JPH03182389A - Sensitizer and thermal recording material - Google Patents

Abstract

PURPOSE:To obtain a thermal recording material having high sensitivity, high whiteness, light fastness, humidity resistance and plasticizer resistance by using a sensitizer composed of a specific compound. CONSTITUTION:A sensitizer composed of a compound represented by formula [wherein Z1 and Z2 are an -R group (R is a 6 or less C hydrocarbon group), an-OR group, a -COOR group, a -CONHR group, a -COR group or a halogen atom, X is an O-atom or an S-atom, Y1 is a 1 or more C lower alkylene group, Y2 is a 2 or more C lower alkylene group, m and n are 0, 1 or 2, r is 0 or 1, s is 1-4 and p is 0 or an integer of l-4] is contained. As 6 or less C hydrocarbon represented by R, methyl, tert-butyl, ally and phenyl are pref. and, as a 1 or more C lower alkylene represented by Y1, a methylene group and an ethylene group are pref. and, as a 2 or more C lower alkylene group represented by Y2, an ethylene group or a propylene group are pref.

Description

[Detailed description of the invention] [Fields of use by M business owner] The present invention relates to a sensitizer and a heat-sensitive recording material.

More specifically, the present invention relates to a heat-sensitive recording material that has extremely high color development sensitivity and excellent whiteness, light resistance, moisture resistance, and plasticizer resistance.

[Prior Art] Heat-sensitive recording materials are produced by melting an electron-donating colorless coloring agent (hereinafter also referred to as coloring agent) and an electron-accepting color developing substance (hereinafter also referred to as coloring agent) with heat to cause them to associate. It is made using the principle of color development.

Thermosensitive recording materials have recently been used for various recording purposes such as facsimiles and POS labels.

Lactone compounds such as crystal violet lactone are used as color formers, and solid acidic substances, phenol compounds, organic acids, or metal compounds thereof are used as color developers.

Furthermore, in recent years there has been a significant demand for faster information, and various high-speed devices have been developed. Along with this, highly sensitive heat-sensitive recording materials have also been developed. For example, in order to improve sensitivity by using color formers and developers in combination, use of sensitizers such as benzyl biphenyls (Japanese Unexamined Patent Publication No. 82382), 1,2-bis(phenoxy) The use of ethane in combination (Japanese Unexamined Patent Publication No. 8O-5B2O3) has been reported.

[Problems to be Solved by the Invention] However, heat-sensitive recording materials using conventional sensitizers have insufficient light resistance, moisture resistance, and plasticizer resistance.

[Means for Solving the Problems] The present inventors have conducted intensive studies to obtain a heat-sensitive recording material that has high sensitivity, high whiteness, light resistance, moisture resistance, and plasticizer resistance, and as a result, the present invention has been achieved. Reached.

That is, the present invention provides a method for the general formula [wherein ZI and Z2 are a -R group (R is a hydrocarbon group having a carbon number of G or less), -OR group, -GoOR group, -C
ONHR group, -0OR group or halogen atom; X is O atom or S atom; Y is lower alkylene group of C1 or more;
Y2 is a lower alkylene group of C2 or more; m and n are 0
．． ■or 2; r is 0 or 1, 8 is 1-4. p is O or an integer of I to 4]; and an electron-donating colorless color former and an electron-accepting color developing substance on a support. A heat-sensitive recording material which is heat-melted and color-developed, characterized by containing the sensitizer according to claim 1 or 2.

There is a (thio)phenol residue which may have one or more substituents selected from the group consisting of an NHR group, a -〇〇R group, and a halogen atom.

These may be the same or different. The term "residue" as used herein means a group obtained by removing an OH group or an SH group from a phenol. m and n are 011 or 2, preferably l.

In general formula (1), hydrocarbons having 6 or less carbon atoms for R include methyl, ethyl, n-propyl, isopropyl,
n-butyl, isobutyl, 5ec-butyl, ter
Straight chain or branched alkyl groups such as t-butyl, pentyl, hexyl; Straight chain or branched alkenyl groups and alkynyl groups such as vinyl, allyl, propenyl, impropenyl, 2-butenyl, ethynyl, 2-propynyl; phenyl, Examples include carbocyclic groups such as cyclopentyl and cyclohexyl groups.

Preferred are methyl, tert-butyl, allyl and phenyl.

Specific examples of (thio)phenol compounds having substituents are as follows.

Alkyl(thio)phenols such as p-methyl(thio)phenol, m-methyl(thio)phenol, and ter-butyl(thio)phenol; alkenyl(thio)phenols such as allyl(thio)phenol and impropenyl(thio)phenol. ; Aryl(thio)phenols such as O-phenyl(thio)phenol and p-phenyl(thio)phenol; O-methoxy(thio)phenol;
Alkoxy(thio)phenols such as p-ethoxy(thio)phenol; Allyloxy(thio)phenols such as 0-phenoxy(thio)phenol and p-phenoxy(thio)phenol; Methyl p-hydroxybenzoate, m-hydroxybenzoic acid Alkoxycarbonylphenols such as methyl; aryloxycarbonylphenols such as phenyl p-hydroxybenzoate, phenyl m-hydroxybenzoate; methyl 0-mercaptobenzoate.

Allyloxycarbonylthiophenols such as ethyl 0-mercaptobenzoate; alkylaminocarbonylphenols such as 2-hydroxybenzoic acid methylamide, 2-hydroxybenzoic acid ethylamide, 2-hydroxybenzoic acid allylamide; 2-hydroxybenzoic acid anilide, etc. Arylaminocarbonylphenol; m-oxyacetophenone.

Oxyarylalkyl ketones such as p-oxyacetophenone and p-oxypropiophenone; Oxyarylaryl ketones such as 0-oxybenzophenone, m-oxyben, siphenon, and p-oxybenzophenone; Mercaptoarylalkyl ketones such as p-mercaptoacetophenone Chlorphenols such as chlorophenol, 2,6-dichlorophenol, and 3,5-dichlorophenol; and chlorothiophenols such as 0-chlorothiophenol and p-chlorothiophenol.

The lower alkylene group with C or more of Y, has a carbon number of 1
-4 alkylene groups such as methylene, ethylene, propylene, butylene groups, preferably methylene and ethylene groups. Examples of the lower alkylene group of 02 or more for Yt include alkylene groups having 2 to 4 carbon atoms, such as ethylene, propylene, and butylene groups, and preferably ethylene and propylene groups.

S and p are integers from I to 4. Preferably! It is.

Specific examples of the compound (A) represented by the general formula (2) are as follows.

[1] Esters of phenyl alkyl carboxylic acids (having an It substituent) and (poly)alkylene (having a substituent) phenyl ethers ■Q-CH* COOCH+ CTo 00 ■Q-H Mayuzumi COOCH! COO OOOCHs■oCH* CO
O C11t CElt O(to0 0■eca.co
ocn. C'Fh 0OGOFrHCHs[phase]DCH
* COOCHt COO OOCOCHs [phase] DC
H* COOCh CFh Oζ appended [phase] CHs4f
:fcHt COOCKH. 0<3@CHs(X5-
COO COOCHt COO oζTo9＠CL＾CH
I COOCIIt Ch o-/' to Cl, etc. [2] Phenylalkyl carbon (having a fi substituent) [ester of T and (poly)alkylene (having a substituent) thiophenyl ether ■Q-CH* COOCIIt CElt SOCHs
■kodo H*COOCH*C■* socoo<I)■Q
CH* COOClit CHs'SQCONHCHa
■(ToFh COOCOO CH2 SGCONH [phase] (:>CHe COOCHt COO SQCOCH
3@CHs OCHCOOOCFh CHI sQo
cas [phase] CH3 VCH* COOCOO Ch
SQC 1 @ CHsOCH Snow C00CL CHI 5
GCOOCHs etc. [3] Esters of phenyl ether alkyl carboxylic acids (having a substituent) and (poly)alkylene phenyl ethers (having a substituent)■GOC! Is C00
CH* CHffiOGCH3■eOcH* C00C
h CIIm Oe○■0OCH* C00CH* C
HI o(]coo.

■(5ocH Elephant C00CH* CHI 0QCONHQ
■(3-QCHICO0CIl* CHI 0QCOQ
@ CHsQOCH* C00CH* Ch Heart @ C
ll5GOCH* C00CIIffiCH* 0QO
CHs [stock] CHsOOCHv C00CTo CHI
O0COQCH*@ CHsOOCH* C00CH
t CL OQCI [phase] CHiQOCHt C00C
H* CHI OQO<I) etc. [4] Esters of (substituted) phenyl alkyl carboxylic acids and (poly)alkylene (substituted) thiophenyl ethers (D C>OCh C00CH* CHI SMC )■
00CHtCOOCHtChSM QQ DOCToCOOCHm CHI 5QOCHs
■eOcIIIa C00CHt elfs S QO
O@ DOCH＊C00CIIt CHt 5Qcoo
cns■C5-OCH* C00CH MayuzhiCH* S-C
＞C00Q■eOcHz C00CHa CHI 5o
-CONHCHs■eOcB* C00CH* Cue
5QCONIQ@l eOcHt C00C! 1*
CHffiSuCOCH＊■eOcI112GOOCH
* C112SQC@DOCHt C00CHt
Cut SOCI[phase]CHpe>0CIla C00C
1l*CHIsu■CHs00cII*C00CHt
CL 5O-C11*@ CB80CH*C00CHf
Preferred compounds (A) such as fiCH*5OOCHs are esters of phenylalkyl carboxylic acids (having a substituent) and thiophenyl ethers (having a substituent), phenyl ether alkyl carboxylic acids and (poly)alkylene (with substituents)
Examples include esters with phenyl ethers.

Particularly preferred are esters of phenyl methyl carboxylic acids (having a substituent) and ethylene glycol (having a substituent) phenyl ethers, phenyl ether methyl carboxylic acids (having a substituent) and ethylene glycol (having a substituent). Examples include esters with phenyl ethers.

Two or more different types of compounds (A) may be used in combination. In addition, the compound (A) described in the specification of Japanese Patent Application No. 128329 filed by the present applicant, the compound (A) described in the specification of Japanese Patent Application No. 1-41! Compound (A) described in specification No.-134080, Japanese Patent Application No. 1-151304
Compound (A) described in the specification, Japanese Patent Application No. 1-15872
Compound (A) described in specification No. 9, Japanese Patent Application No. 1-2582
Compound (A) described in specification No. 20, patent application No. 1-251
Compound (A) described in Specification No. 1i221, Patent Application No. 1999-
Compound (A) described in the specification of No. 263551, patent application Hei!
-288747 and the compound (A) described in the patent application dated November 15, 1989 (title of invention: sensitizer and heat-sensitive recording material). good.

Compound (A) (sensitizer of the present invention) represented by general formula (1) can be produced by any method, for example, by adding alkylene oxide to p-, methylphenol or phenol. It can be obtained by then subjecting phenylacetic acid or phenoxyacetic acid to an esterification reaction.

The alkylene oxide is added to p-methylphenol or phenol using a known method, for example, using an alkaline catalyst such as caustic soda, caustic potash, metallic sodium, or methylate, under pressure, at 120~! This can be done by adding at 90°C. The number of moles of alkylene oxide added can be changed arbitrarily within the range of p from 1 to 4, but 1 is preferable.

The esterification reaction between p-methylphenol or an alkylene oxide adduct of phenol and phenylacetic acid or phenoxyacetic acid can be carried out using conventional methods, such as sulfuric acid,
P-) The reaction can be carried out at 100 to 250°C under normal pressure or reduced pressure in the presence of an acidic catalyst such as luenesulfonic acid or phosphoric acid or an alkaline catalyst such as caustic soda or caustic potash.

As the color forming agent constituting the recording layer in the heat-sensitive recording material of the present invention, those used in conventional heat-sensitive or pressure-sensitive recording materials can be used. For example, color formers such as triarylmethane, diphenylmethane, xanthine, phenothiazine, and spiropyran are preferably used.

As a triarylmethane coloring agent, 3,3-bis(
p-dimethylaminophenyl)-6-dimethylaminophthalide (crystal violet lactone, hereinafter abbreviated as CYL), 3,3-bis(p-dimethylaminophenyl)
Phthalide, 3-(p-dimethylaminophenyl)-3-
(1,2-dimethylindol-3-yl)phthalide,
3-(p-dimethylaminophenyl)-3-(2-methylindol-3-yl)phthalide, 3-(p-dimethylaminophenyl)-3-(2-phenylindole-
3-yl)phthalide, 3,3-bis(1,2-dimethylindol-3-yl)-5-dimethylaminophthalide, 3,3-bis~(l,2-dimethylindole-3-
yl)-todimethylaminophthalide, 3,3-bis(toethylcarbazol-3-yl)-5-dimethylaminophthalide, 3,3-bis(2-phenylindole-3
-yl)-5-dimethylaminophthalide, 3-p-dimethylaminophenyl-3-(1-methylvirol-2-
yl)-6-dimethylaminophthalide and the like.

Examples of diphenylmethane color formers include 4.V-bis-dimethylaminobenzhydrin benzyl ether, N-halophenylleucoauramine, and N-2.4.5-trichlorophenylleucoauramine.

As the xanthine coloring agent, rhodamine B-anilinolactam, rhodamine B (p-nitroanilino)lactam, rhodamine B (p-chloroanilino)lactam, 3
-dimethylamino-6-methoxyfluoran, 3-diethylamino-7-methoxyfluoran, 3-diethylamino-7-chloro-6-methylfluoran, 3-diethylamino-7-(acetylmethylamino)fluoran,
3-diethylamino-7-(dibenzylamino)fluoran, 3-diethylamino-7-(methylbenzylamino)fluoran, 3-diethylamino-7-(chloroethylmethylamino)fluorane, 3-diethylamino-
Examples include 7-(diethylamino)fluoran.

Examples of the phenothiazine color former include benzoyl leucomethylene blue, p-nitrobenzoyl leucomethylene blue, and the like.

As a spiropyran coloring agent, 3-methyl-spiro-
dinaphthopyran, 3-ethyl-spiro-dinaphthopyran, 3,3'-cyclolosevirodinaphthopyran, 3-
Examples include benzyl-spiro-dinaphthopyran, 3-methyl-naphtho-(3-methoxy-benzo)-spiropyran, and 3-provirose biro dibenzodipyran.

These coloring agents may be used alone or in a mixture of 2N or more.

On the other hand, as the color developer, various electron-accepting substances that react with the color former when heated to develop color can be used. As such an electron-accepting substance, a phenolic substance, an organic or inorganic acidic substance, or a salt thereof can be used. As a known color developer, for example, "Paper Valve Technology Times", "Publisher Tic Time Co., Ltd., Vol. 30, 6.
"Color developer for thermal recording paper (1) - (complete), written by Takashi Shiga" in "Vol. 31, No. 3" and "Vol. 32, No. 4 - Vol. 32, No. 10"
``Color developer for thermal recording paper (1) to (complete), written by Takashi Shiga'', but any of them can be used. Specifically, the following can be mentioned.

(1) Bisphenol color developer (1-1) Non-sulfur-containing bisphenol color developer 2-(4
-hydroxyphenyl)propane, 2-(3'-hydroxyphenyl)propane, tetrabromobisphenol A14,4'-isopropylidenediphenol, 4. v
- Bisphenol A derivative compounds such as butylidene bis(2-t-butyl-5-methylphenol), 4. v-methylenebis(2-cyclohexyl-5-methylphenol), 4.4'-isopropylidenebis(2-cyclohexyl-5-methylphenol), 4.4'-butylidenebis(2-cyclohexyl-5-methylphenol)
, 4,4'-cyclohexylidene bis(2-cyclohexyl-5-methyl ester), 3,3-bis(3-
Ethyl cyclohexyl-4-hydroxy-5-methylphenol)butanoate, 4-[1,1-bis[4-hydroxyphenyl)ethyl]biphenyl, 2-(:1.1-
bis(4-hydroxyphenyl)ethyl]naphthalene,
Tophenyl-1,1-bis(4-hydroxyphenyl)
Butane, 1.1-bis(p-hydroxyphenyl)cyclohexane, 4. Bisphenol A related compounds such as v-butylidene bis(2-cyclohexyl-5-methylphenol), methyl-phenyl-methylidene bisphenol, tit-bis(tohydroxyphenyl)acetic acid, 2
．． 2-bis(4-hydroxyphenyl)propionic acid,
bis(4-hydroxyphenyl)acetic acid methyl ester,
bis(4-hydroxyphenyl)acetate-n-butyl, bis(4-hydroxyphenyl)propargyl acetate, bis(
4-hydroxyphenyl) cinnamyl acetate, bis(4-
hydroxyphenyl)benzyl acetate, bis(4-hydroxyphenyl)phenyl acetate, bis(4-hydroxyphenyl)phenethyl acetate, bis(4-hydroxyphenyl)acetate-β-(4'-ethoxyphenoxy)ethyl,
2,2-bis(4-hydroxyphenyl)acetate-3-phenoxypropyl, 2,2-bis(tohydroxyphenyl)valerate-β-(V-methylphenoxy)ethyl, bis(4-hydroxyphenyl)stearic acid Amido!
, 3-bis(4-hydroxyphenyl)propane, 2,
4-bis(tohydroxyphenyl)-4-methylpentane,! , 3-di[2-(4-hydroxyphenyl)-2
-propyl] benzene,! , 3-di[2-(3,5-dimethyl-4-hydroxyphenyl)-2-propylgobenzene, bisphenol 1.1-bis(hydroxyphenyl)-1-phenylethane and other bis(hydroxyphenyl) acids Compound (IL2) Sulfur-containing bisphenol color developer 4, v dihydroxyphenyl diphenyl sulfone, 2.4' dihydroxyphenyl diphenyl sulfone, bis-(3-allyl-4-hydroxyphenyl) sulfone, bis-(3-
Allyl-4-hydroxyphenyl)sulfone, 3-3'
-Bisphenolsulfone derivatives such as sulfonylbis(4-hydroxybenzoic acid methyl ester) and 1,3-bis(p-hydroxyanilinosulfonyl)benzene; 4
-hydroxy-V-benzyloxydiphenylsulfone,
Monoethers of bisphenolsulfone such as 4-hydroxy-V-impropoxydiphenylsulfone; bis(3,5-dimethyl-4-hydroxyphenyl)sulfide, bis(2-methyl-5-isopropyl-4-hydroxyphenyl)sulfide, 4. v-thiobis (B-
ter-butyl-3-methylphenol), 1,5-di(4-hydroxyphenylthio)-3-oxypentane, ■, 8-di(4-hydroxythio)-3,8-dioxaoctane, 1. 3-di(4-hydroxyphenylthio)acetone, 1,7-di(4-hydroxyphenylthio)-3,5-dione,! , 2-di(4-hydroxyphenylthio)phenylethane, l,2-di(4-hydroxyphenylthio)-1-(4-chlorophenyl)ethane, 4-hydroxyphenylthio-4-hydroxyphenyl)methyl acetate, Bis(4-hydroxyphenylthio)
Bisphenol sulfide such as methyl acetate, 4-benzyloxyphenyl-4-hydroxyphenyl sulfide; (2) Hydroxyarylcarboxylic acid color developer (2-1
) Hydroxybenzoic acid color developer p-hydroxybenzoic acid, monosalicylic acid p-hydroxybenzoate, methyl p-hydroxybenzoate, benzyl p-hydroxybenzoate, β-p-methoxyphenoxy p-hydroxybenzoate Hydroxybenzoic acid and p -Hydroxybenzoic acid ester; octadecyl 2,4-dihydroxybenzoate, β-p-ethoxyphenoxyethyl 2,4-dihydroxybenzoate, 2,4
-β-methallyloxyethyl dihydroxybenzoate,
2.4-dihydroxybenzoic acid-β-ethyloxyethyl, 2,4-dihydroxy-β-phenylthioethyl,
Hydroxybenzoic acid derivatives (2-2) such as l,4-cyclohexanedimethanol-bis-(p-hydroxybenzoic acid) ester and l,4-ethylene glycol-bis-(p-hydroxybenzoic acid) ester; Colorant gold salicylate 14#1cZn, Mg, Ca, Al), 4
-tetradecyloxysalicylic acid, 4-β-1)-)lioxyethoxysalicylic acid, 3.5-di(α-methylbenzyl)salicylic acid, 3,5-di(α,α-dimethylbenzyl)salicylic acid, 3.5 -di-tert-butylsalicylic acid, 3-isopropenyl-5-tert-butylsalicylic acid, 3-vinyl-5-cyclohexanoic acid, 3-vinyl-5-benzylsalicylic acid, 5-myristoylsalicylic acid, 5-phenylacetylsalicylic acid, methylphenoxyacetyl Salicylic acid, 4-myristoylaminosalicylic acid, 4-phenylacetylsaminosalicylic acid,
2.2-bis(3-carboxy-4-hydroxyphenyl)propane, l,4-bis(3-carboxy-4-hydroxycumyl)benzene, bis(2-hydroxy-3
- Salicylic acid derivatives (2-3) such as calfoxito (alpha-phenethylphenyl) methane, etc. Other hydroxyarylcarboxylic acid color developers 4-Dimethyl hydroxyphthalate, 3,4,5.8-tetrachlorophthalic acid -mono 2- Zinc salt of hydroxyethyl, phthalic acid derivatives such as zinc salt of mono-3-hydroxy-2,2-dimethylpropyl 3.4,5.8-tetrachlorophthalate, P-chlorobenzyl gallate, hensyl gallate , gallic acid derivatives such as p-vinylbenzyl gallate; l-hydroxy-4-benzyloxy-
2-naphthoic acid, l-acyloxy-4-benzyloxy-2-naphthoic acid, 2-acyloxy-4-benzyloxy-! - naphthoic acids, Z n1M g of these acids
Naphthoic acid derivatives such as polyvalent metal salts such as; (2-4) Other carboxylic acid color developers 0-methyl fumarate, p-methyl fumarate, 0-ethyl fumarate,
p-benzyl fumarate, 0-naphthylmethyl fumarate,
Zinc indole-2-carboxylate, calcium indole-2-carboxylate, zinc l-methylindole-2-carboxylate, zinc p-nitrobenzoate, tin p-nitrobenzoate, L-ascorbic a [(3) sulfone Color developer methyl 4-hydroxybenzenesulfonate, ethyl 4-hydroxy-3-methyl-5-bromobenzenesulfonate, ethyl 4-hydroxy-3,5-dibromobenzenesulfonate, 4-hydroxy-41-methyldiphenyl Sulfone-3', 1'trimethylene-4-hydroxydiphenylsulfonesulfonyl)naphthalene, 1-(4-hydroxybenzenesulfonyl)naphthalene, 3-allyl-4-hydroxy-4'-methyldiphenylsulfone, 3-allyl-4 −
Hydroxy-V-methoxydiphenylsulfone, 3-allyl-4-hydroxy-4'-(2-phenoxyethoxy)diphenylsulfone, 3,4-dihydroxyphenyl-p-)lylsulfone, 2,2'-bis(4-hydroxy) Benzenesulfonyl-V-isopropoxydiphenylsulfone, 4-hydroxy-V-chlorodiphenylsulfone, 3,5-di-
Sulfonic color developers such as β-phenoxyethoxycarbonylbenzenesulfonic acid, 2-β-naphthoxyethoxynaphthalene-6-sulfonic acid; N-benzenesulfonyl-
Peng-aminophenol, N-(α-naphthalenesulfonyl)-■-aminophenol, l,3-bis(p-hydroxyanilinosulfonylbenzene, N-(2-phenoxyethyl)-4-hydroxybenzenesulfonamide% N -(3-phenoxypropyl)-4-hydroxybenzenesulfonamide, N-(phenylsulfonyl)-p-)luenesulfonamide, n-phthyl-N-(
Sulfonamide compounds such as o-carboxyphenylsulfonyl)-p-aminobenzoate, N-(dimethylsulfamoylnyp-)luenesulfonamide, N,N'-diphenylsulfonamide; α-naphthalenesulfonyl chloride, p-phenyl Sulfonyl chloride compounds such as benzenesulfonyl chloride These color developers may be used alone or in combination of two or more.

In the heat-sensitive recording material of the present invention, the amount of compound (A) represented by general formula (1) used is usually 1 to 200 parts by weight, preferably 3 to 100 parts by weight, based on 100 parts by weight of the color developer. Particularly preferably, the amount is in the range of 10 to 70 parts by weight. If the amount of compound (A) used is less than 1 part by weight, the effect of improving sensitivity in thermal recording is poor, and if it exceeds 200 parts by weight, the effect of improving sensitivity is already saturated and is uneconomical.

The ratio of the color former to the color developer is usually 5 to 100 parts by weight, preferably 10 parts by weight per 100 parts by weight of the color former.
~70 parts by weight, particularly preferably 20-50 parts by weight. If the amount of color developer used is less than 5 parts by weight, the desired color density will be low, and if it exceeds 100 parts by weight, the color density will reach equilibrium and it is no longer economical to use any more.

Next, a method for producing the heat-sensitive recording material of the present invention will be described.

Compound (A), a color former, and a color developer are separately dispersed to produce a suspension solution. Next, mix each suspension solution,
The mixture (coating liquid) is coated on a support to produce a heat-sensitive recording material.

In detail, the compound (A) and the binder, the color former and the binder, and the color developer and the binder are each mixed in water with a surfactant (2-ethylhexylsulfosuccinate soda salt, naphthalenesulfonic acid), if necessary. 10 μ or less, preferably 3
Pulverize and disperse into particles smaller than μ to make a coating liquid.

Examples of the binder include polyvinyl alcohol, starch and its derivatives, cellulose derivatives such as methoxycellulose, hydroxyethylcellulose, carboxymethylcellulose, methylcellulose, and ethylcellulose; sodium polyacrylate, polyvinylpyrrolidone, acrylic amide/acrylic ester copolymer, Acrylic acid amide/acrylic ester/methacrylic acid terpolymer, styrene/maleic anhydride copolymer alkali salt, imbutylene/maleic anhydride copolymer alkali salt,
In addition to water-soluble polymers such as polyacrylamide, sodium alginate, gelatin, and casein, polyvinyl acetate, polyurethane, styrene/butadiene copolymer, polyacrylic acid, polyacrylic acid ester, vinyl chloride/vinyl acetate copolymer, and Latex such as butyl methacrylate, ethylene/vinyl acetate copolymer, styrene/butadiene/acrylic copolymer, etc. can be used.

- The coating solution is prepared by combining suspension solutions of each compound as shown in Table 1 below.

Table - The mark O in Table 1 means that, for example, coating liquid (b) is a mixture of a suspension solution of compound (A) and a suspension solution of a color former.

Further, each coating liquid may contain, if necessary, auxiliary additive components commonly used in this type of heat-sensitive recording material, such as fillers, thermofusible substances, lubricants, and the like. Examples of fillers include calcium carbonate, silica, zinc oxide,
In addition to fine inorganic powders such as titanium oxide, aluminum hydroxide, zinc hydroxide, barium sulfate, clay, kaolin, talc, and surface-treated calcium carbonate and silica, urea/
Formalin resin, styrene/methacrylic acid copolymer tk-
11141i Miso 廁什 y は right lump Gendigeichoushi 1 (reduced). As thermofusible substances and lubricants, for example, in addition to higher fatty acids or their esters, amides, or metal salts,
Various waxes, condensates of aromatic carboxylic acids and amines, benzoic acid phenyl esters, higher linear glycols, 3
・50-2 such as thermofusible substances such as 4-epoxy-hexane
Examples include those having a melting point of about 00°C.

Examples of the support include paper, synthetic paper, and synthetic resin film, with paper being preferred.

As a coating method, the following methods (I) to (■) can be used. That is, the coating liquids (a) to (g) are applied to the support.
) can be coated using a method such as an air knife coater, blend coater, roll coater or wipe press to form a heat-sensitive recording layer.

(I) Coating the coating liquid (a) onto the support. FIG. 1 shows the heat-sensitive recording material obtained. In FIG. 1, 1 is a support, and 2 is a layer containing a mixture of compound (A), a color former, and a color developer.

(n) Coating the coating liquid (d) on the support, and further coating the coating liquid (e) on top of the coating liquid (d). FIG. 2 shows the heat-sensitive recording material obtained. In FIG. 2, 5 is a layer containing a mixture of a color former and a color developer, and 8 is a layer of compound (A).

(III) Coating liquid (e) is applied onto the support, and coating liquid (d) is further applied on top of the coating liquid (e). FIG. 3 shows the heat-sensitive recording material obtained. In Figure 3, 6 is a compound (A
), layer 5 is a layer containing a mixture of a color former and a color developer.

(IV) Coating liquid (g), coating liquid (e), and coating liquid m are sequentially coated on the support so as to be laminated. FIG. 4 shows the heat-sensitive recording material obtained. In FIG. 4, 8 is a color developer layer, 6 is a compound (A) layer, and 7 is a color former layer.

(V) Coating liquid (f), coating liquid (e), and coating liquid (g) are sequentially layered on the support. The obtained thermosensitive recording material is shown in FIG. In FIG. 5, 6 is a layer of compound (A), 7 is a layer of color former, and 8 is a layer of color developer.

(VI) Coating liquid (b) is coated on the support, and coating liquid (c) is further coated on top of the coating liquid (b). The obtained thermosensitive recording material is shown in FIG. In Figure 6, 3 is compound (A)
4 is a layer containing a mixture of compound (A) and a color developer, and 4 is a layer containing a mixture of compound (A) and a color developer.

(■) Coating liquid (C) is applied onto the support, and coating liquid (b) is further applied on top of the coating liquid (C). The obtained thermosensitive recording material is shown in FIG. In FIG. 7, 4 is a layer containing a mixture of compound (A) and a color developer, and 3 is a layer containing a mixture of compound (A) and a color former.

The preferred coating method and heat-sensitive recording material are (n)(Vl
) and (■).

The coating thickness of each layer is determined depending on the form of the heat-sensitive recording material and other conditions. The coating amount is not particularly limited, but it is usually 0.5 to 20 g/-1 in terms of dry weight, preferably 1 to 15 g//, particularly preferably 3 to 1 Og/lie.
It is.

[Example 2] The present invention will be further explained below with reference to Examples, but the present invention is not limited thereto. Parts and percentages in the examples are by weight. Further, the test methods in the examples are shown below.

(Test Method) 71) Color Development I) Dynamic Color Development Test The produced thermal recording paper was tested for the relationship between operating time (pulse width) and color density using an MSI type thermal head printing device. 0.1 to 1.0 m5ec, voltage 22v0 Color density was determined by measuring reflection density using a Macbeth densitometer (manufactured by Macbeth). The larger the value, the higher the color density.

2) Static color development test The prepared thermal recording paper was heated using a thermal gradient heat sealer at a temperature range of 70°C to 100'C and a printing pressure of 2 kg/crs.
l The color was developed under the conditions of 2 seconds of pressure bonding time and the color density was measured. The densitometer is the same as l).

(2) Whiteness (background fog) Hunter white discoloration before coloring of thermal recording paper, B value is Mu
lti 5pectra Co1our Meter
Measurement was performed using MSC-2 type. The larger the value, the higher the degree of whiteness.

(4) Light resistance The colored image area in the color development test was irradiated at 80° C. for 72 hours using a fade meter, and the color temperature of the irradiated area was measured.

The densitometer is the same as I).

(5) Humidity Resistance Test The color developed image area in the color development test was left in a constant temperature and humidity chamber at 45° C. and 90% RH for 24 hours, and then the color density of the image area was measured. The densitometer is the same as l).

(4) Plasticizer Resistance Test A plastic eraser was placed on the image area that had been colored in the color development test, and after being left for 24 hours, the color density of the image area was measured. The densitometer is the same as l).

Examples 1 to 3, Comparative Examples 1 and 2 The following liquids A, B, or C were each ground and dispersed in a ball mill for 24 hours, and then each liquid was thoroughly mixed to prepare coating liquids I to H. Apply this coating liquid to high-quality paper (basis weight 50g/l).
) with a doctor blade to a dry solid content of 6 g/l, and after drying, thermal recording paper (Examples 1 to 3) was prepared.

As Comparative Examples 1 and 2, comparative sensitizer suspension solutions ■-1 and ■-2 were used instead of the suspension solution of the sensitizer of the present invention in Solution A.
(Comparative Examples 1 and 2) was prepared in the same manner using (a conventional suspension solution of a compound).

Table 2 [Liquid A: Suspension solution of sensitizer] (Part) Compound (1); ()-ocas C00CH2CIt o<) Compound (
2); eOcHtcOOcB*c11tOW Compound (3); 0SChCOOCH2CHNi00 Compound (4) (conventional product); Q-cH2 (to0 Compound (5) (conventional product): Q-OCHt CHt 04f:) Compound (6); Calcium carbonate compound (7); Hydroxyethyl cellulose (5%
Aqueous solution) [Suspension solution of liquid B dichromator] 3-(Toethyl N-pentylamino-6-methyl-7-
Anilinofluorane [S-205 manufactured by Yamada Chemical Co., Ltd.]
10 parts Hydroxyethylcellulose 40 parts (5% aqueous solution) [Liquid C: Suspension solution of color developer] Bisphenol A Calcium carbonate polyvinyl alcohol (5% aqueous solution) Water table-3 [Coating liquid] 30 parts 10 parts 40 parts 20 parts (Part) [Performance of recording paper] Table 4 Dynamic coloring test table 5 Static coloring test table 6 As is clear from Tables 4 to B, the coloring property of the thermal recording paper of the present invention is better than that of the conventional thermal recording paper. It was superior to the recording paper (Comparative Example 1.2). The light resistance, moisture resistance, and plasticizer resistance of the thermal recording paper of the present invention were superior to those of conventional thermal recording paper (Comparative Examples 1.2).

Examples 4 to 6, Comparative Example 3 The following solutions D and E were ground in a ball mill for 24 hours.
After being dispersed, a coating solution was prepared. Apply this coating liquid to high-quality paper (basis weight B
Methods (I), (Vl), and (■), namely (I), involve applying a mixture of liquids D and E (1/1 weight ratio) to paper with a dry solid content of 8 g/■2. It was applied with a doctor blade and dried. For (VI), the coating liquid is applied to paper using a doctor blade so that the dry solid content is 4 g/l, and then coating liquid E is applied on this layer in the same manner.
Dry. (■) is the opposite of (Vl), in which liquid E was applied first, and then liquid D was applied. The coating amount was the same as (VI).

cD solution: mixed suspension solution of sensitizer and color former] CP-OCH
*C00CH* CH* 00 10 parts 3-diethylamino-6-methyl 7-anilinofluorane 30 parts calcium carbonate 5 parts polyvinyl alcohol (5% water soluble m) 35 parts water
40 parts [Liquid E: Mixed suspension of sensitizer and developer C:)-0CH* C00
CIIt CH* o-O5 parts Bisphenol A
20 parts 1.5-di(4-hydroxyphenylthio)-3-oxapentane 10 parts Calcium carbonate 51y.

Polyvinyl alcohol (5% aqueous solution) 35 parts water

25 parts, thermal recording paper prepared by coating methods (I), (Vl) and (■) were designated as Examples 4.5 and 8, respectively.

Further, as Comparative Example 3, thermosensitive recording paper (Comparative Example 3) was prepared by using rosebenzyl biphenyl instead of compound (A) in Liquid D and Liquid E and applying the coating method of (I).

[Performance of recording paper] Table 7 Dynamic coloring test table 8 Static coloring test table 9 As is clear from Tables 7 to 9, the coloring performance of the thermal recording paper of the present invention is higher than that of conventional thermal recording paper ( It was superior to Comparative Example 3). Lightfastness of the thermal recording paper of the present invention.

The moisture resistance and plasticizer resistance of conventional thermal recording paper (Comparative Example 3)
) was superior to the others.

Furthermore, among the coating methods, method (Vl) was the most excellent for producing thermal recording paper.

[Effects of the Invention] The heat-sensitive recording material containing the sensitizer of the present invention has significantly better coloring sensitivity and whiteness (background fog) than conventional materials.

Additionally, the image area provides high quality performance such as light fastness, moisture resistance and plasticizer resistance.

[Brief explanation of drawings]

Figures 1 to 7 are explanatory diagrams of the heat-sensitive recording material of the present invention.
sectional view). DESCRIPTION OF SYMBOLS 1... Support, 2... Layer containing a mixture of compound (A), a color former, and a color developer, 3... Layer containing a mixture of compound (A) and a color former, 4... Compound (A) ) and a color developer, 5-... a layer containing a mixture of a color former and a color developer, 6... a layer of compound (A), 7... a color former layer, 8... a developer layer. coloring agent

Claims (1)

[Claims] 1. General formula ▲ Numerical formula, chemical formula, table, etc. ▼ [In the formula, Z_1 and Z_2 are -R group (R is a hydrocarbon group having 6 or less carbon atoms), -OR group , -COOR group,
-CONHR group, -COR group or halogen atom; or 1, s is 1-4
, p is 0 or an integer of 1 to 4]. 2. The sensitizer according to claim 1, wherein m and n are 0 or 1 in general formula (1). 3. A heat-sensitive recording material which has an electron-donating colorless color former and an electron-accepting color developer on a support and which develops color by heat melting, which contains the sensitizer according to claim 1 or 2. A heat-sensitive recording material characterized by: 4. The heat-sensitive recording material is a layer containing a mixture of an electron-donating colorless color former and an electron-accepting color developing substance on a support, and a layer of a compound (A) represented by general formula (1) is laminated thereon. The material according to claim 3, characterized in that it is made of: 5. A layer in which the heat-sensitive recording material is a mixture of a compound (A) represented by the general formula (1) and an electron-donating colorless coloring agent on a support;
4. The material according to claim 3, further comprising a layer containing a mixture of the compound (A) and an electron-accepting color developing substance. 6. A layer in which the heat-sensitive recording material is a mixture of a compound (A) represented by the general formula (1) and an electron-accepting color developing substance on a support;
4. The material according to claim 3, further comprising a layer containing a mixture of the compound (A) and an electron-donating colorless coloring agent.