CA1215834A - Heat-sensitive recording unit - Google Patents
Heat-sensitive recording unitInfo
- Publication number
- CA1215834A CA1215834A CA000436863A CA436863A CA1215834A CA 1215834 A CA1215834 A CA 1215834A CA 000436863 A CA000436863 A CA 000436863A CA 436863 A CA436863 A CA 436863A CA 1215834 A CA1215834 A CA 1215834A
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- Prior art keywords
- heat
- sensitive recording
- recording unit
- bis
- methine
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Abstract
ABSTRACT
A heat-sensitive recording unit formed by supporting a methine-type chromogenic reactant and oxidizing organic compound on a base. A color production sensitivity regulator may further be supported on the base. It is also feasible to add a quaternary ammonium salt, tertiary alkanol amine or water-soluble ion sequestering agent for avoiding undesirable color production of the methine-type chromogenic reactant.
The ammonium salt, amine or ion sequestering agent may be added upon forming the methine-type chromogenic reactant into an aqueous suspension in order support the methine-type chromogenic reactant on the base.
A heat-sensitive recording unit formed by supporting a methine-type chromogenic reactant and oxidizing organic compound on a base. A color production sensitivity regulator may further be supported on the base. It is also feasible to add a quaternary ammonium salt, tertiary alkanol amine or water-soluble ion sequestering agent for avoiding undesirable color production of the methine-type chromogenic reactant.
The ammonium salt, amine or ion sequestering agent may be added upon forming the methine-type chromogenic reactant into an aqueous suspension in order support the methine-type chromogenic reactant on the base.
Description
HEAT-SENSITIVE RECORDING UNIT
This invention relates to a novel heat-sensitive recording unit making use of production of a color by a novel oxidation-reduction reaction., More specifically, it relates to a heat-sensitive recording unit comprising, as .
5 essential components, a methine-type chromogenic reactant and an oxidizing organic compound supported on a base.
A variety of methods has heretofore been proposed as to the heat-sensitive recording system which provides a record of images or marks by utilizing a physical or chemical change that a substance undergoes under the influence of thermal energy. Among these heat-sensitive recording methods, the so-called chromogenic reactant based color production-type heat-sensitive recording method and heat-sensitive recording paper making use of the recording method, which are proposed in Japanese Patent Publication No. 14039/1970, etc., have found wide-spread commercial utility in output console units such as computer, console units and facsimiles, reflecting recent technical advancement in thermal printers led by the development of thermal heads making use of resistor elements, because the above particular heat-sensitive recording .
method is free of such problems as noise and offensive odor and it permits high-speed recording. Accordingly, the chromogenic reactant based color production-type heat-sensitive recording method and heat-sensitive recording paper which makes use of the above recording method are expected to find still more acceptance in the future.
These chromogenic reactant based color production-type heat-sensitive recording paper are each formed, generally speaking, of (A) a lactone-type chromogenic reactant, for example,3-bis(4-dimethylaminophenyl)-6-dimethylaminophthaltide (crystal Violet Lactose) and (B) an acidic substance, for example, a finlike compound such as 2-bis(4-hydroxyphenyl)-propane (bisphenol A), which are supported together with a binder and other additives on a base. An application of heat causes at least one of the reactants (A) and (B) to melt and the reactants (A) and (~) are hence allowed to contact with each other, thereby forming a color image or mark with the thus-acidified lactone-type chromogenic reactant on the base.
Heat-sensitive recording paper making use of the color production by the contact of a lactone-type chromogenic reactant and an acidic finlike compound is however accompanied by the following serious problems:
(1) It is necessary to Corey chromogenic reactant and its matching color-developing agent both in large amounts on a base if one wants to obtain a color image or mark having .
. _ . . . . .
sufficient density. A lot of energy is thus required to melt either one or both of the chromogenic reactant and color-developing agent so as to bring them into mutual contact, thereby making the heat-sensitive recording paper difficult to meet the recent trend toward still faster recording in data communication (facsimiles); and
This invention relates to a novel heat-sensitive recording unit making use of production of a color by a novel oxidation-reduction reaction., More specifically, it relates to a heat-sensitive recording unit comprising, as .
5 essential components, a methine-type chromogenic reactant and an oxidizing organic compound supported on a base.
A variety of methods has heretofore been proposed as to the heat-sensitive recording system which provides a record of images or marks by utilizing a physical or chemical change that a substance undergoes under the influence of thermal energy. Among these heat-sensitive recording methods, the so-called chromogenic reactant based color production-type heat-sensitive recording method and heat-sensitive recording paper making use of the recording method, which are proposed in Japanese Patent Publication No. 14039/1970, etc., have found wide-spread commercial utility in output console units such as computer, console units and facsimiles, reflecting recent technical advancement in thermal printers led by the development of thermal heads making use of resistor elements, because the above particular heat-sensitive recording .
method is free of such problems as noise and offensive odor and it permits high-speed recording. Accordingly, the chromogenic reactant based color production-type heat-sensitive recording method and heat-sensitive recording paper which makes use of the above recording method are expected to find still more acceptance in the future.
These chromogenic reactant based color production-type heat-sensitive recording paper are each formed, generally speaking, of (A) a lactone-type chromogenic reactant, for example,3-bis(4-dimethylaminophenyl)-6-dimethylaminophthaltide (crystal Violet Lactose) and (B) an acidic substance, for example, a finlike compound such as 2-bis(4-hydroxyphenyl)-propane (bisphenol A), which are supported together with a binder and other additives on a base. An application of heat causes at least one of the reactants (A) and (B) to melt and the reactants (A) and (~) are hence allowed to contact with each other, thereby forming a color image or mark with the thus-acidified lactone-type chromogenic reactant on the base.
Heat-sensitive recording paper making use of the color production by the contact of a lactone-type chromogenic reactant and an acidic finlike compound is however accompanied by the following serious problems:
(1) It is necessary to Corey chromogenic reactant and its matching color-developing agent both in large amounts on a base if one wants to obtain a color image or mark having .
. _ . . . . .
sufficient density. A lot of energy is thus required to melt either one or both of the chromogenic reactant and color-developing agent so as to bring them into mutual contact, thereby making the heat-sensitive recording paper difficult to meet the recent trend toward still faster recording in data communication (facsimiles); and
(2) Color images or marks, which are obtained by the reaction between an chromogenic reactant and color-developing agent when either one or both of the chromogenic reactant and color-developing agent are melted by heat, are extremely unstable and are susceptible of undergoing easy discoloration or fading upon exposure to light, whereby making the color images or marks unlegible. Furthermore, such color images or marks readily disappear upon contact with an oil or the like.
There it a strong outstanding demand for the improvement to these problems in the above heat-sensitive recording method which is expected to become the dominant method in facsimiles which have been finding more and more acceptance in recent years. A variety of extensive researches and investigations have been made in recent years with respect to chromogenic reactants, color-developing agents, additives and coating formulations for heat sensitive recording paper. Under the circumstances, none of such researches and investigations appear to have resulted in any breakthrough improvement.
In accordance with the present invention, there is provided a heat-sensitive recording unit comprising a methine-ty~e.chromogenic reactant represented by the following general formula (I):
Y
X-CH-Z (I) wherein X, Y and Z may be the same or different and mean individually a substituted or unsubstituted phenol, naphthyl, stroll or aromatic heterocyclic residual group, two of X, Y and Z may be coupled together to form a ring, and the substituted or unsubstituted phenol, naphthyl or stroll group has at least one amino, substituted amino or lower ..
alkoxyl group at the para-position relative to the central methane group of the molecule when one or none of X, Y and Z is the aromatic heterocyclic residual group and an oxidizing organic compound, both, supported on a base.
The above heat-sensitive recording unit is totally different from conventional color systems which relied upon acid-base reactions between lactone-type chromogenic reactants and acidic substances and has solved the above-described various problems ox conventional heat-sensitive recording paper of the chromogenic reactant based color production type.
The main feature of the heat-sensitive recording unit according to this invention resides in that, although conventional heat-sensitive recording units provide or form color images or marks by the equilibrium reactions between acids (acidic color-developing agents represented by bisphen`ols) and bases (lactone-type chromogenic reactants led by CAL), i.e., in accordance with the following chemical equation:
Acidic color-developing agent + Color images or marks, Basic chromogenic reactant the heat-sensitive recording unit of this invention makes use of an oxidation-reduction reaction which is considered to proceed substantially in a non-reversible fashion, namely, which is expressed as follow:
Oxidizing organic color-developing agent + ? Color images or marks Methine-type chromogenic reactant .
In the heat-sensitive recording unit according to this invention, color images or marks formed on the base thereof by heating the unit and allowing the reactants to contact .
with each other are extremely stable to the environment.
Methine-type chromogenic reactants useful in the present invention are a group of compounds represented by the above general formula (It s illustrative aromatic heterocyclic residual groups represented by X, Y and/or Z, may be mentioned those having the following basic structures:
I', ~.~.
It should however be borne in mind that the aromatic:.heterocyclic residual groups are snot limited to those given above In addition, as substituent groups which may be bonded to carbon and/or hotter atoms of the phenol, naphth.yl, stroll or aromatic heterocyclic residual group, may, for example, be mentioned halogen atoms; lower alkyd groups;
halogenated lower alkyd groups; cycloalkyl groups; lower k~J
~LZ~5~
alkoxy groups; azalea group; carboalkoxy groups; cyanoalkyl groups; cyan group; hydroxyl group; vitro group; substituted or unsubstituted aralkyl~, phenol, airlocks, aralkylalko~y and amino groups; substituted amino groups containing, as subset-tent group or groups, one or two lower alkyd, cycloalkyl, cyanoalkyl, halogenated alkyd, hydroxyalkyl, substituted-or unsubstituted aureole, or substituted or unsubstituted aralkyl groups; polymethyleneamino groups (for example, pyrrolidino and piperidino groups); and morpholino group. Two of such substituent groups may be coupled together to form a ring.
Specifically speaking, the following compounds may be mentioned:
(A) Triaminotriphenylmethane-type chromogenic reactants:
4,4',4"-tris-dimethylamino-triphenylmethane;
4,4',`4"-tris-diethylamino-triphenylmethane;
4,4'-bis-methylamino-4"-dimethylamino-triphenylmethane;
4,4'-bis-dimethylamino-4"-methylamino-triphenylmethane;
4,4'-bis-diethylamino-4"-ethylamino-triphenylmethane;
4,4'-bis-diethylamino-4"-amino-triphenylmethane;
4,4'~bis-dimethylamino-3"-methyl-4'-amino-triphenylmethane;
4,4'-bis-dimethylamino-3"-me.thyl-4"-methylamino-triphenylmethane;
4,4',4"-trisphenylamino-triphenylmethane;
4,4',4"-tris(N-methyl-N'-phenylamino)-triphenyl-methane;
.. . .
I21~
4,4'~bismorpholino-4"-dimethylamino-triphenylmethane;
4,4',4"-tris-dimethylamino-2,2'-dimethyl-triphenylmethane;
4,4',4"-tris-dimethylamino 3,3'-dimethyl-triphenylmethane;
4,4',4"-tris-dimethylamino-2-methoxy-triphenylmethane;
4,4',4"-tris-dimethylamino-3-methyl-triphenylmethane;
4,4'-bis~dimethylamino-4"-N-benzylamino-triphenylmethane;
4,4'-bis-dimethylamino-4"-N-benzylamino-
There it a strong outstanding demand for the improvement to these problems in the above heat-sensitive recording method which is expected to become the dominant method in facsimiles which have been finding more and more acceptance in recent years. A variety of extensive researches and investigations have been made in recent years with respect to chromogenic reactants, color-developing agents, additives and coating formulations for heat sensitive recording paper. Under the circumstances, none of such researches and investigations appear to have resulted in any breakthrough improvement.
In accordance with the present invention, there is provided a heat-sensitive recording unit comprising a methine-ty~e.chromogenic reactant represented by the following general formula (I):
Y
X-CH-Z (I) wherein X, Y and Z may be the same or different and mean individually a substituted or unsubstituted phenol, naphthyl, stroll or aromatic heterocyclic residual group, two of X, Y and Z may be coupled together to form a ring, and the substituted or unsubstituted phenol, naphthyl or stroll group has at least one amino, substituted amino or lower ..
alkoxyl group at the para-position relative to the central methane group of the molecule when one or none of X, Y and Z is the aromatic heterocyclic residual group and an oxidizing organic compound, both, supported on a base.
The above heat-sensitive recording unit is totally different from conventional color systems which relied upon acid-base reactions between lactone-type chromogenic reactants and acidic substances and has solved the above-described various problems ox conventional heat-sensitive recording paper of the chromogenic reactant based color production type.
The main feature of the heat-sensitive recording unit according to this invention resides in that, although conventional heat-sensitive recording units provide or form color images or marks by the equilibrium reactions between acids (acidic color-developing agents represented by bisphen`ols) and bases (lactone-type chromogenic reactants led by CAL), i.e., in accordance with the following chemical equation:
Acidic color-developing agent + Color images or marks, Basic chromogenic reactant the heat-sensitive recording unit of this invention makes use of an oxidation-reduction reaction which is considered to proceed substantially in a non-reversible fashion, namely, which is expressed as follow:
Oxidizing organic color-developing agent + ? Color images or marks Methine-type chromogenic reactant .
In the heat-sensitive recording unit according to this invention, color images or marks formed on the base thereof by heating the unit and allowing the reactants to contact .
with each other are extremely stable to the environment.
Methine-type chromogenic reactants useful in the present invention are a group of compounds represented by the above general formula (It s illustrative aromatic heterocyclic residual groups represented by X, Y and/or Z, may be mentioned those having the following basic structures:
I', ~.~.
It should however be borne in mind that the aromatic:.heterocyclic residual groups are snot limited to those given above In addition, as substituent groups which may be bonded to carbon and/or hotter atoms of the phenol, naphth.yl, stroll or aromatic heterocyclic residual group, may, for example, be mentioned halogen atoms; lower alkyd groups;
halogenated lower alkyd groups; cycloalkyl groups; lower k~J
~LZ~5~
alkoxy groups; azalea group; carboalkoxy groups; cyanoalkyl groups; cyan group; hydroxyl group; vitro group; substituted or unsubstituted aralkyl~, phenol, airlocks, aralkylalko~y and amino groups; substituted amino groups containing, as subset-tent group or groups, one or two lower alkyd, cycloalkyl, cyanoalkyl, halogenated alkyd, hydroxyalkyl, substituted-or unsubstituted aureole, or substituted or unsubstituted aralkyl groups; polymethyleneamino groups (for example, pyrrolidino and piperidino groups); and morpholino group. Two of such substituent groups may be coupled together to form a ring.
Specifically speaking, the following compounds may be mentioned:
(A) Triaminotriphenylmethane-type chromogenic reactants:
4,4',4"-tris-dimethylamino-triphenylmethane;
4,4',`4"-tris-diethylamino-triphenylmethane;
4,4'-bis-methylamino-4"-dimethylamino-triphenylmethane;
4,4'-bis-dimethylamino-4"-methylamino-triphenylmethane;
4,4'-bis-diethylamino-4"-ethylamino-triphenylmethane;
4,4'-bis-diethylamino-4"-amino-triphenylmethane;
4,4'~bis-dimethylamino-3"-methyl-4'-amino-triphenylmethane;
4,4'-bis-dimethylamino-3"-me.thyl-4"-methylamino-triphenylmethane;
4,4',4"-trisphenylamino-triphenylmethane;
4,4',4"-tris(N-methyl-N'-phenylamino)-triphenyl-methane;
.. . .
I21~
4,4'~bismorpholino-4"-dimethylamino-triphenylmethane;
4,4',4"-tris-dimethylamino-2,2'-dimethyl-triphenylmethane;
4,4',4"-tris-dimethylamino 3,3'-dimethyl-triphenylmethane;
4,4',4"-tris-dimethylamino-2-methoxy-triphenylmethane;
4,4',4"-tris-dimethylamino-3-methyl-triphenylmethane;
4,4'-bis~dimethylamino-4"-N-benzylamino-triphenylmethane;
4,4'-bis-dimethylamino-4"-N-benzylamino-
3'-methoxytriphenylmethane;
4,4'-bis-dimethylamino-4"-N-benzylamino-3"-methyltriphenylmethane;
4,4'-bis-dimethylamino-3'-chloro-4'-N-benzylaminotriphenylmethane;
4,4'-bis-dimethylamino-4"-(N-benzyl-N-methylamino))-triphenylmethane;
4,4'-bis-dimethylamino-4"-(N-o-chlorobenzyl-N-methylamino)-triphenylmethane;
4,4'-bis-dimethylamino-4"-(N-p-chlorobenzyl-N-methylamino)-triphenylmethane;
4,4'-bis-dimethylamino-4"-(N-p-methylbenzyl-N-methyl)-triphenylmethane;
4,4'-bis-dimethylamino-4"-(N,N-dibenzylamino)-triphenylmethane;
4,4'-bis-dimethylamino-4"-(N-phenyl-N-methyl-amino)-triphenylmethane;
4,4'-bis-dimethylamino-4"-morpholino-triphenyl-methane;
4,4'-bis-N-benzylamino-4"-dimethylamino-triphenylmethane;
, 4,4'-bis-(N-benzyl-N-methylamino)-4"-dimethyl-aminotriphenylmethane;
4,4'-bis-(N-parachlorobenzyl-N-methylamino)-4"-dimethylamino-triphenylmethane;
4,4'-bis(N-parabromobenzyl-N-ethylamino?-4"-diethylamino-triphenylmethanei 4,4'-bis-pyrrolidyl-4"-dimethylaminotriphenyl-methane;
4,4'-bis(N-orthochlorobenzyl-N-methylamino)-4"-dimethylamino-triphenylmethane;
4,4'-bis-pyrrolidyl-4"-(N-benzyl-N-methylamino)-triphenylmethane;
3,3'-dichloro-4,4'-bis(N-benzylamino)-4"-dimethyl--amino-triphenylmethane;
4,4'-bis(N-p-methylbenzyl-N methylamino)-4"-dimethyl-amino-triphenylmethane;
4,4'-bis(N-p-methylbenzyl-N-ethylamino)-4"-diisopropylamino-triphenylmethane;
3,3'-dimethyl-4,4'-bis(p-methylbenzylamino)-4"- I.
dimethylaminotriphenylmethane;
3,3'-dimethyl-4,4'-bis(N-benzylamino)-4"-dimethylamino-triphenylmethane, 3,3'-dibutyl-4,4'-bis-N-benzylamino-4"-diethyl-amino-triphenylmethane etc.
(B) Diaminotriphenylmethane-type chromogenic reactants:
4,4'-bis-dimethylamino-triphenylmethane;
4,4'-bis-dimethylamino-4"-methyl-triphenylmethane;;
4,4'-bis-(N-benzyl-N-ethylamino)triphenyl-methane;
4,4'-bis-dimethylamino-2-chloro-triphenylmethane;
4,4'-bisdiisopropylamino-3"-bromotriphenylmethane;;
4,4'-bisdimethylamino-4"-methoxytriphenylmethane;
4,4'-bisdimethylamino-4"-ethoxytriphenylmethane;
4,4'-bisdimethylamino-3"-methyl-4"-methoxy-triphenylmethane;
4,4'-bisdimethylamino-3"-methyl-4"-ethoxytriphenyll-methane;
4,4'-bisdimethylamino-3",4"-dimethoxytriphenyl-methane;
4,4'-bisdimethylamino-2",4"-dimethoxytriphenyl-methane;
4,4'-bis-diethylamino-3'-ethyl-4"-etho~y-triphenylmethane;
4,4'-bis-methylamino-3,3'-dimethyl-3"-butyl-4"-butoxy-triphenylmethane;
4,4'-bis-dimethylamino-3"-cyclohexyl-4"-methoxy-triphenylmethane;
4,4'-b.is-propylamino-3"-phenyl-4"-propoxy-triphenylmethane;
4,4'-bis(N-benzyl-N-methylamino)-3'-propyl-4"-methoxytriphenylmethane;
4,4'-bis(N-benzyl-N-methylamino)-3"-methyl-4"-ethoxytriphenylmethane;
4,4'-bis-N-pyrrolidyl-3"-methyl-4"-methoxy-triphenylmethane;
4,4'-bis-N-piperidyl-3"-methyl-4"-ethoxy-triphenylmethane;
4,4'-dimethylamino-3"-tert-butyl-4"-methoxy-triphenylmethane;
etc.
(C) ~onoaminotriphenylmethane-type chromogenic reactants:
4,4'-dimethoxy-4"-dimethylaminotriphenylmethane;
4,4'-dimethoxy-3"-methyl-4"-methylamino-triphenylmethane;
4,4'-diethoxy-4"-diethylaminotriphenylmethane ....
1 1 r 4,4'~dimethoxy-4'1-(N-benzyl.N-methylamino)-triphenylmethane, 3,3'-dimethyl-4,4'-dimethoxy-4"-dimethyl-aminotriphenylmethane;
4,4'-dimethoxy-4"-pyrrolidinotriphenylmethane;
4,4'-dimethyl-4"-diethylaminotriphenylmethane;
4-methoxy-4'-dimethylaminotriphenylmethane;
etc.
(D) Naphthylmethane-type chromogenic reactants:
bis(4-dimethylamino-naphthyl-1)-4-dimethyl-aminophenylmethane;
bis(4-ethylamino-naphthyl-1)-4'-dimethylamino-phenylmethane, bis(4-N-paratolyl-N-methylamino-naphthyl-1)-4'-isopropylaminophe~ylmethane;
tris(4-dimethylamino-naphthyl-1)methane;
bis(4-dimethylamino-naphthyl-1)-4'-N-morpholino-phenylmethane;
bis(4-diethylaminophenyl)-4'-~-phenylamino-naphthyl-l'-methane;
bis(4-diethylami~ophenyl)-4'-ethylaminonaphthyl-methane bis(4-N-phenyl-N-methylaminonaphthyl-l)-~-styryl-methane;
bis(4-dimethylamino-naphthyl-1)-p-chlorostyryl-` methane;
bis(4-dimethylaminophenyl)-2'-methoxynaphthyl-1'-methane;
bis(4-dimethylaminophenyl)-4'-methoxynaphthyl-methane bis(4-dimethylaminophenyl)-naphtyl-2'-methane;
bis(4-N-propylaminophenyl)-4'-propo~ynaphthyl-2-methane;
-. - 12 -bis(4-dimethylaminonaphthyl~ 2'-pyridylmethane;
bis(4-dimethylaminonaphthyl-1)-2'-pyrazylmethane;
bis(4-dibenzylaminonaphthyl-1~-quinolin~3'-yl-methane;
etc.
(E) Diphenyl-g-styrylmethane-type chromogenic reactants:
bis(4-dimethylaminophenyl)-~-styrylmethane;
bis(3-methyl-4-N-phenylaminophenyl)-~-styrylmethanno;
bis(4-N-~enzyl-N-methylaminophenyl)-~-styrylmethanno, bls(4-dimethylaminophenyl)-B-(4'-dimethylamino-styryl)methane;
bis(4-dimethylaminophenyl)-B-(4'-methoxystyryl)metthan;
bis(4-diethylaminophenyl)-B-(3'-methyl-4'-ethoxystyryl)methane;
bis(3-methyl-4-ethox~phenyl)-g-(4'-diethyl-aminostyryl)-methane;
4-methylphenyl-4'-diethylaminophenyl-B-(3'-tert-butyl-4'-dimethylaminostyryl)-methane;
etc.
(F) Indolylmethane-type chromogenic reactants:
phenyl-bis(l-ethyl-2-methyl-indol-3-yl)methane;
4-methoxyphenyl-bis(l'-ethyl-2'-methylindol-3'-yl)methane;
3-methyl-4-methoxyphenyl-bis(l'-ethyl-2'-methylindol-3i-yl)methane;
3,4-dimethoxyphenyl-bis(l'-ethyl-2'-methyl-indol-3'-yl)methane;
2,4-dimethoxyphenyl-bis(l'-ethyl-2'-methyl-indol-3'-yl)methane;
3,4-diethoxyphenyl-bis(l'-ethy]-2-methylindol~
` 3'-yl)methane;
. .
. .
3-butyl-4-methoxyphenyl-bis~ bottle'-methylindol-3'-yl)methane;
4-ethoxyphenyl-bis(l'-ethyl-2'-phenylindol-3'-yl)methane;
4-ethoxyphenyl-bis(l'-ethyl-2'-methylindol-3'-yl)methane;
phenyl-bis(l'-n-butyl-2'-methylindol-3'-yl)methanee;
phenyl-bis(l'-methyl-2'-phenylindol-3'-yl)methàne;;
bis-(4-dimethylaminophenyl)-1'-ethyl-2'-methyl-indol-3'-yl)methane;
bis(l-ethyl-2-methylindol-3-yl)-2'-naphthylmethanee;
bis(l-ethyl-2-methylindol-3-yl)-1'-naphtylmethane;;
tris(l-ethyl-2-methylindol-3-yl)methane;
tris(l-n-butyl-2-methylindol-3-yl)methane; -bis(l-ethyl-2-methylindol-3-yl)-3'-chloro-4'-methoxyphenylmethane;
bis(l-propyl-2-phenylindol-3-yl)phenylmethane;
bis(l-octyl-2-methylindol-3-yl)phenylmethane;
bis(l-benzyl-2-methylindol-3-yl)phenylmethane;
bis(l-ethyl-2-methylindol-3-yl)-2'-methylphenyl-methane;
bis(l-ethyl-Z-methylindol-3-yl)-3'-methylphenyl-methane;
bis(l-ethyl-2-methylindol-3-yl)-4'-methylphenyl-methane;
bis(l-ethyl-2-methylindol-3-yl)-2'-methoxyphenyl-methane;
bis(l-ethyl-2-methylindol-3-yl)-41-f].uorophenyl-methane;
bis(l-ethyl-2-methylindol-3-yl)-4'-bromophenyl-methane, bis(l-hexylindol-3-yl)phenylmethane;
bis(l-ethyl-2-methylindol-3-yl)-3'-nitrophenyl-methane;
bis(l-ethyl-2-methylindol-3-yl)-3',4'-dichloro~
phenylmethane;
bis(l-ethyl~2-methylindol-3-yl)-2'-thienylmethane;;
bis(l-ethyl-2-methylindol-3-yl)-4'-methyl-2'~
thienylmethane;
bis(l-butyl-2-methylindol-3-yl)-4'-pyridylmethane;;
etc.
(F) Other leucomethine-type chromogenic reactants:
3,6-bis-dimethylamino-9-phenylxanthene;
: 3,6-bis-diethylamino-9-phenylxanthene;
3,6-bis-dimethylamino-9-(3'-me~hyl-4'-dimethyl-aminophenyl)xanthene;
3-diethylamino-6,7-dimethyl-9~phenylxanthene;
3,6-dimethoxy-9-(4'-dimethylaminophenyl)xanthene;
3,6-diethoxy-9-(4'-dimethyl-naphthyl-l')xanthene;
3,6-bis(N-methyl-N-phenylamino)-9-(3',4'-dimethoxyphenyl)xanthene;
3,6-bis-dimethylamino-9-phenylthioxanthene;
3,6-dimethylamino-9-(4'-methoxydiphenyl)-10-methyl-9,10-dihydroacridine;
3,6-bisdimethylamino-9-(4'-dimethylmaino-phenyl)fluorene;
etc.
It should however be borne in mind that the methane-type chromogenic reactant useful in the practice of this invention is not necessarily limited to the above-recited illustrative compounds.
On the other hand, the oxidizing organic compound useful in the practice of this invention means such an oxidizing organic compound that, when either one or both of the chromogenic reactant and oxidizing organic compound are molten owing to an application of heat thereto, it is brought into contact with the methine-type chromogenic reactant and oxidizes the methine-type chromogenic reactant, thereby providing a color image or mar with the thus-o,~idized methine-type chromogenic reactant on the base. As preferred compounds, may be mentioned quinine derivatives which have oxidizing capacity and are practically insoluble in water.
More preferably, may be mentioned water-insoluble quinine derivatives which have each been substituted by an electron-attractive group. Queen derivatives substituted by an electron-attractive group, notably multi-substituted by a plurality of electron-attractive groups are compounds having high oxidation-reduction potentials and are of the most preferable compound forms.
Since these quinine derivatives are required to be present in a stable state on heat-sensitive recording paper, it is not preferred to use compounds having low molecular weights or those having sublimely property More specifically, it is preferred to use benzoquinone derivatives represented by the general formula (II) or (III):
(II) IT
in which at least one of Al - I which aye individually a halogen atom or a cyan, nltro, carboxyl,- alkoxycarbonyl, aryloxycarbonyl, aralkyloxycarbonyl, alkylsulfonyl, arylsulfonyl, aralkylsulfonyl, alkoxysulfonyl, aryloxysulfonyl, aralkyloxysulfonyl or azalea group is contained as substituent group(s) in the molecule and the remaining substituent group(s) is individually a hydrogen atom or an allele, aureole, aralkyl , alkoxy, airlocks, aralkyloxy, alkylthio or arylthio group and where the adjacent carboxyl groups may form an imide ring.
As exemplary benzoquinone derivatives represented by the general ormolu IT or (III), may be mentioned:
2,3-dicyano-5,6-dichloro-1"4-benzoquinone;
2,3,5,6-tetracyano-1,4-benzoquinone;
3,4-dibromo-.5,6-dicyano-1,2-benzoquinone;
3,4,5,6-tetr.acyano-1,2-benzoquinone;
2,3,5,6-tetrabromo-1,4-benzoquinone;
2,3,5,6-tetraiodo-1,4-benzoquinone;
2,3,5,6-tetramethoxycarbonyl-1,4-benzoquinone;
2,3,5,6-tetraethoxycarbonyl-1,4-benzoquinone;
2,3,5,6-tetra-i-butoxycarbonyl-1,4-benzoquinone;
2,3,5,6-tetra-n-hexyloxycarbonyl-1,4-benzoquinone;;
2,3,5,6-tetra-(2'-ethylhexyloxycarbonyl)-1,4-benzoquinone;
2,3,5,6-tetradodecyloxycarbonyl-1,4-benzoquinone;
2,3,5,6-tetraphenoxycarbonyl-1,4-benzoquinone;
Jo 2,3,5,6-tetra-p-toluyloxycarbonyl-1,4-benzoquinonee;
- ~L5~q 2,3,5,6 tetrabenzyloxycarbonyl-1,4-benzoquinone;
2,3,5,6-tetranaphthoxycarbonyl-1,4 benzoquinone;
3,4,5,6-tetrapropyloxycarbonyl-1,2-benzoquinone;
3,4,5,6-tetra-n-butoxycarbonyl-1,2-benzoquinone, 2,5-dimethoxycarbonyl-3,6-dichloro-1,4-benzoquinonno;
2,5-diethoxycarbonyl-3,6-dibromo-1,4-benzoquinone 2,5-di-i-butoxycarbonyl-3,6-dibromo-1,4-benzo-quinine;
2,5-di-n-octoxycarbonyl-3,6-dibromo-1,4-benzo-quinine;
2,5-diphenoxycarbonyl-3,6-dliodo-1,4-benzoquinone;;
2,5-dibenzyloxy-3,4-dichloro-1,2-benzoquinone;
3,6-di-n-pentyloxycarbonyl-3,4-dichloro-1,4-benzoquinone;
2`,5-dibenzyloxycarbonyl-1,4-benzoquinone;
2,5-dibenzoyl-3,6-dichloro-1,4-benzoquinone;
2,5-dibenzoyl-3,6-dibromo-1,4-benzoquinone;
2,5-dibenzoyl-3-bromo-1,4-benzoquinone;
2,5-diacetyl-3,6-dibromo-1,4-benzoquinone;
2,5-diethoxycarbonyl-3,6-diphenylsulfonyl-1,4-benzoquinone;
2,5 di-n-butoxycarbonyl-3,6-di-4'-tolylsulfonyl-1,4-benzoquinone;
2,5-di-n-hexyloxycarbonyl-3,6-diphenylsulfonyl-1,4-benzoquinone;
2,5-di-i-propylox~carbonyl-3,6-di-p-tolylsulfonyl--1,4-benzo~uinone;
2,5-di-i-butoxycarbonyl-3,6-di-p-cyclohexylphenyl--sulfonyl-1,4-benzoquinone;
2,5-di-(2'-ethylhexyloxycarbonyl)-3,6-di-4'-diphenylsulfonyl-1,4-benzoquinone;l , 2,5-di-n~propyloxycarbonyl-3,6-di-4'-chlorophenyl--sulfonyl-1,4-benzoquinone;
2,5~diethoxycarbonyl-3,6-di-4'-methoxyphenyl-sulfonyl-1,4-benzoquinone;
2,5-di-benzyloxycarbonyl-3,6-di-4'-tolylsulfonyl-1,4-benzoquinone;
2,5-di-n-octyloxycarbonyl-3,6-diethylsulfonyl-1,4-benzoquinonei 2,5-diethoxycarbonyl-3,6-(2'-naphthylsulfonyl)-1,4-benzoquinone;
2,5-dimethoxycarbonyl-3-toluylsulfonyl-1,4-benzoquinone;
3,6-diethoxycarbonyl-4,5-diphenylsulfonyl-1~2 benzoquinone;
2,3,5,6-tetra-4'-toluylsulfonyl-1,4-benzoquinone;
2,3,5,6-tetraphenylsulfonyl-1,4-benzoquinone;
2,3,5,6-tetraethylsulfonyl-1,4-benzoquinone;
3,4,5,6-tetra-i-butylsulfonyl-1,2-benzoquinone;
2,3,5,6-tetra-n-octylsulfonyl-1,4-benzoquinone;
2,3,5,6-tetrabenzyloxysulfonyl-1,4-benzoquinone;
2,5-di-n-propyloxycarbonyl-3,6-dibenzoyl-1,4-benzoquinone;
2,5-di-i-butoxycarbonyl-3-benzoyl-1,4-benzoquinonee;
2,3-dichloro-1,4 benzoquinone-5,6-dicarboxylic butylimide;
1,4-benzoquinone-2,3,5,6-tetracarboxylic diphenyl-imide;
1,2-benzoquinone-3,4,5,6-tetracarboxylic di-n-octyl-imide;
2,5-diethoxysulfonyl-1,4-benzoquinone;
2,5-diphenoxysulfonyl-3,6-dichloro-1,4-benzoquinonno;
2,5-di-n-butoxycarbonyl-3,6-dibutoxysulfonyl-1,4~benzoquinone;
Z,S-di-p-toluylsulfonyl-3,6-dibromo-1,4-benzoquinoone;
2,5-di-n-hexylsulfonyl-3,~-dichloro-1,4-benzoquinoone;
2,5-dibenzoyl-1,4-benzoquinone;
2,5-di(4'-methylbenzoyl)-1,4-benzoquinone;
2,5-di(4'-ethylbenzoyl)-1,4-benzoquinone;
2,5-di(3',4'-dimethylbenzoyl)-1,4-benzoquinone;
2,5-di(4'-chlorobenzoyl)-1,4-benzoquinone;
2,5-di(p-bromobenzoyl)-1,4-benzoquinone;
2,5-di(2',5'-dichlorobenzoyl)-1,4-benzoquinone;
etc.
Among the above-described benzoquinone derivatives, 2,5-dibenzoyl-1,4-benzoquinone derivatives represented by the general formula IVY): no no O
wherein R means a hydrogen or halogen atom or a lower alkyd group, and n stands for an integer up to 3 are particularly preferred due to their excellent storage stability, light resistant stability and anti-solvent stability. 2,5-Dibenzoyl-1,4-benzoquinone is the most suitable compound because its raw materials are easy to obtain and are easy to handle during its synthesis.
Even if a quinine derivative has great oxidizing capacity and has been substituted by one or more electron-,~34~-~
attractive groups, the quinine derivative such as 2,3,5,6-tetrachloro-1,4-benzoquinone(Chloroanil), 2,3,5,6-tetrafluoro-1,4benzoquinone(Fluoroanil),2,3,5-trichloro-1,4-benzooquinone, dichlorobenzoquinone, difluorobenzoquinone, eta, cannot be used as is for the following reasons where it has a small molecular eight and is sublimable:
(1) It undergoes gradual sublimation from the heat-sensitive recording paper during its storage and the color-producing capacity of the heat-sensitive recording paper is thus lowered 2) The thus-sublimated quinine derivative reacts with the methine-type chromogenic reactant, thereby causing the heat-sensitive recording paper to show an undesired or inconvenient color which is the thus-oxidized methine-type chromogenic reactant; and ..
(3) The working environment is adversely affected.
._ .
Accordingly, it is necessary to use some sublimatlon-suppressing means if one wants to employ such a quinine derivative as is.
The methine-type chromogenic reactant useful in the practice of this invention and represented by the general formula (I) is generally unstable to its storage and, in many instances, tends to show such tendency that it considerably colors an aqueous suspension, aqueous coating formulation or the coated surface of a heat-sensitive recording paper respect lively in its dispersion step in a liquid (i.e., the step to convert the methine-type chromogenic reactant to the aqueous suspension in which the reactant is present as fine particles), in the preparation step of the methIne-type chromogenic reactant together with a color-developing agent and other additives into the aqueous coating formulation or in the coating step of the aqueous coating formulation on a base to prepare the heat-sensitive recording paper; and the resulting heat-sensitive recording paper is colored during its storage or upon exposure to light. Therefore, the methine-type chromogenic reactant Milwaukee utility in some instances, in the production of heat-sensitive recording paper if it is used as is.
Accordingly, it is preferred to use (A) a qua ternary ammonium salt, (B) an alkanol amine having a tertiary amino group or (C) a water-soluble metal ion sequestering agent along with the methine-type chromogenic reactant and oxidizing organic compound which are basically essential in the present invention.
As exemplary qua ternary ammonium sells, may - be mentioned specifically:
lauryltrimethylammonium chloride;
stearyltrimethylammonium chloride;
distearyldimethylammonium chloride;
dodecyltrimethylammonium chloride;
octadecyltrimethylammonium chloride;
tetradecyldimethylbenzylammonium chloride;
etc.
As specific examples of the alkanol amine containing a tertiary amino, may be mentioned:
tris-N-(2-hydroxyethyl)amine;
tris-N-(2-hydroxypropyl)amine;
tris-N-(3-hydroxypropyl)amine;
tris-N-(hydroxydibutyl)amine;
N,N-dimethyl-N-(2-hydroxyethyl)amine;
N,N-diethyl-N-(2-hydroxyethyl)amine;
N,N-dipropyl-N-(2-hydroxyethyl)amine;
N,N-dibutyl-N-(2-hydroxyethyl)amine;
N-methyl-N-phenyl-N-(2-hydroxyethyl)amine;
N,N-diphenyl-N-(2-hydroxyethyl)amine;
N,N-dimethyl-N-(2-hydroxypropyl)amine;
N,N-diethyl-N-(2-hydroxypropyl)amine;
N,N-dipropyl-N-(2-hydroxypropyl)amine;
N,N-dibutyl-N-(2-hydroxypropyl)amine;
N,N-diphenyl-N-(2-hydroxypropyl)amine;
N-methyl-N,N-di(2-hydroxyethyl)amine;
N-ethyl-N,N-di(2-hydroxyethyl)amine;
N-phenyl-N,N-di(2-hydroxyethyl)amine;
N-methyl-N,N-di(2-hydroxypropyl)amine;
N-acetyl-N,N-di(2-hydroxyethyl)amine;
N-methyl-N,N-di(2-hydroxypropyl)amine;
N-acetyl-N,N-di(2-hydroxyethyl)amine;
N-acetyl-N,N-di(2-hydroxypropyl)amine;
N-hydroxyethylmorpholine;
N-hydorxypropylmorpholine;
N-tetradecyl-N,N-di(~-hydroxyethylpolyoxyethylene))-amine N-dodecyl-N,N-di(~-hydroxyethylpolyoxye-thylene)ammine;
N-octadecyl-N,N-di(~-hydroxyethylpolyoxyethylene)--amine;
N,N-didodecyl-N-(~-hydroxyethylpolyoxyethylene)amiire;
N,N-di(cis-octadecenyl)-N-(~-hydroxyethylpolyoxy-ethylene amine N,N-dioctadecyl-N (~-hydroxyethylpolyoxyethylene)-amine compounds formed by adding alkaline dioxides to aliphatic dominoes, for example, those represented by the following structural formula:
(CH2CH20)zH (CH2cH2o)xH
\(CH2CH20)y}I
wherein R is an aliphatic chain and x, y and z are each a positive integer;
N,N-~-hydroxyalkylpolyoxyalkylene-substituted aliphatic asides, for example, those represented by the following structural formula:
ill ( CH2CH20 ) oh (CH2CH20)yH
wherein R means an aliphatic chain and x and y stand individually for a positive integer;
reaction products between ammonia and glycidols (2-amino-propylene glycol derivatives);
etc.
The metal ion sequestering agent is bonded with multivalent metal ions present in a system dispersing the Jo chromogenic reactant, i.e., the layer of the chromogenic reactant applied on the hose of a heat-sensitive recording paper so as to form a stable chelates compound, thereby retarding the inconvenient coloring tendency of the methane-type chromogenic reactant in the presence of such multivalent metal ions. As metal ion sequestering agents having such an effect, may for example be mentioned water-soluble metal ion sequestering agents such as ethylenediaminetetraacetic acid, N-hydroxyethyl-ethylenediamine-N,N',N'-triacetic acid, diethylenetriamine-pentaacetic acid, triethylenetetrammine-pentaacetic acid, nitrilotriacetic acid, N-hydroxyethyl-iminodiacetic acid, diethanol Gleason, ethylenediamine-N,N'-diabetic acid, glycolether-diaminetetraacetic acid, 1,3-diaminopropan-2-ol-tetraacetic acid, tartaric acid, citric acid, gluconic acid and saccharin acid , and their alkali metal salts, salts of polyacrylic acid, and metal salts of ligninsulfonic acid.
These coloration-inhibitory additives may be used in an amount of 0.1 - 1000 parts by weight per 100 parts by weight of the methine-type chromogenic reactant. Among these additives, the water-soluble qua ternary ammonium sell can bring about the greatest effect when used even in a relatively small amount.
The heat-sensitive recording unit according to this invention is basically formed of a methine-type chromogenic reactant and oxidizing organic compound, both supported as . .
mutually-isolated wine particles on a base. Accordingly, the production of a color by the reaction between the methane-type chromogenic reactant and oxidizing organic compound is allowed to take place upon application of heat energy that raises either one or both of the methine-type chromogenic reactant and oxidizing organic compound to its melting point or their respective melting points. Therefore, it is required to have heat-sensitive recording paper produce its color at an elevated temperature where the chromogenic reactant and/or oxidizing organic compound, notably, the oxidizing organic compound is a high mop. compound. Consequently, a heavy load is applied to thermal heads or heat pens which are used as sources for supplying thermal energy. Such heat-sensitive recording paper can hardly meet the high-speed printing. It is thus preferred to adjust the color-producing temperature characteristics by using a color production sensitivity regulator in combination.
In the case of high mop. compounds such as buoyancy-unwon derivatives which are particularly-preferred oxidizing organic compounds, for example, 2,5-dibenzoyl-1,4-benzoquinones, it is preferred to use a color production temperature adjusting agent in combination.
As such color production sensitivity regulators, there are employed compounds which have melting points in the range of 70 - 150 C and, when molten, dissolve the methine-type chromogenic reactant and/or oxidizing organic I
compound. As specific compounds, may for example be mentioned as follows:
(1) Higher fatty acid asides and their derivatives, for example, Starkey acid aside, linoleic acid aside, myristic acid aside and oleic acid aside and their methylol derivatives, ethylene-bis-stearoamide, and ethylene-bis-stearoamide;
(2) alkylbiphenyls, alkylnaphthalenes and biphenylalkanes, e.g., 4,4'-dimethylbiphenyl, 2,6-diisopropylnaphthalene, etc.;
(3) kittens, for example, diundecyl kitten, diheptadecyl kitten, etc.;
(4) Carboxylic and sulfonic acid esters of phenol derivatives, for example, diphenyl preappoint, diphenyl cyclohexylcarboxylate, diphenyl phenylsulfonate, diphenyl bonniest, knothole bonniest, p-cyclohexylphenyl bonniest, p-cyclohexylphenyl Tulane sulfonate, p-cyclohexylphenyl cinnamate, p-tert-butylphenyl bonniest, p-tert-octylphenyl bonniest, p-acetylphenyl bonniest, resorsine dibenzoate, 4,4'-thiobisphenol dibenzoate, bus-phenol A-di(phenylsulfonate), phenyl-p-toluenesulfonate, p-tert-butylphenyl-p-toluenesulfonate, diphenyl isophthalate, di-p-sec-butylphenyl isophthalate, di(o-cyclohexylphenyl) isophthalate, di(o-octoxycarbonylphenyl)isophthalate, dip-sec-butylphenyl)terephthalate, Dow sec-butylphenyl) lore-phthalate, and o-phenoxycarbonylphenyl bonniest;
4,4'-bis-dimethylamino-3'-chloro-4'-N-benzylaminotriphenylmethane;
4,4'-bis-dimethylamino-4"-(N-benzyl-N-methylamino))-triphenylmethane;
4,4'-bis-dimethylamino-4"-(N-o-chlorobenzyl-N-methylamino)-triphenylmethane;
4,4'-bis-dimethylamino-4"-(N-p-chlorobenzyl-N-methylamino)-triphenylmethane;
4,4'-bis-dimethylamino-4"-(N-p-methylbenzyl-N-methyl)-triphenylmethane;
4,4'-bis-dimethylamino-4"-(N,N-dibenzylamino)-triphenylmethane;
4,4'-bis-dimethylamino-4"-(N-phenyl-N-methyl-amino)-triphenylmethane;
4,4'-bis-dimethylamino-4"-morpholino-triphenyl-methane;
4,4'-bis-N-benzylamino-4"-dimethylamino-triphenylmethane;
, 4,4'-bis-(N-benzyl-N-methylamino)-4"-dimethyl-aminotriphenylmethane;
4,4'-bis-(N-parachlorobenzyl-N-methylamino)-4"-dimethylamino-triphenylmethane;
4,4'-bis(N-parabromobenzyl-N-ethylamino?-4"-diethylamino-triphenylmethanei 4,4'-bis-pyrrolidyl-4"-dimethylaminotriphenyl-methane;
4,4'-bis(N-orthochlorobenzyl-N-methylamino)-4"-dimethylamino-triphenylmethane;
4,4'-bis-pyrrolidyl-4"-(N-benzyl-N-methylamino)-triphenylmethane;
3,3'-dichloro-4,4'-bis(N-benzylamino)-4"-dimethyl--amino-triphenylmethane;
4,4'-bis(N-p-methylbenzyl-N methylamino)-4"-dimethyl-amino-triphenylmethane;
4,4'-bis(N-p-methylbenzyl-N-ethylamino)-4"-diisopropylamino-triphenylmethane;
3,3'-dimethyl-4,4'-bis(p-methylbenzylamino)-4"- I.
dimethylaminotriphenylmethane;
3,3'-dimethyl-4,4'-bis(N-benzylamino)-4"-dimethylamino-triphenylmethane, 3,3'-dibutyl-4,4'-bis-N-benzylamino-4"-diethyl-amino-triphenylmethane etc.
(B) Diaminotriphenylmethane-type chromogenic reactants:
4,4'-bis-dimethylamino-triphenylmethane;
4,4'-bis-dimethylamino-4"-methyl-triphenylmethane;;
4,4'-bis-(N-benzyl-N-ethylamino)triphenyl-methane;
4,4'-bis-dimethylamino-2-chloro-triphenylmethane;
4,4'-bisdiisopropylamino-3"-bromotriphenylmethane;;
4,4'-bisdimethylamino-4"-methoxytriphenylmethane;
4,4'-bisdimethylamino-4"-ethoxytriphenylmethane;
4,4'-bisdimethylamino-3"-methyl-4"-methoxy-triphenylmethane;
4,4'-bisdimethylamino-3"-methyl-4"-ethoxytriphenyll-methane;
4,4'-bisdimethylamino-3",4"-dimethoxytriphenyl-methane;
4,4'-bisdimethylamino-2",4"-dimethoxytriphenyl-methane;
4,4'-bis-diethylamino-3'-ethyl-4"-etho~y-triphenylmethane;
4,4'-bis-methylamino-3,3'-dimethyl-3"-butyl-4"-butoxy-triphenylmethane;
4,4'-bis-dimethylamino-3"-cyclohexyl-4"-methoxy-triphenylmethane;
4,4'-b.is-propylamino-3"-phenyl-4"-propoxy-triphenylmethane;
4,4'-bis(N-benzyl-N-methylamino)-3'-propyl-4"-methoxytriphenylmethane;
4,4'-bis(N-benzyl-N-methylamino)-3"-methyl-4"-ethoxytriphenylmethane;
4,4'-bis-N-pyrrolidyl-3"-methyl-4"-methoxy-triphenylmethane;
4,4'-bis-N-piperidyl-3"-methyl-4"-ethoxy-triphenylmethane;
4,4'-dimethylamino-3"-tert-butyl-4"-methoxy-triphenylmethane;
etc.
(C) ~onoaminotriphenylmethane-type chromogenic reactants:
4,4'-dimethoxy-4"-dimethylaminotriphenylmethane;
4,4'-dimethoxy-3"-methyl-4"-methylamino-triphenylmethane;
4,4'-diethoxy-4"-diethylaminotriphenylmethane ....
1 1 r 4,4'~dimethoxy-4'1-(N-benzyl.N-methylamino)-triphenylmethane, 3,3'-dimethyl-4,4'-dimethoxy-4"-dimethyl-aminotriphenylmethane;
4,4'-dimethoxy-4"-pyrrolidinotriphenylmethane;
4,4'-dimethyl-4"-diethylaminotriphenylmethane;
4-methoxy-4'-dimethylaminotriphenylmethane;
etc.
(D) Naphthylmethane-type chromogenic reactants:
bis(4-dimethylamino-naphthyl-1)-4-dimethyl-aminophenylmethane;
bis(4-ethylamino-naphthyl-1)-4'-dimethylamino-phenylmethane, bis(4-N-paratolyl-N-methylamino-naphthyl-1)-4'-isopropylaminophe~ylmethane;
tris(4-dimethylamino-naphthyl-1)methane;
bis(4-dimethylamino-naphthyl-1)-4'-N-morpholino-phenylmethane;
bis(4-diethylaminophenyl)-4'-~-phenylamino-naphthyl-l'-methane;
bis(4-diethylami~ophenyl)-4'-ethylaminonaphthyl-methane bis(4-N-phenyl-N-methylaminonaphthyl-l)-~-styryl-methane;
bis(4-dimethylamino-naphthyl-1)-p-chlorostyryl-` methane;
bis(4-dimethylaminophenyl)-2'-methoxynaphthyl-1'-methane;
bis(4-dimethylaminophenyl)-4'-methoxynaphthyl-methane bis(4-dimethylaminophenyl)-naphtyl-2'-methane;
bis(4-N-propylaminophenyl)-4'-propo~ynaphthyl-2-methane;
-. - 12 -bis(4-dimethylaminonaphthyl~ 2'-pyridylmethane;
bis(4-dimethylaminonaphthyl-1)-2'-pyrazylmethane;
bis(4-dibenzylaminonaphthyl-1~-quinolin~3'-yl-methane;
etc.
(E) Diphenyl-g-styrylmethane-type chromogenic reactants:
bis(4-dimethylaminophenyl)-~-styrylmethane;
bis(3-methyl-4-N-phenylaminophenyl)-~-styrylmethanno;
bis(4-N-~enzyl-N-methylaminophenyl)-~-styrylmethanno, bls(4-dimethylaminophenyl)-B-(4'-dimethylamino-styryl)methane;
bis(4-dimethylaminophenyl)-B-(4'-methoxystyryl)metthan;
bis(4-diethylaminophenyl)-B-(3'-methyl-4'-ethoxystyryl)methane;
bis(3-methyl-4-ethox~phenyl)-g-(4'-diethyl-aminostyryl)-methane;
4-methylphenyl-4'-diethylaminophenyl-B-(3'-tert-butyl-4'-dimethylaminostyryl)-methane;
etc.
(F) Indolylmethane-type chromogenic reactants:
phenyl-bis(l-ethyl-2-methyl-indol-3-yl)methane;
4-methoxyphenyl-bis(l'-ethyl-2'-methylindol-3'-yl)methane;
3-methyl-4-methoxyphenyl-bis(l'-ethyl-2'-methylindol-3i-yl)methane;
3,4-dimethoxyphenyl-bis(l'-ethyl-2'-methyl-indol-3'-yl)methane;
2,4-dimethoxyphenyl-bis(l'-ethyl-2'-methyl-indol-3'-yl)methane;
3,4-diethoxyphenyl-bis(l'-ethy]-2-methylindol~
` 3'-yl)methane;
. .
. .
3-butyl-4-methoxyphenyl-bis~ bottle'-methylindol-3'-yl)methane;
4-ethoxyphenyl-bis(l'-ethyl-2'-phenylindol-3'-yl)methane;
4-ethoxyphenyl-bis(l'-ethyl-2'-methylindol-3'-yl)methane;
phenyl-bis(l'-n-butyl-2'-methylindol-3'-yl)methanee;
phenyl-bis(l'-methyl-2'-phenylindol-3'-yl)methàne;;
bis-(4-dimethylaminophenyl)-1'-ethyl-2'-methyl-indol-3'-yl)methane;
bis(l-ethyl-2-methylindol-3-yl)-2'-naphthylmethanee;
bis(l-ethyl-2-methylindol-3-yl)-1'-naphtylmethane;;
tris(l-ethyl-2-methylindol-3-yl)methane;
tris(l-n-butyl-2-methylindol-3-yl)methane; -bis(l-ethyl-2-methylindol-3-yl)-3'-chloro-4'-methoxyphenylmethane;
bis(l-propyl-2-phenylindol-3-yl)phenylmethane;
bis(l-octyl-2-methylindol-3-yl)phenylmethane;
bis(l-benzyl-2-methylindol-3-yl)phenylmethane;
bis(l-ethyl-2-methylindol-3-yl)-2'-methylphenyl-methane;
bis(l-ethyl-Z-methylindol-3-yl)-3'-methylphenyl-methane;
bis(l-ethyl-2-methylindol-3-yl)-4'-methylphenyl-methane;
bis(l-ethyl-2-methylindol-3-yl)-2'-methoxyphenyl-methane;
bis(l-ethyl-2-methylindol-3-yl)-41-f].uorophenyl-methane;
bis(l-ethyl-2-methylindol-3-yl)-4'-bromophenyl-methane, bis(l-hexylindol-3-yl)phenylmethane;
bis(l-ethyl-2-methylindol-3-yl)-3'-nitrophenyl-methane;
bis(l-ethyl-2-methylindol-3-yl)-3',4'-dichloro~
phenylmethane;
bis(l-ethyl~2-methylindol-3-yl)-2'-thienylmethane;;
bis(l-ethyl-2-methylindol-3-yl)-4'-methyl-2'~
thienylmethane;
bis(l-butyl-2-methylindol-3-yl)-4'-pyridylmethane;;
etc.
(F) Other leucomethine-type chromogenic reactants:
3,6-bis-dimethylamino-9-phenylxanthene;
: 3,6-bis-diethylamino-9-phenylxanthene;
3,6-bis-dimethylamino-9-(3'-me~hyl-4'-dimethyl-aminophenyl)xanthene;
3-diethylamino-6,7-dimethyl-9~phenylxanthene;
3,6-dimethoxy-9-(4'-dimethylaminophenyl)xanthene;
3,6-diethoxy-9-(4'-dimethyl-naphthyl-l')xanthene;
3,6-bis(N-methyl-N-phenylamino)-9-(3',4'-dimethoxyphenyl)xanthene;
3,6-bis-dimethylamino-9-phenylthioxanthene;
3,6-dimethylamino-9-(4'-methoxydiphenyl)-10-methyl-9,10-dihydroacridine;
3,6-bisdimethylamino-9-(4'-dimethylmaino-phenyl)fluorene;
etc.
It should however be borne in mind that the methane-type chromogenic reactant useful in the practice of this invention is not necessarily limited to the above-recited illustrative compounds.
On the other hand, the oxidizing organic compound useful in the practice of this invention means such an oxidizing organic compound that, when either one or both of the chromogenic reactant and oxidizing organic compound are molten owing to an application of heat thereto, it is brought into contact with the methine-type chromogenic reactant and oxidizes the methine-type chromogenic reactant, thereby providing a color image or mar with the thus-o,~idized methine-type chromogenic reactant on the base. As preferred compounds, may be mentioned quinine derivatives which have oxidizing capacity and are practically insoluble in water.
More preferably, may be mentioned water-insoluble quinine derivatives which have each been substituted by an electron-attractive group. Queen derivatives substituted by an electron-attractive group, notably multi-substituted by a plurality of electron-attractive groups are compounds having high oxidation-reduction potentials and are of the most preferable compound forms.
Since these quinine derivatives are required to be present in a stable state on heat-sensitive recording paper, it is not preferred to use compounds having low molecular weights or those having sublimely property More specifically, it is preferred to use benzoquinone derivatives represented by the general formula (II) or (III):
(II) IT
in which at least one of Al - I which aye individually a halogen atom or a cyan, nltro, carboxyl,- alkoxycarbonyl, aryloxycarbonyl, aralkyloxycarbonyl, alkylsulfonyl, arylsulfonyl, aralkylsulfonyl, alkoxysulfonyl, aryloxysulfonyl, aralkyloxysulfonyl or azalea group is contained as substituent group(s) in the molecule and the remaining substituent group(s) is individually a hydrogen atom or an allele, aureole, aralkyl , alkoxy, airlocks, aralkyloxy, alkylthio or arylthio group and where the adjacent carboxyl groups may form an imide ring.
As exemplary benzoquinone derivatives represented by the general ormolu IT or (III), may be mentioned:
2,3-dicyano-5,6-dichloro-1"4-benzoquinone;
2,3,5,6-tetracyano-1,4-benzoquinone;
3,4-dibromo-.5,6-dicyano-1,2-benzoquinone;
3,4,5,6-tetr.acyano-1,2-benzoquinone;
2,3,5,6-tetrabromo-1,4-benzoquinone;
2,3,5,6-tetraiodo-1,4-benzoquinone;
2,3,5,6-tetramethoxycarbonyl-1,4-benzoquinone;
2,3,5,6-tetraethoxycarbonyl-1,4-benzoquinone;
2,3,5,6-tetra-i-butoxycarbonyl-1,4-benzoquinone;
2,3,5,6-tetra-n-hexyloxycarbonyl-1,4-benzoquinone;;
2,3,5,6-tetra-(2'-ethylhexyloxycarbonyl)-1,4-benzoquinone;
2,3,5,6-tetradodecyloxycarbonyl-1,4-benzoquinone;
2,3,5,6-tetraphenoxycarbonyl-1,4-benzoquinone;
Jo 2,3,5,6-tetra-p-toluyloxycarbonyl-1,4-benzoquinonee;
- ~L5~q 2,3,5,6 tetrabenzyloxycarbonyl-1,4-benzoquinone;
2,3,5,6-tetranaphthoxycarbonyl-1,4 benzoquinone;
3,4,5,6-tetrapropyloxycarbonyl-1,2-benzoquinone;
3,4,5,6-tetra-n-butoxycarbonyl-1,2-benzoquinone, 2,5-dimethoxycarbonyl-3,6-dichloro-1,4-benzoquinonno;
2,5-diethoxycarbonyl-3,6-dibromo-1,4-benzoquinone 2,5-di-i-butoxycarbonyl-3,6-dibromo-1,4-benzo-quinine;
2,5-di-n-octoxycarbonyl-3,6-dibromo-1,4-benzo-quinine;
2,5-diphenoxycarbonyl-3,6-dliodo-1,4-benzoquinone;;
2,5-dibenzyloxy-3,4-dichloro-1,2-benzoquinone;
3,6-di-n-pentyloxycarbonyl-3,4-dichloro-1,4-benzoquinone;
2`,5-dibenzyloxycarbonyl-1,4-benzoquinone;
2,5-dibenzoyl-3,6-dichloro-1,4-benzoquinone;
2,5-dibenzoyl-3,6-dibromo-1,4-benzoquinone;
2,5-dibenzoyl-3-bromo-1,4-benzoquinone;
2,5-diacetyl-3,6-dibromo-1,4-benzoquinone;
2,5-diethoxycarbonyl-3,6-diphenylsulfonyl-1,4-benzoquinone;
2,5 di-n-butoxycarbonyl-3,6-di-4'-tolylsulfonyl-1,4-benzoquinone;
2,5-di-n-hexyloxycarbonyl-3,6-diphenylsulfonyl-1,4-benzoquinone;
2,5-di-i-propylox~carbonyl-3,6-di-p-tolylsulfonyl--1,4-benzo~uinone;
2,5-di-i-butoxycarbonyl-3,6-di-p-cyclohexylphenyl--sulfonyl-1,4-benzoquinone;
2,5-di-(2'-ethylhexyloxycarbonyl)-3,6-di-4'-diphenylsulfonyl-1,4-benzoquinone;l , 2,5-di-n~propyloxycarbonyl-3,6-di-4'-chlorophenyl--sulfonyl-1,4-benzoquinone;
2,5~diethoxycarbonyl-3,6-di-4'-methoxyphenyl-sulfonyl-1,4-benzoquinone;
2,5-di-benzyloxycarbonyl-3,6-di-4'-tolylsulfonyl-1,4-benzoquinone;
2,5-di-n-octyloxycarbonyl-3,6-diethylsulfonyl-1,4-benzoquinonei 2,5-diethoxycarbonyl-3,6-(2'-naphthylsulfonyl)-1,4-benzoquinone;
2,5-dimethoxycarbonyl-3-toluylsulfonyl-1,4-benzoquinone;
3,6-diethoxycarbonyl-4,5-diphenylsulfonyl-1~2 benzoquinone;
2,3,5,6-tetra-4'-toluylsulfonyl-1,4-benzoquinone;
2,3,5,6-tetraphenylsulfonyl-1,4-benzoquinone;
2,3,5,6-tetraethylsulfonyl-1,4-benzoquinone;
3,4,5,6-tetra-i-butylsulfonyl-1,2-benzoquinone;
2,3,5,6-tetra-n-octylsulfonyl-1,4-benzoquinone;
2,3,5,6-tetrabenzyloxysulfonyl-1,4-benzoquinone;
2,5-di-n-propyloxycarbonyl-3,6-dibenzoyl-1,4-benzoquinone;
2,5-di-i-butoxycarbonyl-3-benzoyl-1,4-benzoquinonee;
2,3-dichloro-1,4 benzoquinone-5,6-dicarboxylic butylimide;
1,4-benzoquinone-2,3,5,6-tetracarboxylic diphenyl-imide;
1,2-benzoquinone-3,4,5,6-tetracarboxylic di-n-octyl-imide;
2,5-diethoxysulfonyl-1,4-benzoquinone;
2,5-diphenoxysulfonyl-3,6-dichloro-1,4-benzoquinonno;
2,5-di-n-butoxycarbonyl-3,6-dibutoxysulfonyl-1,4~benzoquinone;
Z,S-di-p-toluylsulfonyl-3,6-dibromo-1,4-benzoquinoone;
2,5-di-n-hexylsulfonyl-3,~-dichloro-1,4-benzoquinoone;
2,5-dibenzoyl-1,4-benzoquinone;
2,5-di(4'-methylbenzoyl)-1,4-benzoquinone;
2,5-di(4'-ethylbenzoyl)-1,4-benzoquinone;
2,5-di(3',4'-dimethylbenzoyl)-1,4-benzoquinone;
2,5-di(4'-chlorobenzoyl)-1,4-benzoquinone;
2,5-di(p-bromobenzoyl)-1,4-benzoquinone;
2,5-di(2',5'-dichlorobenzoyl)-1,4-benzoquinone;
etc.
Among the above-described benzoquinone derivatives, 2,5-dibenzoyl-1,4-benzoquinone derivatives represented by the general formula IVY): no no O
wherein R means a hydrogen or halogen atom or a lower alkyd group, and n stands for an integer up to 3 are particularly preferred due to their excellent storage stability, light resistant stability and anti-solvent stability. 2,5-Dibenzoyl-1,4-benzoquinone is the most suitable compound because its raw materials are easy to obtain and are easy to handle during its synthesis.
Even if a quinine derivative has great oxidizing capacity and has been substituted by one or more electron-,~34~-~
attractive groups, the quinine derivative such as 2,3,5,6-tetrachloro-1,4-benzoquinone(Chloroanil), 2,3,5,6-tetrafluoro-1,4benzoquinone(Fluoroanil),2,3,5-trichloro-1,4-benzooquinone, dichlorobenzoquinone, difluorobenzoquinone, eta, cannot be used as is for the following reasons where it has a small molecular eight and is sublimable:
(1) It undergoes gradual sublimation from the heat-sensitive recording paper during its storage and the color-producing capacity of the heat-sensitive recording paper is thus lowered 2) The thus-sublimated quinine derivative reacts with the methine-type chromogenic reactant, thereby causing the heat-sensitive recording paper to show an undesired or inconvenient color which is the thus-oxidized methine-type chromogenic reactant; and ..
(3) The working environment is adversely affected.
._ .
Accordingly, it is necessary to use some sublimatlon-suppressing means if one wants to employ such a quinine derivative as is.
The methine-type chromogenic reactant useful in the practice of this invention and represented by the general formula (I) is generally unstable to its storage and, in many instances, tends to show such tendency that it considerably colors an aqueous suspension, aqueous coating formulation or the coated surface of a heat-sensitive recording paper respect lively in its dispersion step in a liquid (i.e., the step to convert the methine-type chromogenic reactant to the aqueous suspension in which the reactant is present as fine particles), in the preparation step of the methIne-type chromogenic reactant together with a color-developing agent and other additives into the aqueous coating formulation or in the coating step of the aqueous coating formulation on a base to prepare the heat-sensitive recording paper; and the resulting heat-sensitive recording paper is colored during its storage or upon exposure to light. Therefore, the methine-type chromogenic reactant Milwaukee utility in some instances, in the production of heat-sensitive recording paper if it is used as is.
Accordingly, it is preferred to use (A) a qua ternary ammonium salt, (B) an alkanol amine having a tertiary amino group or (C) a water-soluble metal ion sequestering agent along with the methine-type chromogenic reactant and oxidizing organic compound which are basically essential in the present invention.
As exemplary qua ternary ammonium sells, may - be mentioned specifically:
lauryltrimethylammonium chloride;
stearyltrimethylammonium chloride;
distearyldimethylammonium chloride;
dodecyltrimethylammonium chloride;
octadecyltrimethylammonium chloride;
tetradecyldimethylbenzylammonium chloride;
etc.
As specific examples of the alkanol amine containing a tertiary amino, may be mentioned:
tris-N-(2-hydroxyethyl)amine;
tris-N-(2-hydroxypropyl)amine;
tris-N-(3-hydroxypropyl)amine;
tris-N-(hydroxydibutyl)amine;
N,N-dimethyl-N-(2-hydroxyethyl)amine;
N,N-diethyl-N-(2-hydroxyethyl)amine;
N,N-dipropyl-N-(2-hydroxyethyl)amine;
N,N-dibutyl-N-(2-hydroxyethyl)amine;
N-methyl-N-phenyl-N-(2-hydroxyethyl)amine;
N,N-diphenyl-N-(2-hydroxyethyl)amine;
N,N-dimethyl-N-(2-hydroxypropyl)amine;
N,N-diethyl-N-(2-hydroxypropyl)amine;
N,N-dipropyl-N-(2-hydroxypropyl)amine;
N,N-dibutyl-N-(2-hydroxypropyl)amine;
N,N-diphenyl-N-(2-hydroxypropyl)amine;
N-methyl-N,N-di(2-hydroxyethyl)amine;
N-ethyl-N,N-di(2-hydroxyethyl)amine;
N-phenyl-N,N-di(2-hydroxyethyl)amine;
N-methyl-N,N-di(2-hydroxypropyl)amine;
N-acetyl-N,N-di(2-hydroxyethyl)amine;
N-methyl-N,N-di(2-hydroxypropyl)amine;
N-acetyl-N,N-di(2-hydroxyethyl)amine;
N-acetyl-N,N-di(2-hydroxypropyl)amine;
N-hydroxyethylmorpholine;
N-hydorxypropylmorpholine;
N-tetradecyl-N,N-di(~-hydroxyethylpolyoxyethylene))-amine N-dodecyl-N,N-di(~-hydroxyethylpolyoxye-thylene)ammine;
N-octadecyl-N,N-di(~-hydroxyethylpolyoxyethylene)--amine;
N,N-didodecyl-N-(~-hydroxyethylpolyoxyethylene)amiire;
N,N-di(cis-octadecenyl)-N-(~-hydroxyethylpolyoxy-ethylene amine N,N-dioctadecyl-N (~-hydroxyethylpolyoxyethylene)-amine compounds formed by adding alkaline dioxides to aliphatic dominoes, for example, those represented by the following structural formula:
(CH2CH20)zH (CH2cH2o)xH
\(CH2CH20)y}I
wherein R is an aliphatic chain and x, y and z are each a positive integer;
N,N-~-hydroxyalkylpolyoxyalkylene-substituted aliphatic asides, for example, those represented by the following structural formula:
ill ( CH2CH20 ) oh (CH2CH20)yH
wherein R means an aliphatic chain and x and y stand individually for a positive integer;
reaction products between ammonia and glycidols (2-amino-propylene glycol derivatives);
etc.
The metal ion sequestering agent is bonded with multivalent metal ions present in a system dispersing the Jo chromogenic reactant, i.e., the layer of the chromogenic reactant applied on the hose of a heat-sensitive recording paper so as to form a stable chelates compound, thereby retarding the inconvenient coloring tendency of the methane-type chromogenic reactant in the presence of such multivalent metal ions. As metal ion sequestering agents having such an effect, may for example be mentioned water-soluble metal ion sequestering agents such as ethylenediaminetetraacetic acid, N-hydroxyethyl-ethylenediamine-N,N',N'-triacetic acid, diethylenetriamine-pentaacetic acid, triethylenetetrammine-pentaacetic acid, nitrilotriacetic acid, N-hydroxyethyl-iminodiacetic acid, diethanol Gleason, ethylenediamine-N,N'-diabetic acid, glycolether-diaminetetraacetic acid, 1,3-diaminopropan-2-ol-tetraacetic acid, tartaric acid, citric acid, gluconic acid and saccharin acid , and their alkali metal salts, salts of polyacrylic acid, and metal salts of ligninsulfonic acid.
These coloration-inhibitory additives may be used in an amount of 0.1 - 1000 parts by weight per 100 parts by weight of the methine-type chromogenic reactant. Among these additives, the water-soluble qua ternary ammonium sell can bring about the greatest effect when used even in a relatively small amount.
The heat-sensitive recording unit according to this invention is basically formed of a methine-type chromogenic reactant and oxidizing organic compound, both supported as . .
mutually-isolated wine particles on a base. Accordingly, the production of a color by the reaction between the methane-type chromogenic reactant and oxidizing organic compound is allowed to take place upon application of heat energy that raises either one or both of the methine-type chromogenic reactant and oxidizing organic compound to its melting point or their respective melting points. Therefore, it is required to have heat-sensitive recording paper produce its color at an elevated temperature where the chromogenic reactant and/or oxidizing organic compound, notably, the oxidizing organic compound is a high mop. compound. Consequently, a heavy load is applied to thermal heads or heat pens which are used as sources for supplying thermal energy. Such heat-sensitive recording paper can hardly meet the high-speed printing. It is thus preferred to adjust the color-producing temperature characteristics by using a color production sensitivity regulator in combination.
In the case of high mop. compounds such as buoyancy-unwon derivatives which are particularly-preferred oxidizing organic compounds, for example, 2,5-dibenzoyl-1,4-benzoquinones, it is preferred to use a color production temperature adjusting agent in combination.
As such color production sensitivity regulators, there are employed compounds which have melting points in the range of 70 - 150 C and, when molten, dissolve the methine-type chromogenic reactant and/or oxidizing organic I
compound. As specific compounds, may for example be mentioned as follows:
(1) Higher fatty acid asides and their derivatives, for example, Starkey acid aside, linoleic acid aside, myristic acid aside and oleic acid aside and their methylol derivatives, ethylene-bis-stearoamide, and ethylene-bis-stearoamide;
(2) alkylbiphenyls, alkylnaphthalenes and biphenylalkanes, e.g., 4,4'-dimethylbiphenyl, 2,6-diisopropylnaphthalene, etc.;
(3) kittens, for example, diundecyl kitten, diheptadecyl kitten, etc.;
(4) Carboxylic and sulfonic acid esters of phenol derivatives, for example, diphenyl preappoint, diphenyl cyclohexylcarboxylate, diphenyl phenylsulfonate, diphenyl bonniest, knothole bonniest, p-cyclohexylphenyl bonniest, p-cyclohexylphenyl Tulane sulfonate, p-cyclohexylphenyl cinnamate, p-tert-butylphenyl bonniest, p-tert-octylphenyl bonniest, p-acetylphenyl bonniest, resorsine dibenzoate, 4,4'-thiobisphenol dibenzoate, bus-phenol A-di(phenylsulfonate), phenyl-p-toluenesulfonate, p-tert-butylphenyl-p-toluenesulfonate, diphenyl isophthalate, di-p-sec-butylphenyl isophthalate, di(o-cyclohexylphenyl) isophthalate, di(o-octoxycarbonylphenyl)isophthalate, dip-sec-butylphenyl)terephthalate, Dow sec-butylphenyl) lore-phthalate, and o-phenoxycarbonylphenyl bonniest;
(5) N-phenylsulfonamide derivatives, for example, N-phenyl-benzenesulfonamide, 4-methyl-N-phenylbenzenesulfonamide, etc.;
(6) aromatic ethers, for example, naphthyl phenol ether;
(7) Aromatic acid asides, or example, benzoic acid N-cyclo-hexylamide;
(8) Aromatic carboxylic acid esters, for example, dim ethyl terephthalate; and
(9) Others, including compounds represented by COO
O H ¦
"COREY
wherein R means a long-chain alkyd group. Needless to say, the color production sensitivity regulator is not limited to the above compounds which are merely illustrative.
Among the above-described compounds, the carboxylic and sulfonic acid esters of phenol derivatives and the N-phenylsul~onamide derivatives are most effective as color production sensitivity regulators in heat-sensitive recording units according to this invention, which units are of the oxidation color production type. These sensitivity regulators may be suitably selected in accordance with the desired temperature and printing speed characteristics of each heat-sensitive recording paper. The regulator may generally be used in an amount of 10 - 500 parts by weight per every 100 parts by weight of a color-developing agent. Similar to the chromogenic reactant and color-developing agent, it is preferred to form the color production sensitivity regulator as fine particles into an aqueous suspension in the presence of a dispersant prior to its application.
-28 - t The usual production process of heat-sensitive recording paper making use of the novel heat-sensitive - recording unit according to this invention will next be described.
The methine-type chromogenic reactant represented by the general formula (I), oxidizing organic compound, preferably a benzoquinone derivative represented by the general formula (II), and, if necessary, a color production sensitivity regulator are separately dispersed as fine particles in the presence of a surfactant or protective colloidal substance in water or an organic solvent. As such a surfactant or protective colloidal substance, may be mentioned polyvinyl alcohol, carboxymethylcellulose, hydroxyethylcellulose, methyl cellulose, hydroxycellulose, polyvinyl pyrrolidone, modified polyvinyl alcohol, gum Arabic gelatin, a high-molecular anionic surfactant, a natural gum or the like.
These methine-type chromogenic reactant dispersion (A), color-developing agent dispersion and, if necessary, color production sensitivity regulator dispersion are then mixed, followed by further mixing with the above-mentioned various additives for controlling the physical properties of the surface of a heat-sensitive recording paper to be produced. A coating formulation has thus been prepared.
It is also feasible to use, in order to adjust the coat ability of the coating formulation and the physical properties of heat-sensitive recording paper to be produced, an inorganic or organic pigment such as kaolin, calcined kaolin, talc, titanium oxide, calcium carbonate 7 zinc oxide, aluminum hydroxide, silica, diatonaceous earth, urea formaldehyde resin or polystyrene micro beads; a lubricant, for example, an animal wax such as bees wax or shellac, ~egerable wax such as carnauba wax, synthetic wax such as petroleum wax, microcrystalline wax or polyethylene wax, or metal soap (metal salt of higher fatty acid) such as calcium Stewart or zinc Stewart; a pressure color production inhibitor;
a binder; a surfactant; a deforming agent; and the like as needed.
In order to apply the thus-prepared coating formulation, a variety of coating methods which are known per so in the art may be employed, including for example the bar coating method, air-knife coating method, glavure coating method, flexocoating method, blade coating method, roller coating method, etc. It is also feasible to incorporate the coating formulation in paper upon making the paper. It should be borne in mind that the above mixing method and coating method do not limit the production process of heat-sensitive recording paper which makes use of the unit according to this invention. Thus, it is possible to employ a variety ox coat worms. or example, the chromogenic reactant and benzoquinone derivative may be coated respectively as separate layers.
Alternatively, it may be possible to apply an overcoat or under-coat layer made of a water-soluble polymer material over the upper or lower surface of a heat-sensitive recording layer so as to enhance the stability to the environment further.
The general coat weight of the heat-sensitive layer is at least 0.5 g/m2, and preferably 1 - 10 g/m2 when measured as a dry coat weight. The relative proportions of various components making up each heat-sensitive recording sheet may be as follows:
Methine-type chromogenic 0.5 - 5 wt.%
reactant Preferably, 1 - 3 wt.%
Oxidizing organic 2 - lo White, preferably, compound 4 - 10 wt.%. -Color production 0 - 20 wt.%
sensitivity regulator The coat weights of both chromogenic reactant and oxidizing organic compound are individually as little as 1/5 1/3 of the phthalide-type compound and acidic I.
finlike color-developing agent which are used most extensively these days as main components in heat-sensitive recording paper. Therefore, the heat-sensitive recording paper according to this invention are extremely advantageous from both industrial and economical viewpoints.
The heat-sensitive recording unit, which makes use of the thus obtained novel color production system, enjoys the following merits compared with conventional chromogenic reactant based color produciton-type heat-sensitive recording paper which relies upon a color production reaction between a phthalide-type or fluoran-type chromogenic reactant and a finlike compound:
.
I
1) The amounts of a chromogenic reactant and color-developing agent, which are applied on a base, have been reduced to significant extents and there is no need to use the color-developing agent in any large excess;
2) Since the energy required to produce a color has been reduced considerably, it is possible to save energy. Besides, it is feasible to meet the speed-up of the heat-sensitive recording system, thereby being successfully adopted in the high-speed facsimile system;
3) Resulting color images or marks feature excellent storage stability. They do not disappear at all by their contact with organic solvents. They do not disappear even when brought Pinto contact with water; and 4) Resulting color images or marks enjoy excellent fastness to light.
Owing to the above-mentioned merits, the heat-sensitive recording paper according to this invention is extremely useful for PUS barricade food Labels which have a big chance to contact with edible oil, plasticizer contained in PVC wrapping films, oils and fats contained in foods and plasticizer present in PVC sheets and in application fields requiring strong storage stability such as commuting passes, to say nothing of facsimiles and other printers.
The present invention will hereinafter be described in further detail by the following examples.
Example 1:
(A) 2,5-dibenzoyl-1,4~benzoquinone 10 g (mop. 232 - 235C)
O H ¦
"COREY
wherein R means a long-chain alkyd group. Needless to say, the color production sensitivity regulator is not limited to the above compounds which are merely illustrative.
Among the above-described compounds, the carboxylic and sulfonic acid esters of phenol derivatives and the N-phenylsul~onamide derivatives are most effective as color production sensitivity regulators in heat-sensitive recording units according to this invention, which units are of the oxidation color production type. These sensitivity regulators may be suitably selected in accordance with the desired temperature and printing speed characteristics of each heat-sensitive recording paper. The regulator may generally be used in an amount of 10 - 500 parts by weight per every 100 parts by weight of a color-developing agent. Similar to the chromogenic reactant and color-developing agent, it is preferred to form the color production sensitivity regulator as fine particles into an aqueous suspension in the presence of a dispersant prior to its application.
-28 - t The usual production process of heat-sensitive recording paper making use of the novel heat-sensitive - recording unit according to this invention will next be described.
The methine-type chromogenic reactant represented by the general formula (I), oxidizing organic compound, preferably a benzoquinone derivative represented by the general formula (II), and, if necessary, a color production sensitivity regulator are separately dispersed as fine particles in the presence of a surfactant or protective colloidal substance in water or an organic solvent. As such a surfactant or protective colloidal substance, may be mentioned polyvinyl alcohol, carboxymethylcellulose, hydroxyethylcellulose, methyl cellulose, hydroxycellulose, polyvinyl pyrrolidone, modified polyvinyl alcohol, gum Arabic gelatin, a high-molecular anionic surfactant, a natural gum or the like.
These methine-type chromogenic reactant dispersion (A), color-developing agent dispersion and, if necessary, color production sensitivity regulator dispersion are then mixed, followed by further mixing with the above-mentioned various additives for controlling the physical properties of the surface of a heat-sensitive recording paper to be produced. A coating formulation has thus been prepared.
It is also feasible to use, in order to adjust the coat ability of the coating formulation and the physical properties of heat-sensitive recording paper to be produced, an inorganic or organic pigment such as kaolin, calcined kaolin, talc, titanium oxide, calcium carbonate 7 zinc oxide, aluminum hydroxide, silica, diatonaceous earth, urea formaldehyde resin or polystyrene micro beads; a lubricant, for example, an animal wax such as bees wax or shellac, ~egerable wax such as carnauba wax, synthetic wax such as petroleum wax, microcrystalline wax or polyethylene wax, or metal soap (metal salt of higher fatty acid) such as calcium Stewart or zinc Stewart; a pressure color production inhibitor;
a binder; a surfactant; a deforming agent; and the like as needed.
In order to apply the thus-prepared coating formulation, a variety of coating methods which are known per so in the art may be employed, including for example the bar coating method, air-knife coating method, glavure coating method, flexocoating method, blade coating method, roller coating method, etc. It is also feasible to incorporate the coating formulation in paper upon making the paper. It should be borne in mind that the above mixing method and coating method do not limit the production process of heat-sensitive recording paper which makes use of the unit according to this invention. Thus, it is possible to employ a variety ox coat worms. or example, the chromogenic reactant and benzoquinone derivative may be coated respectively as separate layers.
Alternatively, it may be possible to apply an overcoat or under-coat layer made of a water-soluble polymer material over the upper or lower surface of a heat-sensitive recording layer so as to enhance the stability to the environment further.
The general coat weight of the heat-sensitive layer is at least 0.5 g/m2, and preferably 1 - 10 g/m2 when measured as a dry coat weight. The relative proportions of various components making up each heat-sensitive recording sheet may be as follows:
Methine-type chromogenic 0.5 - 5 wt.%
reactant Preferably, 1 - 3 wt.%
Oxidizing organic 2 - lo White, preferably, compound 4 - 10 wt.%. -Color production 0 - 20 wt.%
sensitivity regulator The coat weights of both chromogenic reactant and oxidizing organic compound are individually as little as 1/5 1/3 of the phthalide-type compound and acidic I.
finlike color-developing agent which are used most extensively these days as main components in heat-sensitive recording paper. Therefore, the heat-sensitive recording paper according to this invention are extremely advantageous from both industrial and economical viewpoints.
The heat-sensitive recording unit, which makes use of the thus obtained novel color production system, enjoys the following merits compared with conventional chromogenic reactant based color produciton-type heat-sensitive recording paper which relies upon a color production reaction between a phthalide-type or fluoran-type chromogenic reactant and a finlike compound:
.
I
1) The amounts of a chromogenic reactant and color-developing agent, which are applied on a base, have been reduced to significant extents and there is no need to use the color-developing agent in any large excess;
2) Since the energy required to produce a color has been reduced considerably, it is possible to save energy. Besides, it is feasible to meet the speed-up of the heat-sensitive recording system, thereby being successfully adopted in the high-speed facsimile system;
3) Resulting color images or marks feature excellent storage stability. They do not disappear at all by their contact with organic solvents. They do not disappear even when brought Pinto contact with water; and 4) Resulting color images or marks enjoy excellent fastness to light.
Owing to the above-mentioned merits, the heat-sensitive recording paper according to this invention is extremely useful for PUS barricade food Labels which have a big chance to contact with edible oil, plasticizer contained in PVC wrapping films, oils and fats contained in foods and plasticizer present in PVC sheets and in application fields requiring strong storage stability such as commuting passes, to say nothing of facsimiles and other printers.
The present invention will hereinafter be described in further detail by the following examples.
Example 1:
(A) 2,5-dibenzoyl-1,4~benzoquinone 10 g (mop. 232 - 235C)
10~ polyvinyl- alcohol 20 g water 20 g I
TOTAL 50 g (B) 4,4',4"-tris-dimethylamino 10 g phenyl-methane (Luke Crystal Violet) 10% polyvinyl alcohol 20 g triethanolamine 1 g water 19 g TOTAL 50 g The compositions (A) and (B) were separately wet-ground in sand grinding mills to form aqueous suspensions.
Using these aqueous suspensions, a 20~ aqueous coating formulation having the following composition was prepared.
Weight ratio (solid matter) 2,5-dibenzoyl-1,4-benzoquinoneS
Luke Crystal Violet 2 calcium carbonate 53 Starkey acid aside 10 polyvinyl alcohol 20 The coating formulation was then applied by a Meyer bar coaler onto a base paper web of 70 g/m2 to give the dry coat weight of 6 g/m2, followed by its drying to obtain a heat-sensitive recording paper. The heat-sensitive recording paper was caused to produce its color by using a commercial thermal printer, thereby obtaining prints of deep bluish So purple. A plasticizer (dioctylphthalate) was dropped on the thus-printed portions. The prints deadweight show any tendency of fading out and non-printed portions were not observed to develop any color. The printed portions did not tend to disappear or become thinner during its storage.
The heat-sensitive recording paper was thus excellent in overall storage stability.
Example 2:
A heat-sensitive recording paper was obtained in the same manner as in Example 1 except that wet-ground fine N-phenyl-p-toluenesulfonamide particles my 96 - 98C) was here in place of Starkey acid aside in the same amount. The heat-sensitive recording paper of the present Example was printed using a G-II model heat-sensitive facsimile machine ("OKIFAX*
5800" manufactured by Ok Electric Industry Co., Ltd.).
Deep bluish purple prints were obtained. The thus-produced color prints were extremely stable as in Example 1.
Examples 3 - 7:
Aqueous suspensions having the following composition were respectively prepared using as their chromoyenic reactants 4,4'-bis(dimethylamino)-3"-cyclohexyl-4"-methoxytrriphenyl-methane, 4,4'-bis(dimethylaminophenyl)-4"-methoxynaphthyl methane 4,4'-bismorpholino-3'-tert-butyl-4"-methoxytri-phenylmethane, bis(4-dimethylaminophenyl)-~-styrylmethane and 4,4'-dimethoxy-4"-dimethylaminotriphenylmethane and process-in them in attritors.
* Trademark Jo (A) chromogenic reactant 10 g 10~ aqueous solution of 20 g hydroxyethylcellulose aqlleous solution of stroll- 1 g trimethylammonium chloride water 19 g TOTAL 50 g Using each of the above-obtained aqueous suspension, the same aqueous suspension of the color-developing agent as prepared in Example i and an aqueous suspension of o-phenoxycarbonylphenyl(m.p. I - 85C)(C) prepared on the side, a 20~ aqueous coating formulation having the following composition was prepared.
Weight ratio (solid matter) 2,5-dibenzoyl-1,4~benzoquinone 7 chromogenic reactant 2 talc 30 calcium carbonate 20 zinc Stewart 5 color production sensitivity regulator hydroxyethylcellulose 20 The above coating formulation was then applied to a base paper web of 50 g/m2 to give a coat weight of 6 g/m2, thereby obtaining a heat-sensitive recording paper.
Example 8:
The procedures of Example 3 were followed to give -a heat-sensitive recording paper having the following composition-color-developing agent [dupe- 5 methylbenzoyl)-1,4-benzoquinone]
chromogenic reactant [3,3'-dimethyl- 3 4,4'-bis(methylamino)-4"-dime~hyl-aminotriphenylmethane]
calcined kaolin 30 precipitated calcium carbonate 22 zinc Stewart 5 color production sensitivity 10 regulator (resorcine bonniest) hydroxyethylcellulose 25 The heat-sensitive recording paper of the present Example gave deep bluish purple prints when printed by a commercial thermal printer.
Example 9:
A heat-sensitive recording paper was obtained yin the same manner as in Example 1 except that the color-developing agent and chromogenic reactant were changed to the following ones:
color-developing agent: 2,5-di-i-butoxycarbonyl-3,6-di(p-tolylsulfonyl)-1,4-benzoquinone chromogenic reactant: bis(4-methylamino-3-methyl-phenyl)-(4'-methoxystyryl)-methane (30 wt.%); Bessel-ethyl-2-methyl-indol-3-yl)-4'-dimethylaminophenylmethane (20 wt.%); and bis(l-ethyl-2-methyl-indol-3-yl)-4'-ethoxyphenylmethane (White.%).
Vised as a mixture.
I.
s The heat-sensitive recording paper of the present Example produced a deep black color when kept for 5 seconds in contact with a hot plate of 200C. The thus-produced color mark did not show at all any tendency to fade out even when brought into contact with plasticizers, oil, fat and the like.
Examples 10 - 13:
Heat-sensitive recording papers were obtained, following the procedures of Example 2 except that the following color-developing agents were used respectively. All the heat-sensitive recording papers were printed by a G-II model facsimile machine. They all gave deep bluish purple prints. Densities of colors which had respectively been obtained by keeping the above heat-sensitive recording papers in contact for 5 seconds with hot plates of 200C were also measured. Results are summarized in Table 1.
Table 1 Example Color-developing agent produced color . . . .... __ 2,3,5,6-tetraethoxycarbonyl- 1.42 1,4-benzoquinone _ . ___
TOTAL 50 g (B) 4,4',4"-tris-dimethylamino 10 g phenyl-methane (Luke Crystal Violet) 10% polyvinyl alcohol 20 g triethanolamine 1 g water 19 g TOTAL 50 g The compositions (A) and (B) were separately wet-ground in sand grinding mills to form aqueous suspensions.
Using these aqueous suspensions, a 20~ aqueous coating formulation having the following composition was prepared.
Weight ratio (solid matter) 2,5-dibenzoyl-1,4-benzoquinoneS
Luke Crystal Violet 2 calcium carbonate 53 Starkey acid aside 10 polyvinyl alcohol 20 The coating formulation was then applied by a Meyer bar coaler onto a base paper web of 70 g/m2 to give the dry coat weight of 6 g/m2, followed by its drying to obtain a heat-sensitive recording paper. The heat-sensitive recording paper was caused to produce its color by using a commercial thermal printer, thereby obtaining prints of deep bluish So purple. A plasticizer (dioctylphthalate) was dropped on the thus-printed portions. The prints deadweight show any tendency of fading out and non-printed portions were not observed to develop any color. The printed portions did not tend to disappear or become thinner during its storage.
The heat-sensitive recording paper was thus excellent in overall storage stability.
Example 2:
A heat-sensitive recording paper was obtained in the same manner as in Example 1 except that wet-ground fine N-phenyl-p-toluenesulfonamide particles my 96 - 98C) was here in place of Starkey acid aside in the same amount. The heat-sensitive recording paper of the present Example was printed using a G-II model heat-sensitive facsimile machine ("OKIFAX*
5800" manufactured by Ok Electric Industry Co., Ltd.).
Deep bluish purple prints were obtained. The thus-produced color prints were extremely stable as in Example 1.
Examples 3 - 7:
Aqueous suspensions having the following composition were respectively prepared using as their chromoyenic reactants 4,4'-bis(dimethylamino)-3"-cyclohexyl-4"-methoxytrriphenyl-methane, 4,4'-bis(dimethylaminophenyl)-4"-methoxynaphthyl methane 4,4'-bismorpholino-3'-tert-butyl-4"-methoxytri-phenylmethane, bis(4-dimethylaminophenyl)-~-styrylmethane and 4,4'-dimethoxy-4"-dimethylaminotriphenylmethane and process-in them in attritors.
* Trademark Jo (A) chromogenic reactant 10 g 10~ aqueous solution of 20 g hydroxyethylcellulose aqlleous solution of stroll- 1 g trimethylammonium chloride water 19 g TOTAL 50 g Using each of the above-obtained aqueous suspension, the same aqueous suspension of the color-developing agent as prepared in Example i and an aqueous suspension of o-phenoxycarbonylphenyl(m.p. I - 85C)(C) prepared on the side, a 20~ aqueous coating formulation having the following composition was prepared.
Weight ratio (solid matter) 2,5-dibenzoyl-1,4~benzoquinone 7 chromogenic reactant 2 talc 30 calcium carbonate 20 zinc Stewart 5 color production sensitivity regulator hydroxyethylcellulose 20 The above coating formulation was then applied to a base paper web of 50 g/m2 to give a coat weight of 6 g/m2, thereby obtaining a heat-sensitive recording paper.
Example 8:
The procedures of Example 3 were followed to give -a heat-sensitive recording paper having the following composition-color-developing agent [dupe- 5 methylbenzoyl)-1,4-benzoquinone]
chromogenic reactant [3,3'-dimethyl- 3 4,4'-bis(methylamino)-4"-dime~hyl-aminotriphenylmethane]
calcined kaolin 30 precipitated calcium carbonate 22 zinc Stewart 5 color production sensitivity 10 regulator (resorcine bonniest) hydroxyethylcellulose 25 The heat-sensitive recording paper of the present Example gave deep bluish purple prints when printed by a commercial thermal printer.
Example 9:
A heat-sensitive recording paper was obtained yin the same manner as in Example 1 except that the color-developing agent and chromogenic reactant were changed to the following ones:
color-developing agent: 2,5-di-i-butoxycarbonyl-3,6-di(p-tolylsulfonyl)-1,4-benzoquinone chromogenic reactant: bis(4-methylamino-3-methyl-phenyl)-(4'-methoxystyryl)-methane (30 wt.%); Bessel-ethyl-2-methyl-indol-3-yl)-4'-dimethylaminophenylmethane (20 wt.%); and bis(l-ethyl-2-methyl-indol-3-yl)-4'-ethoxyphenylmethane (White.%).
Vised as a mixture.
I.
s The heat-sensitive recording paper of the present Example produced a deep black color when kept for 5 seconds in contact with a hot plate of 200C. The thus-produced color mark did not show at all any tendency to fade out even when brought into contact with plasticizers, oil, fat and the like.
Examples 10 - 13:
Heat-sensitive recording papers were obtained, following the procedures of Example 2 except that the following color-developing agents were used respectively. All the heat-sensitive recording papers were printed by a G-II model facsimile machine. They all gave deep bluish purple prints. Densities of colors which had respectively been obtained by keeping the above heat-sensitive recording papers in contact for 5 seconds with hot plates of 200C were also measured. Results are summarized in Table 1.
Table 1 Example Color-developing agent produced color . . . .... __ 2,3,5,6-tetraethoxycarbonyl- 1.42 1,4-benzoquinone _ . ___
11 2,5-di-n-butylsulfonyl-3,6- OWE
diethylcarbonyl-1,4-benzoquinone __ _ . . _ _ ._ _
diethylcarbonyl-1,4-benzoquinone __ _ . . _ _ ._ _
12 2,5-diphenylsulfonyl-3,6-di- 1.38 i-butoxycarbonyl-1,4-benzoquinone __
13 2,5-dibromo-3,6-di-cyclohexyl- 1.39 oxycarbonyl-1,4-benzoquinone _ r All the heat-sensitive recording papers exhibited good stability with respect to their respective color images.
Comparative Example I
Bisphenol A and Crystal Violet Lactose were respectively wet-ground into fine particles and then framed into aqueous suspensions in the same manner as in Example 1.
Using the above aqueous suspensions, an aqueous coating formulation having the following composition was prepared.
Weight parts (solid matter) bisphenol A 20 Crystal Violet Lactose 8 Starkey acid aside 20 calcium carbonate 32 polyvinyl alcohol 20 The above aqueous coating formulation was applied on a base paper web of 70 g/m to give the dry coat weight ox 7 g/m2, followed by its drying to obtain a heat-sensitive recording paper. The heat-sensitive recording paper produced a deep bluish purple color when printed by a thermal printer.
Printed portions were brought into contact with ductile phthalate. The color image disappeared immediately and become unlegible.
Comparative Example 2:
Bouncily p-oxybenzoate and 3-diethylamino-6-methyl-7-anilinofluoran were respectively wet-ground into fine ~.2~8~
particles and then converted into aqueous suspensions in the same manner as in Example 1.
Using these aqueous suspensions, an aqueous coating formulation having the following composition was prepared.
weight parts (solid matter) bouncily p-oxybenzoate 20 3-diethylamino-6-methyl-7- 9 anilinofluoran zinc Stewart 10 talc 41 polyvinyl alcohol 20 The above aqueous coating formulation was applied on a base paper web of 70 g/m2 to give the coat weight of 7 g/m2. The heat-sensitive recording paper of the present Comparative Example produced a deep black color when printed by a G-II model facsimile machine. When cotton seed oil was brought into contact with the thus-printed portions, the black disappeared immediately and became unlegible. The thus-printed paper was stored at a dark place in a room. It showed the tendency of natural fading. The color images or marks, produced on the heat-sensitive recording paper, were generally poor in stability.
Referential Example l:
Each of the heat-sensitive recording papers ox Examples l and 2 was caused to produce its color by keeping it in contact with a metal block having the temperature gradient of 60C - 200C, for 5 seconds and under the pressure of 10 g/cm2, using Thermotest Rhodlaceta muddle 7401;
manufactured by SETARAM Corporation). Upon an elapsed time of 10 minutes, the relationship between the color densities and color production temperatures was studied using a Macbeth densitometer (visible filter). A higher color density indicates a deeper color. Results are summarized in Hirable 2.
Table 2 __ _ Color production temperature (C)60 70 80 85 90 95 100 Example 10.06 0~06 0.10 0.20 0.28 0.35 0.42 Example 2 ¦ 0.06 0.06 0.10¦ 0.21 0.40 Color production I 110 120 1 130 ¦ 140 150 ¦160 temperature ( C) I _ ! I
Example 1 ¦ 0.57 0.71 ¦ 0.86¦ 1.00 1.12 1.20 _ ' . .
sample 2 ! 1.20_ 1 31 1.35l 1.35 1.35 1.35 Referential Example 2:
Each of the heat-sensitive recording papers of Examples 1 and 3 - 7 was kept for 5 seconds in contact with a metal block having the surface temperature of 200C to produce a color thereon. Furthermore, it was subjected to POS(point of sales) bar code printing, using a desk-top bar code label printer (Model BP-70; manufactured by Turk Seiko OK The heat-sensitive recording papers produced marks of the corresponding colors respectively. Anti-ester _ . _ ~1:2~
;' property and storage stability tests were carried out on the marks p r so, which were produced by the metal blocks, and the recording papers bearing the marks respectively.
Test results are shown in Table 3:
Table 3 .
. Ant Lester Storage En. Color aenslty(hue) property* stability*
1 blush purple) 1.42 1.41 . . .____ _ ..
3 dupe green) 1.38 1.38 4 Derek blue) 1.25 1.21 _ . . .. . ...
1.35tdeep green) 1.36 1.35 _ . _~_ ___ .
6 Derek green) 1.34 1.33 7 Rudy) 1.36 1.38 Note: * Each of the marked papers was brought into contiguous relation with a paper file made of soft polyvinyl chloride ("Right Clear Pocket") and then kept for 24 hours and at 60C in a constant-temperature chamber while maintaining the load of 1 kg per 0.01 my. Thus, the marked paper was kept in contact with a plasticizer (ester) present in the polyvinyl chloride. The extent of fading of the mark was measured.
** Storage stability test:
Each marked paper was stored at a dark place for 6 months to investigate any change in the density of the produced color.
Comparative Example I
Bisphenol A and Crystal Violet Lactose were respectively wet-ground into fine particles and then framed into aqueous suspensions in the same manner as in Example 1.
Using the above aqueous suspensions, an aqueous coating formulation having the following composition was prepared.
Weight parts (solid matter) bisphenol A 20 Crystal Violet Lactose 8 Starkey acid aside 20 calcium carbonate 32 polyvinyl alcohol 20 The above aqueous coating formulation was applied on a base paper web of 70 g/m to give the dry coat weight ox 7 g/m2, followed by its drying to obtain a heat-sensitive recording paper. The heat-sensitive recording paper produced a deep bluish purple color when printed by a thermal printer.
Printed portions were brought into contact with ductile phthalate. The color image disappeared immediately and become unlegible.
Comparative Example 2:
Bouncily p-oxybenzoate and 3-diethylamino-6-methyl-7-anilinofluoran were respectively wet-ground into fine ~.2~8~
particles and then converted into aqueous suspensions in the same manner as in Example 1.
Using these aqueous suspensions, an aqueous coating formulation having the following composition was prepared.
weight parts (solid matter) bouncily p-oxybenzoate 20 3-diethylamino-6-methyl-7- 9 anilinofluoran zinc Stewart 10 talc 41 polyvinyl alcohol 20 The above aqueous coating formulation was applied on a base paper web of 70 g/m2 to give the coat weight of 7 g/m2. The heat-sensitive recording paper of the present Comparative Example produced a deep black color when printed by a G-II model facsimile machine. When cotton seed oil was brought into contact with the thus-printed portions, the black disappeared immediately and became unlegible. The thus-printed paper was stored at a dark place in a room. It showed the tendency of natural fading. The color images or marks, produced on the heat-sensitive recording paper, were generally poor in stability.
Referential Example l:
Each of the heat-sensitive recording papers ox Examples l and 2 was caused to produce its color by keeping it in contact with a metal block having the temperature gradient of 60C - 200C, for 5 seconds and under the pressure of 10 g/cm2, using Thermotest Rhodlaceta muddle 7401;
manufactured by SETARAM Corporation). Upon an elapsed time of 10 minutes, the relationship between the color densities and color production temperatures was studied using a Macbeth densitometer (visible filter). A higher color density indicates a deeper color. Results are summarized in Hirable 2.
Table 2 __ _ Color production temperature (C)60 70 80 85 90 95 100 Example 10.06 0~06 0.10 0.20 0.28 0.35 0.42 Example 2 ¦ 0.06 0.06 0.10¦ 0.21 0.40 Color production I 110 120 1 130 ¦ 140 150 ¦160 temperature ( C) I _ ! I
Example 1 ¦ 0.57 0.71 ¦ 0.86¦ 1.00 1.12 1.20 _ ' . .
sample 2 ! 1.20_ 1 31 1.35l 1.35 1.35 1.35 Referential Example 2:
Each of the heat-sensitive recording papers of Examples 1 and 3 - 7 was kept for 5 seconds in contact with a metal block having the surface temperature of 200C to produce a color thereon. Furthermore, it was subjected to POS(point of sales) bar code printing, using a desk-top bar code label printer (Model BP-70; manufactured by Turk Seiko OK The heat-sensitive recording papers produced marks of the corresponding colors respectively. Anti-ester _ . _ ~1:2~
;' property and storage stability tests were carried out on the marks p r so, which were produced by the metal blocks, and the recording papers bearing the marks respectively.
Test results are shown in Table 3:
Table 3 .
. Ant Lester Storage En. Color aenslty(hue) property* stability*
1 blush purple) 1.42 1.41 . . .____ _ ..
3 dupe green) 1.38 1.38 4 Derek blue) 1.25 1.21 _ . . .. . ...
1.35tdeep green) 1.36 1.35 _ . _~_ ___ .
6 Derek green) 1.34 1.33 7 Rudy) 1.36 1.38 Note: * Each of the marked papers was brought into contiguous relation with a paper file made of soft polyvinyl chloride ("Right Clear Pocket") and then kept for 24 hours and at 60C in a constant-temperature chamber while maintaining the load of 1 kg per 0.01 my. Thus, the marked paper was kept in contact with a plasticizer (ester) present in the polyvinyl chloride. The extent of fading of the mark was measured.
** Storage stability test:
Each marked paper was stored at a dark place for 6 months to investigate any change in the density of the produced color.
Claims (12)
1. A heat-sensitive recording unit comprising a methine-type chromogenic reactant represented by the following general formula:
wherein X, Y and Z may be the same or different and mean individually a substituted or unsubstituted phenyl, naphthyl, .beta.-styryl or aromatic heterocyclic residual group, two of X, Y and Z may be coupled together to form a ring, and the substituted or unsubstituted phenyl, naphthyl or .beta.-styryl group has at least one amino, substituted amino or lower alkoxyl group at the para-position relative to the central methine group of the molecule when one or none of X, Y and Z is the aromatic heterocyclic residual group and an oxidizing organic compound, both, supported on a base.
wherein X, Y and Z may be the same or different and mean individually a substituted or unsubstituted phenyl, naphthyl, .beta.-styryl or aromatic heterocyclic residual group, two of X, Y and Z may be coupled together to form a ring, and the substituted or unsubstituted phenyl, naphthyl or .beta.-styryl group has at least one amino, substituted amino or lower alkoxyl group at the para-position relative to the central methine group of the molecule when one or none of X, Y and Z is the aromatic heterocyclic residual group and an oxidizing organic compound, both, supported on a base.
2. A heat-sensitive recording unit according to Claim 1, wherein a color production sensitivity regulator is further supported on the base.
3. A heat-sensitive recording unit according to Claim 1, wherein the oxidizing organic compound is a benzo-quinone derivative substituted with an electron-attractive group.
4. A heat-sensitive recording unit according to Claim 3, wherein the oxidizing organic compound is soluble in water and unsublimable.
5. A heat-sensitive recording unit according to Claim 3, wherein the oxidizing organic compound is a 2,5-dibenzoyl-1,4-benzoquinone derivative represented by the general formula:
wherein R denotes a hydrogen or halogen atom or a lower alkyl group and n stands for an integer of 3 or smaller.
wherein R denotes a hydrogen or halogen atom or a lower alkyl group and n stands for an integer of 3 or smaller.
6. A heat-sensitive recording unit according to Claim 2, wherein the color production sensitivity regulator is the carboxylic or sulfonic acid ester of a phenol derivative or an N-phenylsulfonamide derivative.
7. A heat-sensitive recording unit according to Claim 1 wherein at least one additive selected from the group consisting of a water-soluble quaternary ammonium salt, tertiary alkanol amine and water-soluble ion sequestering agent is further supported on the base.
8. A heat-sensitive recording unit according to Claim 7, wherein the at least one additive is incorporated upon forming the methine-type chromogenic reactant into an aqueous suspension in order to support the methine-type chromogenic reactant on the base.
9. A heat-sensitive recording unit according to Claim 8, wherein the at least one additive is the water-soluble quaternary ammonium salt.
10. A heat-sensitive recording unit according to Claim 2, wherein at least one additive selected from the group consisting of a water-soluble quaternary ammonium salt, tertiary alkanol amine and water-soluble ion sequestering agent is further supported on the base.
11. A heat-sensitive recording unit according to Claim 10, wherein the at least one additive is incorporated upon forming the methine-type chromogenic reactant into an aqueous suspension in order to support the methine-type chromogenic reactant on the base.
12.A heat-sensitive recording unit according to Claim 11, wherein the at least one additive is the water-soluble quaternary ammonium salt.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000436863A CA1215834A (en) | 1983-09-16 | 1983-09-16 | Heat-sensitive recording unit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000436863A CA1215834A (en) | 1983-09-16 | 1983-09-16 | Heat-sensitive recording unit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1215834A true CA1215834A (en) | 1986-12-30 |
Family
ID=4126090
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000436863A Expired CA1215834A (en) | 1983-09-16 | 1983-09-16 | Heat-sensitive recording unit |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1215834A (en) |
-
1983
- 1983-09-16 CA CA000436863A patent/CA1215834A/en not_active Expired
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