JP2020066148A - Heat-sensitive recording material and n,n'-diphenylurea derivative - Google Patents

Abstract

To provide a heat-sensitive recording material that is excellent in whiteness and color development density of a non-printed part and in storage stability of a printed part, and to provide a N,N'-diphenylurea derivative that can be used as a developer for the heat-sensitive recording material.SOLUTION: Provided is a heat-sensitive recording material having a heat-sensitive recording layer containing a basic dye of no color or light color at room temperature and a developer capable of coloration upon contact with the dye by heating and provided on a support, which is characterized in that the developer contains an N,N'-diphenylurea derivative represented by the following formula (1). In the formula, A is a methyl group, and n is an integer of 0 to 3.SELECTED DRAWING: None

Description

  The present invention relates to a heat sensitive recording material and an N, N'-diphenylurea derivative. More specifically, it relates to a heat-sensitive recording material using an N, N'-diphenylurea derivative as a developer.

  Generally, in a heat-sensitive recording material, a colorless or light-colored basic dye and an organic developer are pulverized and dispersed into fine particles at room temperature, and then both are mixed, and a sensitizer, a binder, a lubricant, and various other additives are added to the mixture. The coating liquid obtained by adding the agent is coated on a support such as paper, plastic film, and processed paper to form a heat-sensitive recording layer. Color addition recording can be obtained by addition.

  Such a heat-sensitive recording material has advantages that a recorded image can be obtained with a relatively simple device, that it is easy to maintain, and that noise is not generated.Measurement recorders, facsimiles, various printers, label printers, It is used in a wide range of fields such as ticket and ticket issuing machines.

  The properties required for the heat-sensitive recording material include the whiteness of the non-printed part, the whiteness of the non-printed part under various environmental conditions, the color density of the printed part and the storability of the printed part. Particularly, regarding the storability of the printed portion, various tests such as wet heat resistance, water resistance, light resistance, oil resistance and plasticizer resistance are required.

  Many developers have been proposed as developers for heat-sensitive recording materials. For example, 4,4′-isopropylidenediphenol (Patent Document 1), 4,4′-dihydroxydiphenylsulfone (Patent Document 2), 4-allyloxy-4′-hydroxy-diphenylsulfone (Patent Document 3), 4- Hydroxy-4′-isopropyloxy-diphenyl sulfone (Patent Document 4), N- [3- (p-toluenesulfonyloxy) phenyl] -N ′-(p-toluenesulfonyl) -urea (Patent Document 5), N- Developers such as [2- (3-phenylureido) phenyl] -benzenesulfonamide (Patent Document 6) have been proposed.

  However, 4,4'-isopropylidene diphenol, 4,4'-dihydroxydiphenyl sulfone, 4-allyloxy-4'-hydroxy-diphenyl sulfone, 4-hydroxy-4'-isopropyloxy-diphenyl sulfone, N- [2 -(3-Phenylureido) phenyl] -benzenesulfonamide does not have sufficient storage stability in the printed part, while N- [3- (p-toluenesulfonyloxy) phenyl] -N '-(p-toluene). Sulfonyl) -urea has improved color development sensitivity and storage stability, but N- [3- (p-toluenesulfonyloxy) phenyl] -N '-(p-toluenesulfonyl) -urea is derived from toluenesulfonyl isocyanate. Derived from the toluenesulfonylurea group and toluenesulfonyl chloride derived Although it has two functional groups of an aromatic sulfonic acid aryl ester group, and the aromatic sulfonic acid aryl ester group is stable to water (Non-Patent Document 1), one toluenesulfonylurea group is originally an amino group. Although it has been utilized as a protecting group for the above, it has a drawback that it is easily hydrolyzed by water.

  The use of thermosensitive recording materials is expanding, including receipts of gas, water, and electricity charges, ATM usage statements of financial institutions, financial-related recording sheets, ticket sheets for theaters, lottery tickets, horse racing, and boat racing. Ballot tickets such as gaming ticket papers, tickets and receipts for railways, buses, aviation tag papers, label papers for logistics, food label papers such as side dishes and rice balls, POS cash register papers for convenience stores and supermarkets, etc. It is used in medical labels, electrocardiographic paper, film thermosensitive films for medical diagnosis, and commuter passes.

U.S. Pat. No. 3,539,375 Japanese Patent Laid-Open No. 57-11088 JP-A-60-208286 JP, 2002-052842, A Japanese Patent Publication No. 2002-532441 International Publication No. 2014/080615

Oshige Shigeru, "Organic Sulfur Chemistry", Kagaku Dojinsha, September 1982, p349

  However, the conventional phenol-based color developers have insufficient whiteness and color density of the non-printed part and various storage stability of the printed part, and in recent years, 4,4'-isopropylidenediphenol and 4,4'- It has been pointed out that'-bisphenol sulfone and the like have environmental health problems such as environmental hormones and mutagenicity.

  The present invention has been made in view of the above circumstances, and provides a heat-sensitive recording material satisfying the required performance as a heat-sensitive recording material such as whiteness of a non-printed portion, color density, and storability of a printed portion. This is an issue.

  As a result of earnest studies, the present inventor has found that the novel N, N'-diphenylurea derivative of the present invention can be used as a developer for a heat-sensitive recording material, and completed the present invention.

That is, the present invention includes the following aspects.
[1] A heat-sensitive recording material comprising a support having thereon a heat-sensitive recording layer containing a basic dye that is colorless or light-colored at room temperature and a developer that can develop a color by contact with the dye when heated. A heat-sensitive recording material, wherein the color developer contains an N, N'-diphenylurea derivative represented by the following formula (1).

（式中、Ａはメチル基であり、ｎは０〜３の整数を示す。）

(In formula, A is a methyl group and n shows the integer of 0-3.)

[2] The N, N′-diphenylurea derivative is N- (3-hydroxyphenyl) -N ′-[3- (p-toluenesulfonyloxy) phenyl] urea, N- (4-hydroxyphenyl) -N. '-[4- (P-Toluenesulfonyloxy) phenyl] urea, N- (3-hydroxyphenyl) -N'-[3- (2,4,6-trimethylbenzenesulfonyloxy) phenyl] urea and N- ( The thermosensitive recording material according to the above [1], which contains at least one compound selected from the group consisting of 3-hydroxyphenyl) -N '-[3- (benzenesulfonyloxy) phenyl] urea.

[3] The heat-sensitive recording layer contains 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,1,3-tris (2-methyl) as a storage stabilizer. -4-hydroxy-5-cyclohexylphenyl) butane, 4,4'-bis [(4-methyl-3-phenoxycarbonylaminophenyl) ureido] diphenylsulfone and diphenylsulfone crosslinked type represented by the following general formula (2) The thermosensitive recording material according to the above [1] or [2], which contains at least one compound selected from the group consisting of compounds.

（式中、ｎは１〜７の整数を表す。）

(In the formula, n represents an integer of 1 to 7.)

[4] An N, N′-diphenylurea derivative represented by the following formula (1).

（式中、Ａはメチル基であり、ｎは０〜３の整数を示す。）

(In formula, A is a methyl group and n shows the integer of 0-3.)

  By using the N, N'-diphenylurea derivative constituting the present invention as a color developer, it is possible to provide a heat-sensitive recording material excellent in whiteness of the non-printed portion, color density, and storage stability of the printed portion.

3 is an IR chart of N- (3-hydroxyphenyl) -N ′-[3- (p-toluenesulfonyloxy) phenyl] urea. 3 is an IR chart of N- (3-hydroxyphenyl) -N ′-[3- (benzenesulfonyloxy) phenyl] urea. 3 is an IR chart of N- (3-hydroxyphenyl) -N ′-[3- (2,4,6-trimethylbenzenesulfonyloxy) phenyl] urea. 3 is an IR chart of N- (3-hydroxyphenyl) -N ′-[3- (m-toluenesulfonyloxy) phenyl] urea. 3 is an IR chart of N- (4-hydroxyphenyl) -N ′-[4- (p-toluenesulfonyloxy) phenyl] urea.

The present invention is a heat-sensitive recording material comprising a support having thereon a heat-sensitive recording layer containing a basic dye which is colorless or light-colored at room temperature and a developer which can be colored by contact with the dye when heated. In addition, in this specification, "normal temperature" means a temperature which is not particularly cooled or heated, that is, a normal temperature, and examples thereof include a temperature of 15 to 25 ° C.
In the heat-sensitive recording material of the present invention, the developer contains an N, N′-diphenylurea derivative represented by the following formula (1).

（式中、Ａはメチル基であり、ｎは０〜３の整数を示す。）

(In formula, A is a methyl group and n shows the integer of 0-3.)

  Examples of the diphenylurea derivative used in the heat-sensitive recording material of the present invention include N- (3-hydroxyphenyl) -N '-[3- (benzenesulfonyloxy) phenyl] urea and N- (3-hydroxyphenyl) -N. '-[3- (p-Toluenesulfonyloxy) phenyl] urea, N- (3-hydroxyphenyl) -N'-[3- (m-toluenesulfonyloxy) phenyl] urea, N- (3-hydroxyphenyl) -N '-[3- (o-toluenesulfonyloxy) phenyl] urea, N- (3-hydroxyphenyl) -N'-[3- (2,4-dimethylbenzenesulfonyloxy) phenyl] urea, N- ( 3-hydroxyphenyl) -N '-[3- (2,5-dimethylbenzenesulfonyloxy) phenyl] urea, N- (3-hydroxyphenyl) -N'-[3- ( 3,5-Dimethylbenzenesulfonyloxy) phenyl] urea, N- (3-hydroxyphenyl) -N ′-[3- (2,4,6-trimethylbenzenesulfonyloxy) phenyl] urea, N- (4-hydroxy Phenyl) -N '-[4- (benzenesulfonyloxy) phenyl] urea, N- (4-hydroxyphenyl) -N'-[4- (p-toluenesulfonyloxy) phenyl] urea, N- (4-hydroxy Phenyl) -N '-[4- (m-toluenesulfonyloxy) phenyl] urea, N- (4-hydroxyphenyl) -N'-[4- (o-toluenesulfonyloxy) phenyl] urea, N- (4 -Hydroxyphenyl) -N '-[4- (2,4-dimethylbenzenesulfonyloxy) phenyl] urea, N- (4-hydroxyphenyl) -N'-[4- (2, -Dimethylbenzenesulfonyloxy) phenyl] urea, N- (4-hydroxyphenyl) -N '-[4- (3,5-dimethylbenzenesulfonyloxy) phenyl] urea, N- (4-hydroxyphenyl) -N' -[4- (2,4,6-Trimethylbenzenesulfonyloxy) phenyl] urea, N- (2-hydroxyphenyl) -N '-[2- (benzenesulfonyloxy) phenyl] urea, N- (2-hydroxy Phenyl) -N '-[2- (p-toluenesulfonyloxy) phenyl] urea, N- (2-hydroxyphenyl) -N'-[2- (m-toluenesulfonyloxy) phenyl] urea, N- (2 -Hydroxyphenyl) -N '-[2- (o-toluenesulfonyloxy) phenyl] urea, N- (2-hydroxyphenyl) -N'-[2- (2,4- Methylbenzenesulfonyl) phenyl]} urea, N-(2-hydroxyphenyl) -N '- [2- (2,5- dimethyl-benzenesulfonyl) phenyl] urea,

  N- (2-hydroxyphenyl) -N '-[2- (3,5-dimethylbenzenesulfonyloxy) phenyl] urea, N- (2-hydroxyphenyl) -N'-[2- (2,4,6 -Trimethylbenzenesulfonyloxy) phenyl] urea, N- (3-hydroxyphenyl) -N '-[4- (benzenesulfonyloxy) phenyl] urea, N- (3-hydroxyphenyl) -N'-[4- ( p-toluenesulfonyloxy) phenyl] urea, N- (3-hydroxyphenyl) -N ′-[4- (m-toluenesulfonyloxy) phenyl] urea, N- (3-hydroxyphenyl) -N ′-[4 -(O-toluenesulfonyloxy) phenyl] urea, N- (2-hydroxyphenyl) -N '-[3- (m-toluenesulfonyloxy) phenyl] urea,

  N- (3-hydroxyphenyl) -N '-[4- (2,4-dimethylbenzenesulfonyloxy) phenyl]} urea, N- (3-hydroxyphenyl) -N'-[4- (2,5- Dimethylbenzenesulfonyloxy) phenyl] urea, N- (3-hydroxyphenyl) -N '-[4- (3,5-dimethylbenzenesulfonyloxy) phenyl] urea, N- (3-hydroxyphenyl) -N'- [4- (2,4,6-Trimethylbenzenesulfonyloxy) phenyl] urea, N- (4-hydroxyphenyl) -N ′-[3- (benzenesulfonyloxy) phenyl] urea, N- (4-hydroxyphenyl) ) -N '-[3- (p-toluenesulfonyloxy) phenyl] urea, N- (4-hydroxyphenyl) -N'-[3- (m-toluenesulfonyloxy) phenyl ] Urea, N- (4-hydroxyphenyl) -N '-[3- (o-toluenesulfonyloxy) phenyl] urea, N- (4-hydroxyphenyl) -N'-[3- (2,4-dimethyl Benzenesulfonyloxy) phenyl] urea, N- (4-hydroxyphenyl) -N '-[3- (2,5-dimethylbenzenesulfonyloxy) phenyl] urea, N- (4-hydroxyphenyl) -N'-[ 3- (3,5-dimethylbenzenesulfonyloxy) phenyl] urea and N- (4-hydroxyphenyl) -N ′-[3- (2,4,6-trimethylbenzenesulfonyloxy) phenyl] urea.

  In particular, N- (3-hydroxyphenyl) -N '-[3- (p-toluenesulfonyloxy) phenyl] urea, N- (4-hydroxyphenyl) -N'-[4- (P-toluenesulfonyloxy) Phenyl] urea, N- (3-hydroxyphenyl) -N '-[3- (2,4,6-trimethylbenzenesulfonyloxy) phenyl] urea and N- (3-hydroxyphenyl) -N'-[3- (Benzenesulfonyloxy) phenyl] urea is preferred. Among them, N- (4-hydroxyphenyl) -N '-[4- (P-toluenesulfonyloxy) phenyl] urea has excellent light resistance, and in the light resistance test, there is little discoloration or decrease in density of the printed part, It is the most excellent substance among N'-diphenylurea derivatives.

  The N, N′-diphenylurea derivative of the present invention is an aryl compound of dihydroxydiphenylurea in the presence of a deoxidizing agent of an organic base such as triethylamine or pyridine, or an inorganic base such as sodium hydroxide, potassium hydroxide, sodium carbonate or potassium carbonate. It can be synthesized by reacting a sulfonyl halide. An example of the reaction formula is shown in the following formula (3).

（式中、Ａはメチル基であり、ｎは０〜３の整数を示す。ＡＯＨは脱酸剤であり、Ｘはハロゲン原子である。）

(In the formula, A is a methyl group, n is an integer of 0 to 3, AOH is a deoxidizing agent, and X is a halogen atom.)

  In the heat-sensitive recording material of the present invention, triphenylmethane-based, fluorane-based, diphenylmethane-based, spiro-based, fluorene-based, and thiazine-based compounds are mentioned as basic dyes which are colorless or light-colored at room temperature, and can be selected from conventionally known leuco dyes. You can

For example, 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide, 3,3-bis (p-dimethylaminophenyl) phthalide, 3- (4-diethylamino-2-ethoxyphenyl) -3 -(1-ethyl-2-methylindol-3-yl) -4-azaphthalide, 3,3-bis (p-methylaminophenyl) -6-dimethylaminophthalide,
3-Diethylamino-7-dibenzylaminobenzo [α] fluorane, 3- (1-ethyl-2-methylindol-3-yl) -3- (4-diethylamino-2-n-hexyloxyphenyl-4-azaphthalide , 3- (1-Ethyl-2-methylindol-3-yl) -3- (4-diethylamino) -2-methylphenyl-4-azaphthalide, 3- (4-diethylaminophenyl) -3- (1-ethyl -2-methylindol-3-yl) phthalide, 3- (2-methyl-1-n-octylindol-3-yl) -3- (4-diethylamino-2-ethoxyphenyl) -4-azaphthalide, 3- (N-Ethyl-N-isopentylamino) -6-methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7-anilinofluorane 3-diethylamino-6-methyl-7- (o, p-dimethylanilino) fluorane, 3- (N-ethyl-N-p-toluidino) -6-methyl7-anilinofluorane, 3-pyrrolidino-6 -Methyl-7-anilinofluorane, 3-dibutylamino-6-methyl-7-anilinofluorane, 3- (N-cyclohexyl-N-methylamino) -6-methyl-7-anilinofluorane, 3-diethylamino-7- (o-chloroanilino) fluorane, 3-diethylamino-7- (m-trifluoromethylanilino) fluorane, 3-di (n-pentyl) amino-6-methyl-7-anilinofluorane , 3- [N- (3-Ethoxypropyl) -N-ethylamino] 6-methyl-7-anilinofluorane, 3- (Nn-hexyl-N-ethylamino)- 7- (o-chloroanilino) fluorane, 3- (N-ethyl-N-2-tetrahydrofurfurylamino) -6-methyl-7-anilinofluorane, 2,2-bis {4- [6 '-( N-cyclohexyl-N-methylamino) -3'-methylspiro [phthalide-3,9'-xanthene] -2'-ylamino] phenyl} propane and 3-dibutylamino-7- (o-chloroanilino) fluorane, 3, 6-dimethoxyfluorane, 3-pyrrolidino-6-chlorofluorane, 3-diethylamino-6-methyl-7-chlorofluorane, 3-diethylamino-7-chlorofluorane, 3-diethylamino-7,8-dibenzofluor Oran, 3-diethylamino-6,7-dimethylfluorane, 3- (N-methyl-p-toluidino) -7-methylfluorane, 3- (N-methyl-N-isoamylamino) -7,8-benzofluorane, 3,3-bis (1-n-amyl-2-methylindol-3-yl) phthalide, 3- (N-methyl -N-isoamylamino) -7-phenoxyfluorane, 3,3-bis (1-n-butyl-2-methylindol-3-yl) phthalide, 3,3-bis (1-ethyl-2-methylindole) -3-yl) phthalide, 3,3-bis (p-dimethylaminophenyl) phthalide, 3- (N-ethyl-Np-tolylamino) -7- (N-phenyl-N-methylamino) fluorane, 3 -Diethylamino-7-anilinofluorane, 3-diethylamino-7-benzylaminofluorane, 3-pyrrolidino-7-dibenzylaminofluorane, and the like, and the present invention It is not limited to these, and may be used in combination of two or more.

In the heat-sensitive recording material of the present invention, it can be used in combination with a conventionally known color developer, and can also be used in combination with the color developer described below.
For example, N, N'-di- [3- (p-toluenesulfonyloxy) phenyl] urea, N, N'-di- [3- (benzenesulfonyloxy) phenyl] urea, N, N'-di- [ 3- (mesitylenesulfonyloxy) phenyl] urea, N-3- (p-toluenesulfonyloxy) phenyl-N′-4- (p-toluenesulfonyloxy) phenylurea, N, N ′ di- [4- (p -Toluenesulfonyloxy) phenyl] urea and other N, N'-diarylurea derivatives.

In the heat-sensitive recording material of the present invention, a sensitizer can be used if necessary, and a conventionally known sensitizer can be used as the sensitizer.
For example, fatty acid amides such as stearic acid amide, bisstearic acid amide, and palmitic acid amide, p-toluenesulfonamide, stearic acid, calcium salts such as behenic acid and palmitic acid, fatty acid metal salts such as zinc and aluminum, and p-benzylbiphenyl. , Diphenyl sulfone, benzyloxybenzoate benzyl, 2-benzyloxynaphthalene, 1,2-bis (p-tolyloxy) ethane, 1,2-bis (phenoxy) ethane, 1,2-bis (3-methylphenoxy) ethane , 1,3-bis (phenoxy) propane, dibenzyl oxalate, p-methylbenzyl oxalate, m-terphenyl, 1-hydroxy-2-naphthoic acid and the like.

Further, the heat-sensitive recording material of the present invention may be used in combination with a conventionally known storage stabilizer.
For example, 2,2'-methylenebis (4-methyl-6-tert-butylphenol), 2,2'-methylenebis (4-ethyl-6-tert-butylphenol), 2,2'-ethylidenebis (4,6- Di-tert-butylphenol), 4,4′-thiobis (2-methyl-6-tert-butylphenol), 4,4′-butylidenebis (6-tert-butylm-cresol), 1,1,3-tris ( 2-Methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,1,3-tris (2-methyl-4-hydroxy-5-cyclohexylphenyl) butane, 4,4′-bis [(4- Methyl-3-phenoxycarbonylaminophenyl) ureido] diphenyl sulfone, tris (2,6-dimethyl-4-tert-butyl-3-hydro) Cibenzyl) isocyanurate, 4,4'-thiobis (3-methylphenol), 4,4'-dihydroxy-3,3 ', 5,5'-tetrabromodiphenyl sulfone, 4,4'-dihydroxy 3,3' , 5,5'-Tetramethyldiphenyl sulfone, 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, 2,2-bis (4-hydroxy-3,5-dichlorophenyl) propane, 2, Hindered phenol compounds such as 2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 1,4-diglycidyloxybenzene, 4,4′-diglycidyloxydiphenyl sulfone, 4-benzyloxy-4 ′ -(2-methylglycyloxy) diphenyl sulfone, glycidyl terephthalate, bisphenol A type epoxy resin type, crezo Epoxy compounds such as novolac type epoxy resin and phenol novolac type epoxy resin, N, N'-di-2-naphthyl-p-phenylenediamine, 2,2'-methylenebis (4,6-di-tert-butylphenyl) Examples thereof include sodium salt or polyvalent metal salt of phosphate, bis (4-ethyleneiminecarbonylaminophenyl) methane, and diphenyl sulfone cross-linking compound represented by the following general formula (2).

（式中、ｎは１〜７の整数を表す。）

(In the formula, n represents an integer of 1 to 7.)

  In particular, 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,1,3-tris (2-methyl-4-hydroxy-5-cyclohexylphenyl) butane, 4,4′-bis [(4-methyl-3-phenoxycarbonylaminophenyl) ureido] diphenyl sulfone and the diphenyl sulfone cross-linking compound represented by the general formula (2) are suitable for further improving the storage stability.

  Examples of the binder used in the heat-sensitive recording layer of the heat-sensitive recording material of the present invention include starches such as oxidized starch, esterified starch and etherified starch, celluloses such as methyl cellulose, carboxymethyl cellulose, methoxy cellulose and hydroxyethyl cellulose, casein, Gelatin, completely (or partially) saponified polyvinyl alcohol, carboxy modified polyvinyl alcohol, acetoacetyl modified polyvinyl alcohol, silicon modified polyvinyl alcohol, amide modified polyvinyl alcohol, sulfonic acid modified polyvinyl alcohol, butyral modified polyvinyl alcohol, and other polyvinyl alcohols, styrene- Maleic anhydride copolymer, styrene-butadiene copolymer resin, vinyl acetate resin, urethane resin, acrylamide resin, acrylic acid ester Le resin, polyvinyl butyral, polystyrene and their copolymer resins, amide resins, silicone resins, petroleum resins, terpene resins, ketone resins, such as chroman resins. These binders may be used alone or in combination of two or more, and may be used by dissolving them in a solvent, or may be used in a state of being emulsified or pasty dispersed in water or another medium.

  Pigments to be mixed in the heat-sensitive recording layer include amorphous silica, amorphous calcium silicate, heavy calcium carbonate, light calcium carbonate, kaolin, calcined kaolin, diatomaceous earth, talc, titanium dioxide, zinc oxide, aluminum hydroxide. , Magnesium hydroxide, barium sulfate, colloidal silica, polystyrene powder, nylon powder, urea-formalin resin filler, styrene-methacrylic acid copolymer, styrene-butadiene copolymer and inorganic or organic pigments such as hollow plastic pigments. To be

  Examples of the auxiliaries include sodium dioctylorosuccinate, sodium dodecylbenzenesulfonate, sodium lauryl alcohol sulfate, dispersants such as fatty acid metal salts, zinc stearate, calcium stearate and higher fatty acid metal salts, stearic acid amide. Waxes such as higher fatty acid amides, paraffin, polyethylene wax, oxidized polyethylene wax, castor wax, ester wax, hydrazide compounds such as adipic acid dihydrazide, glyoxal, boric acid, dialdehyde starch, methylol urea, glyoxylate, epoxy Examples include water-proofing agents such as system compounds, defoaming agents, coloring dyes, fluorescent dyes, and pigments.

  In the heat-sensitive recording material of the present invention, the type and the amount of the basic dye, developer, sensitizer, binder, pigment and other additives used in the heat-sensitive recording layer are required for the heat-sensitive recording layer. It is appropriately determined according to the quality performance.

  In the heat-sensitive recording layer of the heat-sensitive recording material of the present invention, the basic dye, the color developer represented by the general formula (1), and other additives are pulverized and dispersed in fine particles, and then mixed. Further, a coating solution obtained by further adding a storage stabilizer, a binder, a sensitizer, a filler, a lubricant, and various other additives is prepared, and this is prepared as a support for paper, plastic film, processed paper, etc. It is formed by coating on top.

  The coating method for forming the heat-sensitive recording layer is not particularly limited, and examples thereof include air knife coating, varibar coating, pure blade coating, rod blade coating, curtain coating, die coating, slide velvet coating, offset gravure. The coating can be carried out by an appropriate coating method such as coating or 5-roll coating.

The heat-sensitive recording layer coating composition thus prepared may be applied directly onto a support to form a heat-sensitive recording layer on the support, or an undercoat layer may be first formed on the support. A heat-sensitive recording layer may be formed on the formed undercoat layer. By providing the undercoat layer, it is possible to improve the sensitivity, the image quality, and the function of absorbing the print residue.
The composition of the undercoat layer may be appropriately selected depending on the purpose, but generally, a binder, a pigment and the like are included.

  The binder used in the undercoat layer may be a resin used in the heat-sensitive recording layer. That is, starches such as oxidized starch, esterified starch and etherified starch, cellulose resins such as methylcellulose, carboxycellulose, methoxycellulose, methoxycellulose and hydroxyethylcellulose, casein, gelatin, completely (or partially) saponified polyvinyl alcohol, carboxy-modified Polyvinyl alcohols such as polyvinyl alcohol, acetoacetyl modified polyvinyl alcohol, silicon modified polyvinyl alcohol, amide modified polyvinyl alcohol, sulfonic acid modified polyvinyl alcohol, butyral modified polyvinyl alcohol, styrene-maleic anhydride copolymer latex, styrene-butadiene copolymer Use system latex, vinyl acetate resin latex, urethane resin latex, acrylic resin latex, etc. Door can be.

  As the inorganic pigment contained in the undercoat layer, metal oxides such as aluminum hydroxide, magnesium hydroxide, barium sulfate, aluminum silicate and calcium carbonate, metal compounds such as metal hydroxides, sulfates and carbonates, amorphous Examples include inorganic white pigments such as silica, calcined kaolin, and talc. Of these, calcined kaolin is particularly preferably used because it is excellent in color development sensitivity, sensitivity and lees absorbability. The particle size of the inorganic pigment is preferably about 0.5 to 3.0 μm.

  The organic pigment contained in the undercoat layer may be obtained by cutting spherical resin particles (so-called solid resin particles), hollow particles, resin particles having through holes, or a part of the hollow resin particles at the modified surface. A resin having such an opening can be used. Hollow resins are preferably used to increase the recording density.

In order to achieve both sensitivity and cake adhesion, it is generally used in combination with an inorganic pigment system and an organic resin system, and the use ratio of the inorganic pigment and the organic pigment is about 90:10 to 30:70 by mass ratio. It is more preferably 70:30 to 50:50.
Furthermore, in order to improve the sensitivity, a foam resin can be used.

The undercoat layer is generally prepared by mixing at least one selected from an inorganic pigment and an organic pigment with a binder using water as a dispersion medium, and a coating amount for the undercoat layer after drying on a support is 1 to 20 g. / M < ² >, preferably about 5 to 15 g / m < ² >. The amount of the binder and pigment used is preferably about 5 to 40% by mass of the binder and about 10 to 95% by mass of the pigment with respect to the total solid content of the undercoat layer. Further, if necessary, various additives such as lubricants such as zinc stearate, calcium stearate, paraffin wax, fluorescent dyes, coloring dyes, surfactants and cross-linking agents can be added to the undercoat layer coating material.
The undercoat layer may be a single layer or, in some cases, two or more layers.

A protective layer containing a film-forming binder as a main component may be provided on the heat-sensitive recording layer. The protective layer coating material is prepared, for example, by using water as a medium, mixing and stirring a binder component, a pigment, and optionally an auxiliary agent.
As the binder, pigment and auxiliary used in the protective layer, those used in the heat-sensitive recording layer are used.

Furthermore, a gloss layer may be provided on the protective layer.
As the gloss layer, for example, a method of applying a coating liquid containing an electron beam or an ultraviolet curable compound as a main component and then irradiating it with an electron beam or an ultraviolet ray to cure it, a method of using an ultrafine core-shell type acrylic resin, etc. Can be mentioned.
Alternatively, an antistatic layer may be provided on the back side of the support.

  The coating material for forming the undercoat layer, the protective layer, the gloss layer, etc. should be applied by an appropriate coating method such as pure blade coating, rod blade coating, curtain coating, offset gravure coating, etc., like the thermal recording layer. And each layer is formed by drying.

  After forming each layer, or after forming all the layers constituting the heat-sensitive recording material, various known processing techniques in the heat-sensitive recording material manufacturing field such as super calendering may be appropriately added.

  In the heat-sensitive recording layer of the heat-sensitive recording material of the present invention, the content of the N, N′-diphenylurea derivative represented by the general formula (1) as a developer is determined by the base of the heat-sensitive recording layer from the viewpoint of color density. 0.3 to 5 parts by mass is preferable, and 0.4 to 3 parts by mass is more preferable, relative to 1 part by mass of the functional dye.

  Further, it is suitable that the sensitizer is 0 to 4 parts by mass with respect to 1 part of the leuco dye, and the binder is 5 to 50% by mass in the total solid content. As the support, paper, recycled paper, synthetic paper, plastic film, non-woven fabric, metal foil or the like can be used. Further, a composite sheet in which these are combined can also be used.

  The basic dye, developer, sensitizer, and optionally a storage stabilizer used in the heat-sensitive recording layer of the heat-sensitive recording material of the present invention may be stirred in a ball mill, attritor, sand mill or the like, for example, using water as a dispersion medium. It is used after being finely dispersed by a pulverizer so that the average particle diameter becomes 2 μm or less.

  A pigment for a heat-sensitive recording layer is prepared by mixing and stirring a pigment, a binder, an auxiliary agent and the like in the dispersion liquid thus finely dispersed, if necessary.

The heat-sensitive recording layer has a coating amount after drying the thus-obtained coating material for heat-sensitive recording layer of about 1.0 to 20 g / m ² , more preferably about 2.0 to 7.0 g / m ^2. It is formed by coating on a support and drying it.

  Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited thereto. In the examples, “parts” and “%” represent “parts by mass” and “mass%”.

[Stability confirmation test of color developer against water]
Some of the color developing agents are decomposed by reacting with water to impair the original color developing ability. The stability of the color developer used in the heat-sensitive recording material of the present invention against water was confirmed in advance. The test method used was the accelerated test method described below.

Test method: 0.5% of the developer of the present invention was dissolved in a mixed solution of acetonitrile and water (acetonitrile / water = 80/20) and stirred at 50 ° C. for 5 hours, and the decomposition amount was high speed liquid manufactured by Shimadzu Corporation. It was measured by chromatography (detection wavelength: 205 nm).
If the amount of decomposition was 10% or more, the resistance to water decomposition was x, and if it was 1% or less, the resistance to water decomposition was ◯.
The results are shown in Table 1.

  A thermal recording material was produced by the following operation.

[Preparation of paint for undercoat]
100 parts of hollow plastic particles (trade name: Lowpaque SN-1055: hollowness: 55% solid content 26.5%), 100 parts of a 50% dispersion of calcined kaolin, styrene-butadiene latex (trade name: L-1571 solid (48%) and 50 parts of a 10% aqueous solution of oxidized starch and 20 parts of water were mixed to prepare an undercoat paint.

[Preparation of coating material for thermal recording layer]
Liquid A (preparation of dye dispersion)
3- (N, N-dibutylamino) -6-methyl-7-anilinofluorane 10 parts 10% aqueous polyvinyl alcohol solution 10 parts water 16.7 parts

Solution B (preparation of developer dispersion)
N- (3-hydroxyphenyl) -N '-[3- (p-toluenesulfonyloxy) phenyl] urea 20 parts 10% aqueous polyvinyl alcohol solution 20 parts water 33.3 parts

Solution C (Preparation of sensitizer dispersion-1)
1,2-Bis (m-tolyloxy) ethane 15 parts 10% aqueous polyvinyl alcohol solution 15 parts water 25 parts

Liquid D (Preparation of sensitizer dispersion-2)
1,1,3-Tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane 5 parts 10% polyvinyl alcohol aqueous solution 5 parts water 8.3 parts

Synthesis Example 1: Synthesis of N- (3-hydroxyphenyl) -N '-[3- (p-toluenesulfonyloxy) phenyl] urea 3,3'-in a 500 ml four-diameter flask equipped with a dropping funnel and a thermometer. 24.4 g of dihydroxydiphenylurea, 150 g of ethyl acetate and 8 g of triethylamine were charged and heated to 50 ° C. An ethyl acetate solution containing 10 g of p-toluenesulfonyl chloride was added dropwise from the dropping funnel. After reacting for 2 hours, water was added and the organic layer was washed with water and separated, and unreacted 3,3′-dihydroxydiphenylurea was washed with water with a sodium hydroxide aqueous solution. After the organic layer was concentrated under reduced pressure, toluene was added to the concentrated residue to crystallize the concentrated residue. The crystals were separated by filtration and then recrystallized from toluene-ethyl acetate.
The melting point range was 172-177 ° C. The IR chart is shown in FIG.

(Example 1)
The dispersion liquids of liquid A, liquid B and liquid C were pulverized with a sand grinder until the average particle diameter became 1 μm or less, and the liquid dispersions were mixed at the following ratios to prepare a coating liquid.
Solution A (dye dispersion) 36.7 parts Solution B (developing agent dispersion) 73.3 parts Solution C (sensitizer dispersion-1) 55.0 parts

  Aluminum hydroxide (trade name: Hydilite H-42 27 parts, amorphous silica (trade name: Mizukasil P-527) 10 parts, 100% 10% dissolved starch starch solution, zinc stearate dispersion: (trade name: A composition comprising 19.4 parts of hydrin Z-8-36) and 50 parts of water was mixed to prepare a coating material for the heat-sensitive recording layer.

[Preparation of thermal recording material]
As a support, an undercoat paint is applied to a high-quality paper (acidic paper) having a basis weight of 53 g so that the mass per area after drying becomes 6 g / m ^2, and then the heat-sensitive recording layer paint is applied. The coating was dried so that the mass per unit area after drying was 3.8 g / m ² .

  This sheet was processed with a super calendar so that the smoothness (JISP8155: 2010) was 900 to 1200 s to prepare a heat-sensitive recording material.

[Various tests]
1. Thermal recording test A thermal recording paper printing tester (TH-PMD manufactured by Okura Electric Co., Ltd.) was applied to the prepared thermal recording material at an applied energy of 0.38 mJ / dot. The print densities of the non-printed portion (that is, the background portion) and the printed portion were measured with a Macbeth reflection densitometer RD-914. This was used as a sample (blank) before the test.

2. Heat resistance test The heat sensitive recording material recorded in the heat sensitive recording test was left for 24 hours in a constant temperature environment of a test temperature of 60 ° C. Then, the image density of the printed part and the density of the non-printed part of the test piece were measured with a Macbeth reflection densitometer.

3. Moisture and heat resistance test The heat sensitive recording material recorded in the heat sensitive recording test was left for 24 hours in an environment of a test temperature of 40 ° C and 90% RH. Then, the image density of the printed part and the density of the non-printed part of the test piece were measured with a Macbeth reflection densitometer.

4. Light resistance test The heat-sensitive recording material recorded in the heat-sensitive recording test was exposed to 5000 Lux for 100 hours. Then, the image density was measured with a Macbeth reflection densitometer.

5. Oil resistance test The thermosensitive recording material recorded in the thermosensitive recording test was immersed in salad oil for 10 minutes. Then, the oil of the test piece was wiped off, and the image density was measured with a Macbeth reflection densitometer.

6. Water resistance test The thermal recording material recorded in the thermal recording test was immersed in water for 15 hours. Then, the test piece was air-dried, and the image density and the non-printed portion were measured with a Macbeth reflection densitometer.

7. Plasticizer resistance test A wrap film (trade name: High Wrap KMA manufactured by Mitsui Chemicals) was wound around a polycarbonate pipe (48 mmφ) in three layers, and the thermal recording material recorded in the thermal recording test was placed on top of the wrap film. It was heavily wound and left for 24 hours in an environment of 20 ° C. and 65% RH. Then, the image density and the non-printed portion were measured with a Macbeth reflection densitometer.
The results of various tests on the heat-sensitive recording material according to this example are shown in Table 1.

Synthesis Example 2: Synthesis of N- (3-hydroxyphenyl) -N '-[3- (benzenesulfonyloxy) phenyl] urea Except that 10 g of p-toluenesulfonyl chloride of Synthesis Example 1 was replaced with 8.6 g of benzenesulfonyl chloride. The same operation as in Synthesis Example 1 was performed to obtain N- (3-hydroxyphenyl) -N '-[3- (benzenesulfonyloxy) phenyl] urea.
The melting point range was 142-145 ° C. The IR chart is shown in FIG.

(Example 2)
N- (3-hydroxyphenyl) -N '-[3- (p-toluenesulfonyloxy) phenyl] urea of the liquid B of Example 1 was replaced with N- (3-hydroxyphenyl) -N'-[3- (benzene. The same operation as in Example 1 was performed except that sulfonyloxy) phenyl] urea was replaced.
The results of various tests on the heat-sensitive recording material according to this example are shown in Table 1.

Synthesis example 3: Synthesis example of N- (3-hydroxyphenyl) -N '-[3- (2,4,6-trimethylbenzenesulfonyloxy) phenyl] urea 2 g of p-toluenesulfonyl chloride of Synthesis example 1 N- (3-Hydroxyphenyl) -N '-[3- (2,4,6-trimethylbenzenesulfonyl) was prepared by the same procedure as in Synthesis Example 1 except that 10.9 g of 4,6-trimethylbenzenesulfonyl chloride was used. Oxy) phenyl] urea was obtained.
The melting point range was 155 to 160 ° C. The IR chart is shown in FIG.

(Example 3)
N- (3-hydroxyphenyl) -N '-[3- (p-toluenesulfonyloxy) phenyl] urea of solution B of Example 1 was added to N- (3-hydroxyphenyl) -N'-[3- (2. , 4,6-Trimethylbenzenesulfonyloxy) phenyl] urea was replaced by the same procedure as in Example 1.
The results of various tests on the heat-sensitive recording material according to this example are shown in Table 1.

Synthesis Example 4: Synthesis example of N- (3-hydroxyphenyl) -N '-[3- (m-toluenesulfonyloxy) phenyl] urea 10 g of p-toluenesulfonyl chloride of Synthesis Example 1 was changed to 10 g of m-toluenesulfonyl chloride. The same operation as in Synthesis Example 1 was performed except that it was replaced to obtain N- (3-hydroxyphenyl) -N '-[3- (m-toluenesulfonyloxy) phenyl] urea.
The melting point range was 113-118 ° C. The IR chart is shown in FIG.

(Example 4)
N- (3-hydroxyphenyl) -N '-[3- (p-toluenesulfonyloxy) phenyl] urea of solution B of Example 1 was added to N- (3-hydroxyphenyl) -N'-[3- (m. -Toluenesulfonyloxy) phenyl] urea was replaced by the same procedure as in Example 1.
The results of various tests on the heat-sensitive recording material according to this example are shown in Table 1.

(Example 5)
The same operation as in Example 1 was carried out except that 18.3 parts of the liquid D was added to the coating material for a thermal recording layer of Example 1.
The results of various tests on the heat-sensitive recording material according to this example are shown in Table 1.

(Example 6)
1,1,3-Tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane of Liquid D was added to the coating material for the heat-sensitive recording layer of Example 5, 1,1,3-Tris (2-methyl-). The same operation as in Example 5 was performed except that 4-hydroxy-5-cyclohexylphenyl) butane was replaced.
The results of various tests on the heat-sensitive recording material according to this example are shown in Table 1.

(Example 7)
To the coating material for the thermosensitive recording layer of Example 5, liquid 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane 4,4'-bis [(4-methyl- The same operation as in Example 5 was performed except that 3-phenoxycarbonylaminophenyl) ureido] diphenylsulfone was used instead.
The results of various tests on the heat-sensitive recording material according to this example are shown in Table 1.

(Example 8)
Liquid 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane of D liquid was added to the coating material for the thermosensitive recording layer of Example 5 by Nippon Soda Co., Ltd. D-90 (product name). The same operation as in Example 5 was performed except that the diphenyl sulfone cross-linking compound represented by the general formula (2) was replaced with
The results of various tests on the heat-sensitive recording material according to this example are shown in Table 1.

Synthesis Example 5: Synthesis of N- (4-hydroxyphenyl) -N '-[4- (p-toluenesulfonyloxy) phenyl] urea 24.4 g of 3,3'-dihydroxydiphenylurea of Synthesis Example 1 was added to 4,4 In the same manner as in Synthesis Example 1 except that 24.4 g of'dihydroxydiphenylurea was used, N- (4-hydroxyphenyl) -N '-[4- (p-toluenesulfonyloxy) phenyl] urea was obtained.
The melting point range was 173-180 ° C. The IR chart is shown in FIG.

(Example 9)
N- (3-hydroxyphenyl) -N '-[3- (p-toluenesulfonyloxy) phenyl] urea of the liquid B of Example 1 was added to N- (4-hydroxyphenyl) -N'-[4- (p. -Toluenesulfonyloxy) phenyl] urea was replaced by the same procedure as in Example 1.
The results of various tests on the heat-sensitive recording material according to this example are shown in Table 2.

[Comparative Example 1]
The N- (3-hydroxyphenyl) -N '-[3- (p-toluenesulfonyloxy) phenyl] urea of the liquid B of Example 1 is 4,4'-isopropylidenediphenol (that is, bisphenol A). The same operation as in Example 1 was performed, except that
The results of various tests on the heat-sensitive recording material according to this comparative example are shown in Table 2.

[Comparative Example 2]
The N- (3-hydroxyphenyl) -N '-[3- (p-toluenesulfonyloxy) phenyl] urea of the liquid B of Example 1 was converted into 4,4'-dihydroxydiphenyl sulfone (that is, bisphenol S). The same operation as in Example 1 was performed except that
The results of various tests on the heat-sensitive recording material according to this comparative example are shown in Table 2.

[Comparative Example 3]
Example except that 4-allyloxy-4′-hydroxy-diphenylsulfone was used instead of N- (3-hydroxyphenyl) -N ′-[3- (p-toluenesulfonyloxy) phenyl] urea of solution B of Example 1. The same operation as 1 was performed.
The results of various tests on the heat-sensitive recording material according to this comparative example are shown in Table 2.

[Comparative Example 4]
Implementation was carried out except that N- (3-hydroxyphenyl) -N '-[3- (p-toluenesulfonyloxy) phenyl] urea of solution B of Example 1 was replaced with 4-hydroxy-4'-isopropyloxy-diphenyl sulfone. The same operation as in Example 1 was performed.
The results of various tests on the heat-sensitive recording material according to this comparative example are shown in Table 2.

[Comparative Example 5]
N- (3-hydroxyphenyl) -N '-[3- (p-toluenesulfonyloxy) phenyl] urea of the liquid B of Example 1 was replaced with N- [3- (p-toluenesulfonyloxy) phenyl] -N'. The same operation as in Example 1 was performed except that-(p-toluenesulfonyl) -urea was replaced.
The results of various tests on the heat-sensitive recording material according to this comparative example are shown in Table 2.

[Comparative Example 6]
N- (3-hydroxyphenyl) -N '-[3- (p-toluenesulfonyloxy) phenyl] urea of the liquid B of Example 1 was added to N- [2- (3-phenylureido) phenyl] -benzenesulfonamide. The same operation as in Example 1 was performed except that
The results of various tests on the heat-sensitive recording material according to this comparative example are shown in Table 2.

  From the examples and Table 1, the heat-sensitive recording materials prepared from the novel diphenylurea derivatives show good color density with high whiteness, and have heat resistance, moisture resistance, light resistance, water resistance, oil resistance and plastic resistance of the printed part. It was also good in all preservability tests of drug properties.

  Moreover, it was confirmed that the result of the stability test against water was also good.

  In the heat-sensitive recording material of the present invention, since the developer used is the diphenylurea derivative represented by the formula (1), there is no fear of endocrine disruption, there is no degradability in water, and the color density is excellent. The whiteness of the non-printed area is high, and good storability is obtained in all storability tests, and its industrial applicability is extremely promising as a substitute for conventional thermal recording materials.

Claims (4)

A heat-sensitive recording material comprising a support having thereon a heat-sensitive recording layer containing a basic dye which is colorless or light-colored at room temperature and a color-developing agent which can be colored by contact with the dye by heating. A heat-sensitive recording material, wherein the agent contains an N, N'-diphenylurea derivative represented by the following formula (1).

(In formula, A is a methyl group and n shows the integer of 0-3.)   The N, N'-diphenylurea derivative is N- (3-hydroxyphenyl) -N '-[3- (p-toluenesulfonyloxy) phenyl] urea, N- (4-hydroxyphenyl) -N'-[. 4- (P-toluenesulfonyloxy) phenyl] urea, N- (3-hydroxyphenyl) -N '-[3- (2,4,6-trimethylbenzenesulfonyloxy) phenyl] urea and N- (3-hydroxy The heat-sensitive recording material according to claim 1, containing at least one compound selected from the group consisting of phenyl) -N '-[3- (benzenesulfonyloxy) phenyl] urea. The heat-sensitive recording layer contains 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,1,3-tris (2-methyl-4-) as a storage stabilizer. Hydroxy-5-cyclohexylphenyl) butane, 4,4′-bis [(4-methyl-3-phenoxycarbonylaminophenyl) ureido] diphenyl sulfone and a diphenyl sulfone cross-linking compound represented by the following general formula (2) The heat-sensitive recording material according to claim 1, which contains at least one compound selected from the group.

(In the formula, n represents an integer of 1 to 7.) An N, N'-diphenylurea derivative represented by the following formula (1).

(In formula, A is a methyl group and n shows the integer of 0-3.)

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