Color developer composition and color developer sheet

A color developer composition exhibiting excellent color developability, resistance to yellowing and light-fastness is disclosed, which comprises a substituted or unsubstituted benzoic acid salt represented by formula (I), or a mixture of a substituted or unsubstituted benzoic acid salt represented by formula (II) and a novolak type phenol resin represented by formula (III): ##STR1## wherein R.sub.1 to R.sub.19, M, M', n, n' and M are defined in the specification.

FIELD OF THE INVENTION 
This invention relates to a color developer composition and a color 
developer sheet for pressure-sensitive recording media. 
BACKGROUND OF THE INVENTION 
Hitherto, various color developers for pressure-sensitive recording media 
(hereafter merely referred to "color developer") have been known, for 
example, (1) inorganic solid acids such as acid clay and apatalgide as 
described in U.S. Pat. No. 2,712,507, (2) semi-synthesized solid acids 
having a magnesium and/or aluminum component incorporated into acid 
treated clay minerals as described in JP-A-58-217389 (the term "JP-A" 
herein used means an unexamined and published Japanese patent application) 
(3) substituted phenols and diphenols as described in JP-B-40-9309 (the 
term "JP-B" herein used means an examined Japanese patent publication), 
(4)p-substituted-phenol/formaldehyde copolymer as described in 
JP-B-42-20144, and (5) metal salts of aromatic carboxylic acids as 
described in JP-B-49-10856 and JP-B-52-1327. In particular, novolak phenol 
resins and metal salts of substituted salicylic acids, which are called 
organic color developers in contrast to inorganic color developers such as 
active clay, have been widely put in practical use for pressure-sensitive 
recording media, as described in JP-B-42-20144 and JP-B-51-25174. These 
color developers are finely ground, dispersed generally in water as a 
medium, mixed with inorganic pigments, adhesives and the like, and coated 
on paper. The thus coated paper is used as a color developer sheet, as 
described in JP-B-48-16341 and JP-A-54-143322. 
Color developer sheets are required to have the following properties: 
exhibiting good color developing ability unchanged even after long 
storage; being free from yellowing due to exposure to radiation (e.g., 
daylight); and providing color images which do not easily disappear or 
fade upon exposure to radiation, or in contact with water or plasticizers. 
Color developers and color developer sheets which have been already 
proposed have both merits and demerits. For instance, inorganic solid 
acids are inexpensive but cause yellowing or deterioration in the color 
developing ability upon adsorption of gas or moisture in air. Substituted 
phenols have insufficient color developing ability and provide color 
images of poor density, and they are often used in the form of a copolymer 
with an aldehyde such as p-phenylphenol novolak resins. The p-phenylphenol 
novolak resins exhibit excellent color developing ability, but their 
coated sheets undergo yellowing by daylight exposure or during the storage 
(particularly due to nitrogen oxides in air) and the color images 
developed markedly fade. 
Metal salts of aromatic carboxylic acids have good properties with respect 
to color developing ability, yellowing and fading. In order to remove 
crystallinity, however, those conventionally used have substituents (e.g., 
an alkyl group, a phenyl group, a cycloalkyl group, etc.) introduced onto 
the benzene ring, so that they are expensive and suffer many problems in 
coating on a sheet due to marked bubbling when dispersed in water. 
Metal salts of substituted salicylic acids are normally non-crystalline 
solid. Since color developers are generally coated in the form of a 
dispersion in water, they are highly desired to have good workability at 
high concentration and good dispersion stability. However, when coarse 
particles of the above metal salt color developer are ground in water with 
a ball mill, a sand grinder or the like to a desired size suitable for 
coating, the resulting dispersion exhibits thixotropic properties and poor 
fluidity, so that it is difficult to handle the dispersion. For improving 
its fluidity, the color developer concentration must be lowered, or a 
large amount of dispersants should be added but in turn, causes remarkable 
bubbling. Alternatively, by dissolving the metal salt color developer in 
an organic solvent and then dispersing it in an aqueous solution 
containing a dispersant with vigorous stirring, an emulsion having good 
fluidity can be obtained even at high concentration. Since the dispersed 
particles are droplets containing the organic solvent, however, the 
dispersed droplets become large in size during long storage of the 
emulsion, and consequently the emulsified state tends to corrupt at the 
vicinity of vessel walls, deteriorating stability of the emulsion. 
SUMMARY OF THE INVENTION 
An object of the present invention is to solve the above problems, i.e., to 
provide an inexpensive color developer composition which exhibits good 
color developing ability, reduced yellowing and minimized fading upon 
light exposure as well as good workability, no bubbling and good stability 
for a long storage when dispersed in water or coated on a sheet, and to 
provide a color developer sheet using such a color developer composition. 
Another object of the present invention is to provide a color developer 
sheet capable of imparting to the developed images high water resistance, 
and chemical resistance, and gloss by heat treatment of the images, 
preventing alteration or improving indelibility of documents, whereby 
commercial value of the sheet is increased. 
These objects can be achieved by a color developer composition comprising, 
as a main component, a substituted or unsubstituted benzoic acid salt 
represented by formula 
##STR2## 
wherein R.sub.1 to R.sub.5 which may be the same or different, each 
represents a hydrogen atom, a halogen atom, a hydroxy group, or a carboxy 
group; M represents zinc, magnesium, calcium, aluminum, iron, cobalt, 
nickel, strontium, or basic ions thereof; and n is the valence of M. 
The objects can also be achieved by a color developer composition 
comprising (i) a substituted or unsubstituted benzoic acid salt 
represented by formula (II): 
##STR3## 
where R.sub.6 to R.sub.10 which may be the same or different, each 
represents a hydrogen atom, a halogen atom, a hydroxy group or a carboxy 
group, provided that when R.sub.6 is a hydroxy group, R.sub.7 to R.sub.10 
each may further represent an alkyl group having 1 to 9 carbon atoms, a 
cycloalkyl group, a phenyl group or an aralkyl group and the adjacent two 
groups of R.sub.7, R.sub.8, R.sub.9 and R.sub.10 may bond to form a ring; 
M' represents zinc, magnesium, calcium, aluminum, iron, cobalt, nickel, 
strontium, or basic ions thereof; and n' is an interger of 1 to 3; and 
(ii) a novolak phenol resin represented by formula (III): 
##STR4## 
wherein R.sub.11 to R.sub.19 which may be the same or different, each 
represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 9 
carbon atoms, a cycloalkyl group, a phenyl group, or an aralkyl group; and 
m is a natural number of 1 to 9.

DETAILED DESCRIPTION OF THE INVENTION 
The color developer composition containing the compound of formula (I) as a 
main component, which is one embodiment of the present invention, further 
includes 0.1 to 10 wt% of an anionic surface active agent and 0.1 to 10 
wt% of a nonionic surface active agent preferably having a molecular 
weight of 400 or more, based on the amount of the compound of formula (I). 
A color developer sheet can be prepared by completely dissolving or 
dispersing the anionic surface active agent in pure water, dissolving or 
dispersing the nonionic surface active agent therein, dispersing the 
compound of formula (I) therein and then coating the resulting aqueous 
dispersion on a sheet. 
The color developer composition containing the compounds of formulae (II) 
and (III), as the other embodiment of the present invention, further 
inlcude 0.1 to 10 wt% of an anionic surface active agent and 0.1 to 10 wt% 
of a nonionic surface active agent preferably having a molecular weight of 
400 or more, based on the total amount of the compounds of formulae (II) 
and (III). It is preferred in view of prevention of the bubbling and 
increase of the dispersing rate that the nonionic surface active agent and 
the compounds of formulae (II) and (III) are dispersed in a solution 
having the anionic surface active agent completely dissolved or dispersed 
in pure water. The thus prepared aqueous dispersion is coated on a sheet 
to produce a color developer sheet. 
The substituted or unsubstituted benzoic acid salts represented by formulae 
(I) and (II) are, in general, crystalline solid. Examples include zinc, 
aluminum, calcium, cobalt, strontium or magnesium salts of benzoic acid or 
substituted benzoic acids such as salicylic acid, isophthalic acid, 
terephthalic acid, m-hydroxybenzoic acid, p-hydroxybenzoic acid, 
protocatechuic acid, 2,3-dihydroxybenzoic acid, .beta.-resorcylic acid, 
2,5-dihydroxybenzoic acid, 2,6-dihydroxybenzoic acid, 3,5-dihydroxybenzoic 
acid, 2,3,4-trihydroxybenzoic acid, gallic acid, o-chlorobenzoic acid, 
p-chlorobenzoic acid, 2,4-dichlorobenzoic acid, 2-fluorobenzoic acid, 
3-fluorobenzoic acid, m-bromobenzoic acid, p-bromobenzoic acid, 
5-bromo-2-hydroxybenzoic acid, o-iodobenzoic acid and p-iodobenzoic acid. 
Examples of substituted or unsubstituted salicylic acid salt represented by 
formula (II) wherein R.sub.6 is a hydroxy group including zinc, magnesium, 
calcium, aluminum, nickel, cobalt, iron or strontium salts of substituted 
salicylic acids such as 3-phenylsalicylic acid, 5-phenylsalicylic acid, 
3-benzylsalicylic acid, 5-benzylsalicylic acid, 
3-(.alpha.-methylbenzyl)salicylic acid, 5- (.alpha.-methylbenzyl)salicylic 
acid, 3-(.alpha.,.alpha.-dimethylbenzyl)salicylic acid, 
5-(.alpha.,.alpha.-dimethylbenzyl)salicylic acid, 
5(.alpha.-.alpha.-methyl-.alpha.-ethylbenzyl)salicylic acid, 
5-(.alpha.-methyl-.alpha.-propylbenzyl)salicylic acid, 
5-(.alpha.,.alpha.-dimethylphenylethyl)salicylic acid, 
3-methyl-5-phenylsalicylic acid, 5- methyl-3-phenylsalicylic acid, 
3-isopropyl-5-phenylsalicylic acid, 5-isopropyl-3-phenylsalicylic acid, 
3-tert-butyl-5-phenylsalicylic acid, 5-tert-butyl-3-phenylsalicylic acid, 
5-tert-octyl-3-phenylsalicylic acid, 5-nonyl-3-phenyl-salicylic acid, 
5-cyclohexyl-3-phenylsalicylic acid, 3-cyclohexyl-5-phenylsalicylic acid, 
3-methyl-5-benzylsalicylic acid, 5-methyl-3-benzylsalicylic acid, 
5-ethyl-3-benzylsalicylic acid, 3-n-propyl-5-benzylsalicylic acid, 
5-n-propyl-3-benzylsalicylic acid, 3-isopropyl-5-benzylsalicylic acid, 
5-isopropyl-3-benzylsalicylic acid, 3-sec-butyl-5-benzylsalicylic acid, 
5-sec-butyl-3-benzylsalicylic acid, 3-tert-butyl-5-benzylsalicylic acid, 
5-tert-butyl-3-benzylsalicylic acid, 3-tert-amyl-5-benzylsalicylic acid, 
5-tert-amyl-3-benzylsalicylic acid, 3-tert-octyl-5-benzylsalicylic acid, 
5-tert-octyl-3-benzylsalicylic acid, 5-nonyl-3-benzylsalicylic acid, 
5-dodecyl-3-benzylsalicylic acid, 5-cyclohexyl-3-benzylsalicylic acid, 
3-methyl-5-(.alpha.-methylbenzyl)salicylic acid, 
5-methyl-3-(.alpha.-methylbenzyl)salicylic acid, 
5-ethyl-3-(.alpha.-methylbenzyl)salicylic acid, 
3-isopropyl-5-(.alpha.-methylbenzyl)salicylic acid, 
5-isopropyl-3-(.alpha.-methylbenzyl)salicylic acid, 
3-sec-butyl-5-(.alpha.-methylbenzyl)salicylic acid, 
5-sec-butyl-3-(.alpha.methylbenzyl)salicylic acid, 
3-tert-butyl-5-(.alpha.-methylbenzyl)salicylic acid, 
5-tert-butyl-3-(.alpha.-methylbenzyl)salicylic acid, 
3-tert-amyl-5-(.alpha.-methylbenzyl)salicylic acid, 
5-tert-amyl-3-(.alpha.-methylbenzyl)salicylic acid, 
5-tert-octyl-3-(.alpha.-methylbenzyl)salicylic acid, 
5-nonyl-3-(.alpha.-methylbenzyl)salicylic acid, 
5-dodecyl-3-(.alpha.-methylbenzyl)salicylic acid, 
5-cyclohexyl-3-(.alpha.-methylbenzyl)salicylic acid, 3-methyl- 
5-(.alpha.,.alpha.-dimethylbenzyl)salicylic acid, 
5-methyl-3-(.alpha.,.alpha.-dimethylbenzyl)salicylic acid, 
3-ethyl-5-(.alpha.,.alpha.-dimethylbenzyl)salicylic acid, 
5-ethyl-3-(.alpha.,.alpha.-dimethylbenzyl)salicylic acid, 
5-n-propyl-3-(.alpha.,.alpha.-dimethylbenzyl)salicylic acid, 
3-isopropyl-5-(.alpha.,.alpha.-dimethylbenzyl)salicylic acid, 
5-isopropyl-3-(.alpha.,.alpha.-dimethylbenzyl)salicylic acid, 
3-sec-butyl-5-(.alpha.,.alpha.-dimethylbenzyl)salicylic acid, 
5-sec-butyl-3-(.alpha.,.alpha.-dimethylbenzyl)salicylic acid, 
3-tert-butyl-5-(.alpha.,.alpha.-dimethylbenzyl)salicylic acid, 
5-tert-butyl-3-(.alpha.,.alpha.-dimethylbenzyl)salicylic acid, 
3-tert-amyl-5-(.alpha.,.alpha.-dimethylbenzyl)salicylic acid, 
5-tert-amyl-3-(.alpha.,.alpha.-dimethylbenzyl)salicylic acid, 
5-tert-octyl-3-(.alpha.,.alpha.-dimethylbenzyl)salicylic acid, 5- 
nonyl-3-(.alpha.,.alpha.-dimethylbenzyl)salicylic acid, 
5-dodecyl-3-(.alpha.,.alpha.-dimethylbenzyl)salicylic acid, 
5-cyclohexyl-3-(.alpha.,.alpha.-dimethylbenzyl)salicylic acid, 
3-methyl-5-(.alpha.-methyl-.alpha.-ethylbenzyl)salicylic acid, 
3,5-diphenylsalicylic acid, 3,5-dibenzylsalicylic acid, 
3,5-di(.alpha.-methylbenzyl)salicylic acid, 
3,5-di(.alpha.,.alpha.-dimethylbenzyl)salicylic acid, 
3-phenyl-5-benzylsalicylic acid, 5-phenyl-3-benzylsalicylic acid, 
3-phenyl-5-(.alpha.-methylbenzyl)salicylic acid, 
5-phenyl-3-(.alpha.-methylbenzyl)salicylic acid, 
3-phenyl-5-(.alpha.,.alpha.-dimethylbenzyl)salicylic acid, 
5-phenyl-3-(.alpha.,.alpha.-dimethylbenzyl)salicylic acid, 
3-benzyl-5-(.alpha.-methylbenzyl)salicylic acid, 
5-benzyl-3-(.alpha.-methylbenzyl)salicylic acid, 
3-benzyl-5-(.alpha.,.alpha.-dimethylbenzyl)salicylic acid, 
5-benzyl-3-(.alpha.,.alpha.-dimethylbenzyl)salicylic acid, 
3-(.alpha.-methylbenzyl)-5-(.alpha.,.alpha.-dimethylbenzyl)salicylic acid, 
5-(.alpha.-methylbenzyl)-3-(.alpha.,.alpha.-dimethylbenzyl)salicylic acid, 
3-(4-methylbenzyl)salicylic acid, 5-(4-methylbenzyl)salicylic acid, 
3,5-di(4-methylbenzyl)salicylic acid, 3-(2-methylbenzyl)salicylic acid, 
5-(2-methylbenzyl)salicylic acid, 3,5-di(2-methylbenzyl)salicylic acid, 
5-(3-methylbenzyl)salicylic acid, 3,5-di(3-methylbenzyl)salicylic acid, 
5-[.alpha.-methyl-4'-(.alpha.-methylbenzyl)benzyl]salicylic acid, 
5-[4'-(2,4,6-trimethylbenzyl)benzyl]salicylic acid, 
1-hydroxy-2-carboxy-4-(.alpha.-methylbenzyl)naphthalene, 
2-hydroxy-1-carboxy-4-(.alpha.-methylbenzyl)naphthalene, 
1-hydroxy-2-carboxy-4-benzylnaphthalene, 
1-hydroxy-2-carboxy-4-(.alpha.,.alpha.-dimethylbenzyl)naphthalene, and 
1-(.alpha.-methylbenzyl)-2-hydroxy-3-carboxynaphthalene. 
As novolak type phenol resins represented by formula (III), polycondensates 
of formaldehyde with phenols (e.g., phenol, p-hydroxyphenol, 
p-methylphenol, p-ethylphenol, p-sec-butylphenol, p-tert-butylphenol, 
p-phenylphenol, p-benzylphenol, p-(4-hydroxybenzyl)phenol, 
p-(.alpha.-methylbenzyl)phenol, p-(.alpha.,.alpha.-dimethylbenzyl)phenol 
and bisphenol A) can be used. Of these, preferred are novolak type phenol 
resins of formula (III) wherein R.sub.11 is one of the following groups: 
##STR5## 
The addition of the novolak type phenol resin in the color developer 
composition is advantageous in that the phenol resin becomes soft when 
heated after color development, and imparts gloss to the image surface. 
Examples of anionic surface active agents which can be used in the present 
invention include alkali salts of alkylbenzenesulfonic acids, 
alkylnaphthalenesulfonic acids, alkylsulfosuccinic acids, alkylsulfuric 
acid esters, alkyl diphenyl ether disulfonic acids or polyoxyethylene 
alkylsulfuric acid esters, and polycarboxylic acid type high molecular 
weight surface active agents, with sodium alkylsulfosuccinates being 
preferred, or a mixture thereof. Of these, sodium dioctylsulfosuccinate is 
particularly preferred as it is inexpensive, exhibits good deforming 
property and minimizes thixotropic properties. Sodium laurylsulfate, 
sodium dodecylbenzenesulfonate, sodium octylnaphthalenesulfonate, sodium 
polyoxyethylene lauryl ether sulfate and the like may also be used alone 
or in combination. 
As the nonionic surface active agents, there may be mentioned polyvinyl 
alcohol, modified polyvinyl alcohols, polyacrylamide, modified 
polyacrylamides, and polyoxyethylene derivatives such as polyoxyethylene 
lauryl ether, polyoxyethylene higher alcohol ethers, polyoxyethylene 
octylphenyl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene 
sorbitan monolaurate, polyoxyethylene sorbitan monostearate and 
polyoxyethylene sorbitan monooleate. 
The color developer compositions containing the ingredients as described 
above are inexpensive, exhibit excellent color developability, and provide 
images with minimized yellowing and fading. Further, since the 
compositions of the present invention do not suffer from bubbling when 
dispersed in water, they can be easily coated to obtain color developer 
sheets. Furthermore, the color developer sheets become glossy upon heating 
after image recording. 
The present invention is further explained with reference to the following 
Examples, but the present invention should not be construed as being 
limited thereto. 
EXAMPLE 1 
Eight grams of an alcohol solution containing sodium dioctylsulfosuccinate 
(effective ingredient: 80 wt%) was completely dissolved in 800 g of pure 
water, to which 20 g of a 20 wt% aqueous solution of polyvinyl alcohol 
(polymerization degree: 500, saponification degree: about 88%) was then 
mixed. The mixture and 600 g of zinc salicylate were charged in a ball 
mill and ground for 24 hours. Thereafter, 400 g of a 7 wt% aqueous 
solution of polyethylene oxide ("PEO-8", produced by Seitetsu Kagaku Co., 
Ltd.) was mixed as a binder. The thus prepared aqueous dispersion of color 
developer composition was coated on a paper (basis weight: 127.9 
g/m.sup.2, "high Grade Dalart A", produced by Mitsubishi Paper Mills, 
Ltd.) using a bar coater (No. 28, diameter: 1/4 inch) and then dried at 
80.degree. C. 
EXAMPLE 2 
Ten grams of an alcohol solution containing sodium dioctylsulfosuccinate 
(effective ingredient: 80 wt%) was completely dissolved in 1000 g of pure 
water, to which 5 g of polyoxyethylene octylphenyl ether ("Emulgen 800 
Series", produced by Kao Corp.) was then mixed. The resulting mixture and 
600 g of zinc benzoate were charged in a ball mill and ground for 24 
hours. Thereafter, 200 g of a 15 wt% aqueous solution of polyvinyl alcohol 
("PVA 200", produced by Kurare Co., Ltd.) was added as a binder. The thus 
prepared aqueous dispersion of color developer composition was coated on a 
paper (basis weight: 127.9 g/m.sup.2, "high Grade Dalart A", produced by 
Mitsubishi Paper Mills, Ltd.) and dried in the same manner as in Example 
1. 
EXAMPLE 3 
Ten grams of an alcohol solution containing sodium dioctylsulfosuccinate 
(effective ingredient 80 wt%) was completely dissolved in 1000 g of pure 
water, to which 5 g of polyoxyethylene nonylphenyl ether ("Emulgen 900 
Series", produced by Kao Corp.) was then mixed. The mixture and 600 g of 
zinc .beta.-resorcylic acid were charged in a ball mill and ground for 24 
hours. Thereafter, 200 g of a 15 wt% aqueous solution of polyvinyl alcohol 
(PVA 220) was mixed as a binder. The thus prepared aqueous dispersion of 
color developer composition was coated on a paper (basis weight: 127.9 
g/m.sup.2, "high Grade Dalart A", produced by Mitsubishi Paper Mills, 
Ltd.) and dried in the same manner as in Example 1. 
COMATIVE EXAMPLE 1 
Eight grams of an alcohol solution containing sodium dioctylsulfosuccinate 
(effective ingredient: 80 wt%) was completely dissolved in 800 g of pure 
water, to which 20 g of a 20 wt% aqueous solution of polyvinyl alcohol 
(polymerization degree: 500, saponification degree: about 88 %) was then 
mixed. The mixture and 600 g of zinc 3,5-di-tertbutylsalicylate were 
charged in a ball mill and ground for 24 hours. Then, 400 g of a 7 wt% 
aqueous solution of polyethylene oxide ("PEO-8", produced by Seitetsu 
Kagaku Co., Ltd.) was added as a binder to obtain an aqueous dispersion of 
color developer composition. However, the aqueous dispersion suffered from 
significant bubbling and could not be used in preparation of color 
developer sheets. 
COMATIVE EXAMPLE 2 
Ten grams of an alcohol solution containing sodium dioctylsulfosuccinate 
(effective ingredient: 80 wt%) was completely dissolved in 1000 g of pure 
water, which was charged in a ball mill together with 600 g of zinc 
3,5-di-tert-butylsalicylate, followed by grinding for 24 hours. Then, 200 
g of a 15wt% aqueous solution of polyvinyl alcohol (PVA 220) was mixed as 
a binder to obtain an aqueous dispersion of color developer composition, 
which was coated on a paper (basis weight: 127.9 g/m.sup.2, "high Grade 
Dalart A", produced by Mitsubishi Paper Mills, Ltd.) and dried in the same 
manner as in Example 1. 
COMATIVE EXAMPLE 3 
Eight grams of an alcohol solution containing sodium dioctylsulfosuccinate 
(effective ingredient: 80 wt%) was completely dissolved in 800 g of pure 
water, which was then charged in a ball mill with 600 g of zinc salicylate 
and ground for 24 hours. Then, 400 g of a 7 wt% aqueous solution of 
polyethylene oxide (PEO-8) was added as a binder to obtain an aqueous 
dispersion of color developer composition, which was coated on a coated 
paper and dried in the same manner as in Example 1. 
COMATIVE EXAMPLE 4 
Ten grams of an alcohol solution containing sodium dioctylsulfosuccinate 
(effective ingredient: 80 wt%) was completely dissolved in 1000 g of pure 
water, to which 5 g of polyoxyethylene octylphenyl ether (Emulgen 800 
Series) was then mixed. The mixture and 600 g of zinc 
3,5-di(.alpha.-methylbenzyl)salicylate were charged in a ball mill and 
ground for 24 hours. Thereafter, 200 g of a 15 wt% aqueous solution of 
polyvinyl alcohol (PVA 220) was added as a binder to obtain an aqueous 
dispersion of color developer composition. However, the aqueous dispersion 
suffered from significant bubbling and could not be used in preparation of 
color developer sheets. 
COMATIVE EXAMPLE 5 
Seven grams of an alcohol solution containing sodium dioctylsulfosuccinate 
(effective ingredient: 80 wt%) was dissolved in 1000 g of pure water. The 
solution and 600 g of a novolak resin of a mixture of phenol and 
p-tert-butylphenol ("CKM-2103", produced by Union Carbide Corp.) were 
charged in a ball mill and ground for 24 hours, to which 200 g of a 15 wt% 
aqueous solution of polyvinyl alcohol (PVA 220) was added as a binder. The 
thus prepared aqueous dispersion of color developer composition was coated 
on a paper (basis weight: 127.9 g/m.sup.2, "high Grade Dalart A", produced 
by Mitsubishi Paper Mills, Ltd.) and dried in the same manner as in 
Example 1. 
COMATIVE EXAMPLE 6 
Two grams of a polycarboxylic acid type high molecular weight surface 
active agent ("Demol EP", produced by Kao Corp.) and 2 g of a 
polyoxyethylene derivative ("Emulgen A-500", produced by Kao Corp.) were 
dissolved in 1000 g of pure water, which was then charged in a ball mill 
with 600 g of a novolak resin of p-phenylphenol ("PS-2880", produced by 
Gun-ei Kagaku Co., Ltd.) and ground for 24 hours. Then, 200 g of a 15 wt% 
aqueous solution of polyvinyl alcohol (PVA 220) was added as a binder to 
obtain an aqueous dispersion of color developer composition which was 
coated on a coated paper and dried in the same manner as in Example 1. 
Properties of the color developer sheets obtained in Examples 1 to 3 and 
Comparative Examples 2, 3, 5 and 6 were measured by the following 
procedures (i) to (vi) and the results are shown in Table 1. However, the 
dispersions of the Comparative Examples 1 and 4 could not be measured 
because they suffered from bubbling. 
(i) Initial Color-developed Density 
A photosensitive and pressure-sensitive microcapsule sheet (Product No. 
5001J, R-630, produced by The Mead Corporation) as described in 
JP-A-62-150242 was put on the above-prepared color developer sheet in the 
face-to face configuration with respect to their coated surfaces, and they 
were passed through a calender roll with linear pressure of 50 kg/cm at 
20.degree. C. and 50% RH to effect color development. The color-developed 
density after one minute was measured using a densitometer ("RD-914", 
produced by Macbeth Co., Ltd.). 
(ii) Color-developed Density After Heat-fixation 
A color-developed sheet which had been subjected to color development as in 
the above procedure (i) was put in an oven at 150.degree. C. for one 
minute to perform heat-fixation, and the color-developed density was 
measured using a densitometer (RD-914). 
(iii) Light-fastness 
An unused color developer sheet was exposed to light for 4 hours using a 
carbon arc fade meter (produced by Suga Shikenki Co., Ltd.), and 
yellowness index of the sheet was measured with a multi-light source 
spectral colorimeter (MSC-2 type, produced by Suga Shikenki Co., Ltd.). 
(iv) Heat Resistance 
An unused color developer sheet was allowed to stand at 80.degree. C. in a 
dark room without controlling humidity, and yellowness index of the sheet 
was measured using a colorimeter as in the procedure (iii). 
(v) Resistance to Yellowing 
An unused color developer sheet was allowed to stand at 25.degree. C. and 
50% RH for 150 days in a dark room, and yellowness index of the sheet was 
measured using a colorimeter as in the procedure (iii). 
(vi) Storage Stability 
The aqueous dispersions of color developer compositions prepared in the 
above Examples and Comparative Examples were stored for 30 days, and then 
the dispersions were observed by naked eyes. In Table 1, A means no 
changes occurred in the dispersion; B means slight separation occurred in 
the dispersion but causing no problems when stirred; and C means complete 
separation occurred in the dispersion so that it does not revert to its 
original state even if stirred. 
EXAMPLE 4 
Ten grams of an alcohol solution containing sodium dioctylsulfosuccinate 
(effective ingredient: 80 wt%) was completely dissolved in 1000 g of pure 
water. The solution was charged in a ball mill together with 20 g of a 20 
wt% aqueous solution of polyvinyl alcohol (polymerization degree: 500, 
saponification degree: about 88 %), 300 g of a novolak resin of 
p-tert-butylphenol ("CKM-2432", produced by Union Carbide Corp.) and 300 g 
of zinc salicylate, and they were ground for 24 hours. Then, 200 g of a 15 
wt% aqueous solution of polyvinyl alcohol (PVA 220) was added as a binder 
to obtain an aqueous dispersion of color developer composition which was 
coated on a paper (basis weight: 127.9 g/m.sup.2, "high Grade Dalart A", 
produced by Mitsubishi Paper Mills, Ltd.)and dried in the same manner as 
in Example 1. 
EXAMPLE 5 
Ten grams of an alcohol solution containing sodium dioctylsulfosuccinate 
(effective ingredient: 80 wt%) was completely dissolved in 1000 g of pure 
water. The solution was charged in a ball mill together with 2 g of a 
polyoxyethylene derivative ("Emulgen A-500"), 300 g of a novolak resin of 
p-phenylphenol (PS-2880) and 300 g of zinc benzoate, and they were ground 
for 24 hours. Then, 200 g of a 15 wt% aqueous solution of polyvinyl 
alcohol (PVA 220) was added as a binder to obtain an aqueous dispersion of 
color developer, which was then coated on a paper (basis weight: 127.9 
g/m.sup.2, "high Grade Dalart A", produced by Mitsubishi Paper Mills, 
Ltd.) and dried in the same manner as in Example 1. 
EXAMPLE 6 
Ten grams of an alcohol solution containing sodium dioctylsulfosuccinate 
(effective ingredient: 80 wt%) was completely dissolved in 1000 g of pure 
water. The solution was charged in a ball mill with 300 g of a novolak 
resin of a mixture of phenol and p-tert-butylphenol (CKM-2103) and 300 g 
of zinc .beta.-resorcylic acid and ground for 24 hours. Then, 200 g of a 
15 wt% aqueous solution of polyvinyl alcohol (PVA 220) was added as a 
binder to obtain an aqueous dispersion of color developer composition 
which was coated on a paper (basis weight: 127.9 g/m.sup.2, "high Grade 
Dalart A", produced by Mitsubishi Paper Mills, Ltd.) and dried in the same 
manner as in Example 1. 
REFERENCE EXAMPLE 
Ten grams of an alcohol solution containing sodium dioctylsulfosuccinate 
(effective ingredient: 80 wt%) was completely dissolved in 1000 g of pure 
water. The solution was charged in a ball mill with 20 g of a 20 wt% 
aqueous solution of polyvinyl alcohol (polymerization degree: 500, 
saponification degree: about 88%) and 600 g of zinc salicylate and ground 
for 24 hours. Thereafter, 200 g of a 15 wt% aqueous solution of polyvinyl 
alcohol (PVA 200) was added as a binder to obtain an aqueous dispersion of 
color developer composition which was coated on a coated paper and dried 
in the same manner as in Example 1. 
COMATIVE EXAMPLE 7 
The grams of an alcohol solution containing sodium dioctylsulfosuccinate 
(effective ingredient: 80 wt%) was completely dissolved in 1000 g of pure 
water. The solution and 600 g of a novolak resin of p-tert-butylphenol 
(CKM-2432) were charged in a ball mill and ground for 24 hours. Then, 200 
g of a 15 wt% aqueous solution of polyvinyl alcohol (PVA 220) was added as 
a binder to obtain an aqueous dispersion of color developer composition 
which was coated on a coated paper and dried in the same manner as in 
Example 1. 
COMATIVE EXAMPLE 8 
Ten grams of an alcohol solution containing sodium dioctylsulfosuccinate 
(effective ingredient: 80 wt%) was completely dissolved in 1000 g of pure 
water. The solution was charged in a ball mill together with 2 g of a 
polyoxyethylene derivative (Emulgen A-500) and 600 g of a novolak resin of 
p-phenylphenol (PS-2880) and ground for 24 hours. Thereafter, 200 g of a 
15 wt% aqueous solution of polyvinyl alcohol (PVA 220) was mixed as a 
binder to obtain an aqueous dispersion of color developer composition 
which was coated on a coated paper and dried in the same manner as in 
Example 1. 
The color developer sheets prepared in Examples 4 to 6, Reference Example 
and Comparative Examples 7 and 8 were subjected to the same tests as in 
Example 1 and further to the following test with respect to gloss of the 
sheet. 
The gloss of the color developer sheet which had been processed in the same 
manner as in the procedure (ii) for measurement of color-developed density 
after heat-fixation was measured at the angle of 75 using a varied-angle 
gloss meter (produced by Suga Shikenki Co., Ltd.). When the same test was 
performed with the color developer sheets prepared in Examples 2 and 3 and 
Comparative Examples 2, 5, 6 and 7, their results were 7.2, 27.8, less 
than 5, 82.9, 86.9 and 74.0, respectively. 
The results obtained are shown in Table 2 below. 
EXAMPLE 7 
Ten grams of an alcohol solution containing sodium dioctylsulfosuccinate 
(effective ingredient: 80 wt%) was dissolved in 1000 g of pure water. The 
solution was charged in a ball mill with 300 g of a novolak resin of 
p-tert-butylphenol (CKM-2432) and 300 g of zinc 
3,5-di-tert-butylsalicylate and ground for 24 hours. Then, 200 g of a 15 
wt% aqueous solution of polyvinyl alcohol (PVA 220) was mixed as a binder 
to obtain an aqueous dispersion of color developer composition which was 
coated on a paper (basis weight: 127.9 g/m.sup.2, "high Grade Dalart A", 
produced by Mitsubishi Paper Mills, Ltd.) and dried in the same manner as 
in Example 1. 
EXAMPLE 8 
Seven grams of an alcohol solution containing sodium dioctylsulfosuccinate 
(effective ingredient: 80 wt%) was dissolved in 1000 g of pure water. The 
solution was charged in a ball mill together with 350 g of a novolak resin 
of a mixture of phenol and p-tert-butylphenol (CKM-2103), 125 g of zinc 
3-phenylsalicylate and 125 g of zinc 5-phenylsalicylate and ground for 24 
hours. Thereafter, 200 g of a 15 wt% aqueous solution of polyvinyl alcohol 
(PVA 200) was mixed as a binder to obtain an aqueous dispersion of color 
developer composition which was coated on a paper (basis weight: 127.9 
g/m.sup.2, "high Grade Dalart A", produced by Mitsubishi Paper Mills, 
Ltd.) and dried in the same manner as in Example 1. 
EXAMPLE 9 
Two grams of a polycarboxylic acid type high molecular weight surface 
active agent (Demol EP) and 2 g of a polyoxyethylene derivative (Emulgen 
A-500) were dissolved in 1000 g of pure water. The solution was charged in 
a ball mill together with 400 g of a novolak resin of p-phenylphenol 
(PS-2880) and 200 g of zinc 3,5-di(.alpha.-methylbenzyl)salicylate and 
ground for 24 hours. Then, 200 g of a 15 wt% aqueous solution of polyvinyl 
alcohol (PVA 220) was mixed as a binder to obtain an aqueous dispersion of 
color developer composition which was coated on a paper (basis weight: 
127.9 g/m.sup.2, "high Grade Dalart A", produced by Mitsubishi Paper 
Mills, Ltd.) and dried in the same manner as in Example 1. 
COMATIVE EXAMPLE 9 
Seven grams of an alcohol solution containing sodium dioctylsulfosuccinate 
(effective ingredient: 80 wt%) was dissolved in 1000 g of pure water. The 
solution was charged in a ball mill with 300 g of zinc 3-phenylsalicylate 
and 300 g of zinc 5-phenylsalicylate and ground for 24 hours. Then, 200 g 
of a 15 wt% aqueous solution of polyvinyl alcohol (PVA 220) was mixed as a 
binder to obtain an aqueous dispersion of color developer composition 
which was coated on a paper (basis weight: 127.9 g/m.sup.2, "high Grade 
Dalart A", produced by Mitsubishi Paper Mills, Ltd.) and dried in the same 
manner as in Example 1. 
COMATIVE EXAMPLE 10 
Two grams of a polycarboxylic acid type high molecular weight surface 
active agent (Demol EP) and 2 g of a polyoxyethylene derivative (Emulgen 
A-500) were dissolved in 1000 g of pure water. The solution and 600 g of 
zinc 3,5-di(.alpha.-methylbenzyl)salicylate were charged in a ball mill 
and ground for 24 hours. Then, 200 g of a 15 wt% aqueous solution of 
polyvinyl alcohol (PVA 220) was mixed as a binder to obtain an aqueous 
dispersion of color developer composition. However, the dispersion 
suffered from bubbling and could not be used for preparation of color 
developer sheets. 
Using the color developer sheets prepared in Examples 7 to 9 and 
Comparative Example 9, the same tests as in Example 4 were performed, and 
the results obtained are shown in Table 3. 
It is apparent from the above description that the color developer 
compositions of the present invention have high color-developability, 
provide color developer sheets having excellent shelf life with respect to 
light-fastness and yellowing and also exhibit good storage stability in 
the form of aqueous dispersion, allowing them to be supplied and put on 
the market in the form of aqueous dispersion, while conventional color 
developers are supplied in the form of powder and have defects in handling 
properties. The color developer compositions of the present invention are 
freed from dust problems, troublesome handling and reprocessing of 
particles, which are developers. Thus, the color developer compositions of 
the present invention are apparently advantageous in the hygienic and 
economical viewpoints. 
In addition, the color developer sheets of the present invention can 
provide a smooth surface upon heat treatment due to softening of the 
phenol resin component contained therein, imparting gloss to the sheet, so 
that not only is the commercial value of the sheet increased but also 
water resistance and chemical resistance are improved and further 
alteration of documents can be prevented. 
The substituted or unsubstituted benzoic acid salt having the formula (I) 
is preferably used in 80 to 99.8 wt%, and the mixture of (II) and (III) ar 
preferably used in 30 to 70 wt% for the former and in 70 to 30 wt% for the 
latter. 
While the invention has been described in detail and with reference to 
specific embodiments thereof, it will be apparent to one skilled in the 
art that various changes and modifications can be made therein without 
departing from the spirit and scope thereof. 
TABLE 1 
__________________________________________________________________________ 
Color-developed Resistance 
Example 
Initial color- 
density after 
Light- 
Heat to Storage 
No. developed density 
heat-fixation 
fastness 
resistance 
yellowing 
stability 
__________________________________________________________________________ 
1 1.23 1.65 6.9 16.1 3.6 B 
2 0.95 1.57 6.0 15.0 3.5 A 
3 1.11 1.62 6.8 14.7 3.5 A 
Comp. Ex. 2 
0.98 1.57 7.3 16.5 3.6 B 
Comp. Ex. 3 
1.27 1.71 6.7 14.1 3.5 C 
Comp. Ex. 5 
0.64 0.84 29.7 
41.8 7.0 A 
Comp. Ex. 6 
0.77 1.05 30.3 
40.2 7.4 B 
__________________________________________________________________________ 
TABLE 2 
__________________________________________________________________________ 
Color-developed Resistance 
Example 
Initial color- 
density after 
Light- 
Heat to Storage 
No. developed density 
heat-fixation 
Gloss 
fastness 
resistance 
yellowing 
Stability 
__________________________________________________________________________ 
4 0.92 1.70 55.7 
12.4 
20.7 3.9 A 
5 0.83 1.63 79.4 
15.7 
23.1 4.1 A 
6 0.79 1.65 77.7 
16.0 
21.5 4.1 A 
Ref. Ex. 
1.25 1.69 22.3 
6.7 15.7 3.7 B 
Comp. Ex. 7 
0.59 0.81 74.0 
24.8 
37.6 5.3 A 
Comp. Ex. 8 
0.75 1.04 85.7 
29.3 
40.1 6.9 B 
__________________________________________________________________________ 
TABLE 3 
__________________________________________________________________________ 
Color-developed Resistance 
Example 
Initial color- 
density after 
Light- 
Heat to Storage 
No. developed density 
heat-fixation 
Gloss 
fastness 
resistance 
yellowing 
Stability 
__________________________________________________________________________ 
7 0.81 1.26 46.0 
11.7 
19.3 4.1 A 
8 1.01 1.45 71.3 
15.6 
21.7 4.4 A 
9 1.23 1.52 78.5 
16.1 
21.9 4.3 A 
Comp. Ex. 9 
1.07 1.61 63.2 
8.5 18.1 4.0 C 
__________________________________________________________________________