Note: Descriptions are shown in the official language in which they were submitted.
l~q~9
1 The present invention relates to a recordiny sheet an~
a color developer therefor, and more particularly to a recording
sheet having coated thereon novel color developer layer and
a novel color developer for the recording sheet.
There have been known recording sheets utilizing a color
reaction of a colorless organic compound (hereinafter, referred
to "color former") and an adsorbent material capable of forming
a distinct color when contacted with the color former.
As the recording sheets using the phenomenon, a pressure-
sensitive recording sheet (USP 2,505,470, USP 2,505,489, USP
2,550,471, USP 2,548,366, USP 2,712,507, USP 2,730,456,USP 2,730,457, USP 3,418,250, etc.) and a heat-sensitive
recording sheet have been well known. Further, it has been known
a printing method, that an ink containing the color former is
applied to the color developer sheet through a medium such as
stencil or not.
In all cases, the above phenomenon of the color reaction
between the color former and the color developer are utilized
under pressure with a pen or stylus, under heat, etc.
The color former may be dissolved in a solvent such as
chlorinated diphenyl, chlorinated paraffine or other organic
solvent. The solution may be dispersed in a binder and/or may
be microencapsulated, and then coated on a support such as
paper, plastic film, resin-coated paper, etc.
In case of heat-sensitive recording sheet, the color
former may be coated on the support together with a thermofusible
material such as acetoanilide which is melted under heating to
dissolve the color former.
On the other hand, the color developer is dissolved or
dispersed in water or an organic solvent together with a binder
,~
l~q~9
such as styrene-butadiene rubDer latex a~d then coated on or
impregnated into a base support before or directly before
recording.
The color former and color developer may be coated on
the same surface or opposite surfaces of support, or the
different supports.
Usually, after the color developer is coated on the
support, a desensitizer is locally coated thereon in order that
unnecessary surface portion is prevented from the color formation
.10 (USP 2,777,780). Another embodiment of the prevention of color
formation is to locally coat the color developer on the support
or the coated layer of color former without using the desensiti-
zer.
As the above described color developer, there are clays
such as acid clay, active clay,attapulgite, zeolite, bentonite,
etc., phenol resins (USP 3,516,845i USP 3,540,911) and organic
compounds such as succinic acid, tannic acid, gallic acid or
phenol compound (USP 3,244,548) are known. Such organic
compound is not practically employed for the reason that the
color developing ability of color developer sheet which is a
support having coated thereon the color developer `is very low
and the color developed on the sheet is low in light resistance
although the compound can be very easily handled in manufacturing
the color developer sheet.
Further, in case where the above color developer is
locally coated on a support to form a color developer sheet,
if large amount thereof (7-10 g per 1 m2 of the support) is
coated, the color developer sheet cannot form sufficient color
when contacted with the color former. As the result, locai
_30
coating method is limited.
-- 2 --
1~19~99
1 In this case, since locally coated portion of the color
developer sheet is thicker than the other portion, the color former
coated on another support, when contacted with the color developer
sheet, is locally pressurized to form unpreferable color (herein-
after, referred to "fog").
The inventors have found that all defects of the color
developer sheet and ink can be completely removed by using a
metallic compound of an aromatic carboxylic acid. That is,the in-
ventors have found that the color developer composed of a metallic
compound of an aromatic carboxylic acid is far stronger in color
developing ability than aromatic carboxylic acid or metallic com-
pound, and that the color formed on the color former sheet is
stronger in light resistance.
The metal compound of aromatic carboxylic acid used in the
color developer of the invention can be prepared by reacting an
alkali metal salt of aromatic carboxylic acid and a water-soluble
metal salt in a solvent in which both are soluble. In this case,
the ratio of the alkali metal salt and water-soluble metal salt is
not particularly limited, but a molar ratio of 1 : 1 is preferable.
The alkali metal salt of aromatic carboxylic acid used in the above
reaction can be prepared by conventional synthetic methods. For
example, it may be prepared by reacting an aromatic carboxylic acid
with an alkali metal hydroxide or carbonate.
The aromatic carboxylic acid used in the present invention
includes, for example, benzoic acid, o-nitrobenzoic acid, m-nitro
benzoic acid, p-nitrobenzoic acid, o-chlorobenzoic acid, m-chloro-
benzoic acid, p-chlorobenzoic acid, o-toluic acid, m-toluic acid,
p-toluic acid, o-bromobenzoic acid, m-bromobenzoic acid, p-bromo-
benzoic acid, o-iodo-benzoic acid, m-iodobenzoic acid, p-iodobenzoic
acid, 4-methyl-3-nitrobenzoic acid, 2-chloro-4-nitrobenzoic acid,
_30
2,3-dichlorobenzoic acid, 2~4-dichlorobenzoic
1~99~99
1 acid, p-isopropylbenzoic acid, 2,5-dinitrobenzoic acid, 3,4-
dinitrobenzoic acid, 3,5-dinitrobenzoic acid, p-tert-butylbenzoic
acid, N-phenyl-antranillic acid, 4-methyl-3-nitrobenzoic acid,
4-acetyl-benzoic acid, salicylic acid, 5-tert-butyl-salicylic
acid, 3-phenyl-salicylic acid, 3-methyl-5-tert-butyl-salicylic
acid, 3,5-di-tert-butyl-salicylic acid, 3,5-di-tert-amyl-
salicylic acid, 3-cyclohexyl-salicylic acid, 5-cyclohexyl-
salicylic acid, 3-methyl-5-isoamyl-salicylic acid, 5-isoamyl-
salicylic acid, 3,5-di-sec-butyl-salicylic acid, 5-nonyl-
salicylic acid, 3-methyl-5-lauryl-salicylic acid, m-hydroxy-
benzoic acid, p-hydroxybenzoic acid, 3,5-dinitrosalicylic acid,
2-hydroxyl-3-methyl-benzoic acid, 2,4-cresotinic acid, 2,5-
cresotinic acid, 2,3-cresotinic acid, 2,4-dihydroxybenzoic acid,
2,5-dihydroxybenzoic acid, 2,6-dihydroxybenzoic acid, l-naphthoic
acid, 2-naphthoic acid, 1-hydroxyl-2-naphthoic acid, 2-hydroxyl-
3-naphthoic acid, 2-hydroxyl-1-naphthoic acid, 5,5'-methylene-
salicylic acid, thiosalicylic acid, trimellitic anhydride,
anacardic acid, benzoic anhydride, 2-carboxybenzaldehyde,
diphenic acid, etc. Above all, aromatic carboxylic acid having
at least one hydroxyl group in the structure, especially ortho
position, are effective.
As metals of metal salts to be reacted with alkali metal
salts of carboxylic acids, there are the group Ib metals such
as copper, silver, etc., the group IIa metals such as magnesium,
calcium, etc., the group Ilb metals such as zinc, cadmium,
mercury, etc., the group IIIb metals such as aluminum, gallium,
etc., the group IVb metals such as tin, lead, etc., the group
VIa metals such as chromium, molybdenum, etc., the group VIIa
metals such as manganese, etc., the group VIII metals such as
_30
cobalt, nickel, etc., and the like. Among these, those wherein
zinc, tin~aluminum or nickel is used, are especially effective.
In using them in the reaction, t~ey are used in the form of
inorganic salt thereof such as chloride, sulfate, nitrate, etc.,
or in the lorm of organic salt thereof such as oxalate, acetate,
etc. These Metal salts or alkali metal salts of the aromatic
ca-~boxylic acid exhibit almost no color-developing ability when
used separately, but, when these reaction products is coated
on,o a support, metal salts of carboxylic acids show the
following excellent color-developing ability.
.10 The metal salt of the aromatic carboxylic acid which is
prepared by the reaction between the alkali metal salt of the
aromatic carboxylic acid and a water-soluble metal salt may be
used as the reaction mixture or, more preferably, after the
separation and the purification.
Further, for the purposes of increasing color developing
ability and light resistance, an inorganic pigment may be added
to the color developer. The inorganic pigment contains aluminum
silicate, zinc silicate, lead silicate, tin silicate, colloidal
hydrated aluminum silicate, zeolite, bentonite, kaolinite active
clay, acid clay, talc and the like. An amount of inorganic pigment
has no critical value, for example, more than 1 part by weight,
preferably S parts by weight per 100 parts by weight of the metal
compound of the aromatic carboxylic acid.
The color developer of the invention can be prepared by
dissolving or dispersing the metal compound of aromatic carboxylic
acid in water or an organic solvent such as methanol, ethanol,
butanol, ethyl acetate, butyl acetate, benzene, toluene acetone,
tetrahydrofuran or methylene chloride. Water and organic solvent
may be mixed. Preferable solvent is capable of dissolving the
_30
organic carboxylic acid. In case of adding the inorganic pigment,
i it may be dispersed in water, the organic solvent, the solution
or the dispersion. A concentration can be decided according to
the conventional manner.
Thus prepared solution or dispersion can be coated on a
support, if necessary, together with a binder such as gum arabic,
ethyl cellulose, styrene-butadiene copolymer, nitro-cellulose,
styrene-butadiene latex, methylmethacrylate-butadiene latex,
etc. An amount of the binder can be easily decided by one
skilled in the art. It should be noted that the coated layer
.10 of color developer can be maintained on the support even if the
binder is not present in the layer.
An amount of the color developer coating composition is
not specifically limited to obtain sufficient color. For example,
it is more than 0.1 g/m2, preferably 0.5 - 5 g/m2. The upper
limit of coating amount is not limited in a point of color
developing activity, and the above range is only due to economical
reason.
The color developer composition on a support can be coated
on a support by all kinds of coating method because the present
.20 invention is basically characterized by using the metallic
compound of the aromatic carboxylic acid.
As another embodiment for preparing a color developer
composition, the binder is dissolved in the organic solvent and
a plasticizer is added and then the metallic compound of aromatic
carboxylic acid is dissolved or dispersed in the resulting
solution.
The plasticizer may contain esters of phosphoric acid,
phthalic acid, adipic acid or sebatic acid (e.g. tributyl phos-
phate, dibutyl phthalate, dioctyl phthalate, butyl adipate,
dibutyl sebacate): hydrocarbon such as chlorinated paraffin; and
-- 6 --
g
1 glycerine of unsaturated fatty acid such as castor oil.
In this case, for the purpose of stabiliziny the color
developer composition which rnay be used as a coatiny ink,
an alkali metal salt of organic acid, or an alkali may be added
to the composition. The alkali metal salt of organic acid is,
for example, lithium salt, sodium salt or potassium salt or
butyric acid, caprylic acid, palmitic acid, oleic acid, linoleic
acid, linolenic acid, benzoic acid, and the like. The alkali
are, for example, sodium hydroxide, potassium hydroxide, sodium
.lO carbonate, sodium silicate, borax and conventional alkali
compound. An amount of the alkali is 0.01 - 1 parts by weight
per 1 part by weight of metal compound of aromatic carboxylic
acid.
Each component is dissolved or dispersed by means of
ball mill or sand mill. Thus prepared color developer ink can
be locally applied to a support.
A color developer sheet and color developer of the
invention can be used in combination with conventional color
former such as crystal violet lactone, benzoyl leuco methylene
blue, malachite green lactone, rhodamine B lactam, fluoranes
(USP 3,501,331; USP 3,514,310; USP 3,514,311; USP 3,540,911),
spiropyrans (USP 3,293,060), a mixture thereof and the like~
The modification of the invention can be easily carried
out by one skilled in the art in accordance with conventional
information, technique and the like.
The color formers for pressure-sensitive copying pa-per
are ordinarily employed in combination in order to secure the
instantaneous color forming property and light fastness of
colored image. For example, a combination of instantaneous
_30
color forming crystal violet, lactone or 3-methyl-2,2'-spirobi
~benzo(f)]-chromene as a ~rimary color former and benzoyl
leucomethylene blue having an excellent liyht fastness has been
most well known, however, the colored image obtained by contacting
the combination of color formers with an aromatic carboxylic
acid tends to disappear, when it is allowed to stand in a room
or is exposed to sunlight, since crystal violet or chromene
fades before benzoyl leuco-methylene blue is color formed.
However, such a defect as described above is removed in the
present invention, since, on the color developer sheet using a
metallic compound of aromatic carboxylie acid and crystal
violet lactone or chromene is strong in light fastness and does
not fade before benzoyl leuco methylene blue is color formed.
This will be clear from the light-fastness of erystal violet
laetone in the below deseribed Examples.
Comparing with the eonventional clay-coated paper, the
color developer sheet of the present invention has the following
advantages:
The conventional clay-coated paper tends to be decreased
in sensitivity of elay, when being allowed to stand in air,
.20 beeause of adsorbing materials in air on the aetive point of
elay. That is, the eolor developing ability of eolor developer
sheet is remarkably lowered with time.
In the eolor developer sheet of the present invention,
sueh defeet has been improved. And, in ease of manufaeturing
a eolor developer sheet in aeeordanee with the present invention,
suffieient eolor developing ability and other properties necessary
to the eolor developer sheet for pressure sensitive paper ean
be satisfied with smaller eoating amount than in the eonventional
elay paper. That is, the amount of eolor developer of the
present invention to be eoated is suffieient with 0.1 to 5 g/m2
~ Q ~$ ~ 9
1 while in the conventional clay paper the amount to be coated is
7 to 10 g/m2. Thus, the color developer sheet is possible to
make a size spray coating by means a machine from that it can
do with a small amount and that the physical properties of liquid
can be freely varied different from clay, and results in a
remarkable effect not only on performance but also on production.
Furthermore, the color developer of the present invention
can give the similar color developing ability with smaller
amount (about 2 g/m ) of it to be coated if a natural or
synthetic high molecular substance or a water repellant is
previously coated on the surface of paper.
The present invention will be illustrated using a
pressure-sensitive recording paper with the following Examples.
The effect of the color developer sheet of the present
invention was confirmed with the following color former sheet.
Microcapsules containing a color former is manufactured,
for example, according to the specification of U.S. Patent
No. 2,800,457, as follows:
10 parts by weight of acid-treated pig skin gelatin and
10 parts by weight of gum arabic were dissolved in 400 parts by
weight of water at 40C and 0.2 part by weight of Turkey red
oil was added thereto as an emulsifier, and 40 parts by weight
of color former oil were emulsified and dispersed therein.
The color former oil is 2~ of crystal violet lactone or
3-dibenzylamino-7-diethylaminofluorane dissolved in an oil con-
sisting of 4 parts by weight of chlorinated diphenyl and 1 part
by weight of kerosene. The emulsification was stopped when the
size of oil droplet became to 5 microns on an average. Water at
40C was added thereto to 900 parts by weight in total and the
_30
stirring was continued. At this time attention must be paid
~ Q 9~
1 so that the liquid temperature does not lower to below 40C.
Next, 10% acetic acid was added thereto to adjust the pH of
system to 4.0 to 4.2 and to cause coacervation. The stirring was
further continued and, after 20 minutes, the system was cooled
with ice to gelate a coacervate film deposited around an oil
droplet. When the liquid temperature became to 20C, 7 parts
by weight of 37% formaldehyde were added thereto and at 10C,
10% aqueous solution of caustic soda was added to ad]ust the
pH to 9. At this time, addition of caustic soda must be carried
-10 out with sufficient attention.
The liquid temperature was raised to 50C by heat under
stirring for 20 minutes. The microcapsule thus obtained was
controlled to 30C and thereafter was coated on 40 g/m2 paper
- in 6 g/m2 as solid content and dried. Also in case of other
color former the recording paper was manufactured in the same
manner as described above.
The alkali metal salt of aromatic carboxylic acid used
for the production of the developing sheet of the invention is
prepared by reacting an aromatic carboxylic acid with an alkali
metal hydroxide or carbonate. An example of the procedure is
as follows: 30 g of sodium hydroxide is dissolved in 300 ml of
water, to which 100 g of salicylic -acid is then added with
agitation. The agitation is continued for a while to dissolve
the salicylic acid completely and then the solution is evaporated
to dryness to obtain 110 g of sodium salicylate.
Sodium salts and potassium salts of aromatic carboxylic
acid may similarly be prepared to that mentioned above.
The following examples are to illustrate the invention
in more detail without limiting the same.
_30
-- 10 --
1 Example 1
0.69 g equivalent of the sodium salt of aromatic carboxylic
acid obtained by the above mentioned procedure was dissolved in
150 ml of warm water. On the other hand, 0.6 g equivalent of
the sulfate was dissolved in 150 ml of warm water and added to
the above mentioned aqueous solution of sodium aromatic carboxylate
with agitation. After a while, the metal compound of aromatic
carboxylic acid was precipitated. It was then filtered and
washed with water several times to obtain the same.
10 g of the following binder was then dissolved in 300
ml of the solvent, in which 70 g of the resulting aromatic
carboxylic acid and 30 g of the inorganic pigment were dispersed
or dissolved. The so obtained solution was applied to an
original paper of 50 g/m2 to give a coating of 3 g/m2 by means
of a coating rod, followed by drying.
Example 2
0.1 g equivalent of the sodium salt of aromatic carboxylic
acid obtained by the above mentioned procedure and 10 g of
gum arabic were dissolved in 150 ml of water. On the other
hand, 0.1 g equivalent of the water-soluble metal salt was
dissolved in 150 ml of warm water and added thereto with agitation.
When the stirring was continued for a while, fine crystals
deposited. 50 g of the following inorganic pigment was dis-
persed in the resulting dispersion and applied to an original
paper of 50 g/m2 to give a coating of 4 g/m2 by means of a
coating rod folloWed by drying.
Comparative Example 1
7 g of the binder was dissolved in 300 ml of the solvent,
in which 70 g of the aromatic carboxylic acid was dispersed.
~ The resulting dispersion was applied to an original paper of
1~9~9 '.
1 50 g/m2 to give a coating of 2.1 y/m2 by means of a coating
rod followed by drying.
Comparative Example 2
0.1 g equivalent of the sodium salt of aromatic carboxylic
acid and 7 g of gum arabic were dissolved in 150 ml of warm water,
to which 0.1 g equivalent of the water-soluble metal salt
dissolved in 150 ml of warm water was added with stirring. When
the stirring was continued for a while, fine crystals deposited.
The resulting dispersion was applied to an original paper of
50 g/m2 to give a coating of 3 g~m2 by means of a coating rod,
followed by drying.
Comparative Test 1
On the developing sheets of Examples 1 and 2, and Com-
parative Examples 1 and 2 were contacted with microcapsule sheets
containing crystal violet lactone and pressurized under a load of
600 kg/cm2. After allowed to stand in the dark for a day and
night, the reflective absorption spectrum at 400 - 700 m~ was
measured, the extinction factor at its absorption maximum (which
will hereinafter be referred to as "density") being defined as
"fresh density". After further exposed to the sunlight for 1 : 2
hours, the reflective absorption spectrum on the developed surface
was measured to give its density. From the foregoing results,
a value of light resistance defined by the following relation
was obtained.
Density of color images after
exposed to sunlight
Light resistance (%) = 2~ 100
Fresh density of color images
These results are shown in Table 1.
_30
- 12 -
~9l~9
o\o
o
~ o o oo o ~ ~ ou~ o u~ ~
~ ~ o~ ~ ~ ~ o~ o ~` o
'~1 O N ~100 CO C5'~ 0~ ~ ~ ~ r~
O 1` 0 ~D OD ~Ci~ O C5~ a~ 1` ~
S~ ~ ~1 0 ~O O O O ~O O O O
O
m a~ u
r ~ C
~ U ~ U
u a~
U
,~ o a~
~ a) o ~1 u ~ ~1 o ~1 ~ o o ~ a
O ~ ~1 ~ d I O I 1~ O
H ~ O ~1 ~1 ~ I a) ¦ N ~: N 11~ ~S I 8
~ Q ~ u~
~ E ¦ N ~ ~ O '1~ 0
U ~1 U
rl > .,1
X ~,
O ~ U = = = , =
~ Id U ~I rl
.¢ u ~ ~a u
~ ~d
a
o .
~,
k ~1 = = = == = =
X
30 z
-- 13 --
~L~99~9
~--~D O O ~ ~ ~ O ~ o U~ t~ ~ U~ O ~ O
.
~ ~ 1~ r~ ~) O ~ u~ N C~l 10 r` ~ O
c~ LO ~ ~ ~ ~ o ~ ~ o ~ U~
O o O O O O O O O O o O O O O O O
~ ~ 0 5 0
V O V ~ ~ ~ ~
= ~ V = ~ ~ =
Q, ~11 ~ al ~ o v
Q)
~V ,_~
3 ~ ,Q a.l
v ~
x ~ o.,l v
~V I o I o I ~ Io Io I o 1.
N I rl I I I U a ~q I XI ~ I X
w o w ~5 a) ~q~ v ~ v o ~ o ,Y
~ u~ V ul ~ V ~ N u~ N V 'I ~ ~
2 0 ~ I V~ I V~
tVd ~V ~V~
V o 1~ V O o o o
~l~rl a) v u s~ ~ ,s:: ~
Id v = - = = o $ ~ ~ N ~
= = = = = = =
~ ~ O N ') ~r ~D
_30
-- 14 --
,~Q~99
Comparative Test 2
The similar tests to Comparative Test 1 were carried out
using a microcapsule sheet containing 3-dibenzylamino-7-diethyl-
aminofluoran to obtain the results as shown in Table 2.
TABLE 2
No. Example Aromatic Water- Inor- Sol- Binder Fresh Light re-
or Com- carboxy- soluble ganicvent den sistance
parative lic acid metal pigment sity after ex-
Example salt posed for
1 1 sali- zinc colloi-etha- ethyl 0.66 86.5
cylic sulfate dal alu- nol cellu-
acid minum lose
silicate
hydrate
~ " 0.50 73.6
2 " ~ tir, zeolite etha- " 0.72 77.5
sulfate nol:
3 1
.l l _ __ 1~ ~ 0.45 51.5
3 " " tin bento- etha- " 0 61 82.0
sulfate nite nol
Il ll ____ ll " 0.53 52.0
4 silicate " 0.63 84.0
" " " kaolin " " 0.65 78.5
6 " " " zinc oxide" " 0.64 79.5
7 calcium ben- 71.2
carbonate zene
" " ---- " " 0.51 42.3
3~
~ '
1 8 2 sali- manga- colloi- water gum 0.34 82.0
cylic nese ~al alu-- arabic
acid sulfate minum
silicate
hydrate
~ " 0.23 60.0
9 `' " cobalt zinc " pol
sulfate oxide vinyl 0.32 97.2
alcohol
~ " 0.24 85.0
10 " ~ sulfate licate arabic
" " ---- " " 0.36 96.0
,1 0
11 " " lead kaolin " " 0.35 30.3
sulfate
" " ---- " " 0.23 23.5
12 " ~ copper kaOlin 0.45 52.6
sulfate
" ., ____ ~ " 0.30 43.0
13 " benzoiczinc colloi- 0.32 31.5
acid sulfate minum si-
licate
hydrate
" " ---- " " 0.28 22.0
14 " o-chloro-zinc kaolin " " 0.46 32.0
benzoicchloride
acid
~20 " " ~ 0.30 22.6
" 2-hydroXY- alUmi~ kaolin butyl nitro-
l-naphthoic num ace~ate cellu-0.48 47.0
acid chloride lose
" " ____ " ~ 0.37 32.6
16 " 2-hydroxy- i k 1 kaolin lose
" ~ ' " 0.35 89.0
.
Com arative Test 3
p
The similar tests to Comparative Test 1 were carried out using
a microcapsule sheet containing 3-methyl-2,2'-spirobi[benzo(f)]
c'nromene as a color former to obtain the results as mentioned in
- 16 -
~9~1~99
1 in Table 3.
TAsL~ 3
No. Example Aromatic Water- Inor- Sol- Binder F-resh Light re-
or Com- carboxy- soluble ganic ven~ den- sistance
parative lic acid metal pigment sity after ex-
Example salt posed for
v _ 2 hrs (~)
1 1 salicy- zinc colloi- etha- ethyl
lic sulfate dal alu- nol cellu- 0.71 76.1
acid minum lose
silicate
1, 1, hydrate 1, ll 0.53 vanished
2 " " tin zeolite ethanol:
sulfate 3 1 0.41 47.5
" " ---- " " 0.32 vanished
3 " " " bento- etha-
nite nol " 0.51 41.6
---- " " 0.34 vanished
4 " . " zinc ll " 0.45 38.5
sillcate
" " " kaolin " " 0.60 52.6
6 " " colloi- ll " 0.72 108.5
dal alu-
minum si-
licate
hydrate
In the case of using the developing sheet of No. 6, exposure
to the sunlight was further carried out for 10 hours to obtain
a light resistance of 81.0%.
As is evident from Tables 1 to 3, the developing sheet
of the invention exhibits, when stacked on a color former-containing
microcapsule sheet and pressed, more excellent developing
capacity than when a metal compound of aromatic carboxylic acid
alone is used, and its developed color matter has a sufficient
light resistance. Similar results were obtained regarding
other color formers.
_30
- 17 -
~C~ ~ 9~ ~3g
1 Example 3
0.6 g equivalent of potassium salicylate prepared by the
method above mentioned was dissolved in 150 ml of warm water
to prepare aqueous potassium salicylate solution. 0.6 g equivalent
of zinc sulfate was dissolved in 150 ml of warm water, then
added to the aqueous sodium salicylate solution under stirring.
Immediately, white crystals were separated out. The resulting
crystals were filtrated out and washed several times with water
to obtain 90 g of white solid. 1 g of ethyl cellulose was
-~ dissolved in 200 ml of the solvent and to this solution, was
added 50 g of the previously prepared white solid to dissolve.
The resulting solution was coated onto a base paper of 50 g/m2
so that the solid ingredient thereof was coated at the thickness
of 3 g/m2, then dried.
Example 4
0.3 gram-equivalent of the sodium salt of the aromatic
carboxylic acid obtained in Example 3 and 10 g of the binder
was dissolved in 150 ml of warm water, then 0.3 gram-equivalent
of the metal salt dissolved in 150 ml of warm water was added
.20 thereto under stirring. After stirring for a while, the liquid
became emulsified due to the formation of fine crystals. This
solution wherein said crystals were dispersed, was coated onto a
base paper of 50 g/m2 with coating rod so that the solid
ingredient was coated at the thickness of 4 g/m2.
Comparative test 4
Microcapsule sheet containing crystal violet lactone was
superposed on the color developer sheet prepared by Examples 3
and 4 and pressurized under the load pressure of 600 I~g/cm2.
Af-cer leaving the sheet for a day in dark, the absorption
spectrum of the color images in the visible region was measured,
- 18 -
~Q g~ g
t and the absorbance (hereinafter referred to as "density") at the
maximum absorption was defined as "fresh density".
In addition, after the irradiation with sunlight for 1
hour, the absorption spectrum of the color images surface in the
visible region was measured to determine its density. From the
above result, the light resistance value was determined. The
results thereof are shown in Table 4. The light resistance value
is defined by the following formula;
The density of colored images
Light resistance after the irradiation with sunlight x 100
value (%) Fresh density of colored images
TABLE 4
No. Exam- Aromatic Metal Solvent Binder Fresh Light resis-
ple carboxy- Salt density tance value
lic acid after the
irradlation
with sun-
light for
1 hour
.
1 3 Salicylic Zinc SulEthanol Ethyl 1 07 91.5
2 " Ethanol lose
:water
.20 (3:1) " 0.95 85.5
3 4 nesge sul- arabic 0.56 75.9
fate Water
" " Cobalt Water " 0.68 67.5
sulfate
" Tin sul~ Water 0.86 79-3
fate
6 " Nickel Water 0.82 84.8
sulfate
7 ll - ChrmiUm Water " 0.64 97.8
8 " Lead Water " 0.39 51.0
sulfate
" cOPPer Water 0.70 66.7
sulfate
_3G 10 " Benzoic Zinc Water " 0.61 63.0
acid sulfate
-- 19 --
11 4 o-Chloro Zinc Water Gum 0.64 56.0
benzoic sulfate arabic
acid
12 " 2-Hydroxy-
l-naphth- Zlnc Water " 0.89 73.5
oic acid chlorlde
13 " ' Tin Water 1.10 80.0
chlorlde
14 " ' Nickel Water " 0.83 95,0
15 " 2-HydrXY~ Aluminum
3-naphth- sulfate " 0.81 67.9
16 " Salicylic
.10 acid " Water " 0-77 72.0
17 " 2-Hydroxy- Manga-
3-naphthoic nese Water " 0.63 94.5
acid sulfate
18 " 5-tert-butyl z nc polyvinyl 1 12 90 3
salicylic chloride alcohol
acid
19 " 3,5-di- I~ Water " 0.95 85.2
tert-
butyl
salicylic
acid
" 3-phenyl " Water " 0.90 69.5
salicylic
acid
21 " 3-methyl-5- " WaterStyrene- 0.94 76.8
tert-butyl butadiene
salicylic latex
acid
22 " 5-cyclo- " Water " 0.97 74.9
hexyl sali-
cylic- acid
23 " 3,5-di- " Water " 0.89 71.4
tert-amyl
salicylic
acid
24 3 3-methyl- " Ethanol Ethyl 0.93 72.3
5-isoamyl cellu-
salicylic lose
acid
" 5-isoamyl " Methyl " 0.92 71.1
salicylic isobutyl
acid ketone
_30
_ 20 -
~o~
26 3 S-tert- Tin ~5ethanol Ethyl 0.91 67.7
butyl sulfate cellu-
salicylic lose
acid
27 " 5-tert- Nickel Methanol Ethyl 0.91 71.7
butyl sulfate cellu-
salicylic lose
acid
28 " 3,5-di- Zinc Acetone " 0.92 70.5
tert-butyl sulfate
salicylic
acid
29 " 3-cyclohexyl
salicylic Copper n-butyl- " 0.71 69.2
acid sulfate acetate
30 " 3-phenyl Mangane- benzene 0.60 61.2
saliCYlic se sul-
acid fate
31 " 3,5-di Zinc toluene " 0.91 59.6
sec-butyl sulfate
salicylic
acid
32 " 5-nonyl- Zinc benzene " 0.90 71.3
salicylic: chlOride
acid
Comparative test 5
The test described in the above color-developing test 3 was
carried out using microcapsule-coated sheet containing 3-dibenzyl-
amino-7-dimethylaminofluoran. The results are shown in Table 5.
_30
-- 21 ~
1 TAsLE 5
No. IExam~ Aroma- IMetal saltl Solventl Binder¦ Fresh Light re-
ple I tic I I I I densi- sistance
carbo- I I i ty value after
xylic ~ i l the irra-
I acid I l diation
with sun-
i light for
, 1 hour
. . j
1 3 Salicylic Zinc Ethanol Ethyl ¦0.75 86.8
acid sulfate cellu- !
lose
2 ., ., " ¦Ethanol ll 0.60 82.5
~10 I:water
(3:1)
3 4 ll Manganese Water Gum 0.45 80.0
sulfate arabic
4 " .. Cobalt .. .- 0.48 92.5
sulfate
~- .. Tin .- .. 0.80 70.5
. sulfate
6 ~. .- Nickel .- .. 0.79 90.5
sulfate
7 ., .- Chromium .. .. 0.72 98.0
sulfate
.20 . .
8 .. .. Lead .. .- 0.44 51.3
sulfate
_ . .
9 ., .- Copper .. .. 0.61 71.5
sulfate
. . ,
¦10 ., Benzoic Zinc - .. 0.56 50.2
i acid sulfate
. .
~11 .- o-Chloro- .. .- .. 0.59 j 54.5
benzoic
acid
- ! ~
12 I" 2-llydroxy- Zinc ,- - 0.73 ~i 79.4
i l-naphth- chloride
' oic acid
_30 , . i
- 22 -
~L~g9~9
1 13 , 4 1 2-llydroxy-l Tin ~ jO-81 79.0
i ! l-naphth- Ichloride , i
I I oic acid ¦
! ~ . ¦
14 ! ~ I Nickel ~ " ¦ " 0.70 94.5
, ¦ sulfate `
; l i
15 ,l 2-Hydroxy- Aluminum I
3-naphth- sulfate j " ll0.67 66.2
oic acid
_ .
16 ll Salicylic ll ll ll 0.73 67.5
_ ~
17 ll 2-Hydroxy- Manganese ll ll 0.57 92.3
3-naphth- sulfate
.10 oie aeid
_ I
18 4 5-tert- Zine Water polyVinYlo 7672.4
butyl sali- ehloride aleohol .
eylie aeid
_ I
19 ll 3,5-di-tert- ,l ll ll 0.7568.3
butyl sall,
eylie aeid
. _
ll 3-phenyl ll ll .l 0.6567.2
salieylie
aeid
21 ll 3-methyl- ll ll Styrene- 0.78 70.2
5-tert- butadi-
salieylie ene late~
.20 aeid
. _
22 'l hexyellO- ,l ., 'l 0.7g68.8
aeid
_ _ .
23 ll 3,5-di- ll ,. . 0.7366.3
tert-amyl
salieylie
acid
24 3 3-methyl- " Ethanol Ethyl 0.76~ 70.0
5-isoamyl eellu-
salieylie lose
_ ~l I
1 25 .l 5-isoamyl 1 Methyl .l 0.75¦ 68.1
_30 ~ salieylie iso-
aeid butyl
ketone
- 23 -
1~99~9
1 26, 3 i 5-tert~ ; Tin MethanoII Ethyl 0.73 65.6
. butyl sulfate ¦ cellu-
salicylic ¦ lose
,1 .
27l ll Nickel
~ sulfate ll ll 0.62 66.9
I
28 'l butyl Zsulnfcate Acetone 'l 0.70 67.1
salicylic
_
29 ll 3-cyclo- Copper n-butyl- ll 0.61 6S.5
salicylic sulfate acetate
. .
3 3-phenyl Manganes~ Benzene Ethyl 0.51 58.0
salicylic sulfate cellu-
31 .. 3,5-di-'. 7.inc
sec-butyl.- sulfate Toluene ll 0.71 56.3
sa~cylic
aclu
32 ll 5-nonyl- Zinc Benzene ll 0.61 62.0
L ~ ~licy:ic cblcr ~
.
.20 It can be understood from Tables 4 and 5 that, when
contacted with a color-former-containing capsule sheet under
pressure, the color developer sheet of this invention shows
sufficient color density and the light resistance of the color
image formed.
In addition, the color image formed on the color developer
sheet has resistance to the "wetting with water". Especially,
when 2-hydroxy-1-naphthoic acid, 2-hydroxy-3-naphthoic acid, etc.
are used, the color image formed did not disappear at all when
wetted with water.
~30 Similar results were obtained about the other color formers.
- 24 -
~9~9
1 Example S
100 parts by weight (hereinafter, "part" means l'part by
weight") of potassium salicylate prepared in the above-described
manner was dissolved in 150 parts of hot water, and into the
solution was added with stirring 60 parts of stannous chloride
dissolved in 150 parts of hot water, whereby stannous salicylate
was immediately precipitated as white crystals. The crystals
were filtered out, washed several times with water, and then
dried to obtain 100 parts of stannous salicylate as solids.
40 parts of nitrocellulose was dissolved in a mixture of lS parts
of butyl acetate, 80 parts of isopropanol and 60 parts of butanol
to give a homogeneous solution, into which 120 parts of above-
described solid stannous salicylate was mixed and totally
dissolved or dispersed by a ball mill to obtain a developer ink
as a white suspension. The ink was diluted with a 1: 1 mixture
of ethyl acetate and ethanol to give a viscosity of about 0.7
poises and printed by a flexographic printing process to give
3 g/m2 of dried coating film.
Example 6
.20 100 parts of sodium 2-hydroxy-3-naphthoic acid was
dissolved into lS0 parts of hot water and into the solution was
added with stirring 40 parts of zinc chloride dissolved in 150
parts of water, whereby zinc 2-hydroxy-3-naphthoate was immediately
precipitated as crystals. The resulting mixture was concentrated
to a total weight of 200 parts. Into a mixture of 15 parts of
dioctyl phthalate, 120 parts of ethyl acetate, 100 parts of
isopropanol and 80 parts of methanol was dissolved 50 parts of
et'nyl cellulose to give a homogeneous solution to which were
added 200 parts of the above-described concentrate and 50 parts
-30 of kaolin and completely dissolved or dispersed in a ball mill to
- 25 -
lQ99~99
1 obtain a developing ink in the form of a suspension. The ink
was diluted with a 1 : 1 mixture of ethyl acetate and ethanol
to give a viscosity of about 0.7 poise and printed by a flexo-
graphic printing process to give 3 g/m2 of dried coating film.
Exam le 7
p
100 parts of sodium o-chlorobenzoic acid obtained by the
aforementioned method was dissolved in 150 parts of hot water
and into the solution was added with stirring a solution of
100 parts of nickel sulfate in 150 parts of hot water, whereby
crystals of nickel o-chlorobenzoic acid were immediately preci-
pitated, the precipitate filtered out, washed several times with
water and dried to obtain 80 parts of solid nickel o-chlorobenzoic
acid~ Into a mixture of butyl adipate, ethyl acetate, 20 parts
of methyl ethyl ketone and toluol was dissolved 8 parts of vinyl
chloride-vinyl acetate copolymer to obtain a homogeneous solution
into which 20 parts of the above-described nickel o-chlorobenzoic
acid and 10 parts of aluminum silicate hydrate (Trade Mark, "Osmos
N", manufactured by Shiraishi Kogyo) were mixed followed by
homogeneous dissolution or dispersion in a ball mill to obtain
.20 a developer ink. The ink was diluted with toluene to give a
viscosity of about 1 poise and subjected to a gravure printing
process to give 3 g/m2 of dried coating film.
Example 8
100 parts of sodium 2-hydroxy-1-naphthoate prepared by
the above method was dissolved in 150 parts of warm water ar.d
into the solution was added with stirring a solution of 60 parts
of aluminum sulfate in 150 parts of warm water whereby crystals of
aluminum 2-hydroxy-1-naphthoate were immediately precipitated.
The precipitate was filtered out, washed several times with
water and dried to obtain 70 parts of solid aluminum 2-hydroxy-1-
- 26 -
~9~
1 naphthoate.
Into a mixture of 2 parts of castor oil 20 parts of
toluene 20 parts of ethyl acetate and 20 parts of n-hexane was
dissolved 8 parts of nitro cellulose to obtain a homogeneous
solution. Into the solution was mixed 20 parts of the above-
described aluminum 2-hydroxy-1-naphthoate and 7 parts of silicon
oxide (Trade Mark "Siloide") followed by homogeneously dissolving
or dispersing by a ball mill to obtain a developer ink. The
resulting ink was diluted with xylol to give a viscosity of
about 1 poise and subjected to a gravure printing process to
give about 2 g/m2 of dried coating film.
Example 9
80 parts of sodium anacardate prepared according to the
aforementioned method was dissolved in 150 parts of hot water
and into the solution was added with stirring a solution of 20
parts of zinc sulfate in 150 parts of hot water to obtain zinc
anacardate. The mixture was concentrated to a total weight of 200
parts and then mixed with a mixture of 40 parts of ethyl
cellulose, 70 parts of ethyl cellulose, 150 parts of ethanol and
.20 40 parts of titanium oxide followed by completely dissolving or
dispersing by a ball mill to afford a developer ink in the form
of an emulsion. The ink was diluted with ethanol to give a
viscosity of about 1 poise and subjected to a flexographic printing
process to give about 3 g/m2 of dried coating film.
Comparative test 6
The above-described paper coated with microcapsules
containing crystal violet lactone was piled on each of the
surfaces printed with each color developer ink in the Examples and
pressurized under pressure load of 600 kg/m2 to form color
~30 images. After allowed to stand in the dark for an hour, the
- 27 -
~LQ~
1 spectral absorption curve was measured within the wave length
ranging from 400 to 700 m~, the density at the absorption maximum
was defined as fresh density.
After further irradiating sunlight for 1 hour and for 3
hours, the spectral absorption curve of the color images was
measured and its light resistance was calculated according to
the following equation.
Density at the absorption maximum
. . after irradiation of sunliqht
Llght reslstance (%) = - x 100
Fresh density at the absorption
.10 maximum
The results are summarized in the following T.able 6.
TABLE 6
Fresh density Light resistance Light resistance (%)
(%) after 1 hour after 3 hours
irradiation of irradiation of
sunlight sunlight
..
Example 5 0.75 82 70
6 0.91 . 87 79
7 0.86 89 85
8 0.89 84 78
~20 9 0.73 80 71
From the Table 6, it is evident that the developer inks
of the present invention are superior in their developing ability
and light resistance even in the case of thin printed layer of
3 g/m
Comparative test 7
A paper coated with microcapsules containing 3-methyl-2,2'-
spirobi (benzo[f~chromene) was placed on each of the surfaces
printed with the color developer ink in the above-described
~30 Examples, and its fresh density and light resistance were measured
- 28 -
c~
1 in the same manner as described above in Comparative test 6.
TABLE 7
,
Fresh density Light resistance Light resistance (%)
(%) after 1 hour after 3 hours
irradiation of irradiation of
sunlight sunlight
.
Example 5 0.70 70 62
6 0.85 73 65
7 0.73 91 87
8 0.82 79 66
.10 9 0.69 68 58
As apparent from the numerical values in the above-
described Table 7, the paper surfaces printed with the developer
inks of the present invention show an excellent developing ability
also for the color former sheet containing 3-methyl-2,2'-
spirobi(benzo[f]chromene). Furthermore, the paper surface printed
with the ink containing aluminum silicate hydrate (Osmos N) was
remarkably improved in the light resistance of the color developed
image o~ 3-methyl-2,2'-spirobi(benzo[f]chromene).
; .20
_30 `
- 29 -
