JPH04118284A - 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 forming a sensitizer from a specific compound. CONSTITUTION:A sensitizer represented by formula l is added to a thermal recording material wherein an electron donating leuco color former and an electron acceptive developing substance are provided on a support and melted thermally to form a color. In the formula 1, Z1 and Z2 are an -R group (wherein R is a 6 or less (hydrocarbon group), an -OR group, a -COOR group, a -COR group, a halogen atom or a CN group, Y1, and Y2 are a lower hydrocarbon group, m and n are 0, 1 or 2 and a and b are an integer of 1-3. Further, R is a straight chain or branched alkyl group such as a methyl group, a straight chain or branched alkenyl or alkynyl group such as a vinyl group or a carbocyclic group such as a cyclopentyl group or a cyclohexyl group and Y and Y2 are a methylene group, contretely, a ketone compound from phenylcarboxylic halide and benzene having a substituent.

Description

[Detailed description of the invention] [Industrial application fields] The present invention relates to a sensitizer and a heat-sensitive recording material.

More specifically, the color development sensitivity is extremely high, and the whiteness and light resistance are 1. This invention relates to a heat-sensitive recording material with excellent 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, as a method for improving sensitivity by using color forming agents and color developers in combination, sensitizers such as benzylbiphenyls are used in combination (Japanese Patent Application Laid-Open No. 82382/1993), 1,2-bis(phenoxy)ethane Concomitant use (JP-A-Sho GO-5 [1588]), p-nitroacetophenone (JP-A-64-40373), etc. have 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 relates to a compound of the general formula [where zI or Z2 is a -R group (R is a hydrocarbon group having 6 or less carbon atoms), -OR group, -COOR group].

-COR group, halogen atom or CN group; Yl or Y
2 is a lower hydrocarbon group: m or n is 0. 1 or 2;
a or b is 0 or 1 to 3 (however, when a=0, b=
(1, when a=1 to 3, b=1 to 3); and a sensitizer comprising a compound (A) represented by A heat-sensitive recording material comprising a sensitizer according to claim 1 or 2, wherein a colorless color-forming agent and an electron-accepting color-developing substance are grown and thermally melted to develop a color. It is.

In general formula (1), the hydrocarbon group having 6 or less carbon atoms for R is methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, 5ec-butyl, te
Straight chain or branched alkyl groups such as rt-butyl, pentyl, hexyl; straight chain or branched fulkenyl and alkynyl groups such as vinyl, allyl, propenyl, isopropenyl, 2-butenyl, ethynyl, 2-propynyl; phenyl, Examples include carbocyclic groups such as cyclopentyl and cyclohexyl groups.

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

Y or the lower hydrocarbon group of the Y symbol includes methylene,
Examples include alkylene groups such as ethylene, propylene, and butylene groups, and alkenylene groups such as vinylene (ethynylene) and propenylene, preferably methylene, ethylene,
It is a vinylene group.

In Zl or Z2, the hydrocarbon group of R having 6 or less carbon atoms can be the same hydrocarbon group as R in the general formula (1) described on this page (the preferred compounds are also the same). m or n is 0. l or 2, 0 or l
is preferred.

a or b is 0 or 1 to 3 (however, when a=O, b=
0, when a=1 to 3, b=i to 3), preferably a and b are 0. Or a and b are 1-2.

The specific examples of the compound (A) represented by the general formula (1) are as follows.

(1) Ketone compound from phenylcarboxylic acid halide and benzene with a substituent 0-Go-0-O Q-co-Q-o-Q Q-co -Q-co CHs Q-co-Q -co-Q Q-Co-Q-CI o-co-o-cN (2) Ketone compound CL-0-Go from alkylphenylcarboxylic acid nitride and benzene having a substituent
-0-O CL -Q-co-Q-OCHz CL -Q-GO-0-QC2H6 CHs-Q-CO-Q-0-Q c H3-0-G 0-Q-c o CH□C113<
)-CO-Q-Go-Q CHpe)Go-Q-CI CH3-Q-co <)-CN etc. (3) 7! Ketone compound 0 (Σco
-Q-o c■3 Q-Q-Co-Q-O Q-O-CO-Q-COC113 o-o-co -Q-co -.

0-Q-COQ-CI QQ-COO-CN tL Ketone compound CHsO-Q-coσOC from (4) alkoxyphenylcarboxylic acid halide and benzene having a substituent
I.

CHs O(FCO-c)-0C* H5C211SO
<Do Co<)-0C*Hscaso-Q-coQ-o@ CHi0-Q-CO-o-COCH* CH20-Q-Co-Q-Go-Q CHaO-Q-cO-Q-cl CHi o-Q -co-0-cl1 (5) Ketone compound o-o -o from aryloxyphenylcarboxylic acid halide and benzene having a substituent
-c o -o-o CHso-o-o-co-o-o
−.

Q-00-G O-O-COCH2 o-o-Q-co-Q-co-Q Q-oQ-co-Q-c+ Q-OQ-GO-o-ON '-C (6)
Ketone compound from alkoxycarbonylphenylcarboxylic acid halide and benzene having a substituent CHsOOCQ-COQ-O CH3o o co-cO, Q-Oc u 1CH3
00C-O-CO-o-OO CHI ooc-Q-co-Q-c! 1Nato(7) Ketone compound from aryloxycarbonylphenylcarboxylic acid halide and benzene having a substituent Q-00CG-COQ-Q Q-o oc -Q-co -Q-o cu zQ
-o o c -o-c o -o-OQo-00CQ
-CO-Q-CNNato(8) Ketone compound CHa co - from acylphenylcarboxylic acid halide and benzene containing a substituent
Q-co -Q-co C112CHa co
-Q-co combined co-QCHs c o -Q-co
-Q-c lCI+3 COQ-COQ-CN
(9) Ketone compound o-co-O-co-o-co- from arylcarbonylphenylcarboxylic acid halide and benzene having a substituent.

Q-CO-Q-CO-Q-CI Q-COQ-Co-Q-ON etc. (10)
Ketone compound CI -Q-G O- from halogenated phenylcarboxylic acid halide and benzene having a substituent
Q-CN B r Q-CO-Q-ON etc. (11
) Ketone compound CM-0-GO-Q-C from cyanophenylcarboxylic acid halide and benzene having a substituent
N etc. (12) Ketone compound from phenylalkylcarboxylic acid and phenylalkylcarboxylic acid having a substituent 0-CH*C0CBa-0-CHa Q-CH2COCH2-Q-Q Q-CH2cocut -o-OCIIIao-cyt
cocm2-o-o-.

Q-cut C0C)+2 ecOcllaQ-CB2
COCH2-Q-CO-Q Q-CH2COCH2-Q-CI Q-CHI C0CHz -Q-CN etc. (
13) Ketone compound C1h-Q-cu2COCHz ecLOH! from an alkylphenylalkylcarboxylic acid and a phenylalkylcarboxylic acid having a substituent. -Q-
cIlacOc:B2-Q-QCHpe3-ca2COC
H2-Q-ocnsCHa-Q-ca2cocn2-o
-o-.

cns -Q-arts cocut -Q-co-Q
CHs-Q-CH*C0CHt-Q-CICHs-Q
-cut COCH2-Q-ON etc. (14)
Ketone compound 0-Q-CH2COC112-Q-OCHlO (yCH
z COCHbeyO o(Xcn2COC1b -Q-cocnsQ-Q-c
112 COC[12-O-c o -QQQ-cn
scoca2-Q-c+ oQ-CBaCOCH2@-CM! '(1
5) Ketone compound CB50-Q-CH2COCH2-o-cllllzCH from alkoxyphenylalkylcarboxylic acid and phenylalkylcarboxylic acid having a substituent
30-Q-CH2COC12@-0C2116CIhO
Q-CH2COC112-Q-o-QCHsO-Q-C
BaCOCH2<)COCHzCIhO-Q-C112
GOCI[2-Q-Co-QCIhO-o-CBaCO
CH2-Q-CICHaO-O-C12GOCI*-Q
-NO*CBs0-Q-CBaCOCHtCJ-CM
etc. (1B) Ketone compound QO-o-CBaCOCH2-Q-OcHsQ-OQ- from aryloxyphenylalkylcarboxylic acid and phenylalkylcarboxylic acid having a substituent
C112COCH2-Q-0-QQ-o-Q-cnzc
ocna-Q-coOQ-0-Q-CToCOCllt
-o-CIQ-o-Q-cnzcocna-Q-aNnato (17) Ketone compound CHs from acylphenylalkylcarboxylic acid and phenylalkylcarboxylic acid having a substituent C0-Q-CH*C0CHt -Q-COCH
ricaaco-Q-cnzcocna-Q-co-Qc
naco-Q-cnzcocna-Q-c+CH*C0
-Q-CH*C0CHt<>CN etc. (18) Ketone compound from phenylacylphenylalkylcarboxylic acid and phenylalkylcarboxylic acid having a substituent Q-c o Q-CH* c o CHbe> CO- 0
Q-co-Q-cnzcocna -Q-CI(:)c
o-Q-cH*cocHt-Q-cm tx Among the compounds (A), preferred are ketone compounds formed from an alkylphenylcarboxylic acid halide and benzene containing a substituent, and ketone compounds formed from an arylphenylcarboxylic acid halide and benzene containing a substituent. a ketone compound from an alkoxyphenylcarboxylic acid halide and a benzene with a substituent, a ketone compound from an acylphenylcarboxylic acid halide and a benzene with a substituent, a cyanophenylcarboxylic acid halide and benzene having a substituent.

Particularly preferred are ketone compounds formed from methylphenylcarboxylic acid halide and benzene having a substituent, and ketone compounds formed from phenylphenylcarboxylic acid halide and benzene having a substituent.

Examples include a ketone compound formed from methoxyphenylcarboxylic acid halide and benzene having a substituent, and a ketone compound formed from acetylphenylcarboxylic acid halide and benzene having a substituent.

Two or more different types of compounds (A) may be used in combination. Also, the compound (A) described in the specification of Japanese Patent Application No. 1-28329 filed by the present applicant, the compound (A) described in the specification of Japanese Patent Application No. 1-41133, the compound (A) described in the specification of Japanese Patent Application No. 1-134080
Compound (A) described in the specification, patent application No. 1-15130
Compound (A) described in Specification No. 4, Japanese Patent Application No. 1-1587
Compound (A) described in Specification No. 29, Patent Application No. 1-256
Compound (A) described in specification No. 220, patent application No. 1-25
Compound (A) described in specification No. 6221, patent application No. 1-2
Compound (A) described in specification No. 63551, patent application
Compound (A) described in specification No. 286747, patent application No.
-297142, compound (A) described in Japanese Patent Application No. 1-323193, compound (A) described in Japanese Patent Application No. 2-5541, Compound (A) described in specification No. 2-42844 and patent application (2) filed on April 20, 1990 (title of invention:
One or more of the compounds (A) described in ``Sensitizers and Heat-sensitive Recording Materials'' may be used in combination.

The compound (A) represented by the general formula (1), a so-called sensitizer, can be produced by any method, for example, 4.4'
- When producing dimethoxybenzophenone, the first method is to obtain a ketone compound by a free delta raft reaction from p-methoxybenzoic acid bromide and anisole, or the second method is to produce a ketone compound by reacting 4,4'-dihydroxybenzophenone with dimethyl sulfate. It can be obtained by etherification reaction.

A known method can be used to obtain a ketone compound from p-methoxybenzoic acid bromide and anisole by Friedel-Crafts reaction.

For example, in the presence of a condensing agent such as aluminum chloride, iron trichloride, tin tetrachloride, zinc chloride, boron fluoride, sulfuric acid, phosphorus pentoxide, phosphoric acid, or hydrofluoric acid, 50% Heat to ~120°C and react. The reaction product is decomposed with cold water, solid insoluble matter is filtered; washed with water, dried, and recrystallized with alcohol to obtain 4,4'-dimethoxybenzophenone.

A known method can be used to obtain a ketone compound by etherifying 4,4'-dihydroxybenzophenone and dimethyl sulfuric acid.

For example, in the presence of an alkali such as potassium carbonate, potassium hydroxide, or sodium methylate, 4,4'-dihydroxybenzophenone and dimethyl sulfate are heated at 50 to 120°C.
React with. The reaction product is recrystallized from alcohol to obtain 4,4'-dimethoxybenzophenone.

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)-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(l,2-dimethylindol-3-yl)-5-dimethylaminophthalide,
3,3-bis-(!・2-dimethylindol-3-yl)-6-dimethylaminophthalide, 3,3-bis(toethylrubazol-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.

As a diphenylmethane color former, 4,4'-bis-
Dimethylaminobenzhydrin benzyl ether, tohalophenyl leukoolamine, N-2・4-5-to IJ
Chlorophenyl leuko auramine causes vignetting.

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.

The spiropyran coloring agent is 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-probyl-spiro dibenzodipyran.

These color formers may be used alone or in combination of two 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. Examples of known color developers include ``Color Developers for Thermal Recording Paper (1) to (Complete)'' in ``Paper Valve Technology Times'', ``Tic Time Co., Ltd., Vol. 30, No. 6 to Vol. 31, No. 3''.
, written by Takashi Shiga" and "Color developers for thermal recording paper (1) to (complete), written by Takashi Shiga" in "Vol. 32, No. 4 to Vol. 32, No. 10", both of which can be used. Specifically, the following can be mentioned.

(1) Bisphenol color developer (t-B non-sulfur containing bisphenol color developer 2-(4-
hydroxyphenyl)propane, 2-(3'-hydroxyphenyl)propane, tetrabromobisphenol A
, 4.4'-isopropylidenediphenol, 4.
Bisphenol AM conductor compounds such as 4'-butylidenebis (2-t-butyl-5-methylphenol); t
pt'-methylenebis(2-cyclohexyl-5-methylphenol), 4,4'-isopropylidenebis(2
-cyclohexyl-5-methylphenol), 4.4'
-butylidene bis(2-cyclohexyl-5-methylphenol), 4,4'-cyclohexylidene bis(2-
cyclohexyl-5-methylphenol), ethyl 3,3-bis(3-cyclohexyl-4-hydroxy-5-methylphenol)butanoate, 4-[1,1-bis(4
-hydroxyphenyl)ethylcopyphenyl, 2-[1
, 1-bis(4-hydroxyphenyl)ethyl]naphthalene, 1-phenyl-1,1-bis(4-hydroxyphenyl)butane, 1,1-bis(p-hydroxyphenyl)cyclohexane, 4,4'-butylidenebis (2-
Bisphenol A related compounds such as cyclohexyl-5-methylphenol) and methyl-phenyl-methylidene bisphenol; 1. ! -bis(4-hydroxyphenyl)acetic acid, 2,2-bis(4-hydroxyphenyl)
Propionic acid, bis(4-hydroxyphenyl)acetic acid methyl ester, bis(4-hydroxyphenyl)acetic acid-
n-Butyl, bis(4-bitroxyphenyl)propargyl acetate, bis(4-hydroxyphenyl)cinnamyl acetate, bis(4-hydroxyphenyl)benzyl acetate, bis(4-hydroxyphenyl)phenyl acetate, bis(4-hydroxyphenyl)acetate
-hydroxyphenyl) phenethyl acetate, bis(4-hydroxyphenyl)acetate-β-(4'-ethoxyphenoxy)ethyl, 2,2-bis(4-hydroxyphenyl)acetate-3-phenoxypropyl, 2,2-bis (4-
Hydroxyphenyl>β-(4'-methylphenoxy)ethyl valerate, bis(4-hydroxyphenyl)stearamide, 1,3-bis(4-hydroxyphenyl)propane, 2,4-bis(4-hydroxy) phenyl)-4-methylpentane, 1,3-di[2-(4-hydroxyphenyl)-2-propyl]benzene, 1,3
-di[:2-(3,S-dimethyl-4-hydroxyphenyl)-2-propylcobenzene, bisphenol 1
．． 1-bis(hydroxyphenyl)-! -Bis(hydroxyphenyl) acid compounds such as phenylethane (1-
2) Sulfur-containing bisphenol color developer 4.4' dihydroxyphenyl diphenyl sulpon 12. 4' dihydroxyphenyl diphenyl sulpon, bis-(3-allyl-
4-hydroxyphenyl)sulfone, bis-(3-allyl-4-hydroxyphenyl)sulfone, 3-3'-sulfonylbis(4-hydroxybenzoic acid methyl ester), 1,3-bis(p-hydroxyanilinosulfonyl) ) bisphenol sulfone m conductor such as benzene; 4
Bisphenolsulfone-4-hydroxyphenyl) sulfide, bis(2-
methyl-5-isopropyl-4-hydroxyphenyl)
Sulfide, 4,4'-thiobis(6-ter-butyl-3-methylphenol), 1,5-di(4-hydroxyphenylthio)-3-oxypentane, l,8-di(4-hydroxythio) -3.6-thioxaoctane,
1,3-di(4-hydroxyphenylthio)acetone,
l,7-di(4-hydroxyphenylthio)-3.5-
Zeon! , 2-di(4-hydroxyphenylthio)phenylethane, l,2-di(4-hydroxyphenylthio)-1-(4-chlorophenyl)ethane, 4-hydroxyphenylthio-4-humantff-t-diphenyl )
Bisphenol sulfides such as methyl acetate, bis(4-hydroxyphenylthio)methyl acetate, and 4-benzyloxyphenyl-4-hydroxyphenyl sulfide; (2) Hydroxyarylcarboxylic acid color developer (2-1
) Hydroxybenzoic acid color developer p-hydroxybenzoic acid, -monohydroxybenzoic acid, salicylic acid, methyl p-hydroxybenzoate, benzyl p-hydroxybenzoate,
p-hydroxybenzoic acid-β-p-methoxyphenoxyethyl, p-hydroxybenzoic acid-β-p-methoxyphenoxyethyl, p-hydroxybenzoic acid-β-p-methoxyphenoxyethyl, p-hydroxybenzoic acid-2-(o-
Hydroxybenzoic acid and p-hydroxybenzoic acid esters such as hydroxyphenylthio)ethyl; 2,4-
Octadecyl dihydroxybenzoate, β-p-ethoxyphenoxyethyl 2,4-dihydroxybenzoate, 2
．． β-methallyloxyethyl 4-dihydroxybenzoate, β-ethyloxyethyl 2,4-dihydroxybenzoate, 2,4-dihydroxy-β-phenylthioethyl,! ,4-cyclohexanedimethanol-rubis-(p
Hydroxybenzoic acid derivatives (2-2) such as -hydroxybenzoic acid) ester, l,4-ethylene glycol-bis-(p-hydroxybenzoic acid) ester, salicylic acid color developer salicylic acid metal salt (Z n * M g, C a
l A l ), 4-tetradecyloxysalicylic acid, 4-β-p-)lyoxyethoxysalicylic acid, 3,5
-di(α-methylbenzyl)salicylic acid, 3,5-di(α,α-dimethylbenzyl)salicylic acid, 3,5-
Di-ter-butylsalicylic acid, 3-impropenyl-
5-ter-butylsalicylic acid, 3-vinyl-5-cyclohexanoic acid, 3vinyl-5-benzylsalicylic acid, 5
-Myristoylsalicylic acid, 5-phenylacetylsalicylic acid, methylphenoxyacetylsalicylic acid, 4-myristoylaminosalicylic acid, 4-phenylacetylaminosalicylic acid, 2.

2-bis(3-carboxy-4-hydroxyphenyl)
Propane, l,4-bis(3-carboxy-4-hydroxycumyl)benzene, salicylic acid derivatives (2-3) such as bis(2-hydroxy-3-carboxy-5-α-phenethylphenyl)methane, and other hydroxy Arylcarboxylic acid color developer dimethyl 4-hydroxyphthalate, 3,4,5.8-tetrachlorophthalic acid-mono Zinc salt of 2-hydroxyethyl, 3,4,5,B-tetrachlorophthalic acid-mono Phthalic acid derivatives such as the zinc salt of 3-hydroxy-2,2-dimethylpropyl, P-chlorobenzyl gallate,
Gallic acid derivatives such as benzyl gallate and p-vinylbenzyl gallate; l-hydroxy-4-benzyloxy-2-naphthoic acid, ■-acyloxy-4-benzyloxy-2-naphthoic acid, 2-acyloxy-4-benzyloxy- 1-naphthoic acid, Z nl of these acids
Naphthoic acid derivatives such as polyvalent metal salts such as Mg; (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, p-nitrobenzoic acid moiety, L-ascorbic acid, etc. (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', 4') dimethylene-4-hydroxydiphenylsulfone, 2-(4-hydroxybenzenesulfonyl)naphthalene, 1-(4-hydroxybenzenesulfonyl)naphthalene, 3-allyl-4-hydroxy-
4'-methyldiphenylsulfone, 3-allyl-4-hydroxy-42-methoxydiphenylsulfone, 3-allyl-4-hydroxy-4'-(2-phenoxyethoxy)diphenylsulfone, 3,4-dihydroxyphenyl-p- Tolylsulfone, 2,2'-bis(4-hydroxybenzenesulfonyl)ethyl ether, 4-hydroxy-4'-isopropoxydiphenylsulfone, 4-
Hydroxy-4'-chlorodiphenylsulfone, 3,5
-di-β-phenoxyethoxycarbonylbenzenesulfonic acid, 2-β-naphthoxyethoxynaphthalene-6-
Sulfonic color developers such as sulfonic acid; N-benzenesulfonyl-aminophenol, N-(α-naphthalenesulfonyl)-11-aminophenol, l,3-bis(
p-hydroxyanilinosulfonylbenzene, N-(2
-phenoxyethyl)-4-hydroxybenzenesulfonamide, N-(3-phenoxypropyl)-4-hydroxybenzenesulfonamide, N-(phenylsulfonyl)-p-)luenesulfonamide, n-butyl-N
-(o-carboxyphenylsulfonyl)-p-7minobenzoate), N-(dimethylsulfamoyl)-p-
) Sulfonamide compounds such as luenesulfonamide and N,N'-diphenylsulfonamide; Sulfonyl chloride compounds such as α-naphthalenesulfonyl chloride and p-phenylbenzenesulfonyl chloride These color developers may be used alone or in combination of two or more. May be used.

(Fan et al.) In the heat-sensitive recording material of the present invention, the amount of the compound (A) represented by general formula (1) used is usually 1 to 200 parts by weight, preferably 1 to 200 parts by weight, based on 100 parts by weight of the color developer. The range is from 3 to 100 parts by weight, particularly preferably from 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 insufficient, 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-ethylhexyl sulfosuccinate sodium salt, naphthalene sulfonate, etc.) if necessary. (acid sorter salt formalin condensate, etc.) by a grinder such as a ball mill, atrider or sand grinder to less than 1Oμ, 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 1 The mark 100 in Table 1 means, for example, that the coating liquid (b) is a mixture of a suspension of compound (A) and a suspension of a coloring agent.

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 inorganic fine powders such as titanium oxide, aluminum hydroxide, zinc hydroxide, chlorium sulfate, clay, kaolin, talc, and surface-treated calcium carbonate and silica, urea/formalin resin, styrene/methacrylic acid copolymer ,
Examples include organic fine powder such as polystyrene resin.

Examples of thermofusible substances and lubricants include higher fatty acids or their esters, amides, or metal salts, as well as various waxes, condensates of aromatic carboxylic acids and amines, benzoic acid phenyl esters, higher linear glycols, 3.4-
Examples include dialkyl epoxy hexahydrophthalate, higher ketones, and other thermofusible substances having a melting point of about 50 to 200°C.

Examples of the support include paper 1 synthetic paper and synthetic resin film, but paper is 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.

(ff) Coating the coating liquid (d) on the support, and then coating the coated shoe with the coating liquid (e). 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 6 is a layer of compound (A).

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

(IV) Coating solution (g), coating solution (e), and coating solution (f) are coated on the support in a layered manner. 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.

(Coating solution (f), coating solution (e), and coating solution (g) are coated on the Vl support in a layered manner in this order. The obtained heat-sensitive recording material is shown in FIG. 5. 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 applied onto the support, and coating liquid (c) is further applied 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.

Preferred coating methods and heat-sensitive recording materials are (II) (V
I) 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 is usually 0.5 to 20 g/ya2, preferably 1 to 15 g/m2, particularly preferably 3 to 10 g/ya2 in terms of dry weight.
m”.

[Example] 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 Methods) (1) Color Development 1) 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～! , 0sec, voltage 22v0
The color density was determined by measuring the reflection density using a Macbeth densitometer (manufactured by Macbeth). This value indicates that the developed color density is high.

2) Static color development test The prepared thermal recording paper was heated using a thermally inclined heat sealer at a temperature range of 70°C to 100°C and a printing pressure of 2 kg/C11.
Color was developed under conditions of 2 seconds for 1 press 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. A large value indicates a high degree of radial chromaticity.

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

The concentration meter is the same as 1).

(4) Moisture resistance test Colored image area in color development test at 45℃, 90% R11
After being left in a constant temperature and humidity chamber for 24 hours, the color density of the image area was measured. The concentration meter is the same as 1).

(5) 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 concentration meter is the same as 1).

Examples 1 to 3, Comparative Examples 1 to 3 Each of the following liquids A, B, or C was ground and dispersed in a ball mill for 24 hours, and then each layer was thoroughly mixed to prepare coating liquids I to H. This coating liquid was applied to high-quality paper (basis weight 5 Gg/m
Coated with a doctor blade to a dry solid content of 6 g/m', and after drying, thermal recording paper (Examples 1 to 3)
It was created.

As Comparative Examples 1 to 3, comparative sensitizer suspensions 1, 2 and 3 (conventional compound suspensions) were used in place of the sensitizer suspension of the present invention in Solution A. Using the same method, thermal paper (Comparative Examples 1 to 3) was prepared and printed.

Table 2 [Liquid A: Sensitizer suspension solution (parts) Compound (2); GHz-Q-co-Q-oc2Bs Compound (3); C2[60-O-CO-O-C2H1 Compound ( 4) (Conventional product); Q-ann Beto compound (5) (Conventional product); Q-oc■2CH20-Q compound (6) (Conventional product); NO2-Q-co-Q compound (7); Calcium carbonate Compound (8); Hydroxyethyl cellulose (5%
Aqueous solution) [Liquid E: Color former suspension solution 3-(N-ethyl N-pentylamino-6-methyl-7
- Anilinofluoranro S-205 manufactured by Yamada Chemical Co., Ltd. 10 parts Hydroxyethyl cellulose 40 parts (5% aqueous solution) Water
50 parts [Liquid C: Color developer suspension solution Cobisphenol A 30 parts Calcium carbonate polyvinyl alcohol (5% aqueous solution) Water Table 3 [Coating liquid 10 parts 40 parts 20 parts (parts) [Recording paper performance coefficient Table 4 Dynamic coloring test table 5 Static coloring test table 6 As is clear from Tables 4 to 6, the coloring properties of the thermal recording paper of the present invention are different from that of the conventional thermal recording paper (Comparative Examples 1 to 3). It was better. 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 papers (Comparative Examples 1 to 3).

Examples 4 to 6, Comparative Example 4 The following liquid E and liquid 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 8
Methods (I), (Vl) and (■), that is, (I), are a mixture of liquids D and E (1/1 weight ratio) on paper with a dry solid content of 8g/m''. For (VI), the coating liquid was applied to paper using a doctor blade so that the dry solid content was 4 g/m2, and then coated on this layer. Solution E was applied and dried in the same manner. (■) is the opposite of (Vl), in which solution E was applied first, then solution D. The amount of coating was the same as (l). did.

[Liquid D: mixed suspension solution of sensitizer and color former] 3-diethylamino-6-methyl 7-anilinofluorane
30 odd calcium carbonate
5m polyvinyl alcohol (5% water m liquid) 351 water
40 ■ [Liquid E: Mixed suspension of sensitizer and developer Copisphenol A 208+ 115-di(4-hydroxyphenylthio)-3-oxapentane 10 parts Calcium carbonate 5 parts Polyvinyl alcohol (5% aqueous solution) 35 parts water
Thermal recording papers prepared by the 25-part coating methods (I), (VI) and (■) were designated as Examples 4.5 and 6, respectively.

Further, as Comparative Example 4, thermosensitive recording paper (Comparative Example 3) was prepared by using parabenzylbiphenyl instead of compound (A) in Liquid D and Liquid E and applying the coating method in (I).

[Performance of Recording Paper] Table 8 Static Color Development Test Table 9 The color development of the recording paper was superior to that of the conventional thermal recording paper (Comparative Example 4). The light resistance, moisture resistance, and plasticizer resistance of the thermal recording paper of the present invention were superior to those of the conventional thermal recording paper (Comparative Example 4).

Furthermore, among the coating methods, method (Vl) was the most excellent for producing heat-sensitive 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 the drawing]

FIGS. 1 to 7 are explanatory views (cross-sectional views) of the heat-sensitive recording material of the present invention. 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 layer of a color former, 8... a color developer. drug calendar

Claims (1)

[Claims] 1. General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (1) [In the formula, Z_1 or Z_2 is a -R group (R is a hydrocarbon group having 6 or less carbon atoms), - OR group, -COOR group, -
COR group, halogen atom or CN group; Y_1 or Y
_2 is a lower hydrocarbon group; m or n is 0, 1 or 2;
a or b is 0 or 1 to 3 (however, when a=0, b=
0, when a=1 to 3, b=1 to 3)] A sensitizer comprising a compound (A). 2. The sensitizer according to claim 1, wherein Z_1 or Z_2 in general formula (1) is -R group and/or -OR group. 3. Containing the sensitizer according to claim 1 or 2 in a heat-sensitive recording material which has an electron-donating colorless coloring agent and an electron-accepting color developer on a support and is heated and melted to develop color. 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.