Note: Descriptions are shown in the official language in which they were submitted.
1 336477
ALKYL SALICYLATE RESIN FOR CARBONLESS
COPY PAPER AND IMAGING USE
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to phenol/
aldehyde condensation products useful in the develop-
rnent of colored images from colorless dyes. The
condensation products are especially useful in the
imaging process described in United States Patent
4,440,846 in which images are produced by a light
imaging process, and in carbonless copy paper
systems.
2. Description of the Prior Art
United States Patent 4,440,846 discloses
an imaging system in which images are formed by
image-wise exposure of a photosensitive encapsul-
ate containing a chromogenic material to actinic
radiation and rupture of the capsules in the presence
of a developer whereby a patterned reaction of the
chromogenic material and developer is obtained
which produces a contrasting image.
More specifically United States Patent
4,440,846 discloses an imaging system basically
having:
a substrate,
a chromogenic material,
a photosensitive composition,
a coating containing said chromogenic material
and said photosensitive composition on one surface0 of the substrate, and
a developer material which is capable of
reacting with the chromogenic material to form a
visible image,
2 t 336477
wherein said photosensitive composition is
encapsulated in a pressure rupturable capsule as an
internal phase.
In U.S. Patent 4,440,846, the term
"encapsulated" refers to both so-called resin
dispersion or open phase systems in which the
internal phase containing the photosensitive
composition and optionally the chromogenic material
is dispersed as droplets throughout a dispersing
medium and systems in which the capsule is formed
with a discrete capsular wall, the latter
- encapsulation typically being in the form of
microcapsules. "Pressure rupturable capsules" are,
accordingly, considered by U.S. Patent 4,440,846 to
exist in either of these "encapsulated" systems.
Furthermore, while the capsules are described as
being "pressure rupturable" other means than
pressure may be used to ruptu-e them.
In accordance with U.S. Patent 4,440,846,
images are formed by exposing the coated composition
containing the chromogenic material and the
encapsulated photosensitive composition to actinic
radiation and rupturing the capsules in the presence
of a developer. The invention system is designed
such that when these steps are carried out, the
image-~orming reaction between the chromogenic
material and the developer discriminately occurs in
the exposed or unexposed areas and produces a
detectable or latent image. This is accomplished
image-wise by photochemically controlling the access
between the chromogenic material and the developer
such that a patterned reaction occurs. By "image-
wise" it is meant that the reaction between the
chrornogenic material and the developer occur
according to the exposure such that a positive or
3 1 336$77
negative image is obtained. The image may be formed
by a change in color or a difference in contrast.
In accordance with the principal embodiment of
U.S. Patent 4,440,846, chromogenic material is
encapsulated with the photosensitive composition.
In general, the photosensitive composition can be
described as having a viscosity which changes upon
exposure to actinic radiation such that upon
exposure there is a change in the viscosity of the
internal phase in the exposed areas which image-wise
determines whether the chromogenic material is
accessible to the developer. The photosensitive
composition may be a radiation curable composition
which, upon exposure to light, increases in
viscosity and immobilizes the chromogenic material,
thereby preventing it from reacting with the
developer material entirely or in proportion to the
tonal depth of the image in the exposed areas. (The
term "curable" as used in U.S. Patent 4,440,846 is
not limited to materials which are cross-linked, but
is open to materials which are simply
polymerized.) In another case, the chromogenic
material may be encapsulated with a substance which
is depolymerized or otherwise decreased in molecular
weight upon exposure, resulting in a decrease in
molecular weight upon exposure, resulting in a
decrease in viscosity which renders the chromogenic
material mobile and accessible to the developer in
the exposed areas upon capsule rupture.
The imaging system described in U.S. Patent
4,440,846 is potentially useful for producing high
quality images, competitive in some cases to those
produced with silver-based photographic materials.
Prior patents disclose a wide variety of
developer compositions for use in developing a
4 1 336477
visible image from colorless chromogenic materials, some
of which are the following:
U.S. Patent of Oda, 3,864,146 discloses a sheet of
record material which is sensitized with a coating to
produce color on contact with colorless chromogenic
compounds. Such coating comprises a binder in an amount
sufficient to adhere the coating to the base sheet and a
color reactant material. The color material essentially
comprises in combination:
a. At least one metal ion of a metal selected from
the group consisting of zinc, aluminum, calcium, mag-
nesium, titanium, nickel, cobalt, manganese, iron, tin,
chromium, copper and vanadium, or at least one water
insoluble inorganic compound of a metal selected from
said metal group, and
b. At least one aromatic carboxylic acid deriva-
tive including as its major functional arrangement the
molecular structure represented by any of the following
formulae:
Xm ~ COOH
and
Xn ~ COOH
..,
.
1 336477
In the above formulae, R is hydroxyl, amino,
amino substituted by at least one lower alkyl group
having 1 to 5 carbon atoms, nitro or chlorine, which
is substituted on one o~ the carbon atoms at the
site adjacent to that of the carboxylic group on the
aromatic ring, each X is substituted or
unsubstituted group containing a monocyclic or
bicyclic carbon ring formed with 6 or 10 carbon
atoms, m is an integer of 1 or 2 and n is an integer
of 1 to 3.
Among the aromatic carboxylic acid derivatives
represented in the above formulae the patent lists
the following specific compounds:
3-phenylsalicylic acid
2-chloro-5-phenylbenzoic acid
3-benzylsalicylic acid
5-(4'-hydroxyphenyl)salicylic acid
2-nitro-3(2'-nitro-3'-carboxyphenyl)benzoic
acid
5,5'-methylenedisalicylic acid
2-nitro-3(3'-carboxylbenzyl)benzoic acid
3-methyl-5-phenylsalicylic acid
3-(4'-aminophenyl)-2-aminosalicylic acid
5-benzyl-6-aminosalicylic acid
3-methyl-5-benzylsalicylic acid
2,6-dihydroxy-3-(s-phenethyl)benzoic acid
2-nitro-5-(4'-methoxystilben)benzoic acid
2-nitro-6-(4'-methylbenzoyl)benzoic acid
3-(4'-chlorobenzyl)5-(tert-butyl)salicylic acid
3-benzyl-5-(2,2'-dimethyl-iso-propyl)salicylic
acid
3-(tert-butyl)-5-[p-(tert-butyl)benzyl]salicylic
acid
3-cyclohexyl-5-t~,~-dimethylbenzyl)salicylic
acid
6 1 336li77
4-phenyl-5-benzoylsalicylic acid
3,5-di-(~,3-dimethylbenzyl)salicylic acid
3-~4'-( 3 ~ ~-dimethylbenzyl)-phenyl]-5-
(~,c-dimethylbenzyl)salicylic acid
2-nitro-3-14'-(~,~-dimethylbenzyl)-phenyl
benzoic acid
3-phenyl-5-~4'-(~,~-dimethylbenzyl)
-Q, 3-dimethylbenzyl]salicylic acid
5-(4'-ethoxycarbonylphenyl)salicylic acid
4-(3'-carboxy-4'-hydroxyphenyl)benzenesulfonic
acid
3-phenyl-5-(~,3-dimethylbenzyl)salicylic acid
3-phenyl-5-hydroxysalicylic acid
4-(5'-methylnaphthyl) salicylic acid
2-hydroxy-1-benzyl-3-naphthoic acid
3,3'-dicarboxy-2,2'-dihydroxy-1,
l'-dinaphthylmethane
l-benzoyl-2-hydroxy-3-naphthoic acid
l-chloro-4'-hydroxy-dinaphthylketone-
3'-carboxylic acid
1,4-di(dimethylamino)-3-phenyl-2-naphthoic acid
2-hydroxy-5-[4'-(tert-butyl)phenyl]-1-naphthoic
acid
3-hydroxy-5-cyclohexyl-2-naphthoic acid
3-hydroxy-4-(2'-hydroxy-3'-carboxyphenyl)
2-naphthoic acid.
Of the above compounds, 3,5-
di(~,~-dim'ethylbenzyl)salicylic acid, 3-[4'-(~
dimethylbenzyl)-phenyl-5-(~
dimethylbenzyl)salicylic acid, 3-cyclohexyl-5-(~
dimethylbenzyl)salicylic acid, 3-phenyl-5-~4'-(~
dimethylbenzyl)-~,~-dimethylbenzyl]salicylic acid,
and 3-phenyl-5-(~,3-dimethylbenzyl)salicylic acid
7 1 336477
are said to be most preferred.
According to U.S. Patent 3,864,146, it was
found that the aforementioned aromatic carboxylic
acid derivatives, per se, do not provide practical
color-forming reactant materials because of their
very slight activity to the colorless chromogenic
materials but they can be highly sensitive color-
forming reactant materials when they are combined
with certain metal ions or certain water-insoluble
inorganic metallic compounds. ln a preferred
embodiment of the invention, the color reactant
material essentially comprises a mixture of the
aromatic carboxylic acid derivatives described and
one or more of oxides, hydroxides and carbonates of
a metal selected from the group consisting of zinc,
aluminum, calcium, magnesium, titanium, nickel,
cobalt, manganese, iron, tin, chromium, copper and
vanadium. Among suitable inorganic metallic
compounds there may be included zinc oxide, aluminum
oxide, calcium oxide, magnesium oxide, titanium
oxide, zinc hydroxide, aluminum hydroxide, calcium
hydroxide, zinc carbonate, calcium carbonate and
magnesium hydroxide. These inorganic metallic
compounds are water insoluble, per se, and exhibit
no substantially color forming reaction even when
brought into contact with the chromagenic
materials. According to U.S. Pa~ent 3,864,146, the
mixing ratio by weight of the ar~i~atic carboxylic
acid derivative or derivatives t: the above
mentioned inorsanic metallic co~ound or compounds
is selected within the range of 95:5 to 5:95. More
preferably, in order to obtain the sensitized record
sheet having a high color forming ability, high
printability and a low production cost, 15 to 25
parts by weight of the aromatic carboxylic acid
8 1 336477
derivative may be mixed with 85 to 75 parts by
weight of the inorganic compound described. A part
of the inorganic metallic compound may be replaced
by other inorganic pigments such as kaolin, clay and
talc.
U.S. Patent 3,723,156 relates to record
material sheets bearing a coating of an oil-soluble
metal salt and an oil-soluble phenol-formaldehyde
novolak resin as a combination co-reactant for
colorless, chromogenic dye-precursor materials to
develop a useful color therein. Prior to this
patent, oil-soluble phenol-formaldehyde novolak
resins, preferably those derived from the
condensation of a para-substituted phenol with
formaldehyde, had long been used, with great
commercial success, in making acid-reactant record
material sheets capable of developing color in oil
solutions of base-reactant colorless, chromosenic
dye-precursor materials. Such resins and the use of
them had been disclosed in U.S. patent application
Serial No. 44,805, filed June 9, 1970 by Robert E.
Miller and Paul S. Phillips, Jr. (now United States
Patent 3,612,935 and U.S. patent application Serial
No. 830,921, filed May 26, 1969 by Robert E. Miller
and Bruce W. Brockett (now United States Patent
3,663,~56).
According to U.S. Patent 3,723,156, it had been
found useful to add metal salts to oil-soluble
phenol-formaldehyde resin for the purposes just
mentioned. The metal salts found useful for use
with oil-soluble phenol-formaldehyde resins in
pressure-sensitive copy-papers of the "NCR Paper"
type according to that patent, include the oil-
soluble salts of aluminum (III), barium (II),
cadmium (II), calcium (II), cerium (III), cesium
9 1 336477
- (I), cobalt (II), copper (III), indium (III), iron
(II), and lead (II), magnesium (II), manganese (II),
molybdenum (V), nickel (II)~ sodium (I), strontium
(II), tin (II), titanium (IV), vanadium (IV), zinc
(II), and zirconium (IV). The great diversity of
the oil-soluble metal resinates tested and found
useful therein was noted inasmuch as they include
metals from Periodic Groups I-A and B, II-A and 8,
III-A and B, IV-A and B, V-B, VI-B, VII-B, and VIII.
Eligible ions of the useful metal salts
according to U.S. Patent 3,723,156 include
acetylacetonate, hexafluoroacetylacetonate,
benzoate, naphthenate, salicylate, 2-ethylhexanoate,
abietate, oleate, and palmitate. In order to be
eligible, it was said that the candidate anion
should confer on the metal salt ready solubility in
the oily solvents used as the core-material
encapsulated chromogenic inks in carbonless copy-
papers. Exemplary of the oils in use are
hydrocarbons such as paraffin oils, aromatic oils
such as xylene and alkylated biphenyls, high
molecular weight esters such as dioctyl adipate and
dioctyl phthalate, halocarbons such as
trichlorobiphenyl, and aromatic ethers such as
diphenyl oxide. The metal modified resins of U.S.
Patent 3,723,156 were said to have been designed to
operate and to have operated well in developing oily
dye-precursor inks of the type described. The oily
vehicle preferred therein was one of low volatility,
such as chlorinated or alkylated biphenyl, which
leaves an essentially wet print on the paper surface
rather than a more volatile one such as xylene that
readily evaporates to leave a dry print. The
enhancement of print intensity by the metal modified
resins of this invention was said to be considerably
lo 1 336477
greater in wet prints than in dry prints. Rapid and
substantial solubility was required to give
satisfactory print speed in use. To fulfill this
requirement, accordin~ to the patent, the metal salt
S anion should have a carbon content of at least four
carbon atoms and preferably six or more carbon
atoms. Metal salts of anions of less than four
carbon atoms will operate to enhance color intensity
and/or fade resistance provided they are still oil-
soluble. However, as the anionic carbon contentgoes below about four carbon atoms, the metal salts
tend toward water solubility, and the imaged prints
developed thereon become spotty and uneven due to
the effect of atmospheric moisture on stored
s~eets. Therefore it was said that metal salts of
carbon content below about four carbon atoms, which
are both oil-soluble and water soluble, were to be
avoided in the record material sheets.
Of the metal ions set out above as having been
found useful in the materials of U.S. Patent
3,723,156, zinc (II) was preferred. All of the
cited metal ions were said to improve the fade
resistance of the developed prints. In addition to
improved fade resistance, print intensity was
markedly improved over known-art sheets by the
preferred zinc (II) and furthermore, print intensity
was improved or at least comparable to good
commercial quality known-art sheets in sheets
containing aluminum (III), cerium (III), cobalt
(II), iron (II), iron (III), indium (III), manganese
(II), and tin (II).
The patent also mentioned that zinc salicylate,
which has a phenolic group in addition to the
metallated carboxy group, gives a blue color with
CVL in oil solution. Oil solutions of some of the
11 1 336477
other eligible metal salts occasionally give a light
blue color when CV~ is added to the solution, but
this was thought to be due to excess acid present as
a contaminant in the metal salt.
U.S. Patent 4,372,583 discloses a pressure-
sensitive chromogenic copy system comprising a
transfer sheet having on at least or.e surface
thereof a color developer capable of reacting with a
chromogen to form a color image, said color
developer comprising an oligomeric aromatic
carboxylic acid. The patent also relates to
transfer sheets utilizing said oligomeric compounds
and to the compounds and method of making them as
more fully described below.
The critical feature described in U.S. Patent
4,372,583 is the controlled reaction of aromatic
carboxylic acids with aldehydes under alkaline
conditions to form "oligomers". While not entirely
understood, the reaction products are similar to
resoles; A-stage resoles or salicylate alcohols,
formed by reacting a phenol with an aldehyde under
alkaline conditions. As used in that patent, the
term "oligomer" is meant to denote such reaction
products as distinguished from dimers and polymers
which result when aromatic carboxylic acids are
polymerized under acidic conditions.
According to U.S. Patent 4,372,583, higher
molecular weight polymers can result in low oil
affinity and hence undesirable slower image
formation when the chromogen-containing oil from the
ruptured microcapsules is transferred to the
transfer sheet containing the acidic polymer.
The aromatic carboxylic acid used by that
patent can be any polymerizable substituted or
unsubstituted salicylic, benzoic, or naphthoic
12 1 336$77
acid. It was preferred to use compounds which do
not contain substituents of a size or location on
the compound so as to create steric hindrances and
thereby retard or even prevent polymerization.
Examples of suitable acids are salicylic acid;
acetyl salicylic acid; disalicylic acid; mono-and
di-Cl-C8 alkyl substituted salicylic acids (such as
methyl salicylic acid and 3,5-di-tertiary butyl
salicylic acid); the corresponding benzoic and
naphthoic acids; 2-nitro benzoic acid; 2-amino
naphthoic acid; and the thio compounds disclosed in
co-pending U.S. patent application Serial No.
173,254, entitled "Chromogenic Copy System", filed
on August 17, 1981, now United States Patent
4,303,719. Of these, the patent preferred the
salicylic acid compounds; particularly salicylic
acid, 3,5-di-tertiary butyl salicylic acid, 3-octyl
salicylic acid, S-octyl salicylic acid, 3-tertiary
butyl salicylic acid, and S-tertiary butyl salicylic
acid and the invention will be particularly
described in connection therewith.
According to U.S. Patent 4,372,583, the
resultant oligomer can be used as such or as the
corresponding metal salts. These are formed by
reacting the acidic oligomer with zinc, aluminum,
monovalent alkali metal compounds, or other known
metallic compounds conventionally used to form salts
of acids used as color developers in carbonless copy
systems.
U.S. Patent 3,772,052 discloses a color
developer that is the metal compound of a polymer of
an aldehyde or ace~ylene and an aromatic carboxylic
acid having at least one hydroxyl group which is a
product produced by the reaction of an alkali metal
salt of the polymer of an aldehyde or acetylene and
13 1 336477
an aromatic carboxylic acid having at least one
hydroxyl group with a water-soluble metal salt in a
solvent in which both reagents are soluble. In this
case, the ratio of the alkali metal salt and water-
soluble metal salt is not limited-particularly, but
a molar ratio of 1 to 1 is preferred. Preparation
of the alkali metal salt of the polymer used in the
above-mentioned reaction can be carried out in a
known manner, for example, by reacting the above-
mentioned polymer with an alkali metal hydroxide orcarbonate.
Illustrative o~ the polymer of an aldehyde and
an aromatic carboxylic acid having at least one
hydroxyl group used in U.S. Patent 3,772,052 are a
salicylic acid-aldehyde polymer, a p-hydroxybenzoic
acid-aldehyde polymer, a 2,6-dihydroxybenzoic acid-
aldehyde polymer and a salicylic acid-acetylene
polymer.
The polymer applicable to U.S. Patent 3,772,052
is a polymer of an aldehyde and an aromatic
carboxylic acid having at least one hydroxyl group,
while metal compounds of phenol-aldehyde polymers
mentioned in Japanese Patent No. 511,757, phenol-
acetylene polymers, maleic acid-rosin resins and
partly or extensively hydrolyzed styrene-maleic
anhydride polymers were said to have no developing
capacity.
The aromatic carboxylic acid used in U.S.
Patent 3,772,052 is a compound having at least one
carboxyl group per aromatic nucleus and includes,
for example, benzoic acid, o-nitrobenzoic acid,
m-nitrobenzoic acid, p-nitrobenzoic acid,
o-chlorobenzoic acid, m-chlorobenzoic acid,
p-chlorobenzoic acid, o-toluic acid, m-toluic acid,
p-toluic acid, o-bromobenzoic acid, m-bromobenzoic
14 1 336477
acid, p-bromobenzoic acid, o-indobenzoic acid,
m-iodobenzoic acid, p-iodobenzoic acid, 4-methyl-
3-nitrobenzoic acid, 2-chloro-4-nitrobenzoic acid,
2,3-dichlorobenzoic acid, 2,4-dichlorobenzoic acid,
p-isopropyl-benzoic acid, 2,5-dinitrobenzoic acid,
3,4-dinitrobenzoic acid, 3,5-dinitrobenzoic acid,
p-tert-butylbenzoic acid, N-phenyl-anthranilic acid,
4-methyl-3-nitrobenzoic acid, 4-acetyl-benzoic acid,
salicylic acid, S-tert-butyl-salicylic acid,
3-phenyl-salicylic acid, 3-methyl-S-tert-butyl-
salicylic acid, 3,5-di-tert-butyl-salicylic acid,
3,5-di-tert-amyl-salicylic acid, 3-cyclohexyl-
salicylic acid, 3-methyl-5-isoamyl-salicylic acid,
S-isoamyl-salicylic acid, 3,5-di-sec-butyl-salicylic
acid, m-hydroxyl-benzoic acid, p-hydroxybenzoic
acid, 3,5-dinitrosalicylic acid, p-hydroxybenzoic
acid, 3,5-dinitrosalicylic acid, 2-hydroxy-3-methyl-
benzoic acid, 2,4-cresotinic acid, 2,5-cresotinic
acid, 2,3-cresotinic acid, 2,4-dihydroxy-benzoic
acid, 2,5-dihydroxybenzoic acid, 2,6-dihydroxy-
benzoic acid, l-naphthoic acid, 2-naphthoic acid,
l-hydroxy-2-naphthoic acid, 2-hydroxy-3-naphthoic
acid, 2-hydroxyl-1-naphthoic acid, 5,5'-methylene-
salicyclic acid, thiosalicylic ac1d, trimellitic
anhydride, anacardic acid, benzoic anhydride,
2-carboxybenzaldehyde, diphenic acid, etc. Above
all, aromatic carboxylic acids having at least one
hydroxyl group in the structure are effective.
Illustrative of the metal salts used in U.S.
Patent 3,772,052 are metals of Group Ib of the
Periodic Table such as copper and silver, Group IIa
such as magnesium and calcium, Group IIb such as
zinc, cadmium and mercury, Group IIb such as
aluminum and gallium, Group IVa such as tin and
lead, Group IVb such as chromium and molybdenum,
1 336477
Group VIIb such as manganese and Group VII such as
cobalt and nickel. In particular, salts of zinc,
tin, aluminum and nickel are preferably used.
U.S. Patent 3,874,895 discloses using a color
developer containing, as necessary constituents, an
acidic polymer and an organic carboxylic acid or a
metal salt thereof.
The organic carboxylic acids used in that
patent include organic compounds having at least one
carboxyl group, and include aliphatic carboxylic
acids and aromatic carboxylic acids. Most preferred
of such acids were those having a maximum of three
carboxyl groups and from about 5 to about 20 carbon
atoms.
~owever, aromatic carboxylic acids were
especially preferred as thev were said to provide
excellent effects and, in particular, aromatic
carboxylic acids havinq at least one hydroxy group
were preferred with those having from one to three
hydroxyl groups being most preferred. Of course,
any organic carboxylic acid exhibits an improved
effect as compared to the use of acidic polymer
alone, and aliphatic carboxylic acids or metal salts
thereof, in particular, the monobasic acids and
dibasic acids thereof were said to be excellent from
the viewpoint of film quality. Monobasic acids were
most preferred, however. The aromatic carboxylic
acid was preferably from the benzene series,
especially salicylic acid derivatives which
preferably have at least one alkyl group having more
than 3 carbon atoms, or at least one aryl group or a
cyclohexyl group, or is substituted with a
combination of such groups.
As the specific examples of organic carboxylic
acids used in U.S. Patent 3,874,895, there were
16 1 336477
mentioned formic acid, acetic acid, caproic acid,
heptanoic acid, caprylic acid, pelargonic acid,
capric acid, n-undecylenic acid, lauric acid,
n-dodecylenic acid, myristylenic acid, n-penta-
decylenic acid, margaric acid, stearic acid, n-non-
adecylenic acid, arachidic acid, heneicosanoic acid,
behenic acid, n-tricosanoic acid, lignoceric acid,
n-pentacosanoic acid, cerotic acid, n-heptacosanoic
acid, montanic acid, n-nonacousanoic acid, melissic
lo acid, n-hentriacontanoic acid, n-dotriacontaonic
acid, n-tetratriacontanoic acid, ceroplastic acid,
n-hexatoriacontanoic acid, n-octatriacontanoic acid,
n-hexatetracontanoic acid, oleic acid, linolenic
acid, linoleic acid, stearolic acid, ~-chlorolauric
acid, ~-chlorostearic acid, ~-bromomyristic acid,
1,8-octanedicarboxylic acid, 1,12-dodecanedicar-
boxylic acid, 2,4-decanedienoic acid, 2-hydroxy-2,4-
dimethylpentanoic acid, o-toluic acid, m-toluic
acid, p-toluic acid, benzoic acid, o-chlorobenzoic
acid, m-chlorobenzoic acid, p-chlorobenzoic acid,
o-~romobenzoic acid, p-nitrobenzoic acid, salicylic
acid, o-chlorosalicylic acid, m-hydroxysalicylic
acid, p-hydroxysalicylic acid, anisic acid, gallic
acid, phthalic acid, trimellitic acid, diphenic
acid, phenylacetic acid, ~-phenyl-n-valerianic acid,
p-isopropylbenzoic acid, 2,4-cresotinic acid,
5-me~hylsalicylic acid, 5-tert-butylsalicylic acid,
3,5-di-sec-butylsalicylic acid, 3,5-di-sec-butyl-
salicylic acid, 3,-methyl-5-tert-butylsalicylic
acid, 3,5-di-tert-butylsalicylic acid, 5-isoamyl-
salicylic acid, 3-phenylsalicylic acid, S-cyclo-
hexylsalicylic acid, and the like.
According to U.S. Patent 3,874,895, metals
forming a metal salt with the organic carboxylic
acids included sodium, lithium, potassium,
17 1 336477
magnesium, calcium, zinc, cadmium, aluminum, tin,
lead, chromium, manganese, cobalt, nickel, and the
like. The patent stated that there is no overly
critical aspect to the selection of the exact metal
used, i.e., substantially all metal salts are
useful.
U.S. Patent 3,896,255 disclosed that when a
coating solution containing a metal compound of
aromatic carboxylic acid was prepared, not only was
the viscosity of the coating solution increased but
metal compound was formed in the orm of particles,
so that the color development power and the film
surface strength of the final color developer layer
were often insufficient, and that improvements can
be attained by incorporating a surface active agent
in a color developer coating solution ccntaining a
metal component of an aromatic c~rboxylic acid.
U.S. Patent 3,896,255 further disclosed that,
while the metal compound of an aromatic carboxylic
acid can be used as a color developing component
alone because it has a color development power
itself, it can also be used together with other
color developers.
The aromatic carboxylic acid of U.S. Patent5 3,896,255 was preferably represented by the formula:
C40~l COOH
~_ or ~
wherein R may be the same or different and
represents a hydrogen atom, a hydroxy group, a
halogen atom such as chlorine, a nitro group, an
alkyl group having 1 to 10 carbon atoms ~preferably
3 to 6 carbon atoms) of which total carbon atoms are
less than 13, an aryl group such as phenyl group, an
arylamino group such as anilino group, and an
18
1 336477
alicyclic group such as hexyl group, m is an integer
of 0 to 7 and n is an integer of 0 to 5, and the
aromatic carboxylic acid may be dimerized through
the substituent R as a methylene group.
More preferable compounds were those
represented by the formula:
COOH COOH
011 I ON
(~A~ ~ (R)~
wherein R, m and n are as defined above.
The most preferable compounds were those
represented by the formula:
co.~
OH
J'2~
wherein R is as defined above, n is l or 2, and R is
attached to the meta-position relative to the
hydroxy group.
Examples of the aromatic carboxylic acids in
U.S. Patent 3,896,255 were benzolc acid, o-, m- or
p-chlorobenzoic acid, o-, m- or p-nitrobenzoic acid,
2-chloro-4-nitrobenzoic acid, 2,3-dichlorobenzoic
acid, 2,4-dichlorobenzoic acid, p-t-butyl benzoic
acid, N-phenyl anthranilic acid, 4-methyl-3-nitro-
benzoic acid, salicylic acid, m-hydroxybenzoic acid,
p-hydro~ybenzoic acid, 3,5-dinitrosalicylic acid,
5-t-butyl salicylic acid, 3-phenylsalicylic acid,
3-methyl-5-butyl salicylic acid, 3,5-di-t-butyl
salicylic acid, 3,5-diamyl salicylic acid,
3-cyclohexyl salicylic acid, 5-cyc;ohexyl salicylic
acid, 3-methyl-5-isoamyl salicylic acid, 5-isoamyl
19 1 336477
salicylic acid, 3,5-di-sec-butyl salicylic acid,
5-nonyl salicylic acid, 2-hydroxy-3-methyl benzoic
acid, 2-hydroxy-5-t-butyl benzoic acid, 2,4-cresotic
acid, 5,5'-methylene disalicylic acid, o-, m- or
p-acetaminobenzoic acid, 2,4-dihydroxy benzoic acid,
2,5-dihydroxy benzoic acid, 2,6-dihydroxy benzoic
acid, anacardic acid, l-naphthoic acid, 2-naphthoic
acid, l-hydroxy-2-naphthoic acid, 2-hydroxy-
3-naphthoic acid, 2-hydroxy-1-naphthoic acid,
thiosalicylic acid, 2-carboxybenzaldehyde and the
~ike.
Above all, aromatic carboxylic acids having at
least one hydroxyl group were said to be especially
effective and those having a hydroxy group in the
o-position, i.e., the aromatic carboxylic acids
represented by the following formulae, were most
effective.
COOH COOH
011 ¦ OH
D g3~ 1~ P--
wherein R, m and n are as defined above.
As the metals which form the metal c~mpound of
the aromatic carboxylic acid used in U.S. Patent
3,896,255, there can be mentioned metals of Group IB
of the Periodic Table as, e.g., copper and silver;
me~als of Group II A as, e.g., magnesium and
calcium; metals of Group II B, e.g., zinc, cadmium
and mercury; metals of Group III B, e.g., aluminum
and gallium; metals of Group IV A, e.g., tin and
lead; metals of Group VI A, e.g., chromium and
molybdenum; metals of Group VII B, e.g., manganese;
1 336477
and metals of Group VIII such as cobalt and
nickel. Among these metals, zinc, tin, aluminum and
nickel were said to be especially effective.
U.S. Patent 3,924,027 discloses a sensitized
sheet for use in a pressure sensitive copy system,
having a coating comprising an acceptor, the
acceptor being a particulate mixture of (a) an
organic acid substance selected from the group con-
sisting o aromatic carboxylic acids and polyvalent
metal salts thereof, and (b) an organic high molecu-
lar weight compound.
An aromatic carboxylic acid to be used for this
purpose is represented by the formula I,
c~
~'
wherein Rl, R2, R3 and R4 each represents hydrogen,
halogen or a hydroxyl, amino, carboxyl, carbamoyl,
N-substituted carbamoyl, alkyl, cycloalkyl, alkoxyl,
aryloxy, aralkyl or alkylaryl group, and any adja-
cent pair or Rl to R6 can, together with the carbon
atoms to which they are attached, complete a ring.
Compounds of formula I wherein Rl o- R5 is a
hydroxyl group are especially important in embodi-
ments of the invention as mentioned in detail here-
inafter.
Examples of aromatic carboxylic acids of for-
mula I wherein Rl and R6 are not a hydroxyl group
include benzoic acid, o-toluic acid, m-toluic acid,
p-toluic acid, p-t-butylbenzoic acid, o-chloroben-
21 1 336477
zoic acid, m-chlorobenzoic acid, p-chlorobenzoic
acid, dichlorobenzoic acid, trichlorobenzoic acid,
te~rachlorobenzoic acid, phthalic acid, isophthalic
acid, terephthalic acid, 2-carboxybiphenol, p-oxy-
benzoic acid, paramethoxybenzoic acid, p-butoxy-
benzoic acid, p-octoxybenzoic acid, gallic acid,
anthranilic acid, phthalic acid monoamide, phthalic
acid monoanilide, 3-tert-butyl-4-hydroxybenzoic
acid, 3-cyclohexyl-4-hydroxybenzoic acid, 3-phenyl-
4-hydroxybenzoic acid, 3-(~-methyl-benzyl)-
4-hydroxybenzoic acid, 3,5-dimethyl-4-hydroxybenzoic
acid, trimellitic acid, pyromellitic acid, c-naph-
thoic acid, s-naphthoic acid, tetrachlorophthalic
acid and 2,2'-dicarboxydiphenyl.
Aromatic carboxylic acids of formula I wherein
Rl or R6 is a hydroxyl group are defined by formula
II,
coo~
wherein R4 to R6 are as defined in Rl to R4 of for-
mula I.
Examples of such carboxylic acids include sali-
cylic acid, o-cresotinic acid, p-cresotinic acid, 3-
ethylsalicylic acid, 4-ethylsalicylic acid, 3-iso-
propylsalicylic acid, 4-isopropylsalicylic acid, 5-
isopropylsalicylic acid, 3-tert-butylsalicylic acid,
5-tert-butylsalicylic acid, 3-cyclohexylsalicylic
22 1 336~77
acid, 5-cyclohexylsalicylic acid, 3-phenylsalicylic
acid, S-phenylsalicylic acid, 3-benzylsalicylic
acid, S-tert-octylsalicylic acid, 3-(~-methylbenzyl)
salicylic acid, S-(~-methylbenzyl) salicylic acid,
S-nonyl salicylic acid, S-( Q~-dimethylbenzyl) sali-
cylic acid, S-chlorosalicylic acid, 5-butoxysali-
cylic acid and S-octoxysalicylic acid.
Compounds of formula II wherein R4 and R6 are
halogen, alkyl, cycloalkyl, aryl, aralkyl or
alkylaryl can be easily derived in commercial scales
from phenols, alkylphenols, arylphenols or halo-
qenated phenols. Examples of such aromatic car-
boxylic acids include 3,5-dichlorosalicylic acid, 3-
chloro-S-tert-butylsalicylic acid, 3-chloro-5-tert-
amylsalicylic acid, 3-chloro-5-tert-octylsalicylic
acid, 3-chloro-5-(Q,~-dimethylbenzyl) salicylic
acid, 3,5-dimethylsalicylic acid, 3-methyl-5-tert-
butylsalicylic acid, 3-methyl-5-cyclohexylsalicylic
acid, 3-methyl-5-tert-octylsalicylic acid, 3-methyl-
5-(Q-methylbenzyl) salicylic acid, 3-methyl-5-nonyl-
salicylic acid, 3-methyl-5-(~,c-dimethylbenzyl sali-
cylic acid, 3,5-diisopropylsalicylic acid, 3,5-di-
sec-butylsalicylic acid, 3-tert-butyl-5-chlorosali-
cylic acid, 3-tert-butyl-5-methylsalicylic acid, 3-
tert-butyl-5-ethylsalicylic acid, 3,5-di-tert-butyl-
salicylic acid, 3-tert-butyl-5-phenylsalicylic acid,
3-tert-butyl-5-(4'-tert-buty~phenyl)salicylic acid
and others.
U.S. Patent 3,934,070 claims to 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.
The aromatic carboxylic acid used in that
patent includes, for example, benzoic acid, o-nitro-
benzoic acid, m-nitrobenzoic acid, p-nitrobenzoic
23 1 336477
acid, o-chlorobenzoic acid, m-chlorobenzoic acid,
p-chlorobenzoic acid, o-toluic acid, m-toluic acid,
p-toluic acid, o-bromobenzoic acid, m-bromobenzoic
acid, p-bromobenzoic acid, o-iodo-benzoic acid,
m-iodobenzoic acid, p-iodobenzoic acid, 4-methyl-
3-nitrobenzoic acid, 2-chloro-4-nitrobenzoic acid,
2,3-dichlorobenzoic acid, 2,4-dichlorobenzoic acid,
p-isopropyl-benzoic acid, 2,5-dinitrobenzoic acid,
3,4-dinitrobenzoic acid, 3,5-dinitrobenzoic acid,
p-tert-butylbenzoic acid, N-phenyl-anthranilic acid,
4-methyl-3-nitrobenzoic acid, 4-acetyl-benzoic acid,
salicylic acid, 5-tert-butylsalicylic acid,
3-phenyl-salicylic acid, 3-methyl-5-tert-butyl-sali-
cylic acid, 3-phenyl-salicyclic acid, 3-methyl-5-
1S tert-butyl-salicylic acid, 3,5-di-tert-butyl-sali-
cy}ic acid, 3,5-dihydroxybenzoic acid, l-naphthoic
acid, 2-naphthoic acid, 1-hydroxy-2-naphthoic acid,
2-hydroxy-3-naphthoic acid, 2-hydroxy-1-naphthoic
acid, 5,5'-methylene-salicyclic acid, thiosalicylic
acid, trimellitic anhydride, anacardic acid, benzoic
anhydride, 2-carboxybenzaldehyde, diphenic acid,
etc. Above all, aromatic carboxylic acids having at
least one hydroxyl group in the structure,
especially in the ortho positon, were said to be
effective.
~ he metals of the metal salts to be reacted
with the aikali metal salts of the carboxYlic acids
in U.S. Patent 3,934,070 included, for example,
Group Ib metals such as copper, silver, etc., Group
IIa metals such as magnesium, calcium, etc., Group
IIb metals such as zinc, cadmium, mercury, etc.,
Group IIIb metals such as aluminum, gallium, etc.,
Group IVb metals such as tin, lead, etc., Group VIa
metals such as chromium, molybdenum, etc., Group
VIIa metals such as manganese, etc., Group VIII
24 1 336477
metals such as cobalt, nickel, etc., and the like.
Among these, those salts wherein zinc, tin, aluminum
or nickel is used are especially effective. In
using them in the reaction, they are used in the
form of the inorganic salts thereof such as chlo-
ride, sulfate, nitrate, etc., or in the form of the
organic salts thereof such as oxalate, acetate,
etc. These metal salts or alkali metal salts of the
aromatic carboxylic acid exhibit almost no color-
developing ability when used separately, but whentheir reaction product is coated onto a support, the
metal salts of the carboxylic acids show excellent
color developing ability.
U.S. Patent 4,134,847 discloses a color
developer which is obtained by the process which
comprises heating a mixture of at least one aromatic
carboxylic acid, at least one water-insoluble
organic polymer and at least one oxide or carbonate
of a polyvalent metal in the presence of water to
melt at least one of aromatic carboxylic acid and
said polymer and to make the mixture into a homogen-
eous mass.
The organic carboxylic acid useful in that
patent is represented by the fol~owing formula I
except for the compounds having a heteroaromatic
ring.
coo~ n
,~,
herein Rl~ R2~ R3~ R4 and Rs each representS
hydrogen, halogen or a hydroxyl, amino, carboxyl,
carbamoyl, N-substituted carbamoyl, alkyl, cyclo-
alkyl, alkoxyl, aryl, aryloxy, aralkyl or alkylaryl
1 336477
group, and any adjacent pair of Rl to R5 can
complete a ring such as naphthalene ring. Compounds
of formula I wherein Rl or R5 is a hydroxyl ~roup
are especially important in embodiments of the
invention as mentioned in detail-hereinafter.
Examples of aromatic carboxylic acids of for-
mula I wherein Rl and R5 are not a hydroxyl group
include benzoic acid, o-toluic acid, m-toluic acid,
p-toluic acid, p-tert-butylbenzoic acid, o-chloro-
benzoic acid, m-chlorobenzoic acid, p-chlorobenzoic
acid, dichlorobenzoic acid, trichlorobenzoic acid,
phthalic acid, isophthalic acid, terephthalic acid,
p-oxybenzoic acid, p-butoxybenzoic acid, p-octoxy-
benzoic acid, gallic acid, anthranilic acid, phtha-
lic acid monoamide, 3-tert-butyl-t-hydroxybenzoic
acid, 3-cyclohexyl-4-hydroxybenzoic acid, 3-phenyl-
4-hydroxybenzoic acid, 3-(~-methylbenzyl)-4-
hydroxybenzoic acid, 3,5-dimethyl-4-hydroxybenzoic
acid, trimellitic acid, pyromellitic acid, ~-naph-
thoic acid, ~-naphthoic acid, tetrachlorophthalic
acid, 2-carboxybiphenyl and 2,2'-dicarboxydiphenyl.
Aromatic carboxylic acids of formula I wherein
Rl or R5 is a hydroxyl group are defined by formula
II,
~OH
wherein R6 to Rg are as defined in Rl to R5 of for-
mula I.
Examples of such carboxylic acids include sali-
cylic acid, o-cresotinic acid, p-cresotinic acid, 3-
26 1 33647,
ethylsalicylic acid, 4-ethylsalicylic acid, 3-
isopropylsalicylic acid, 4-isopropylsalicylic acid,
5-isopropylsalicylic acid, 3-tert-butylsalicylic
acid, 5-tert-butylsalicylic acid, 3-cyclo-
hexylsalicylic acid, 5-cyclohexylsalicylic acid,
3-phenylsalicylic acid, 5-phenylsalicylic acid,
3-benzyl-salicylic acid, 5-tert-octylsalicylic acid,
3-(~-methylbenzyl) salicylic acid, 5-(~-methyl-
benzyl) salicylic acid, 5-nonylsalicylic acid,
5-(~,~-dimethylbenzyl) salicylic acid, 5-
chlorosalicylic acid, 5-butoxysalicylic acid and
5-octoxysalicylic acid.
Compounds of formula II wherein R6 and R8 are
halogen, alkyl, cycloalkyl, aryl, aralkyl or alky-
laryl can be easily derived in commercial scalesfrom phenols, alkylphenols, arylphenols or halogen-
ated phenols. Examples of such aromatic carboxylic
acids, include 3,5-dichlorosalicylic acid, 3-chloro-
5-~ert-butylsalicylic acid, 3-chloro-5-tert-amyl-
salicylic acid, 3-chloro-5-tert-octylsalicylic acid,
3-chloro-5~ -dimethylbenzyl) salicylic acid, 3,5-
dimethylsalicylic acid, 3-methyl-5-tert-butylsali-
cylic acid, 3-methyl-5-cyclohexylsalicylic acid, 3-
methyl-5-tert-octylsalicylic acid, 3-methyl-5-(~-
methyl-benzyl) salicylic acid, 3-methyl-5-nonyl-
salicylic acid, 3-methyl-5~ -dimethylbenzyl)
salicylic acid, 3,5-diisopropylsalicylic acid, 3,5-
sec-butylsalicylic acid, 3-tert-butyl-5-chlorosali-
cylic acid, 3-te~t-butyl-5-methylsalicylic acid, 3-
tert-butyl-5-ethylsalicylic acid, 3,5-di-tert-butyl-
salicylic acid, 3-tert-butyl-5-cyclohexyl-salicylic
acid, 3-tert-butyl-5-phenylsalicylic acid, 3-tert-
butyl-5-(4'-tert-butylphenyl) salicylic acid, 3-
tert-amyl-5-chlorosalicylic acid, 3-tert-amyl-5-
methylsalicylic acid, 3-tert-amyl-5-ethylsalicylic
27 1 336477
acid, 3,5-di-tert-amyl-salicylic acid, 3-tert-amyl-
5-cyclohexylsalicylic acid, 3-tert-amyl-5-phenyl-
salicylic acid, 3-tert-amyl-5-(4'-tert-amylphenyl)
salicylic acid, 3-cyclohexyl-5-chlorosalicylic acid,
3-cyclohexyl-5-methylsalicylic acid, 3-cyclohexyl-5-
ethylsalicylic acid, 3,5-dicyclohexylsalicylic acid,
3-cyclohexyl-5-phenylsalicylic acid, 3-cyclohexyl-5-
(4'-cyclohexylphenyl) salicylic acid, 3-phenyl-t-
chlorosalicylic acid, 3-phenyl-t-isopropyl-salicylic
acid, 3-phenyl-5-tert-butylsalicylic acid, 3-phenyl-
5-cyclohexylsalicylic acid, 3-phenyl-5-benzylsali-
cylic acid, 3-phenyl-5-tert-octylsalicylic acid, 3-
phenyl-5-(~-methylbenzyl) salicylic acid, 3-phenyl-
5-nonylsalicylic acid, 3-phenyl-5-(~,~-dimethyl-
benzyl) salicylic acid, 3-benzyl-5-chlorosalicylic
acid, 3-benzyl-5-methylsalicylic acid, 3-benzyl-5-
ethylsalicylic acid, 3-benzyl-5-cyclohexylsalicylic
acid, 3-benzyl-5-phenylsalicylic acid, 3,5-dibenzyl-
salicylic acid, 3-benzyl-5-tert-octyl-salicylic
acid, 3-benzyl-5-nonylsalicylic acid, 3-benzyl-5-
(a,~-dimethylbenzyl) salicylic acid, 3-tert-octyl-5-
chlorosalicylic acid, 3-tert-octyl-5-methylsalicylic
acid, 3-tert-octyl-5-ethylsalicylic acid, 3-tert-
octyl-5-cyclohexylsalicylic acid, 3-tert-octyl-5-
phenylsalicylic acid, 3,5-di-tert-octylsalicylic
acid, 3-(Q-methylbenzyl)-5-chlorosalicylic acid, 3-
(~-methylbenzyl)-5-methylsalicylic acid, 3-(c-
methylbenzyl)-5-ethylsalicylic acid, 3-(~-methyl-
benzyl)-5-cylohexylsalicylic acid, 3-(~-methyl-
benzyl)-5-phenylsalicylic acid, 3~5-di(Q-meth
benzyl) salicylic acid, 3-(~-methylbenzyl)-5-(~
dimethylbenzyl) salicylic acid, 3-(~-methylbenzyl)-
5-{4'-~-methylbenzyl)phenyl~ salicylic acid, 3-
nony;-5-chlorosalicylic acid,
28 1 336477
3-nonyl-5-methylsalicylic acid, 3-nonyl-S-ethylsali-
cylic acid, 3-nonyl-S-phenylsalicylic acid, 3,5-
dinonylsalicylic acid, 3-(~,~-dimethylbenzyl)-5-
chlorosalicylic acid, 3-(~,~-dimethylbenzyl)-5-
methylsalicylic acid, 3-(3,3-dimethylbenzyl)-5-
ethyl-sali--ylic acid, 3-(~,~-dimethylbenzyl)-S-t-
amylsalicylic acid, 3-(~,~-dimethylbenzyl)-S-cyclo-
hexylsalicylic acid, 3(~,~-dimethylbenzyl)-S-phenyl-
salicylic acid, 3-(~,~-dimethylbenzyl)-5-(~-methyl-
benzyl) salicylic acid, 3,5-di(~,~-dimethylbenzyl)
salicylic acid, 3-(4'-tert-butylphenyl)-5-tert-
butylsalicylic acid, 3-(4'-cyclohexylphenyl)-5-
cyclohexylsalicylic acid and
3-{4'-(~,Q-dimethylbenzyl) phenyl}-S-(~ dimethyl-
benzyl) salicylic acid.
Aromatic carboxylic acids of formula II inwhich R7 or Rg is alkyl or phenyl can be derived
from, for example, metacresol, metapropylphenol,
metaphenylphenol, 2,3-xylenol, 2,5-xylenol, 3,4-
xylenol and 3,5-xylenol. Examples of such car-
boxylic acids include 3,4-dimethylsalicylic acid,
4,5-dimethylsalicylic acid, 4,6-dimethylsalicylic
acid, ~-methyl-5-isopropylsalicylic acid, 4-methyl-
5-sec-butylsalicylic acid, 4-methyl-5-tert-butyl-
salicylic acid, 4-methyl-5-tert-amylsalicylic acid,
4-methyl-5-cyclohexylsalicylic acid, 4-methyl-5-
benzyl-salicylic acid, 4-methyl-S-tert-octylsali-
cylic acid, 4-methyl-5-t~-methylbenzyl) salicylic
acid, 4-methyl-S-nohylsalicylic acid,
4-methyl-5-(~,~-dimethylbenzyl) salicylic acid, 3,6-
dimethylsalicylic acid, 3-tert-butyl-6-methylsali-
cylic acid, 3-tert-amyl-6-methylsalicylic acid, 3-
cyclohexyl-6-methylsalicylic acid, 3-tert-octyl-6-
methylsalicylic acid, 3-(~-methylbenzyl)6-methyl-
salicylic acid, 3,6-diisopropylsalicylic acid,
29 1 336477
3-tert-butyl-6-isopropylsalicylic acid, 3-tert-
octyl-6-isopropylsalicylic acid, 3-(~
dimethylbenzyl)-6-isopropylsalicylic acid, 3-tert-
butyl-6-phenylsalicylic acid, 3-tert-amyl-6-
phenylsalicylic acid, 3-cyclohexyl-6-phenylsalicylic
acid, 3-tert-octyl-6-phenylsalicylic acid, 3-(-
methyl-benzyl)-6-phenylsalicylic acid or 3-t~
dimethylbenzyl)-6-phenylsalicylic acid.
Aromatic carboxylic acids derived from, for
example, bisphenol A, 4,q'-dihydroxycyclohexylidene-
biphenyl, 4,4'-dihydroxymethylenebiphenyl and 2,2'-
dihydroxydiphenyloxide are regarded as condensates
of salicyclic acid. Examples of these carboxylic
acids include 5-(4'-hydroxybenzyl) salicylic acid,
5-(3'-carboxy-4'-hydroxybenzyl) salicylic acid
(methylene-bissalicylic acid), 3-tert-butyl-5-
(3',5'-di-tert-butyl-4-hydroxybenzyl) salicylic
acid, 3-(3,~-dime'hylbenzyl)-5-{3',5'-di(~
dimethylbenzyl)-4'-hydroxybenzyl} salicylic acid, 3-
tert-butyl-5-(~,~-dimethyl-3',5'-di-tert-butyl-4'-
hydroxy-benzyl) salicylic acid, 5-(~,~-dimethyl-3'-
carboxy-4'-hydroxybenzyl) salicylic acid, 5-(~
dimethyl-4'-hydroxybenzyl) salicylic acid, 3-(2'-
hydroxyphenoxy) salicylic acid, 3-(2'-hydroxy-3'-
carboxyphenoxy) salicylic acid, 3-(2'-hydroxy-3'-
carboxy-5'-tert-butylphenoxy)-5-tert-butyl-salicylic
acid, 3-(2'-hydroxy-3',5'-di-tert-butylphenoxy-5-
tert-butyI-salicylic ac-d, 3-{2'-hydroxy-3'-carboxy-
S'(~,~-dimethyl-benzyl)phenoxy)-5~ -dimethyl-
benzyl) salicylic acid, 3-{2'-hydroxy-3',5'-di(~
dimethylbenzyl) phenoxy)-5-(~,~-dimethylbenzyl)
salicylic acid or 3-(2'-hydroxy-3',5'-dicyclohexyl-
phenoxy)-5-cyclohexyl-salicylic acid.
Furthermore, a large number of aromatic car-
boxylic acids of ~eneral formula II which are diffi-
1 336477
cult to express in the chemical nomenclature aresaid to be useful for the purposes of U.S. Patent
4,134,847. For instance, there are indicated con-
densation products o~ formaldehyde with salicylic
acid or nucleus-substituted salicylic acids and
phenols, salicylic acid or nucleus-substituted sali-
cylic acid adducts of propylene polymer or isobuty-
lene polymer, salicylic acid or nucleus-substituted
salicylic acid adducts of benzylchloride poly-con-
lo densation products, salicylic acid or nucleus-sub-
stituted salicylic acid adducts of styrene polymers,
salicylic acid or nucleus-substituted salicylic acid
adducts of Q-methylstyrene polymers, salicylic acid
or nucleus-substituted salicylic acid condensates of
aldehydes or acetylene, salicylic acid or nucleus-
substituted salicylic acid condensates of ketones,
and salicylic acid or nucleus-substituted salicylic
acid adducts of compounds having an unsaturated
bond.
The organic polymers which U.S. Patent
4,134,847 discloses for mixture with these acids
include polymers of ~-methyl styrene. U.S. Patent
4,199,619 discloses use of organic acceptors includ-
ing various aromatic carboxylic acids such as ben-
zoic acid, p-tert-butyl-benzoic acid, 4-methyl-3-
nitro benzoic acid, salicylic acid, 3-phenyl sali-
cylic acid, 3-cyclohexyl salicylic acid, 3-tert-
butyl-5-methyl salicyclic acid, 3,5,-di-tert-butyl
salicylic acid, 3-methyl-5-benzyl salicylic acid, 3-
phenyl-5~ -dimethylbenzyl) salicylic acid, 3-
cyclohexyl-5-al2-dimethylbenzyl) salicylic acid, 3-
~ -dimethylbenzyl)-5-methyl salicylic acid, 3,5-
dicyclohexyl salicylic acid, 3,5-di(Q-methylbenzyl)
salicylic acid, 3,5-di(~,~-dimethylbenzyl) salicylic
acid, 3-t~-methylbenzyl)-5-(~,~-dimethylbenzyl)
31 1 336477
salicylic acid, 4-methyl-5-cyclohexyl salicylic acid, 2-
hydroxy-l-benzyl-3-naphthoic acid, 1-benzoyl-2-hydroxy-3-
naphthoic acid, 3-hydroxy-5-cyclohexyl-2-naphthoic acid
and the like, and polyvalent metallic salts thereof such
as zinc salts, aluminum salts, magnesium salts, calcium
salts and cobalt salts as disclosed in U.S. Patent Nos.
3,864,146, 3,924,027 and 3,983,292.
U.S. Patent 4,219,219 discloses the use of (i)
developers comprising a polyvalent metal salt of a
substituted salicylic acid represented by the following
general formula (I) or (II) and (ii) developers com-
prising a polyvalent metal salt of a substituted sali-
cylic acid represented by the following general formula
(I) or (II) and one or more oxides, hydroxides, carbon-
ates or carboxylic acid salts of zinc, aluminum, tita-
nium, silicon, boron, magnesium and calcium or inorganic
pigments such as activated clay, kaolin talc and the
like:
OH Ar \ OH
R~c(I) /c~'~C(IH)
Ar-C-Rl R
Ar'
wherein R represents a hydrogen atom, an alkyl group, an
aralkyl group or an aryl group, Rl represents a hydrogen
atom, an alkyl group, an aralkyl group or an aryl group
and Ar and Ar' which may be the same or different, each
represents an aryl group.
U.S. Patent 4,234,212 discloses a recording sheet
coated with a color developer obtained from a dispersion
containing a melamine resin and/or a urea resin, a poly-
valent metal salt of an aromatic carboxylic acid and a
.~
,. I
1 3364 7 7
32
water-soluble polymer containing hydroxyl groups.
Suitable polyvalent metal salts of aromatic carbox-
ylic acids which can be employed include those polyvalent
metal salts of aromatic carboxylic acids represented by
the following general formula (I):
COOH
R1 ~ R5 (I)
R2 ~ R4
R3
wherein R1, R2, R3, R4 and R5, which may be the same or
different, each may have up to 18 carbon atoms and
represents, for example, a hydrogen atom, a halogen atom
(e.g., a chlorine atom or a bromine atom), a hydroxy
group, an amino group, an alkylamino group (e.g., an
alkylamino group substituted with one or two alkyl groups
containing 1 to 12 carbon atoms, such as a methylamino
group, an ethylamino group, an isobutylamino group, an
octylamino group, a dodecylamino group, a diethylamino
group, a dibutylamino group, a di-2-ethylhexylamino
group, an N-ethyl-N-octylamino group, etc.), a nitro
group, an aldehyde group, an alkyl group (e.g., an alkyl
group containing 1 to 12 carbon atoms, such as a methyl
group, an ethyl group, a butyl group, an octyl group, a
t-butyl group, a dodecyl group, etc.), a cycloalkyl group
(e.g., a cycloalkyl group containing 5 to 7 carbon atoms,
e.g., a cyclohexyl group, a methylcyclohexyl group,
etc.), an aryl group (e.g., an aryl group containing 6 to
10 carbon atoms, such as a phenyl group, a naphthyl
group, etc.), an alkylaryl group (e.g., a phenyl group or
a naphthyl group substituted with one or more alkyl
groups containing 1 to 12 carbon atoms, such as a methyl-
phenyl group, an ethylphenyl group, a 2,4-di-t-amyl-
33 1 336477
phenyl group, an octylphenyl group, a dodecylphenyl~roup, a methylnaphthyl group, etc.), an aralkyl
group (e.g., an aralkyl group containing 7 to 20
carbon atoms, such as a benzyl group, a phenethyl
group, a methylbenzyl group, etc.), an alkoxy group
(e.g., an alkoxy group containing 1 to 12 carbon
atoms, such as an ethoxy group, a methoxy group, a
butoxy group, etc.), and so on. Also, Rl and R2, R3
and R4 and/or R4 and R5 may combine and form a 5- or
a 6-membered ring (e.g., a 5- or 6-membered carbon-
containin~ ring).
Of the compounds represented by the above-
described general formula (I), those compounds in
which at least either Rl or R5 is a hydroxy group
and which are substituted with an alkyl group, an
aryl group, an aralkyl group or other groups in
positions ortho and para to such a hydroxy group,
are especially useful in the present invention.
Specific examples of aromatic carboxylic acids
represented by the general formula (I) include 2,4-
dichlorobenzoic acid, p-isopropylbenzoic acid, 2,5-
dinitrobenzoic acid, p-t-butylbenzoic acid, N-
phenylanthranilic acid, 4-methyl-3-nitrobenzoic
acid, salicylic acid, m-hydroxybenzoic acid, p-
hydroxybenzoic acid, 3,5-dinitrosalicylic acid, 5-t-
butyl-salicylic acid, 3-phenylsalicylic acid, 3-
methyl-5-t-butylsalicylic acid, 3,5-di-t-amylsali-
cylic acid, 3-cyclohexylsalicylic acid, 5-
cyclohexylsalicylic acid, 3-methyl-5-isoamylsali-
cylic acid, 5-isoamylsalicylic acid, 3,5-di-sec-
butylsalicylic acid, 5-nonylsalicylic acid, 2-
hydroxy-3-methylbenzoic acid, 2-hydroxy-5-t-butyl-
benzoic acid, 2,4-cresotinic acid, 5,5-methylenedi-
salicylic acid, acetoamino-benzoic acids (o-, m- and
p-)~ 2,4 dihydroxybenzoic acid, 2,5-dihydroxybenzoic
1 336477
acid, anacardic acid, l-naphthoic acid, 2-naphthoic
acid, l-hydroxy-2-naphthoic acid, 2-hydroxy-3-
naphthoic acid, 2-hydroxy-1-naphthoic acid, thio-
salicylic acid and the like. Preferred examples of
aromatic carboxylic acids represented by the general
formula (I) include 3,5-di(~-methyl-benzyl)salicylic
acid, 3-(~-methylbenzyl)-5-~,c-dimethyl-benzyl)sali-
cylic acid, 3-(4'-~-dimethylbenzyl)phenyl-5-(~
dimethylbenzyl)salicylic acid, 3,5-di-t-butylsali-
lo cylic acid, 3,5-di-5-octylsalicylic acid, 3-cyclo-
hexyl-5-(~,~-dimethylbenzyl)salicylic acid, 3-
phenyl-5-t~,~-dimethylbenzyl)-salicylic acid, 3,5-
di(Q,~-dimethylbenzyl)-salicylic acid and so on.
Suitable polyvalent metals forming salts with
the above-described aromatic carboxylic acids which
are disclosed in U.S. Patent 4,234,212 are, for
example, magnesium, aluminum, calcium, scandium,
titanium, vanadium, chromium, manganese, iron,
cobalt, nickel, copper, zinc, gallium, germanium,
strontium, yttrium, zirconium, molybdenum, silver,
cadmium, indium, tin, antimony, barium, tunssten,
lead, bismuth and so on. Of these metals,
especially effective polyvalent metals include zinc,
tin, aluminum, magnesium, calcium and the like. The
most preferred polyvalent metal is zinc.
In the compositions of U.S. Patent 4,234,212,
a specific binder is employed in preparin~ a coating
solution containing a color developer. The binder
is selected depending upon the strength of the film
which the binder forms, the dispersibility of the
color developer to be employed into the binder, and
the extent of influence of the binder upon the color
development capability of the color developer.
Examples of suitable water-soluble polymers
which can be used as binders include water-soluble
1 336477
binders where crystals and cross-linking are not
present and containing hydroxyl groups, carboxyl
groups, sulfo groups, or salts thereof, for example,
natural macromolecular compounds such as proteins
(e.g., gelatin, albumin, casein, etc.), starches
(e.g., cereal starch, ~-starch, oxidized starch,
etherified starch, esterified starch, etc.), cellu-
loses (e.g., carboxymethyl cellulose, hydroxymethyl
cellulose, etc.), saccharides (e.g., agar, sodium
lo alginate, carboxymethyl starch, gum arabic, etc.)
and the like, and water-soluble, synthetic high
polymers, such as polyvinyl alcohol (PVA), polyvinyl
pyrrolidone, polyacrylic acid, polyacrylamide,
maleic acid copolymers and the like.
Examples of suitable latex binders disclosed by
U.S. Patent 4,234,212 include styrene-butadiene
latex (SBR), acrylonitrile-butadiene latex, acrylic
acid type latexes, vinyl acetate type latexes,
methylmethacrylate-butadiene latex, and the carboxy
denatured latexes thereof.
U.S. Patent 4,374,671 discloses a process for
producing a color developer in which zinc oxide is
combined with at least one acid selected from the
group consisting of salicylic acid and nuclear sub-
stituted salicylic acids and at least one metalsilicate as an inorganic pigment. The salicylic
acid compound used in U.S. Patent 4,374,671 can be
represented by the following general formula:
o~ .
~, ~ o~
~2
wherein Rl and R2 represents hydrogen, chlorine, a
saturated and unsaturated alkyl group having 1 to 15
36 1 336477
carbon atoms, a phenyl group, a cyclohexyl group, a
phenyl alkyl group having 7 to 21 carbon atoms, an
alkyll phenyl alkyl2 group wherein the alkyll and
alkyl2 groups have l to 15 carbon atoms, a 1-
hydroxy-2-carboxy benzyl group and a 4-hydroxy-3-
carboxy benzyl group.
The nuclear substituted salicylic acid
includes, for example, 5-tert-butylsalicylic acid,
3-phenylsalicylic acid, 3-methyl-5-tert-butylsali-
lo cylic acid, 3,5-di-isopropylsalicylic acid, 3,5-di-
tert-butylsalicylic acid, 3,5-di-tert-amylsalicylic
acid, 3-cyclohexylsalicylic acid, S-cyclohexylsali-
cylic acid, 3-methyl-5-isoamylsalicylic acid, 5-
isoamylsalicylic acid, 3,5-di-sec-butylsalicylic
acid, 5-laurylsalicylic acid, 3-methyl-5-laurylsali-
cylic acid, 3-methylsalicylic acid, 2-4-cresotonic
acid, 2,5-cresotonic acid, 2,3-cresotonic acid, 4-
hydroxysalicylic acid, 5-hydroxysalicylic acid, 6-
hydroxysalicylic acid, 5,5'-methylenesalicylic acid,
anacardic acid, 5-benzylsalicylic acid, 3,5-bis-(2-
phenyl-isopropyl) salicylic acid, 3-(2-phenyl-iso-
propyl)-5-methylsalicylic acid, 4-chlorosalicylic
acid, etc.
Developer materials of the type described in
these patents are not satisfactory for the image
forming systems described in U.S. Patent
4,440,846. For the purposes of such imaging
systems, it is desirable for the developer to pro-
vide a number of related properties, including the
following:
1. Glossing. When the image is processed by
heating, it is desirable for the developer to be
capable of forming a glossy surface. It is
important that the developer be capable of glossing
at a temperature which is not inconsistent with
37 1 336477
temperatures which are suitable for other materials
in the imaging material.
2. Transparency. The developer must be trans-
parent in-the areas which do not develop a visible
image. This is particularly important in imaqing
systems coated onto a transparent backing, for use
in producing transparencies.
3. The refractive index of the developer must
be similar to that of other materials on the imaging
~ sheet.
4. The density of the image produced by the
- developed image should be high.
5. The color purity must be high.
6. The resolution of the image must be high.
7. The developer must have a high enough
softening temperature that it is not glossed during
coating of the product on a support, during manufac-
ture.
8. The developer should not produce a yellow
background in non-imaged areas.
9. The developed image s~hould not fade.
10. The developer should not emit toxic vapors
either at normal temperatures or at the elevated
temperatures used for glossing.
11. The developer must adhere well to the sup-
port materials used for the imaging system,
especially oriented polyester film used for trans-
parency materials.
12. The developer must be capable of forming a
fine dispersion, so that, prior to development, the
particles of developer on the support will be small.
13. The developer must be capable of forming a
dispersion which is easily coated.
38 1 336477
lq. The developer must have good shelf-life
prior to formation of an image and development. In
particular, the coated substrate must be non-
blocking.
lS. The developer must not undergo yellowing
prior to development.
16. The developer must not cause problems with
sheet feeding mechanisms used for automated imaging
apparatus.
SUMMARY OF THE INVENTION
In accordance with ~he present invention,
phenol/aldehyde condensation products useful in the
development of colored images from colorless dye are
produced by the interaction of an alkyl-substituted
salicylic acid, an alkyl-substituted phenol, an
aldehyde and a metal source.
The phenol/aldehyde condensation product is
synthesized by combining and then heating the alkyl-
substituted salicylic acid, the alkyl-substituted
phenol, the aldehyde, the metal source and water.
After the reaction has occurred, the mixture is
cooled and then filtered to obtain the
phenol/aldehyde condensation proauct.
DETAILED DESCRIPTION OF THE INVENTION
The developers of the present invention are
particuiarly useful in a photosensitive imaging
system in which images are formed by image-wise
reaction of one or more chromogenic materials with
the developer, and in carbonless copy paper systems.
The presently disclosed developers are produced
by the interaction of an alkyl-substituted salicylic
acid, an alkyl-substituted phenol, an aldehyde and a
metal source to form a phenol/aldehyde condensation
product.
39 1 336477
The alkyl-substituted salicylic acid is prefer-
ably substituted with at least one alkyl group con-
taining three or more carbon atoms. Desirably, the
alkyl group contains at least four carbon atoms,
especially four to twelve carbon~atoms.
Particularly useful are salicylic acids of the for-
mula:
COO~
R ~ OH
where R is an alkyl group containing from four to
twelve carbon atoms. In particular, the group R is
octyl or ronyl, especially tertiary-octyl (derived
from di-isobutene) and nonyl (derived from propylene
trimer). The group R may also be a dodecyl group.
The currently preerred materials use the nonyl
group.
The alkylphenol component preferably contains
at least one alkyl group containing at least three
carbon atoms, especially four to twelve carbon
atoms. In particular, the phenols are phenols sub-
stituted in the ~ara-position with an alkyl group
containing four to twelve carbon atoms, particularly
tertiary-butyl, tertiary-octyl, nonyl (derived from
propyiene trimer) and dodecyl. The currently pre-
ferred materials use the tertiary-octyl group.
The aldehyde is preferably formaldehyde,
although the formaldehyde may be supplied, f~r
example, from paraformaldehyde or a similar source
of formaldehyde.
The preferred metal source is zinc oxide.
1 336477
The exact composition of the product is not
known, but it is believed to have the general for-
mula: - -
OH OH
H ~ CH~ - ~ COO Zn
R R
- _n 2
The phenol/aldehyde condensation product may be
synthesized by combining and heating the alkyl-sub-
stituted salicylic acid, the alkyl-substituted
phenol, the aldehyde, the metal source and water.
The following is a general example of a suitable
manufacturing process:
750 parts nonylsalicylic acid, 523 parts ~-t-
octylphenol, l99 parts 50% formaldehyde solution, 3
parts of Daxad 30 (a wetting agent of proprietary
composition available from W.R. Grace & Co.), 69
parts water and 103 parts of zinc oxide are heated
to reflux with agitation. After the reaction takes
place, heating is discontinued and additional
wetting agent is added. The mixture is cooled with
agitation, and further diluted wi.h water. The
mixture is then filtered to obtain the
phenol/aldehyde condensation product.
The following examples serve to illustrate the
manufacturing process of the present invention in
greater detail. Carbonless copy paper testing of
the produced image developers is also described. In
addition, variations of the percent content of alkyl-
substituted salicylic acid to alkyl-substituted
phenol are considered. These examples are included
for illustrative purposes and should not be con-
sidered to limit the present invention.
41 1 336477
Example 1
Carboxylation of Alkylphenols
1320 parts ~-nonyl phenol, 1200 parts xylene,
and 240 parts sodium hydroxide pellets were added to
a kettle with agitation. The batch was heated until
the removal of water by azeotropic distillation was
complete at 144 to 146C. The batch was then cooled
to 125C and carbon dioxide was introduced via a
subsurface sparge to a pressure of 100 psig. These
conditions were maintained for ten hours. The batch
was then cooled to less than 100C and the carbon
dioxide pressure was released. 400 parts of water
were added, then the batch was neutralized with 900
parts of 20% hydrochloric acid. The pH was adjusted
to 1 to 2 with 1 to 100 parts of 20% hydrochloric
acid. When a p~ of 1 to 2 was achieved, agitation
was terminated and the batch was allowed to phase
separate. The water layer was removed, and 500
parts of water were added with agitation. The batch
was heated to 80 to 90C, then allowed to phase
separate. Again, the water layer was removed, and
the organic layer was washed with 500 parts of water
and allowed to phase separate. The final water wash
layer 'was removed and the remaining organic layer
was vacuum distilled at 26 inches ~g to 160C. The
batch was cooled to yield the final product as a
very viscous, dark-amber transparent liquid which
solidified or formed crystals at temperatures below
30C. The product, nonylsalicylic acid (NSA), had
an acid number of 180 to 204 and a conversion of
85.5 to 97.6%. The nonylsalicylic acid was ready
for use in the aldehyde condensation reactions
described below.
42 1 336477
According to the same general procedure
described above, dodecylphenol was carboxylated to
provide a raw material suitable for use in the
aldehyde condensation reactions of the present
invention. The carboxylation procedure took place
at the same time, temperature and pressure para-
meters described above. The product, dodecylsaii-
cylic acid, had an acid number of 163 to 184 and a
conversion of 85 to 96%.
o Example 2
Aldehyde Condensation Reactions
The aldehyde condensation reactions of the
present invention produced a product which was in
both dispersed and solid form.
1. Dispersions
238 parts of nonylsalicylic acid, 166 parts of
~-t-octylphenol, and 60 parts of 50% formaldehyde
were added to a kettle with agitation. The batch
was heated to a temperature in the range of 120 to
125C. At 120C, a slurry of 21.9 parts of water, 1
part of a sodium salt of a proprietary electrolyte
supplied by W.R. Grace, and 32.7 parts of zinc oxide
were added. The batch was heated to atmospheric
reflux and maintained at reflux until the free
formaldehyde content of the batch was less than or
equal to 0.2%. At this point, 19.8 parts of
polyvinyl alcohol and 55 parts of water were added
to the batch. When phase inversion occurred and
particle size distribution was acceptable, letdown
43 1 336477
water was added to adjust solids as desired. The
batch was then filtered through a 100 micron filter
to yield the final dispersion product.
The final dispersion product was a white,
smooth, slightly viscous liquid. The product had a
p~ of 5.4 to 6.4, a viscosity of 20 to 1300 centi-
poise, non-volatiles of 50 to 60%, and a Tg of 45 to
65.
Using the same general procedure described
above, p-nonylphenol, ~-t-butylphenol, and dodecyl-
phenol each replaced ~-t-octylphenol as the alkyl-
substituted phenol in the aldehyde condensation
procedure.
Other parameters,which were varied while con-
tinuing to yield a product which satisfied perform-
ance re~uirements were as follows:
1. The alkyl-substituted salicylic acid
content in the batch was varied within
the range of from 30 to 75 molar
of the total phenol content.
2. The zinc content in the batch was
varied within the range of from 3.88 to
15.11% by weight of the final resin
content.
3. The formaldehyde content in the batch
was varied within the range of from
0.25 to 0.70 molar ratio formaldehyde
to total phenol content.
2. Solid Resins
(a) 238 parts of nonylsalicylic acid,
166 parts of ~-t-octyl phenol, and 60 parts of 50%
formaldehyde were added to a kettle with
agitation. The batch was heated to a temperature in
the range of 120 to 125F. At 120F, a slurry of
44 1 336477
21.9 parts of water, 1 part of a sodium salt of a
proprietary electrolyte supplied by W.R. Grace, and
32.7 parts of zinc oxide were added. The batch was
heated to atmospheric re~lux and maintained at
reflux until the free formaldehyde content of the
batch was less than or equal to 0.2%. The batch was
then distilled to 160C at 24 inches vacuum and held
for 15 minutes.
The final product was a dark-amber, solid
resin. The resin had a ball and ring melt point of
}25 to 133C.
Using the same general procedure described
above, ~-nonylphenol, ~-t-butylphenol and dodecyl-
phenol each replaced p-t-octyl phenol as the alkyl
substituted phenol in the aldehyde condensation
procedure. In each case, a solid resin was obtained
which satisfied performance requirements.
(b) 238 parts of nonylsalicylic acid,
166 parts of ~-t-octylphenol, and 1.4 parts of a
mixed ~-toluene sulfonic acid and ~-xylene sulfonic
acid supplied by Witco Chemicals were added to a
kettle with agitation. The batch was heated to a
temperature in the range of 75C to 95C. At 75C,
60 parts of 50% formaldehyde was added. The batch
was heated to atmospheric reflux and maintained at
reflux until the free formaldehyde content of the
batch was less than or equal to 0.2%. At this
point, a slurry of 21.9 parts of water, 1 part of a
sodium salt of a proprietary electrolyte supplied by
W. R. Grace, and 27.8 parts of zinc oxide were
added. The batch was held at atmospheric reflux for
2 hours. The batch was then distilled to 160C at
24 inches vacuum and held for 15 minutes.
4S 1 336477
The final product was a dark-amber, solid
resin. The resin had a ball and ring melt point of
125C to 135C.
Example 3
Carbonless Copy Paper Test Procedures
The performance of the obtained phenol/aldehyde
condensation products in developing colored images
from colorless dyes was evaluated by performing
carbonless copy paper testing on samples of the
products in both dispersed and solid form.
According ~o usual procedures, the samples were
first combined with other components of a water-
based coated front (CF) sheet coating formulation.
The formulation was then coated on a sheet of paper.
The test coating formulation was typical of the
CF formulations used by the carbonless copy paper
industry. All resins were in the dispersed form.
Other components of the coating formulation were in
slurry form.
The CF coating formulation was prepared in the
following manner:
Slurry Composition
Components Wet Weight, g Solid Weight, g
Kaolin Clay 43.0 30.0
Calcium Carbonate 62.5 45.0
Penford Gum 280 Starch30.0 6.0
Dow 620 Latex 8.0 4.0
Water 36.0
When all the components were combined and
mixed, the resulting slurry was homogeneous. The
46 1 336477
amount of resin dispersion to be added to the coat-
ing slurry was calculated as 2.5 grams divided by
the resin's active resin content. This amount of
resin dispersion was added to 23.9 grams of slurry.
Water was then added to bring thè total solution
weight to 83.3 grams. After sufficient agitation,
the slurry was ready for coating.
The slurry was drawn down on a sheet of paper
to create a coated ront sheet according to the
following procedure: Using a pipette, a bead of
slurry was drawn along a tl4 Meyer Rod across the
paper to be coated. The paper was then drawn
smoothly from under the rod, coating the paper. The
coated samples were dried for a minimum of twenty
minutes and were then ready for carbonless copy
paper testing.
Carbonless copy paper testing on the coated
samples included calender intensity, 3-day oven
aging at 140C and S-day lightbox aging.
Example 4~
Calender Intensity
A coated front sheet and a coated back sheet
were placed face to face and passed through the nip
of a two roll calender to create an image. A BNL-2
Opacimeter sold by Technidyne Corp. was used to
determine image intensity and the speed of image
development (print speed). Image intensity was
expressed as the ratio of the reflectance from the
imaged area to the reflectance from a white stan-
dard:
4' 1 336477
Imaqe Relectance
Image Intensity: white ReflectanCe 100
The coated samples were calendered and theimaged surface read in one spot with the opacimeter
at intervals of 20, 40 and 50 seconds. One minute
and one hour readings were taken in five spots and
reported as averages. Image intensity was measured
on a scale of 1 to 100, with the lower numbers being
the more intense values.
The samples of the present invention were com-
pared to HRJ-4002, an industrial standard dispersion
(manufactured by Schenectady Chemicals, Inc.) used
by the carbonless copy paper industry. The results
are summarized in Table 1.
Table 1
Calender Intensity
Product Disp/Solid 20 sec 40 sec 50 sec 1 min 1 hr
PTBP~NSA S 35.4 33.2 32.4 30.6 25.5
PTOP~NSA S 33.7 32.4 32.2 32.2 28.4
PTBP~DSA S 32.3 30.0 29.S 28.7 2S.5
PTBP~NSA D 33.1 30.9 30.4 29.4 25.5
PTOP~NSA D 30.2 29.2 29.0 28.7 25.5
PTBP~DSA D 29.4 28.4 2~.9 27.6 25.1
HRJ-4002 D 33.3 31.4 31.2 30.5 27.8
PTBP = E~-t-butylphenol
NSA = nonylsalicylic acid
PTOP = ~-t-octylphenol
DSA = dodecylsalicylic acid
q8 1 336477
Prior to the present invention, HRJ-4002 pro-
duced the best results as an industrial standard in
carbonless copy paper testing. However, a review of
the above data, as well as the data in the following
Tables, indicates that the presently disclosed
phenol/aldehyde condensation products are, for the
most part, better than or equal to ~RJ-4002 in per-
formance.
The calender intensity values of Table 1 show
that in every case, the presently disclosed disper-
sions performed better in calender intensity testing
that did HRJ-4002. The resins performed at least as
well as HRJ-4002, with PTBP+DSA resin performing
slightly better than HRJ-4002.
Example S
Oven Aging
This test measured the desree to which exposure
of an unimaged CF sheet of carbonless paper to an
elevated temperature affected its ability to develop
an image.
Unimaged samples were aged in an oven for three
days at 140C. After oven aging was complete, the
samples were imaged by calendering with a coated
back (C8) sheet and tested for print speed and image
intensity with an opacimeter. Measurements were
taken at 20, 40 and 50 second intervals after calen-
dering. One minute and 1 hour readings were taken
five times each at different spots of the sample and
reported as an average of the five individual mea-
surements. These intensity measurements at varioustime intervals were compared with intensity measure-
ments oE f reshly coated samples taken at identical
time intervals. The loss of image intensity after
1 336477
49
oven aging was reported as a decline in image per-
ormance after heat aging. The results are sum-
marized in Table 2.
Table 2
3-Day Oven Aging at 140-C
Product Disp/Solit 20 sec 40 sec 50 sec 1 min 1 hr
PTBP~NSA S 38.6 35.0 34.0 34.1 26.4
PTOP~NSA S 36.2 33.4 32.7 34.3 27.6
PTBP~DSA S 36.8 33.9 33.0 32.3 25.9
PTBP~NSA D 43.7 38.0 36.0 34.7 25.9
PTOP+NSA D 33.3 30.8 29.9 30.0 25.5
PTBP~DSA D 36.6 34.0 33.2 33.7 27.4
HRJ-4002 D 37.1 34.1 33.3 38.9 27.8
1 336477
A review of Table 2 shows that the presently
disclosed dispersions were better or equal in
performance to ~RJ-4002 follcwing 3-day oven aging
at 140-C. As to the resins, their performance was
equal to that of HRJ-qO02.
Example 6
Lightbox Aging
This test was carried out according to ASTM's
F 767-82 test method: "Image Stability of Chemical
Carbonless Paper to Light." ASTM (American Society
for Testing and Materials) describes this test
method as determining the "image stability of chemi-
cal carbonless paper by exposure to fluorescent
light for a controlled time period."
Imaged samples were tested for image intensity
on the opacimeter for use as a baseline. These
imaged samples were then subjected to five days in a
fluorescent lightbox as specified according to the
ASTM F 767-82 test method. In~tensity values were
again determined with the opacimeter. The magnitude
of the difference between initial intensity values
and image intensity after lightbox exposure was
taken as the measure of the degree of image fade.
These results are shown in Table 3.
Sl 1 336477
Table 3
5-Day ~ightbox Aging
Produc~ Disp/Solid Une~poset Exposed Change
PTBP~NSA S 26.8 29.9 3.l
PTOP~NSA S 28.~ 33.3 4.6
PTBP~DSA S 26.9 28.7 1.8
PTBP~NSA D 26.9 2g.6 2.7
PTOP~NSA D 28.2 31.2 3.0
PIBP~DSA D 27.9 29.9 2.0
HRJ-4002 D 32.3 32.~ 0.4
It is clear from the above data that the light-
box aging results greatly favored the presently
disclosed dispersions and resins over the conven-
tional HRJ-4002. Even though HRJ-4002 showed the
least amount of change, or fade, the images for all
the dispersions and resins performed better, or were
darker, than both the exposed and unexposed test
sheets of HRJ-4002. In other words, even the
exposed values of the presently disclosed disper-
sions and resins performed better than the unexposedvalues of HRJ-4002.
Example 7
NSA Variations
The percentase of nonylsalicylic acid to total
phenol content (alkyl phenols plus nonylsalicylic
acid) was varied to optimize the performance and
cost effectiveness of the presently disclosed
phenol/aldehyde condensation products. The
procedures for these reactions were identical to
those of Examples 1 and 2 described above.
52 1 336~77
Carbonless copy paper testing was performed on
the obtained products with nonylsalicylic acid
contents of 30, 40, 50 and 75 percent of the total
phenols content. Testing consisted of calender
intensity measurements, oven aging, lightbox aging,
YI 313 measurements and color shift
determinations. The same general procedures
described in Examples 4 through 6 above (with the
specific parameters given in Tables 4 through 6)
lo were used in calender intensity testing, oven aging
and lightbox aging.
The YI 313 method was used to measure back-
ground yellowing and report it as a numerical value
or "yellowness index." YI 313, a test method
developed by ASTM, is described by ASTM as "the
attribute by which an object color is judged to
depart from a preferred white toward yellow."
According to this method, a Hunter Colorquest
Spectrophotometer was used to measure the reflect-
ance spectrum of a sample of freshly coated CF
paper. Then, by means of computer software, the
"yellowness index", or YI 313 value, was calculated
according to the formula specified in ASTM's YI 313
method.
The sample was then placed in a lightbox con-
taining fluorescent bulbs of the type described in
ASTM's test method F 767 - 82. The sample was
exposed to the fluorescent light for five days, then
removed from the lightbox. The yellowness index or
YI 313 value was again measured using the ~unter
Colorquest Spectrophotometer. The difference in the
YI 313 value of the test CF sheet before and after
lightbox exposure was taken as the measure of the
degree of yellowing of the unimaged coating when
exposed to light.
53 1 336477
Color shift was also determined using a Hunter
Colorquest Spectrophotometer. The results of this
test are from the L, a, and b scales based on the
opponent-colors theory of color visions. Color
shift testing requires a baseline and was performed
on imaged samples. After baseline values were
determined, the samples were subjected to lightbox
aging, according to standard methods described
above. New L, a, and b values were determined after
lightbox aging and changes in color, as expressed by
changes in the ~, a, b values, were noted.
Calender intensity measurements, oven aging,
lightbox aging, YI 313 measurements and color shift
determinations are carbonless copy paper test
methods widely used by the industry. These tests
are designed to measure what are considered to be
some of the important attributes of carbonless copy
paper, i.e., print speed, image intensity, and fad-
ing or color change due to the environment.
The results of the tests on phenol/aldehyde
condensation products with nonylsalicylic acid
contents of 30, 40, 50 and 75 percent are summarized
in Tables 4 through 8 below.
Table 4
Calender Intensity
Res in 1 min 5 min 20 min 1 hr24 hr
30X ~S~ 30.6 28.8 27.2 26.726.3
40Z NSA 29.7 28.2 27.7 27.226.3
50X NSA 29.2 28.1 27.1 26.726.2
3075X NSA 40.4 31.2 29.0 28.227.1
54 1 336477
Table 5
72-Hour Oven Aginq
Resin 1 min 2 min 20 min 1 hr24 hr
-
30X NSA 32.9 30.8 29.6 29.028.1
5 40Z NSA 28.3 27.1 26.2 25.625.7
50X NSA 31.3 28.0 27.0 26.726.9
75X NSA 50.4 41.4 33.0 28.726.5
Table 6
- 5-Day Lightbox Aging
10 Resin Before Light Fate Change
30X NSA 26.3 32.5 3.8
40Z NSA 26.4 33.8 7.4
50Z NSA 26.2 33.0 6.8
75Z NSA 27.1 34.7 7.6
Table 7
YI-313 (Background Yellowing-Unimaged-Lightbox)
Resin Before Light Fade Change
30X NSA 5.86 8.40 2.55
40X NSA 5.89 9.77 3.88
50X NSA 5.79 9.66 3.87
75X NSA 5.92 9.40 3.48
1~364/1
Table 8
Color Shift (5-Day Lightbox-Imaged)
Resin Before Lightbox Light Fade
L a b L a b
5 30X NSA 40.29 2.71 -2.91 53.34 9.16 -3.33
~0~ NSA 49.18 2.14 -3.33 53.31 10.1~ -3.54
50~ NS~ 50.03 1.53 -3.31 52.66 9.41 -3.91
75~ NSA 50.30 2.38 -3.68 54.31 10.56 -3.22
10 Resin Change
L a b
30~ NSA 4.05 6.46 -0.42
40Z NSA 4.13 8.03 -0.21
50Z NSA 2.63 7.89 -0.61
1575Z NSA 4.01 8.18 0.46
As is clear from the above data, varying the
percentage of nonylsalicylic acid to total phenol
content has little or no effect on the performance
of the phenol/aldehyde condensation product, except
for very high levels of nonylsalicylic acid (75%
nonylsalicylic acid). 30 and 40% nonylsalicylic
acid resuits are identical to 50% nonylsalicylic
acid results in calender intensity, lightbox aging,
and YI-313 measure~ents. Oven age testing indicates
40% nonylsal cylic acid is slightly better in
performance than 50% nonylsalicylic acid.
The results from this series of carbonless copy
paper testing indicate no detrimental effects on the
56 1 336477
performance of phenol/aldehyde condensation products
with substantially lower percentages of nonyl-
salicylic acid.
The invention having been described, it will be
appreciated by those skilled in the art, that var-
ious modifications can be made within the scope of
the following claims.
