 to C7) such as cyclopropylsulfonylamino, cyclobutylsulfonylamino, cyclopentylsulfonylamino, cyclohexylsulfonylamino, cycloheptylsulfonylamino Preferably linear or branched, more preferably linear.

In one embodiment of the present invention, 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 and the like.

In one embodiment of the present invention, the monoalkylamino group in R ^{1 to} R ⁵ of the general formula (1) includes a linear, branched, or cyclic monoalkylamino group, and a mono C1 to C10 alkylamino group. Specific examples thereof include methylamino, ethylamino, n-propylamino, n-butylamino, n-pentylamino, n-hexylamino, n-heptylamino, n-octylamino, n-nonylamino, n Straight chain such as decylamino; isopropylamino, isobutylamino, sec-butylamino, t-butylamino, isoamylamino, t-amylamino, isohexylamino, t-hexylamino, isoheptylamino, t-heptylamino, Isooctylamino, t-octylamino, 2-ethylhexylamino, iso Branched chain (preferably C3 to C10) such as nylamino, isodecylamino; cyclic (preferably C3 to C7) such as cyclopropylamino, cyclobutylamino, cyclopentylamino, cyclohexylamino, cycloheptylamino; preferably Is linear or branched, more preferably linear.

In one embodiment of the present invention, 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 diC1-C10 alkylamino group is preferable. Specific examples thereof include dimethylamino, diethylamino, di-n-propylamino, di-n-butylamino, di-n-pentylamino, di-n-hexylamino, di-n-heptylamino, di-n. -Straight chain such as octylamino, di-n-nonylamino, di-n-decylamino; diisopropylamino, diisobutylamino, di-sec-butylamino, di-t-butylamino, diisoamylamino, di-t- Amylamino, diisohexylamino, di-t-hexylamino, diisoheptylamino, di-t-heptylamino, diisooctyl A branched chain (preferably having two C3-C10 branched chains) such as diaminopropyl, di-t-octylamino, di- (2-ethylhexyl) amino, diisononylamino, diisodecylamino; Cyclic (preferably having two C3 to C7 cyclic groups) such as cyclobutylamino, dicyclopentylamino, dicyclohexylamino, dicycloheptylamino; preferably linear or branched, more preferably linear Can be mentioned.

In one embodiment of the present invention, 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-C12 arylamino group is preferable. Examples include phenylamino (anilino), naphthylamino, biphenylamino and the like. Similarly, examples of the diC6-C12 arylamino group as the arylamino group include diphenylamino, dinaphthylamino, di (biphenyl) amino and the like.

According to a preferred embodiment of the present invention, R ^{1 to} R ⁵ in the general formula (1) are an alkyl group or a hydrogen atom, more preferably a linear C1 to C4 alkyl group or a hydrogen atom, and a methyl group or a hydrogen atom. Atoms are particularly preferred.

According to a preferred embodiment of the present invention, R ¹ , R ² , R ⁴ , and R ⁵ in the general formula (1) are hydrogen atoms, and R ³ is a hydrogen atom, a halogen atom, or a 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 aryl An amino group, a hydrogen atom or an alkyl group is more preferable, a hydrogen atom or a C1-C8 alkyl group (preferably a linear alkyl group) is further preferable, and a hydrogen atom or a C1-C4 alkyl group (preferably a linear alkyl group is preferable). Group) is particularly preferred, and a methyl group is most preferred.

The substitution position of the partial skeleton represented by the following general formula (3) 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.

According to a preferred embodiment of the present invention, in the color developing compound, R ^{1 to} R ⁵ are an alkyl group or a hydrogen atom, and the substitution position of the partial skeleton represented by the general formula (3) is the benzene ring. It is a compound of the above general formula (1) that is ortho-position or meta-position with respect to the above aminocarbonyl group, and more preferably, R ^{1 to} R ⁵ are a linear C1-C8 alkyl group or a hydrogen atom. And the substitution position of the partial skeleton represented by the general formula (3) is a compound of the above general formula (1), which is meta-position to the aminocarbonyl group on the benzene ring, and more preferably R ¹ to R ⁵ is a C1~C4 alkyl group or a hydrogen atom, linear, formula (3) substitution positions of the partial skeleton represented by the, is meta to the amino group on the benzene ring In the compound of the general formula (1) Ri, particularly preferably, R ¹ to R ⁵ is a methyl group or a hydrogen atom, substitution position of the partial skeleton represented by the general formula (3) is meta to the amino group on the benzene ring It is a compound of the said General formula (1) which is.

According to another preferred embodiment of the present invention, the color developing compound is such that R ¹ , R ² , R ⁴ , and R ⁵ are hydrogen atoms, and R ³ is 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 The above-mentioned general formula (1), which is an arylamino group and the substitution position of the partial skeleton represented by the general formula (3) is ortho, meta, or para with respect to the aminocarbonyl group on the benzene ring. Preferably, R ¹ , R ² , R ⁴ , and R ⁵ are hydrogen atoms, and R ³ is a hydrogen atom or alkyl And the substitution position of the partial skeleton represented by the general formula (3) is a compound of the above general formula (1), which is ortho-position or meta-position with respect to the aminocarbonyl group on the benzene ring, Preferably, R ¹ , R ² , R ⁴ , and R ⁵ are hydrogen atoms, R ³ is a linear C1-C8 alkyl group or a hydrogen atom, and the partial skeleton represented by the general formula (3) Is a compound of the above general formula (1) in which the substitution position is meta to the aminocarbonyl group on the benzene ring, and more preferably, R ¹ , R ² , R ⁴ , and R ⁵ are hydrogen R ³ is a linear C1-C4 alkyl group or a hydrogen atom, and the substitution position of the partial skeleton represented by the general formula (3) is meta-positioned to the aminocarbonyl group on the benzene ring. Which is a compound of the above general formula (1) Preferably, R ¹ , R ² , R ⁴ , and R ⁵ are hydrogen atoms, R ³ is a methyl group, and the substitution position of the partial skeleton represented by the general formula (3) is the benzene ring It is a compound of the above general formula (1) that is meta to the aminocarbonyl group.

Specific examples of the compound represented by the general formula (1) in the present invention include those shown in Table 1 below, but are not limited thereto.

（式中、Ｒ^１〜Ｒ^５は、前記と同義である。） The compound represented by the general formula (1) used in the present invention is produced by combining the following two known production methods.
[Manufacturing process 1]

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

（式中、Ｒ^１〜Ｒ^５は、前記と同義である。） In the presence or absence of a base, the compound of the above general formula [1-2] is an aminophenol of the formula [1-1] and an acid halide of the following formula [1-5] or a formula [1-6]. It can manufacture by making an acid anhydride of react.

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

  The usage-amount of the acid halide or acid anhydride used for this reaction is 0.1-50 mol times with respect to 1 mol of aminophenols of 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 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.

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

  In general, an acid anhydride can be produced by reacting the compound represented by the above general formula [1-4] with phosphorus pentoxide, dicyclohexylcarbodiimide or the like.

  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 should just be 0.1-50 mol times with respect to 1 mol of aminophenols of Formula [1-1], Preferably it may be 1-5 mol times.

（式中、Ｒ^１〜Ｒ^５は、前記と同義である。） [Manufacturing process 2]

(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 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 [1-2], 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 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 is usually 10 minutes to 24 hours.

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

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; triethylamine, pyridine, diisopropylethylamine, and the like. Of the organic base. The usage-amount of these bases is 0.1-50 mol times 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。） [Manufacturing process 4]

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

（式中、Ｒ^１〜Ｒ^５は、前記と同義である。） The compound of the above general formula [1-3] is a compound of the formula [2-1] and an acid halide represented by the formula [1-5] or a formula [1-6] in the presence or absence of a base. It can manufacture by making the acid anhydride represented by these react.

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

  The usage-amount of the acid halide or acid anhydride used for this reaction is 0.1-50 mol times 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 should just be 0.1-50 mol times with respect to 1 mol of compounds of Formula [2-1], Preferably it may be 1-5 mol times.

  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 is usually 10 minutes to 24 hours.

  The heat-sensitive recording material according to the present invention contains a compound represented by the above general formula (1) as a color developing compound and 1,3-diphenylurea as a preservability improver. Contains a light-coloring compound. Further, if necessary, other color developing compounds and sensitizers, as well as preservability improvers, binders, fillers, and other additives can be included. These chemicals may be contained in the heat-sensitive recording layer, but when it has a multilayer structure, for example, when an overcoat layer (protective layer) or an undercoat layer is provided above and / or below the heat-sensitive recording layer Can be contained in each of these layers.

  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. In one embodiment of the present invention, examples of the color forming compound include a fluoran compound, a triarylmethane compound, a spiro compound, a diphenylmethane compound, a thiazine compound, a lactam compound, a fluorene compound, and a vinylphthalide compound. And fluorane compounds are preferred.

  The fluorane compound is not particularly limited, and specific examples thereof include 3-diethylamino-6-methyl-7-anilinofluorane and 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-isobutylamino) -6-methyl-7-anilinofluorane, 3- [N-ethyl-N- (3-ethoxypropyl) amino] -6-methyl-7-anilino Fluorane, 3- (N-ethyl-N-hexylamino) -6-methyl-7-anilinofluorane, 3-dipentylamino-6-methyl-7-anilinofluorane, 3- (N-methyl) N-propylamino) -6-methyl-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) fluoro 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, 2-methyl-6- (Np-tolyl-N-ethylamino) fluorane (RED520), 9- (N- Ethyl-N-isopentylamino) spiro [benzo [a] xanthene-12,3′-phthalide] (RED500), 2′-anilino- 6 ′-(N-ethyl-N-isopentylamino) -3′-methylspiro [phthalide-3,9′-xanthene] (S-205), 2′-anilino-6 ′-(N, N-dipentane- 1-ylamino) -3′-methyl-3H-spiro [isobenzofuran-1,9′-xanthen] -3-one (Black305), 2′-anilino-6 ′-(dibutylamino) -3′-methylspiro [ Phthalide-3,9'-xanthene] (Black400), 2'-anilino-6 '-[N-ethyl-N- (4-tolyl) amino] -3'-methyl-3H-spiro [isobenzofuran-1, 9′-xanthen] -3-one (ETAC), 6- (diethylamino) -2-[(3-trifluoromethyl) anilino] xanthene-9-spiro-3′-phthalide (Black1) 0), 1-ethyl-8- [N-ethyl-N- (4-methylphenyl) amino] -2,2,4-trimethyl-1,2-dihydrospiro [11H-chromeno [2,3, -g] ] Quinoline-11,3'-phthalide] (H-1046), 3-dibutylamino-6-methyl-7-bromofluorane, 3- [4- (diethylamino) phenyl] -3- (1-ethyl-2) -Methyl-1H-indol-3-yl) -1 (3H) -isobenzofuranone (Blue 502) and the like, and 3-dibutylamino-6-methyl-7-anilinofluorane is preferred.

  The triarylmethane compound is not particularly limited, but specific examples thereof include 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide (also known as crystal violet lactone or CVL). 3,3-bis (p-dimethylaminophenyl) phthalide, 3- (p-dimethylaminophenyl) -3- (1,2-dimethylaminoindol-3-yl) phthalide, 3- (p-dimethylaminophenyl) ) -3- (2-methylindol-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-dimethyl Aminophthalide, 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, 3- (4-diethylamino-2-methylphenyl) -3- (1-ethyl-2-methylindole- 3-yl) -4-azaphthalide (Blue200), 3- [4- (diethylamino) -2-hexyloxyphenyl] -3- (1-ethyl-2-methylindol-3-yl) -4-azaphthalide (Blue203) ), 3- (4-diethylamino-2-methylphenyl) -3- (1-ethyl-2-methyl-1H-indol-3-yl) -4-aza Talide (Blue220), 7- (4-diethylamino-2-ethoxyphenyl) -7- (1-ethyl-2-methyl-1H-indol-3-yl) furo [3,4-b] pyridine-5 (7H ) -On (Blue 63).

  The spiro compound is not particularly limited, and specific examples thereof include 3-methylspirodinaphthopyran, 3-ethylspirodinaphthopyran, 3,3′-dichlorospirodinaphthopyran, 3-benzyl. Spirodinaphthopyran, 3-propylspirobenzopyran, 3-methylnaphtho- (3-methoxybenzo) spiropyran, 1,3,3-trimethyl-6-nitro-8'-methoxyspiro (indoline-2,2'-benzopyran The diphenylmethane compound is not particularly limited, and specific examples thereof include N-halophenyl-leucooramine, 4,4-bis-dimethylaminophenylbenzhydrylbenzyl ether, N-2, 4,5-trichlorophenyl leucooramine, etc .; thiazine compounds are particularly limited Specific examples thereof include benzoyl leucomethylene blue, p-nitrobenzoyl leucomethylene blue and the like; lactam compounds are not particularly limited, but specific examples thereof include rhodamine B anilinolactam, rhodamine B- p-chloroanilinolactam and the like; the fluorene compound is not particularly limited, and specific examples thereof include 3,6-bis (dimethylamino) fluorene spiro (9,3 ′)-6′-dimethyl. Aminophthalide, 3,6-bis (dimethylamino) fluorene spiro (9,3 ′)-6′-pyrrolidinophthalide, 3-dimethylamino-6-diethylaminofluorene spiro (9,3 ′)-6′- Pyrrolidinophthalide, etc .; vinyl phthalide compounds are not particularly limited, but specific examples thereof 3- [2,2-bis (4-diethylaminophenyl) vinyl] -6-dimethylaminophthalide (H-3035), 3,3-bis [2- (4-dimethylaminophenyl) -2- (4 -Methoxyphenyl) vinyl] -4,5,6,7-tetrachlorophthalide (NIR Black 78), and the like. These color forming compounds can be used alone or in combination.

  In one embodiment of the present invention, another color developing compound may be combined with the compound represented by the general formula (1). Such a color developing compound is not particularly limited. For example, a benzotriazole derivative, a saccharin derivative, a sulfonamide derivative, a malonamide derivative, a thiourea derivative, a sulfonylurea derivative, a diphenylsulfone derivative substituted with an amino group. And 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, 1, 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.

  In one embodiment of the present invention, a sensitizer (thermofusible compound) may be included. Specific examples of the sensitizer (thermofusible compound) 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 , Aromatic ketone derivatives, aromatic hydrocarbon compounds and the like.

  The waxes are not particularly limited, and specific examples thereof include wood wax, carnauba wax, shellac, paraffin, montan wax, oxidized paraffin, polyethylene wax, oxidized polyethylene, etc. Specific examples thereof include stearic acid, behenic acid and the like, and higher fatty acid amides are not particularly limited, but specific examples thereof include stearic acid amide and 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., and higher fatty acid anilide is not particularly limited, Examples include stearic acid anilide, linoleic acid anilide, etc. The naphthalene derivatives are not particularly limited, but specific examples thereof include 1-benzyloxynaphthalene, 2-benzyloxynaphthalene, 1-hydroxynaphthoic acid phenyl ester, 2,6-diisopropylnaphthalene and the like. Specific examples of the aromatic ether include, but are not limited to, 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, etc. The aromatic carboxylic acid derivative is not particularly limited, and specific examples thereof include p-hydroxybenzoic acid benzyl ester, p-benzyloxybenzoic acid benzyl ester, terephthalic acid dibenzyl ester, and the like. The group sulfonic acid ester derivatives are not particularly limited, but specific examples thereof include p-toluenesulfonic acid phenyl ester, phenyl mesitylene sulfonate, 4-methylphenyl mesitylene sulfonate, 4-tolyl mesitylene sulfonate, and the like. The carbonic acid or oxalic acid diester derivative is not particularly limited, but specific examples thereof include carbonic acid diphenyl, oxalic acid dibenzyl ester, oxalic acid di (4-chlorobenzyl) ester, oxalic acid diester. (4-methylbenzyl) esters etc. The biphenyl derivative is not particularly limited, and specific examples thereof include p-benzylbiphenyl, p-allyloxybiphenyl, and the like, and the terphenyl derivative is not particularly limited. Specific examples thereof include m-terphenyl and the like, and the sulfone derivative is not particularly limited, but specific examples thereof include p-toluenesulfonamide, benzenesulfonanilide, p-toluenesulfonanilide. The aromatic ketone derivative is not particularly limited, but specific examples thereof include 4,4′-dimethylbenzophenone, dibenzoylmethane and the like, and aromatic hydrocarbon compounds. Is not particularly limited, but specific examples thereof include p-acetoluidine and the like. It is below.

  In one embodiment of the present invention, a storage stability improver may be included, and specific examples of storage stability improvers include 2,2′-methylenebis (4-methyl-6-tert-butylphenol), 2,2 '-Methylenebis (4-ethyl-6-t-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) -T- Tilphenyl) butane, tris (2,6-dimethyl-4-tert-butyl-3-hydroxybenzyl) 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) Hindered phenol compounds such as propane, 2,2-bis (4-hydroxy-3,5-dichlorophenyl) propane, 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 1,4-di Glycidyloxybenzene, 4,4′-diglycidyloxydiphenylsulfone, 4-benzyloxy-4 ′-(2-methylglycidyloxy) E) Epoxy compounds such as diphenyl sulfone, diglycidyl terephthalate, cresol novolac epoxy resin, phenol novolac epoxy resin, bisphenol A epoxy resin, N, N′-di-2-naphthyl-p-phenylenediamine, 2,2 Examples include sodium or polyvalent metal salts of '-methylenebis (4,6-di-t-butylphenyl) phosphate, 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.

  In one embodiment of the present invention, a binder may be included. Specific examples of the binder include cellulose derivatives such as methyl cellulose, methoxy cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, sodium carboxymethyl cellulose, and cellulose, polyvinyl alcohol (PVA). ), Carboxy-modified polyvinyl alcohol, sulfonic acid-modified polyvinyl alcohol, silyl-modified polyvinyl alcohol, diacetone-modified polyvinyl alcohol, acetoacetyl-modified polyvinyl alcohol, etc. Soda, starch and derivatives thereof, sulfosuccinic acid esters such as dioctyl sodium sulfosuccinate, dodecylben Of sodium sulfonate, sodium salt of lauryl alcohol sulfate, fatty acid salt, casein, gelatin, water-soluble isoprene rubber, alkali salt of styrene / maleic anhydride copolymer, iso (or diiso) butylene / maleic anhydride copolymer Water-soluble ones such as alkali salts, or (meth) acrylic acid ester copolymers, styrene / (meth) acrylic acid ester copolymers, polyurethanes, polyester polyurethanes, polyether polyurethanes, polyvinyl acetate, ethylene / acetic acid Vinyl copolymer, polyvinyl chloride, vinyl chloride / vinyl acetate copolymer, polyvinylidene chloride, polystyrene, styrene / butadiene (SB) copolymer, carboxylated styrene / butadiene (SB) copolymer, styrene / butadiene / Acrylic acid copolymer, Acrylonitrile / butadiene (NB) copolymer, carboxylated acrylonitrile / butadiene (NB) copolymer, colloidal silica and (meth) hydrophobic polymer emulsion such as composite particles of the acrylic resin.

  In one embodiment of the present invention, a filler may be included. Specific examples of the filler include calcium carbonate, magnesium carbonate, magnesium oxide, magnesium hydroxide, aluminum oxide, titanium oxide, zinc oxide, kaolin, Regular silica, white carbon, talc, clay, calcined kaolin, diatomaceous earth, synthetic aluminum silicate, aluminum hydroxide, barium sulfate, inorganic pigments such as surface-treated calcium carbonate and silica; urea-formalin resin, styrene-methacrylic acid copolymer Examples thereof include organic pigments such as resins, polystyrene resins and raw starch particles.

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

  In the present invention, the composition ratio of each component of the heat-sensitive recording material is not particularly limited, but according to one embodiment of the present invention, the heat-sensitive recording material usually contains 1 to 50% by mass, preferably 5% of the chromogenic compound. ~ 30% by mass; the compound represented by the general formula (1) is usually 1 to 70% by mass, preferably 10 to 50% by mass; the sensitizer is usually 1 to 80% by mass, and the storage stability improver is usually 0. -30% by mass, binder is usually 1-90% by mass, filler is usually 0-80% by mass, other lubricants, surfactants, antifoaming agents, UV absorbers are each in any proportion, for example, usually each It can contain 0-30 mass% (mass% is solid content conversion mass ratio of each component which occupies in a thermosensitive recording material).

  In preferable embodiment of this invention, the compound represented by General formula (1) is 0.5-20 mass parts normally with respect to 1 mass part of color-forming compounds, More preferably, 1-5 mass parts of solid content It is included at a converted mass ratio, and 1,3-diphenylurea is included at a solid content converted mass ratio of 0.1 to 2.5 parts by mass with respect to 1 part by mass of the compound represented by the general formula (1).

Next, a method for preparing a heat-sensitive recording material of the present invention and a heat-sensitive recording sheet such as a heat-sensitive recording paper using the same will be described. According to one embodiment of the present invention, the thermal recording material is coated on a support using a thermal recording layer coating solution and dried to produce a thermal recording sheet having the thermal recording material of the present invention. be able to. For example, water is used as a dispersion medium, and a color developing compound and a compound represented by the general formula (1), 1,3-diphenylurea, together with a binder and other additives as necessary, are mixed with a ball mill, an Thermal recording layer coating prepared by mixing and stirring dispersion, pulverized and dispersed with a dispersing machine such as a lighter, sand mill, high-pressure jet mill, etc., if necessary, binder, filler, and other additives The liquid is usually placed on a support such as paper (plain paper, fine paper, coated paper, etc.), synthetic paper, laminated paper, recycled paper such as waste paper pulp, film, plastic film, foamed plastic film, non-woven fabric, etc. A heat-sensitive recording sheet having the heat-sensitive recording material of the present invention can be prepared by coating and drying so that the dry mass is 1 to 20 g / m ² .

If necessary, an undercoat layer or an overcoat layer (protective layer) may be provided on the heat-sensitive recording layer between the support and the heat-sensitive recording layer. The undercoat layer and overcoat layer (protective layer) are pulverized and dispersed as necessary, for example, in the same manner as in the preparation of the thermal recording layer coating solution, together with the above-mentioned binder or other additives as required. The undercoat layer coating solution or the overcoat layer (protective layer) coating solution is then applied to a dry mass of about 0.1 to 10 g / m ² and dried. A heat-sensitive recording sheet having the heat-sensitive recording material can be produced.

  The method for applying each of the coating liquids on the support is not particularly limited, but according to one embodiment of the present invention, bar coating, air knife coating, varivar blade coating, pure blade coating, rod blade Any known coating method such as coating, short dwell coating, curtain coating, die coating, etc. may be used. In addition, each coating solution may be applied and dried one layer at a time to form each layer, or the same coating solution may be applied in two or more layers. Furthermore, simultaneous multi-layer coating in which two or more layers are simultaneously coated may be performed.

  In one embodiment of the present invention, from the viewpoint of improving the recording sensitivity and improving the image uniformity, the super processing may be performed in an arbitrary process after the formation of each layer or after the formation of all the layers. The smoothing process may be performed using a known method such as a calendar or a soft calendar.

  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, “part” means mass part, and “%” means mass%.

２５％苛性ソーダ水溶液５２．８部中に３−アミノフェノール［３−１］（東京化成工業株式会社）３０．０部を加え攪拌し、６５℃に昇温した。次いでｐ−トルエンスルホニルクロリド（東京化成工業株式会社）５２．９部を添加し、同温度で１時間攪拌した後、析出物を濾別し、濾過物を水で洗浄し乾燥することで、上記化合物［３−２］を黄褐色固体として得た（３４．１部）。
ＭＳ（ＥＳＩ）：［Ｍ＋Ｈ］^＋：ｃａｌ．：２６４．１，ｆｏｕｎｄ：２６４．１。
［工程２］

ＤＭＦ２５部中に上記化合物［３−２］５．０部を加え攪拌し、次いでイソシアン酸フェニル（東京化成工業株式会社）２．３部を室温で滴下した。同温度で１時間攪拌した後、反応液を水２５０部中に滴下することで結晶を析出させた。析出物をジクロロメタン、水で順次洗浄し、乾燥することで、表１の化合物番号２［３−３］を白色固体として４．１部得た。
ＭＳ（ＥＳＩ）：［Ｍ−Ｈ］⁻：ｃａｌ．：３８１．１，ｆｏｕｎｄ：３８１．１。 [Synthesis Example 1] Synthesis of Compound No. 2 in Table 1 [Step 1]

In 52.8 parts of 25% aqueous sodium hydroxide solution, 30.0 parts of 3-aminophenol [3-1] (Tokyo Chemical Industry Co., Ltd.) was added and stirred, and the temperature was raised to 65 ° C. Next, 52.9 parts of p-toluenesulfonyl chloride (Tokyo Kasei Kogyo Co., Ltd.) 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. Compound [3-2] was obtained as a tan solid (34.1 parts).
MS (ESI): [M + H] ⁺ : cal. : 264.1, found: 264.1.
[Step 2]

In 25 parts of DMF, 5.0 parts of the above compound [3-2] was added and stirred, and then 2.3 parts of phenyl isocyanate (Tokyo Chemical Industry Co., Ltd.) 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 number 2 [3-3] in Table 1 as a white solid.
MS (ESI): [M−H] ⁻ : cal. : 381.1, found: 381.1.

[Example 1] Production of thermosensitive recording material and thermosensitive recording paper containing the same Compound No. 2 in Table 1 obtained in Synthesis Example 1 was subjected to laser diffraction / scattering particle size distribution measuring apparatus LA with a sand grinder with the following composition. A dispersion liquid [A] of a color developing compound was prepared by pulverizing and dispersing so that the median particle diameter by -950 (Horiba, Ltd.) was 0.8 μm.
[A] Liquid Compound No. 2 listed in Table 1 30.0 parts 20% aqueous solution of sulfone-modified polyvinyl alcohol (Gocenex L-3266, Nihon Gosei Co., Ltd.) 15.0 parts Water 55.0 parts

Dispersion of chromophoric compound by pulverizing and dispersing a mixture having the following composition with a sand grinder using a laser diffraction / scattering particle size distribution measuring device LA-950 (Horiba, Ltd.) so that the median particle size is 0.5 μm. Liquid [B] was prepared.
[B] Liquid 3-dibutylamino-6-methyl-7-anilinofluorane 30.0 parts 20% aqueous solution of sulfone-modified polyvinyl alcohol (Gocenex L-3266, Nihon Gosei Co., Ltd.) 15.0 parts Water 55.0 Part

A mixture of the following composition was pulverized and dispersed with a sand grinder using a laser diffraction / scattering particle size distribution measuring apparatus LA-950 (Horiba, Ltd.) so that the median particle diameter was 1 μm. [C] was prepared.
[C] Liquid 1,3-diphenylurea (Tokyo Chemical Industry Co., Ltd.) 30.0 parts 20% aqueous solution of sulfone-modified polyvinyl alcohol (Gocenex L-3266, Nihon Gosei Co., Ltd.) 15.0 parts Water 55.0 parts

Next, each liquid obtained above and the following chemicals were mixed in the following composition to prepare a thermal recording layer coating liquid, and the weight of the chromophoric compound at the time of drying on a fine paper having a basis weight of 50 g / m ² was as follows. After applying and drying so as to be 0.5 g / m ² , calendering was performed to prepare a thermal recording paper having the thermal recording material of the present invention.
[A] Liquid 16.7 parts [B] Liquid 10.0 parts [C] Liquid 10.0 parts 67% calcium carbonate aqueous dispersion 9.0 parts 48% modified styrene / butadiene copolymer latex 8.0 parts 37 % Zinc stearate aqueous dispersion 2.6 parts water 53.5 parts

[Comparative Example 1]
Each of the liquids obtained above and the following chemicals were mixed in the following composition to prepare a thermal recording layer coating liquid. The weight of the coloring compound when dried on a fine paper having a basis weight of 50 g / m ² was 0.00. After applying and drying so as to be 5 g / m ² , calendering was performed to prepare a thermal recording paper.
[A] Liquid 16.7 parts [B] Liquid 10.0 parts 67% calcium carbonate aqueous dispersion 6.8 parts 48% modified styrene-butadiene copolymer latex 6.0 parts 37% zinc stearate aqueous dispersion 2 .6 parts Water 54.0 parts

[Comparative Example 2]
A thermal recording paper was prepared in the same manner as in Example 1 except that the [C] liquid was used instead of the color developing compound dispersion [A] of Comparative Example 1.

[Comparative Example 3]
In preparing the dispersion [C] of the storage stability improver of Example 1, a urea urethane compound (Kemipro Kasei Co., Ltd., trade name UU) represented by the following formula (10) is used instead of 1,3-diphenylurea. A heat-sensitive recording paper was prepared in the same manner as in Example 1 except that.

[Dynamic coloring sensitivity test]
About each produced thermal recording paper, it printed with the applied energy 0.37mJ / dot using the thermal printer (TH-M2 / PP) by Okura Engineering Co., Ltd., and the optical density of a printing part is a reflection densitometer (brand name) : FD-7, manufactured by Konica Minolta Co., Ltd.), measurement method: reflection measurement, illumination condition: C, observation field of view: 2 °, density white standard: absolute value. It can be seen that the larger the numerical value, the higher the density of printing, and the better the thermal response.

[Plasticizer resistance test for printed parts]
A vinyl chloride film (containing a plasticizer) is wound on a glass plate in a single layer, and an applied energy of 0.37 mJ / min is applied on it using a thermal printer (TH-M2 / PP) manufactured by Okura Engineering Co., Ltd. Each heat-sensitive recording paper printed with dot was placed, and further a vinyl chloride wrap film was wound on it in a single layer, and held at 40 ° C. for 15 hours. The optical density of the printed part before and after the test was measured using a reflection densitometer (trade name: FD-7, manufactured by Konica Minolta Co., Ltd.), measuring method: reflection measurement, illumination condition: C, observation field of view: 2 °, density white standard : Absolute value. The remaining ratio of the printed part was calculated by the following formula. It can be seen that the higher the residual ratio, the better the plasticizer resistance of the printed part.
Residual rate (%) = (reflection density of printed part after test) / (reflection density of printed part before test) × 100

[Storage stability test of the skin under high humidity]
About each produced thermal recording paper before printing, it was 40 degreeC and 90% R. Using the constant temperature and humidity machine (brand name Enviros KCL-2000A type | mold) by Tokyo Rika Instruments Co., Ltd. H. Held under for 24 hours. Using a reflection densitometer (trade name: FD-7, manufactured by Konica Minolta Co., Ltd.), the measurement method: reflection measurement, illumination condition: C, observation field: 2 °, density white standard: The absolute value was measured. The larger the numerical value after the test, the better, and it can be seen that the storage stability of the background under high humidity environment is excellent.

[Alcohol resistance test of printed part]
About each produced thermal recording paper, it printed with the applied energy 0.37mJ / dot using the thermal printer (TH-M2 / PP) made from Okura engineering, and was immersed in 20% ethanol aqueous solution at 25 degreeC for 2 hours. It was. The optical density of the printed part before and after the test was measured using a reflection densitometer (trade name: FD-7, manufactured by Konica Minolta Co., Ltd.), measuring method: reflection measurement, illumination condition: C, observation field of view: 2 °, density white standard : Absolute value. The remaining ratio of the printed part was calculated by the following formula. It can be seen that the higher the residual rate, the better the alcohol resistance of the printed part.
Residual rate (%) = (reflection density of printed part after test) / (reflection density of printed part before test) × 100

[Skin Alcohol Resistance Test]
Each of the produced thermal recording paper before printing was immersed in a 20% ethanol aqueous solution at 25 ° C. for 2 hours. Using a reflection densitometer (trade name: FD-7, manufactured by Konica Minolta Co., Ltd.), the measurement method: reflection measurement, illumination condition: C, observation field: 2 °, density white standard: The absolute value was measured. The larger the numerical value after the test, the better, and it can be seen that the background has excellent alcohol resistance.

  As is apparent from Table 2 below, the thermal recording paper comprising the thermal recording material of the present invention containing the compound represented by the general formula (1) as the color developing compound and 1,3-diphenylurea as the storage stability improver is as follows. The plasticizer resistance and alcohol resistance are higher than those of Comparative Example 1 that does not contain a preservability improver, and is comparable to Comparative Example 3 that contains a urea urethane compound that is a conventionally known preservative improver. Shows plasticizer resistance and alcohol resistance. Further, it can be seen that the heat-sensitive recording paper containing the heat-sensitive recording material of the present invention is superior to Comparative Example 3 in the storage stability of the background under high humidity environment and alcohol. Since Comparative Example 2 containing 1,3-diphenylurea as a color developing compound has lower thermal responsiveness, plasticizer resistance, and alcohol resistance than Example 1, the thermal sensitivity containing the thermosensitive recording material of the present invention. It can be seen that the recording paper is excellent in plasticizer resistance and alcohol resistance in the printing portion, and in the high humidity environment and in the storage stability of the background against alcohol.

Claims (7)

In a heat-sensitive recording material comprising a support and a heat-sensitive recording layer comprising a color developing compound and a color developing compound as main components, the compound represented by the following general formula (1) is developed in the heat-sensitive recording layer. And a 1,3-diphenylurea as a preservability improving agent.

(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.) It contains 1,3-diphenylurea in a solid content converted mass ratio of 0.1 to 2.5 parts by mass with respect to 1 part by mass of the color developing compound represented by the general formula (1). Item 2. The heat-sensitive recording material according to Item 1. The heat-sensitive recording material according to claim 1 or 2, wherein the compound of 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 heat-sensitive recording material according to claim ³ , wherein R ³ in formula (2) is a methyl group. The heat-sensitive recording material according to claim 1, wherein the color-forming compound is a fluoran compound. 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 layer according to claim 6.