Note: Descriptions are shown in the official language in which they were submitted.
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IMPROVED SUBSTRATES AND COLORANT STABILIZERS
Technical Field
The present invention relates to improved substrates for
use with colorants, and especially with a family of colorants
and colorant stabilizers. The colorant stabilizers, according to
the present invention, are capable of stabilizing a colorant
when it is exposed to electromagnetic radiation. The colorant
stabilizers enable the production of an ink set wherein each ink
of the ink set, regardless of color, possesses substantially
similar light fastness properties. The present invention further
relates to improved substrates for use with colorants, and
especially with the colorants and colorant stabilizers of the
present invention. The improved substrates enable the
production of a printed substrate having superior print quality
compared to conventional substrates.
Background of the Invention
A major problem with colorants is that they tend to fade
when exposed to electromagnetic radiation such as sunlight or
artificial light and the like. It is believed that most of the
- fading of colorants when exposed to light is due to
photodegradation mechanisms. These degradation mechanisms
include oxidation or reduction of the colorants depending upon
the environmental conditions in which the colorant is placed.
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Fading of a colorant also depends upon the substrate upon
which they reside.
Product analysis of stable photoproducts and
intermediates has revealed several important modes of
photodecomposition. These include electron ejection from the
colorant, reaction with ground-state or excited singlet state
oxygen, cleavage of the central carbon-phenyl ring bonds to
form amino substituted benzophenones, such as
triphenylmethane dyes, reduction to form the colorless leuco
dyes and electron or hydrogen atom abstraction to form
radical intermediates.
Various factors such as temperature, humidity, gaseous
reactants, including 02, 03> S02, and N02, and water soluble,
nonvolatile photodegradation products have been shown to
influence fading of colorants. The factors that effect colorant
fading appear to exhibit a certain amount of interdependence.
It is due to this complex behavior that observations for the
fading of a particular colorant on a particular substrate cannot
be applied to colorants and substrates in general.
Under conditions of constant temperature it has been
observed that an increase in the relative humidity of the
atmosphere increases the fading of a colorant for a variety of
colorant-substrate systems (e.g., McLaren, K., J. Soc. Dyers
Colour, 1956, 72, 527). For example, as the relative humidity
of the atmosphere increases, a fiber may swell because the
moisture content of the fiber increases. This aids diffusion of
gaseous reactants through the substrate structure.
The ability of a light source to cause photochemical
change in a colorant is also dependent upon the spectral
distribution of the light source) in particular the proportion of
radiation of wavelengths most effective in causing a change in
the colorant and the quantum yield of colorant degradation as a
function of wavelength. On the basis of photochemical
principles, it would be expected that light of higher energy
(short wavelengths) would be more effective at causing fading
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than light of lower energy (long wavelengths). Studies have
. revealed that this is not always the case. Over 100 colorants of
different classes were studied and found that generally the
most unstable were faded more efficiently by visible light
while those of higher lightfastness were degraded mainly by
ultraviolet light (McLaren, K., J. Soc. Dyers Colour, l956,
72, 86).
The influence of a substrate on colorant stability can be
extremely important. Colorant fading may be retarded or
promoted by one or more chemical groups within the
substrate. Such a group can be a ground-state species or an
excited-state species. The porosity of the substrate is also an
important factor in colorant stability. A high porosity can
promote fading of a colorant by facilitating penetration of
moisture and gaseous reactants into the substrate. A substrate
may also act as a protective agent by screening the colorant
from light of wavelengths capable of causing degradation.
The purity of the substrate is also an important
consideration whenever the photochemistry of dyed technical
polymers is considered. For example, technical-grade cotton,
viscose rayon, polyethylene, polypropylene, arid polyisoprene
are known to contain carbonyl group impurities. These
impurities absorb light of wavelengths greater than 300 nm,
which are present in sunlight, and so, excitation of these
impurities may Iead to reactive species capable of causing
colorant fading (van Beek, H.C.A., Col. Res. Appl., 1983,
8(3), 176). -
Conventional print substrates result in acceptable print
quality; however, certain print defects still exist resulting in
less than desirable print quality. Printing defects, such as
' "feathering" and "wicking", undesirably spread the colorant or
colorant composition beyond the desired print pattern and/or
pull the colorant or colorant composition into the print
substrate. The result is a smeared print pattern, wherein a
substantial portion of the colorant or colorant composition
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migrates below and beyond the intended -area of the print
substrate.
Therefore, there exists a need for methods and
compositions which are capable of stabilizing a wide variety of
colorants from the effects of both sunlight and artificial light.
There also exists a need for improved substrates which are
capable of providing superior print quality, which minimizes
print defects, such as "feathering" and "wicking" of a colorant
composition. Further, there exists a need for such an
improved substrate, which minimizes print defects while
providing significant light stability from the effects of both
sunlight and artificial light for a wide variety of colorants and
colorant compositions.
Summary of the Invention
The present invention addresses the needs described
above by providing compositions and methods for stabilizing
colorants against radiation including radiation in the visible
wavelength range. The present invention also provides an
improved substrate for colorants and colorant compositions.
The improved substrates enable the production of superior
print quality while providing enhanced lightfastness for
colorants and colorant compositions against radiation including
radiation in the visible wavelength range.
The present invention also relates to colorant
compositions having improved stability, wherein the colorant
is associated with a colorant stabilizer. In one embodiment,
the colorant stabilizer comprises one or more porphines that
have an extremely short triplet state lifetime. (See e.g., Kubat,
et al., Photophysical properties of metal complexes of meso-
tetrakis (4-sulphonatophenyl) porphyrin, J. Photochem. and
Photbio. A: Chemistry 96 ( l996), pgs 93-97 which is
incorporated herein by reference). Particularly suitable
porphines include, but are not limited to, porphines having the
following general structure:
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wherein R is any proton-donating moiety and M is iron, cobalt
5 or copper. Desirably, R is S03H,
S03H ~ \ COOH ~ \ N-CH3
COON, or R 1 COOH wherein R 1 is an alkyl group of from 1 to
6 carbons.
Examples of such porphines are Cu-meso-tetra-(~.
sulfanatophenyl)-porphine (designated CuTPPS4) and Cu
meso-tetra-(N-methyl-4-pyridyl)-porphine, having the
following structures:
H03 03H
H03S S03H
and
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H :H3
CH3 CH3
The copper ion can also be substituted with an iron or cobalt
ion. Other- metal ions can be substituted in the porphine
molecule as long as the molecule has a relatively short-lived
triplet state.
In a further embodiment of the present invention, the
colorant stabilizer comprises at Least one porphine in
combination with at least one metal or metal salt.
Unexpectedly, it has been discovered that the incorporation of
a relatively small concentration of metal or metal salt into a
porphine-containing composition results in superior colorant
stability. Preferred metals or metal salts include, but are not
limited to, lanthanides and lanthanide salts. Lanthanide
elements include scandium, yttium, lanthanum, cerium
praseodymium, neodymium, promethium, samarium,
europium, gadolinium, terbium, dysprosium, holmium,
erbium, thulium, ytterbium, and lutetium.
In order to improve the solubility of the metal or metal
salt in solution, metal solubility-enhancing agents may be
added. Particularly useful metal solubility-enhancing agents
include) but are not limited to, chelating agents. Optionally, a
surfactant can be added to the metal/porphine composition to
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increase the interaction of the metal or metal salt and the
porphine. In addition to surfactants, other additives such as
TINUVIN~ compounds {Ciba-Geigy Corporation) may be
incorporated into the colorant composition.
The substrates to which the colorant stabilizers are
applied include, but are not limited to, paper, wood, a wood
product or composite, woven fabric, nonwoven fabric, textile,
plastic, glass, metal, or any other substrate that would benefit
from having a stabilized colorant thereon. In another
embodiment, a colorant stabilizer is present in a polymer
coating of a heat transfer product, such as is used for
transferring graphic images onto clothing.
Accordingly, each of the embodiments of the present
invention provide stabilizing molecules that, when one or more
of the stabilizing molecules are associated with a colorant,
stabilizes the colorant. Therefore, the stabilizing molecules
can be used as an additive to any colorant composition. For
example, as certain of the stabilizing molecules are poorly
soluble in water, they can be directly added to solvent or oil
based (not water based) colorant compositions. Additionally,
the stabilizing molecules can be added to other colorant
compositions that contain additives enabling the solubilization
of the stabilizing molecule therein. Further, the stabilizing
molecules can be solubilized in an aqueous solution by
_ attaching the molecule to a large water soluble molecule, such
as a cyclodextrin.
The colorant stabilizers are particularly effective in ink
jet inks. Use of the colorant stabilizers, as described herein,
intensifies the colors and stabilizes the colors when exposed to
- light. Additionally, the colorant stabilizers are particularly
effective in paper such as paper designed for use with ink jet
printers. Use of the colorant stabilizers in a substrate, as
described herein, stabilizes a colorant to which it is applied.
Also, colorant stabilizers in a substrate has been found to have
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the unexpected result of reducing the yellowing of the
substrate itself upon exposure to light.
The colorant stabilizers are of particular interest in the
formation of ink sets, wherein each ink of the ink set,
regardless of color, possesses substantially identical light
fastness properties as the other inks in the ink set. The ink set
enables the production of mufti-color text and/or graphics,
which uniformly retain their color over extended periods of
time and/or upon extended exposure to light.
The present invention is also directed to improved
substrates having thereon colorant compositions, such as the
colorant compositions described above. High print quality,
print vibrance, and colorant stability is achieved by combining
the aforementioned improved substrates and colorant
compositions.
These and other features and advantages of the -present
invention will-become apparent after a review of the following
detailed description of the disclosed embodiments and the
appended claims.
Detailed Description of the Invention
The present invention is directed to compositions and
methods for stabilizing colorants against radiation including
radiation in the visible wavelength range. The present
invention is further directed to ink sets comprising one or
more inks, each of which possesses substantially similar light
stability upon exposure to radiation, including radiation in the
visible wavelength range. The present invention is further
directed to improved substrates for colorants and colorant
compositions. The improved substrates enable the production
of superior print quality while providing enhanced
lightfastness for colorants and colorant compositions against
radiation, including radiation in the visible wavelength range.
The compositions and methods relating to stabilizing a colorant
by admixing a stabilizing molecule with a colorant solution
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will first be addressed below. Subsequently, the compositions
and methods relating to stabilizing a colorant by applying the
colorant to a treated substrate containing a stabilizing molecule
will be discussed.
As used herein, the term "composition" and such
variations as "colored composition" are used herein to mean a
colorant and one or more colorant stabilizers of the present
invention. The composition can optionally include a molecular
includant.
As used herein, the term "colorant" is meant to include,
without limitation, any material which typically will be an
organic material, such as an organic colorant or dye. The term
is meant to include a single material or a mixture of two or
more materials.
The term "light-stable" is used herein to mean that the
colorant, when associated with one of the colorant stabilizing
molecules of the present invention, is more stable to
. electromagnetic radiation, including, but not limited to,
sunlight or artificial light, than when the colorant is not
associated with such a compound.
The term "molecular includant," as used herein, is
intended to mean any substance having a chemical structure
which defines at least one cavity. That is, the molecular
includant is a cavity-containing structure. As used herein, the
term "cavity" is meant to include any opening or space of a
size sufficient to accept at least a portion of the colorant.
The term "functionalized molecular includant" is used
herein to mean a molecular includant to which one or more
molecules of a colorant stabilizer are covalently coupled to
each molecule of the molecular includant. The term "degree
of substitution" is used herein to refer to the number of these
molecules or leaving groups {defined below) which are
covalently coupled to each molecule of the molecular
includant.
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The term "derivatized molecular includant" is used
herein to mean a molecular includant having more than two
leaving groups covalently coupled to each molecule of
molecular includant. The term "leaving group" is used herein
to mean any leaving group capable of participating in a
bimolecular nucleophilic substitution reaction. Examples of
molecular includants include, but are not limited to, the
cyclodextrins.
The term "artificial light" is used herein to mean light
having a relatively broad bandwidth that is produced from
conventional light sources, including, but not limited to,
conventional incandescent light bulbs and fluorescent light
bulbs.
The term "thereon" is used herein to mean thereon or
therein. For example, the present invention includes a
substrate having a colored composition thereon. According to
the definition of "thereon" the colored composition may be
present on the substrate or it may be in the substrate.
Admixing Stabilizing Molecules Into Colorant Solutions.
The present invention relates to colorant compositions
having improved stability, wherein the colorant stabilizer is
associated with a colorant solution. Desirably, the colorant
stabilizer is admixed with a colorant solution. The colorant
stabilizer is desirably one or more porphines alone or in
combination with at least one metal or metal salt. The colorant
stabilizers of the present invention are admixed with a colorant
to stabilize the colorant when the admixture is exposed to
electromagnetic radiation such as artificial light or sunlight.
The present invention further relates to a method of
stabilizing a colorant comprising associating one or more of
the colorant stabilizers with the colorant solution. Optionally,
the colorant stabilizer may be associated with a molecular
includant, chelating agent, or other material to improve
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solubility and/or interaction of the colorant stabilizer and the
colorant.
In another embodiment of the present invention, a
colorant stabilizer is represented by porphines having an
extremely short triplet state lifetime. (See e.g., Kubat, et al.,
Photophysical properties of metal complexes of meso-tetrakis
(4-sulphonatophenyl) porphyrin, J. Photochem. and Photbio.
A: Chemistry 96 ( 1996), pgs 93-97 which is incorporated
herein by reference). Particularly suitable porphines include,
but are not limited to, porphines having the following
structure:
wherein R is any proton-donating moiety and M is iron, cobalt
or copper. Desirably, R is S03H,
S03H f ~ COOH ~ N-CH3
COOH, or R 1 COOH wherein R 1 is an alkyl group of from 1 to
6 carbons.
Desirably, the colorant stabilizer is represented by the
porphines Cu-meso-tetra-(4-sulfanatophenyl)-porphine
(designated CuTPPS4) and Cu-meso-tetra-(N-methyl-4-
pyridyl)-porphine (designated CuTMPS4), having the
following structure:
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H03 03H
U35 503H
or
CH
w3
The copper ion can also be substituted with an iron or cobalt
ion. It is also understood that in the case of FeTPPS4,
CuTPPS4 or CoTPPS4, the sulfuric acid moieties may be
substituted with salts when in solution, such as sodium salts.
The colorant solution may be stabilized with about 0.1 % to
10% wt/wt porphine, more preferably about 0.3 % to 1 %
wt/wt porphine, and more preferably about 0.5% wt/wt
porphine.
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In another embodiment, the colorant stabilizer
comprises one or more porphines in combination with one or
more metals or metal salts, such as lanthanides and lanthanide
salts. Desirably, the amount of metal or metal salt in the
colorant solution is from about 0.01 % to 10% wt/wt metal,
more desirably about 0.03% to 1% wt/wt metal, and most
desirably about 0.05% wt/wt metal. Although lanthanides and
lanthanide salts are desired metals, other metals, may also be
used such as magnesium, iron, zinc, and other transition
metals. To improve the solubility of the metal or metal salt in
solution, metal solubility-enhancing agents may be added.
Particularly useful metal solubility-enhancing agents include,
but are not limited to, chelating agents, including, but not
limited to, EDTA (ethylenediaminetetraacetic acid) or EGTA
(ethylene glycol-bis(13-aminoethyl ether)).
In a further embodiment, the colorant stabilizer
comprises a porphine and a lanthanide, such as europium.
Desirably, the amount of porphine in the colorant solution is
from about 0.1 % to 10% wt/wt porphine, more desirably
about 0.3% to 1% wt/wt porphine, and most desirably about
0.5% wt/wt porphine. Desirably, the amount of lanthanide in
the colorant solution is from about 0.01 % to 10% wt/wt
lanthanide, more desirably about 0.03% to 1% wt/wt
lanthanide, and most desirably about 0.05% wtlwt lanthanide.
Although europium and europium salts are desired lanthanides,
other metals in the lanthanides series may also be used.
Although not wanting to be limited by the following, it
is theorized that the above stabilizing compounds of the present
invention; either admixed with a colorant solution or on or in
a substrate to which the colorant is applied, act by quenching
the excited state of a dye molecule by efficiently returning it to
a ground state. This reduces the likelihood of an oxidative or
other chemical reaction occurring which would render the dye
chromophore colorless.
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The quenching process can occur by a number of
processes. One such process is referred to as the heavy atom
effect (internal or external) in which atoms with a high atomic
number, such as iodine, xenon and lanthanides, can effect the
excited electronic transitions of the dye molecule by allowing
here to fore forbidden electronic transitions to occur and by
decreasing the excited state lifetimes. This effect permits the
rapid return of the dye to its ground state.
Another quenching process involves back electron
transfer. In this case, quenching of the excited dye molecule
_ occurs through sequential electron transfer. The additive or
quencher, and dye form an ion pair through electron donation
within which back electron transfer leads to an overall
deactivation of the excited energy donor, i.e., the dye.
Another quenching process involves a condition in
which the quencher (additive) molecule has an excited energy
state lower than the excited dye. In this case, it may be
possible to transfer the excited energy to the quencher thereby
allowing the dye molecule to return to its ground state. These
mechanisms are more fully discussed in Chemistry and Light,
Suppan, P., Published by The Royal Society of Chemistry,
1994, pgs 65 - 69 which is incorporated herein by reference.
The dye or colorant, for example, may be an organic
dye. Organic dye classes include, by way of illustration only,
. triarylmethyl dyes, such as Malachite Green Carbinol base { 4
(dimethylamino)-oc-[4-(dimethylamino)phenyi]-a-phenyl-
benzene-methanol}, Malachite Green Carbinol hydrochloride
{ N-4-[[4-(dimethylamino)phenyl]phenyl-methylene]-2,5-
cyclohexyldien-1-ylidene]-N-methyl-methanaminium chloride
or bis[p-(dimethylamino)phenyl]phenylmethylium chloride },
and Malachite Green oxalate { N-4-[[4-(dimethylamino)-
phenyl]-phenylmethylene]-2,5-cyclohexyldien-1-ylidene]-N-
methyl-methanaminium chloride or bis[p-(dimethylamino)-
phenyl]phenylmethylium oxalate}; monoazo dyes, such as
Cyanine Black, Chrysoidine [Basic Orange 2; 4-(phenylazo)-
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1,3-benzenediamine monohydrochloride), Victoria Pure Blue
BO, Victoria Pure Blue B, basic fuschin and !3-Naphthol
Orange; thiazine dyes, such as Methylene Green, zinc chloride
double salt [3,7-bis(dimethylamino)-6-nitrophenothiazin-5-ium
chloride, zinc chloride double salt); oxazine dyes, such as
Lumichrome (7,8-dimethylalloxazine); naphthalimide dyes,
such as Lucifer Yellow CH { 6-amino-2-[{hydrazino-
carbonyi)amino)-2,3-dihydro-1,3-dioxo-1 H-benz[de)iso-
quinoline-5,8-disulfonic acid dilithium salt}; azine dyes, such
IO as Janus Green B { 3-(diethylamino)-7-[[4-(dimethyl-
amino)phenyl]azo]-5-phenylphenazinium chloride } ; cyanine
dyes, such as Indocyanine Green { Cardio-Green or Fox Green;
2-[7-[1,3-dihydro-1,1-dimethyl-3-(4-sulfobutyl)-2H-
benz[e]indol-2-ylidene]-1,3,5-heptatrienyl]-1,1-dimethyl-3-(4-
sulfobutyl)-IH-benz[eJindolium hydroxide inner salt sodium
salt}; indigo dyes, such as Indigo {Indigo Blue or Vat Blue 1;
2-( 1,3-dihydro-3-oxo-2H-indol-2-ylidene)-1,2-dihydro-3H-
indol-3-one } ; coumarin dyes, such as 7-hydroxy-4-methyl-
coumarin (4-methylumbelliferone); benzimidazole dyes, such
as Hoechst 332S8 [bisbenzimide or 2-(4-hydroxyphenyl)-5-(4-
methyl-1-piperazinyl)-2,5-bi-1 H-benzimidazole trihydro-
chloride pentahydrateJ; paraquinoidal dyes, such as
Hematoxylin {Natural Black l; 7,11b-dihydrobenz[bJ-
indeno[ 1,2-d]pyran-3,4,6a,9,10(6H)-pentol } ; fluorescein dyes,
such as Fluoresceinamine (5-aminofluorescein); diazonium salt
dyes, such as Diazo Red RC (Azoic Diazo No. 10 or Fast Red
RC salt; 2-methoxy-5-chlorobenzenediazonium chloride, zinc
chloride double salt); azoic diazo dyes, such as Fast Blue BB
salt (Azoic Diazo No. 20; 4-benzoylamino-2,5-diethoxy-
benzene diazonium chloride, zinc chloride double salt);
phenylenediamine dyes, such as Disperse Yellow 9 [N-(2,4-
dinitrophenyl)-1,4-phenylenediamine or Solvent Orange 53J;
diazo dyes, such as Disperse Orange 13 [Solvent Orange 52; 1-
phenylazo-4-(4-hydroxyphenylazo)naphthalene]; anthra-
quinone dyes, such as Disperse Blue 3 [Celliton Fast Blue FFR;
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1-methylamino-4-(2-hydroxyethylamino)-9,1D-anthraquinone],
Disperse Blue 14 [Celliton Fast Blue B; 1,4-bis(methylamino)-
9,10-anthraquinone], and Alizarin Blue Black B (Mordant
Black 13); trisazo dyes, such as Direct Blue 71 { Benzo Light
Blue FFL or Sirius Light Blue BRR; 3-[(4-[(4-[(6-amino-1-
hydroxy-3-sulfo-2-naphthalenyl)azo]-6-sulfo-1-naphthalenyl )-
azo]-1-naphthalenyl)azo]-1,5-naphthalenedisulfonic acid
tetrasodium salt } ; xanthene dyes, such as 2,7-dichloro-
fluorescein; proflavine dyes, such as 3,6-diaminoacridine
hemisulfate (Proflavine); sulfonaphthalein dyes, such as Cresol
Red (o-cresolsulfonaphthalein); phthalocyanine dyes, such as
Copper Phthalocyanine { Pigment Blue 15; (SP-4-1 )-[29H,31 H-
phthalocyanato(2-)-N29,N30,N31~N32]copper}; carotenoid
dyes, such as traps-13-carotene (Food Orange 5); carminic acid
dyes, such as Carmine, the aluminum or calcium-aluminum
lake of carminic acid (7-a-D-glucopyranosyl-9,10-dihydro-
3,5,6,8-tetrahydroxy-1-methyl-9,10-dioxo-2-anthracene-
carbonylic acid); azure dyes, such as Azure A [3-amino-7-
(dimethylamino)phenothiazin-5-ium chloride or 7-(dimethyl-
amino)-3-imino-3H-phenothiazine hydrochloride]; and acridine
dyes, such as Acridine Orange [Basic Orange 14; 3,8-
bis(dimethylamino)acridine hydrochloride, zinc chloride
double salt] and Acriflavine (Acriflavine neutral; 3,6-diamino-
10-methylacridinium chloride mixture with 3,6-acridine-
diamine).
In some embodiments of the present invention, the
colorant and/or colorant stabilizer is associated with a
molecular includant. The term "associated" in its broadest
sense means that the colorant and/or colorant stabilizer is at
least in close proximity to the molecular includant. For
example, the colorant and/or colorant stabilizer may be
maintained in close proximity to the molecular includant by
hydrogen bonding, van der Waals forces, or the like.
Alternatively, the colorant and/or colorant stabilizer may be
covalently bonded to the molecular includant; although this
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normally is neither desired nor necessary. As a further
- example, the colorant and/or colorant stabilizer may be at least
partially included within the cavity of the molecular includant.
The molecular includant can be added to the colorant
solution or incorporated into a substrate, such as paper) which
is subsequently coated with the colorant solution. The
molecular includant can be inorganic or organic in nature. In
certain embodiments, the chemical structure of the molecular
includant is adapted to form a. molecular inclusion complex.
Examples of molecular includants are, by way of illustration
only, clathrates or intercalates, zeolites) and cyclodextrins.
Examples of cyclodextrins include, but are not limited 'to, a-
cyclodextrin, ~i-cyclodextrin, y-cyclodextrin, b-cyclodextrin,
hydroxypropyl (3-cyclodextrin, hydroxyethyl (3-cyclodextrin,
hydroxyethyl a cyclodextrin, carboxymethyl oc cyclodextrin,
carboxymethyl ~3 cyclodextrin, carboxymethyl y cyclodextrin,
octyl succinated a cyclodextrin, octyl succinated
cyclodextrin, octyl succinated 'y cyclodextrin and sulfated ~i
cyclodextrin and sulfated 'y-cyclodextrin (Cerestar U.S.A.,
Incorporated) Hammond, Indiana).
The term "derivatized cyclodextrin" as used herein
means a cyclodextrin having more than two leaving groups
covalently coupled to each molecule of cyclodextrin. The term
"leaving group" is used herein to mean any leaving group
capable of participating in a bimolecular nucleophilic
substitution reaction. Examples of derivatized cyclodextrin
includes, but is not limited to, hydroxypropyl (3-cyclodextrin,
hydroxyethyl (3-cyclodextrin, hydroxyethyl a cyclodextrin,
carboxymethyl a cyclodextrin) carboxymethyl (3 cyclodextrin,
carboxymethyl 7 cyclodextrin, octyl succinated a cyclodextrin,
octyl succinated ~i cyclodextrin, octyl succinated 'y cyclodextrin
and sulfated (3 and 'y-cyclodextrin. A desired derivatized
cyclodextrin is ethylhydroxy ~3-cyclodextrin.
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A desired molecular includant is y-cyclodextrin.
Another desirable molecular includant is ~i-cyclodextrin. In
other embodiments, the molecular includant is an ethyl
hydroxy (3-cyclodextrin. Although not wanting to be bound by
the following theory, it is believed that the molecular includant
inhibits the aggregation of the colorant molecule in solution.
Other aggregation inhibitors that can be used in practicing the
present invention are starches, pectins, amyloses, clathrates and
the crown ethers. It is to be understood that the addition of
derivatized cyclodextrins to an ink formulation for the purpose
of inhibiting aggregation and/or stabilizing the dyes in the inks
is considered one aspect of the present invention.
As a practical matter, the colorant, the colorant
stabilizer and molecular includant are likely to be solids
depending upon the constituents used to prepare the molecules.
However, any or a11 of such materials can be a liquid. The
colored -composition can be a liquid either because one or
more of its components is a liquid, or, when the molecular
includant is organic in nature, a solvent is employed. Suitable
solvents include, but are not limited to, amides, such as N,N-
dimethylformamide; sulfoxides, such as dimethylsulfoxide;
ketones, such as acetone, methyl ethyl ketone, and methyl butyl
ketone; aliphatic and aromatic hydrocarbons, such as hexane,
octane, benzene, toluene, and the xylenes; esters, such as ethyl
acetate; water; and the like. When the molecular includant is a
cyclodextrin, particularly suitable solvents are the amides and
sulfoxides.
In an embodiment where the composition of the present
invention is a solid, the effectiveness of the above compounds
on the colorant is improved when the colorant and the selected
compounds are in intimate contact or in an association that
approaches van der Waals radii. To this end, the thorough
blending of the components, along with other components
which may be present, is desirable. Such blending generally is
accomplished by any of the means known to those having
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19
ordinary skill in the art. When the colored composition
includes a polymer, blending is facilitated if the colorant and
the colorant stabilizer are at least partly soluble in softened or
molten polymer. In such case, the composition is readily
prepared in, for example, a two-roll mill. Alternatively, the
composition of the present invention can be a liquid because
one or more of its components is a liquid.
For some applications, the composition of the present
invention typically will be utilized in particulate form. In
other applications, the particles of the composition should be
very small. Methods of forming such particles are well known
to those having ordinary skill in the art.
The colored composition optionally may also contain a
carrier, the nature of which is well known to those having
ordinary skill in the art. For many applications, the carrier
will be a polymer, typically a thermosetting or thermoplastic
polymer, with-the latter being the more common. Examples
of thermoplastic polymers include, but are not limited to_: end-
capped polyacetals, such as poly(oxymethylene) or
polyformaldehyde, poly(trichloroacetaldehyde), poly(n-
valeraldehyde), poly(acetaldehyde), poly(propionaldehyde),
and the like; acrylic polymers, such as polyacrylamide,
poly(acrylic acid), poly(methacrylic acid), poly(ethyl
acrylate), poly(methyl methacrylate), and the like;
fluorocarbon polymers, such as poly(tetrafluoroethylene),
perfluorinated ethylenepropylene copolymers, ethylene-
tetrafluoroethylene copolymers, poly-(chlorotrifluoro-
ethylene), ethylene-chlorotrifluoroethylene copolymers,
poly(vinylidene fluoride), polyvinyl fluoride), and the like;
epoxy resins, such as the condensation products of
epichlorohydrin and bisphenol A; polyamides, such as poly(6-
aminocaproic acid) or poly(-caprolactam), poly(hexa-
methylene adipamide), poly(hexamethylene sebacamide),
_ poly(11-aminoundecanoic acid), and the like; polyaramides,
such as poly(imino-1,3-phenyleneiminoisophthaloyl) or
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poly(nZ- phenylene isophthalamide), and the like; parylenes,
- such as poly-p-xylylene, poly(chloro-p-xylene), and the like;
polyaryl ethers, such as poly(oxy-2,6-dimethyl-1,4-phenylene)
or polyp-phenylene oxide), and the like; polyaryl suifones,
5 such as poly(oxy-1,4-phenylenesulfonyl-1,4-phenyleneoxy-1,4
phenylene-isopropylidene-1,4-phenylene), poly(sulfonyl-1,4-
phenyleneoxy-1,4-phenylenesulfonyl-4,4-biphenylene), and the
like; polycarbonates, such as poly(bisphenol A) or
poly(carbonyldioxy-1,4-phenyieneisopropylidene-1,4-
10 phenylene), and the like; polyesters, such as polyethylene
terephthalate), poly(tetramethyiene terephthalate), poly(cyclo-
hexylene-1,4-dimethylene terephthalate) or poly(oxy-
methylene-1,4-cyclohexylenemethyleneoxyterephthaloyl), and
the like; polyaryl sulfides, such as polyp-phenylene sulfide) or
15 poly(thio-1,4-phenylene), and the like; polyimides, such as
poly(pyromellitimido-1,4-phenylene), and the like;
polyolefins, such as polyethylene, polypropylene, poly(1-
butene), poly(2-butene), poly( 1-pentene), poly(2-pentene),
poly(3-methyl-1-pentene), poly(4-methyl-1-pentene), 1,2-poly-
20 1,3-butadiene, 1,4-poly-1,3-butadiene, polyisoprene,
polychloroprene, polyacrylonitrile, polyvinyl acetate),
poly(vinylidene chloride), polystyrene, and the like; and
copolymers of the foregoing, such as acrylonitrile-buta-
dienestyrene (ABS) copolymers, styrene-n-butylmethacrylate
copolymers, ethylene-vinyl acetate copolymers, and the like.
Some of the more commonly used thermoplastic
polymers include styrene-n-butyl rnethacrylate copolymers,
polystyrene, styrene-n-butyl acrylate copolymers, styrene-
butadiene copolymers, polycarbonates, poly(methyl
methacrylate), poly(vinylidene fluoride), polyamides (nylon-
12), polyethylene, polypropylene, ethylene-vinyl acetate
copolymers, and epoxy resins.
Examples of thermosetting polymers include, but are not
- limited to, alkyd resins, such as phthalic anhydride-glycerol
_ resins, malefic acid-glycerol resins, adipic acid-glycerol resins,
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and phthalic anhydride-pentaerythritol resins; allylic resins, in
which such monomers as diallyl phthalate, diallyl isophthalate
diallyl maleate, and diallyl chlorendate serve as nonvolatile
cross-linking agents in polyester compounds; amino resins,
such as aniline-formaldehyde resins, ethylene urea-
formaldehyde resins, dicyandiamide-formaldehyde resins,
melamine-formaldehyde resins, sulfonamide-formaldehyde
resins, and urea-formaldehyde resins; epoxy resins, such as
cross-linked epichlorohydrin-bisphenol A resins; phenolic
resins, such as phenol-formaldehyde resins, including Novolacs
and resols; and thermosetting polyesters, silicones, and
urethanes.
In addition to the colorant, colorant stabilizer, and
optional molecular includant, the colored composition of the
present invention also can contain additional components,
depending upon the application for which it is intended.
Examples of such additional components include, but are not
limited to, charge carriers; stabilizers against thermal
oxidation; viscoelastic properties modifiers; cross-linking
agents; plasticizers; charge control additives such as a
quaternary ammonium salt; flow control additives such as
hydrophobic silica, zinc stearate, calcium stearate, lithium
stearate, polyvinylstearate, and polyethylene powders; fillers
such as calcium carbonate, clay and talc; surfactants; buffer/pH
adjusters; chelating agents; wetting agents; corrosion
inhibitors; biocides; and TINUVIN~ compounds; among other
additives used by those having ordinary skill in the art.
Charge carriers are well known to those having ordinary skill
in the art and typically are polymer-coated metal particles.
Desirable surfactants include, but are not limited to, C 12 to
C 1 g surfactants such as cetyl trimethyl ammonium chloride,
carboxymethylamylose, and acetylene glycols such as
SURFYNOL~ 104E. Desirable buffer/pH adjusters include,
but are not limited to, borax, hydrochloric acid and sodium
hydroxide. Desirable chelating agents include, but are not
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limited to, EDTA and EDTA complexes or salts. Desirable
wetting agents include, but are not limited to, ethylene glycol
and glycerine. Desirable corrosion inhibitors include, but are
not limited to, a benzotriazole sold under the tradename
COBRATEC~ 99. Desirable biocides include, but are not
limited to, 2,6-dimethyl-m-dioxan-4-of acetate sold under the
tradename GIV-GARD DXN~. TINUVIN~ compounds are a
class of compounds produced by Ciba-Geigy Corporation,
which includes benzophenones, benzotriazoles and hindered
amines. Desirable TINUVIN~ compounds include, but are
not limited to, 2-(2'-hydroxy-3'-sec-butyl-5'-tert-butylphenyl)-
benzo-triazole, poly-(N-(3-hydroxyethyl-2,2,6,6-tetramethyl-
4-hydroxy-piperidyl succinate and 2-(2'-hydroxy-3',5'-ditert
butylphenyl)-5-chloro-benzotriazole. The identities and
amounts of such additional components in the colored
composition are well known to one of ordinary skill in the art.
When the colorant stabilizers of the present invention
are used to stabilize the dyes in ink jet inks, it is desirable to
filter the compositions through a small pore filter (0.4~ p,)
such as a Millipore~ filter before the ink formulation is placed
in an ink jet cartridge. This will reduce or eliminate clogging
of the cartridge ink nozzles due to particulate matter.
The colorant stabilizers of the present invention enable
the formation of ink sets comprising one or more inks,
wherein each ink of the ink set, regardless of color, possesses
similar light fastness properties as the other inks in the ink set.
Such ink sets may be used to produce mufti-color text and/or
graphics; which uniformly retain their color over extended
periods of time and/or upon extended exposure to light. One
desirable ink set includes cyan, magenta, yellow and black
inks, wherein the magenta ink contains colorant stabilizers in
the form of a porphine and a metal, such as europium, and the
yellow ink contains a colorant stabilizer in the form of a
porphine without the metal. Another desirable ink set includes
cyan, magenta, yellow and black inks, wherein the cyan ink
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contains a colorant stabilizer in the form of a benzophenone,
and the magenta and yellow inks contain colorant stabilizers in
the form of a porphine and a metal) such as europium.
It is to be understood that in any desired ink set, a single
ink may be stabilized according to the present invention or
several of the inks may be stabilized utilizing one or more of
the stabilizing agents described herein. Other ink sets are
within the scope of the present invention. Included in the
present invention are ink sets wherein the black color is a'
pigment and the other colors in the ink set are dyes. Although
ink sets wherein the inks possess substantially identical light
fastness properties are desirable, in some embodiments, it may
be desirable to produce ink sets wherein the inks within the ink
set have specifically controlled, varying light fastness
properties.
The substrates to which the colorant and colorant
stabilizers are applied include, but are not limited to, paper,
wood, a wood product or composite, woven fabric, nonwoven
fabric, textile, plastic, glass, metal, or any other substrate that
would benefit from having a stabilized colorant thereon. A
plastic substrate includes, but is not limited to, a plastic film, a
plastic nonwoven web, or a plastic woven web. A preferred
substrate is paper. Any existing or future type of paper or
paper products may be used in the present invention.
Examples of paper or paper products include, but not
limited to, printing and writing papers, packaging and
industrial papers, paperboard, and tissue papers. Examples of
printing and writing papers include, but are not limited to the
following: wood-free coated papers; wood-containing coated
papers; wood-free uncoated papers such as bond and writing
paper, envelopes, offset and opaque circular, carbonless,
tablet, forms bond, ledger, mimeograph, and manifold,
duplication, fax base, thermal base, technical papers,
supercalandered, and specialty papers; uncoated wood-
containing papers such as supercalandered, directory, specialty
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converting and publishing; bristols such as coated bristols,
uncoated bleached bristols, tag, coated tag papers, file folders,
and tabulating; and thin papers such as cigarette paper, bible
paper, lightweight paper, lightweight specialty, manifold,
cotton fiber papers, and specialty thin papers.
Examples of packaging and industrial papers include,
but are not limited to the following: breached Kraft paper
such as grocers bags, shipping sacks, wrapping paper, and
converting paper; unbleached Kraft paper such as grocers
bags, shipping sacks converting paper, wrapping paper, and
envelopes. Examples of paperboard include, but are not
limited to the following: containerboard such as unbleached
linerboard, bleached linerboard, corrugated medium, and chip
and filler board; folding boxboard/folding cartonboard such as
solid bleached sulfite, bleached and unbleached bristols, coated
recycled board, coated unbleached Kraft, milk, cup, plate and
foodservice stock (coated or uncoated), and folding board;
gypsum wallboard; and tube/can and drum paperboard.
Examples of tissue papers include, but are not limited to,
sanitary tissues such as bathroom tissue, facial tissue, napkins,
toweling, wiper stock, and other sanitary tissue papErs.
Improved substrates of the present invention are
particularly suitable for colorants and colorant compositions.
The improved substrates enable the production of superior
print quality while providing enhanced lightfastness for
colorants and colorant compositions against radiation including
radiation in the visible wavelength range. The improved
substrates are suitable for use with any colorant or colorant
composition, and especially colorant or colorant compositions
containing one or more light stabilizers as described above.
The improved substrate of the present invention
comprises a base layer coated with a binder composition
containing one or more polymeric binders in combination with
one or more cyclodextrins. The base layer, to which the
binder composition is applied, includes, but is not limited to,
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paper, wood, a wood product or composite) woven fabric,
nonwoven fabric, textile, plastic, Glass, metal, or any other
substrate capable of maintaining the binder composition
thereon. Examples of suitable substrates are disclosed above.
5 The base layer may comprise one or more of the above-
mentioned layers. Desirably, the base layer is a coated or
uncoated fiber-containing substrate such as Photoglossy Base,
Presentation Matte Photobase, and High Quality Matte papers
and Wetstrength Media; a film such as White Opaque Films
10 (e.g. KIMDURA~, K-C), Clears Films (e.g. MELINEX~,
ICI) Backlit Films, and Vinyl; or a nonwoven such as
TY V EK~ . More desirably, the base layer is a coated or
uncoated paper. Most desirably, the base layer is a coated
paper comprising a cellulose sheet coated with a polymeric
I S film, such as polyethylene.
The binder composition contains one or more polymeric
binders. Suitable binder materials include, but are not limited
to, naturally-occurring polymers, synthetically-modified
naturally-occurring polymers or synthetic polymers as
20 exemplified in Water-Soluble Polymers, C. L. McCormick, J.
Bock, and D. N. Schulz, in Vol. 17, Enc~~edia of Polymer
Science and Engineering, John Wiley and Sons, Publishers
( 1989), pgs. 730-84. Desirably, the binder composition
contains one or more of the following polymers:
25. polyvinylpyrrolidone (PVP), polyvinylalcohol (PVOH),
polyhydroxyethyl acrylate, polyhydroxyethyl methacrylate,
polyacrylamide, polymethacrylamide, polyethylene glycol,
carboxymethyl cellulose, sodium carboxymethyl cellulose,
hydroxypropyl cellulose, hydroxyethyl cellulose, polyacrylic
acid and polyacrylic acid salts, polymethacrylic acid and
polymethacrylic acid salts, polyvinylsulfonate and
polyvinylsulfonate salts, poly-2-acrylamido-2-
methylpropanesulfonic acid and poly-2-acrylamido-2-
methylpropanesulfonic acid salts, polyacryloxy-
trimethylammonium chloride, polymethacryloxytrimethyl-
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ammonium chloride, and polydiallyldimethylammoniurn
chloride. Desirably, the binder composition contains sodium
carboxymethyl cellulose, polyvinylpyrrolidone (PVP),
polyvinylalcohol (PVOH) or a combination thereof.
The binder composition also contains one or more
cyclodextrins. Suitable cyclodextrins include, but are not
limited to) a-cyclodextrin, (3-cyclodextrin, y-cyclodextrin, b-
cyclodextrin, hydroxypropyl ~3-cyclodextrin, hydroxyethyl (3-
cyclodextrin, hydroxyethyl a cyclodextrin, carboxymethyl a
cyclodextrin, carboxymethyl (3 cyclodextrin, carboxymethyl ~y
cyclodextrin, octyl succinated a cyclodextrin, octyl succinated
(3 cyclodextrin, octyl succinated 'y cyclodextrin and sulfated (3
cyclodextrin and sulfated y-cyclodextrin (Cerestar USA
Incorporated, Hammond, Indiana). Desirably) the binder
composition contains (3-cyclodextrin (~i-CD), hydroxypropyl
~i-cyclodextrin (hp-(3-CD), or a combination thereof.
In one-embodiment of the present invention, the binder
composition contains from about 90 to about 10 weight percent
polymeric binder and from about 10 to about 90 weight
percent cyclodextrin. More desirably, the binder composition
contains from about 75 to about 25 weight percent polymeric
binder and from about 25 to about 75 weight percent
cyclodextrin. Most desirably, the binder composition contains
from about 65 to about 25 weight percent polymeric binder
and from about 35 to about 75 weight percent cyclodextrin.
In addition to the polymeric binder and the cyclodextrin,
the binder composition of the present invention may also
contain additional components. Examples of such additional
components include, but are not limited to, charge carriers;
stabilizers against thermal oxidation; viscoelastic properties
modifiers; cross-linking agents; plasticizers; charge control
additives such as a quaternary ammonium salt; flow control
additives such as hydrophobic silica, zinc stearate, calcium
stearate, lithium stearate, polyvinylstearate, and polyethylene
powders; fillers such as calcium carbonate, clay and talc;
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surfactants; detacktifiers; chelating agentsr_and TINUVINQ
compounds; among other additives used by those having
ordinary skill in the art. Charge carriers are well known to
those having ordinary skill in the art and typically are
polymer-coated metal particles. Desirable surfactants include,
but are not limited to, C 12 to C 1 g surfactants such as cetyl
trimethyl ammonium chloride and carboxymethylamylose, and
other surfactants such as Triton X- l00 and SURFYNOL~ 420.
TINUVIN~ compounds are a class of compounds produced by
Ciba-Geigy Corporation, which includes benzophenones,
benzotriazoles and hindered amines. Desirable TINUVIN~
compounds include, but are not limited to, 2-(2'-hydroxy-3'-
sec-butyl-5'-tent-butylphenyl)-benzo-triazole, poly-(N-f3-
hydroxyethyl-2,2,6,6-tetramethyl-4-hydroxy-piperidyl
succinate and 2-(2'-hydroxy-3',5'-ditertbutyiphenyl)-5-
chloro-benzotriazole. The identities and amounts of such
additional components in the colored composition are well
known to one of ordinary skill in the art. Typically, one or
more of the above additives are present in the binder
composition in an amount of from about 1 to 14 weight
percent based on the total weight of the binder composition.
In one embodiment of the present invention, the binder
composition contains filler material in the form of particles.
The incorporation of selected particulate material in the binder
composition results in a rougher outer coating surface, which
improves processibility (i.e., printer rolls grab the substrate
more readily), and prevents "set-off" (i.e., prevents extensive
contact between the printed image and an adjacent sheet or
substrate). Particles having a particle size than less or equal to
the coating thickness have been found to provide desirable
print quality. Any particle may be used in the binder
composition provided that the particle does not dull the gloss
of the improved substrate. Suitable particles include, but are
not limited to, starch particles, polyamide particles,
polyethylene particles and aluminum trihydrate particles.
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Desirably, the particles comprise polyamide particles having a
particle size of about 12 to about 50 microns.
The binder composition is coated onto the base layer by
any conventional coating method including, but not limited to)
rod coating, dip coating, spray coating, gravure coating, knife
coating, slot coating, and roller coating. Desirably, the binder
composition is applied to the base layer by a process wherein
the binder composition is transferred from a bath onto a roller
which extends into the bath, and onto at least one surface of the
base layer. Optionally, the same or a different coating may be
provided on the same or an opposite side of the base layer.
The coated base layer then passes under or over a rod, which
meters excess coating from the base layer. Once coated, the
base layer is dried in a conventional oven or by any other
means.
The amount of binder composition coated onto a surface
of the base layer may vary depending upon the type of base
layer used and the application of the final product. For
example, a base layer in the form of an uncoated paper may
require more binder composition coating than a base layer in
the form of a coated paper or film due to the increased
porosity of the base layer. Desirably, the binder composition
is applied to a base layer to produce a coating weight of from
about 3.0 to about 60.0 g/m2 of base layer surface area. More
desirably, the coating weight is from about 9.0 to about 23.0
g/m2 of base layer surface area. More desirably, the coating
weight is from about 15.0 to about 20.0 g/m2 of base layer
surface area.
Although not wanting to be limited by the following, it -
is theorized that the improved substrates of the present
invention and the above stabilizing compounds act by
quenching the excited state of a dye molecule by efficiently
returning it to a ground state. This reduces the likelihood of
an oxidative or other chemical reaction occurring which would
render the dye chromophore colorless. The improved
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substrates of the present invention, alone or in combination
- with the above stabilizing compounds, provide stability to any
dye or colorant, including those mentioned above.
The improved substrate of the present invention may
also be suitable for use with colored compositions within a
carrier. For many applications, the carrier will be a polymer,
typically a thermosetting or thermoplastic polymer, with the
latter being the more common. Examples of suitable
thermosetting and thermoplastic .polymers are disclosed above.
The present invention is further described by the
examples which follow. Such examples, however, are not to
be construed as limiting in any way either the spirit or scope
of the present invention. In the examples, a11 parts are parts
by weight unless stated otherwise.
EXAMPLE 1
Preparation and Testing of Inks Containing Porphine Colorant
Stabilizers
This example reports the results of fade testing of
various inks, either with or without the stabilizing additives of
the present invention, on treated or untreated paper. More
particularly, the paper is untreated Hewlett-Packard premium
paper, or treated Hewlett-Packard premium paper prepared
using a solution of about 50% wt/wt hydroxypropyl 'y
cyclodextrin to ink, in or on the paper in a concentration of
about 5 to 15 % wt/wt solution to paper.
The stabilizing additives of this example are porphines.
Specifically, the porphines Cu-meso-tetra-(4-sulfanatophenyl)-
porphine (designated CuTPPS4) and Cu-meso-tetra-(N-methyl-
4-pyridyl)-porphine (designated CuTMPS4) (available from
Porphyrin Products, Inc., Logan, UT) were used, which are
represented by the following structures, respectively:
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H03 03H
11U35 S03H
and
H
CH
,....3
5
The invention provides that the metal ions Cu, Co or Fe
may be used interchangeably in the porphine structures of the
present invention. Additional background on the chemistry of
porphines can be found in Kubat et al. "Photophysical
10 properties of metal complexes of meso-tetrakis (4-
sulphonatophenyl) Porphyrin," Journal of Photochemistry and
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Photobiology A: Chemistry 96 ( l996) 93-97, and references
cited therein, hereby incorporated by reference.
Printed sheets of paper were placed in the Atlas
weatherometer and exposed for the designated number of
hours under the following conditions: 0.54 W/m2 at 440 nm,
55% humidity, 45~C black panel temperature, borosilicate
filters.
The change in magenta color is measured by the Xrite
Colorimeter {Model 938, SpectroDensitometer, Grandville,
Michigan) which measures the ~E* values, based on the L, a~',
b* as described by Cielab, D-50-2. The results are reported in
the tables below.
The treated and untreated paper is printed with inks
designated Al, A2, A3, A4, B1, B2, B3, B4, C1, C2, C3, and
C4) prepared as follows:
A1 Ink __ DI Water 84.80%
2 Pyrrolidone 10.00
GIV-GARD DXN~ 00.20 --
COBRATEC~ 99 00.10
Triethanolamine 00.50
Reactive Red 120 4.00
Acid Red 52 0.40
A2 Ink DI Water 85.40%
2 Pyrrolidone 10.00
GIV-GARD DXN~ 00.20 _
COBRATEC~ 99 00.10
Triethanolamine 00.50
Reactive Red 120 3.00
Acid Red 52 0.80
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- A3 Ink DI Water 86.00%
2 Pyrrolidone l0.00
GIV-CARD DXN~ 00.20
COBRATEC~ 99 00.10
Triethanolamine 00.50
Reactive Red 120 2.00
Acid Red 52 1.20
A4 Ink DI Water 86.60%
2 Pyrrolidone 10.00
GIV-GARD DXN~ 00.20
COBRATEC~ 99 00.10
Triethanolamine 00.50
Reactive Red l20 1.00
Acid Red 52 1.60
B 1 Ink DI Water 83.02%
2 Pyrrolidone 10.00
GIV-GARD DXN~ 00.20
COBRATEC~ 99 00.10
Triethanolamine 00.50
Reactive Red 120 5.78
Acid Red 52 0.40
B2 Ink DI Water 84.07%
2 Pyrrolidone I0.00
GIV-GARD DXN~ 00.20
COBRATEC~ 99 00.l0
Triethanolamine 00.50
Reactive Red 120 4.33
Acid Red 52 0.80
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B3 Ink DI Water 85.11 %
2 Pyrrolidone l0.00
GIV-GARD DXN~ 00.20
COBRATEC~ 99 00.l0
Triethanolamine 00.50
Reactive Red l20 2.89
Acid Red 52 l.20
B4 Ink DI Water 86.16%
2 Pyrrolidone l0.00
GIV-GARD DXN~ 00.20
COBRATEC~.99 00.10
Triethanolamine 00.50
Reactive Red l20 1.44
Acid Red 52 1.60
C 1 Ink DI Water 82.62%
2 Pyrrolidone l0.00
GIV-GARD DXN~ 00.20
COBRATEC~ 99 00.10
Triethanolamine 00.50
Reactive Red I20 6.18
Acid Red 52 0.40
C2 Ink DI Water 82.62%
2 Pyrrolidone _ 10.00
GIV-GARD DXN~ 00.20
COBRATEC~ 99 00.l0
Triethanolamine 00.50
Reactive Red 120 4.63
Acid Red 52 0.80
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C3 Ink DI Water 84.9I %
2 Pyrrolidone 10.00
GIV-GARD DXN~ 00.20
COBRATEC~ 99 00.10
Triethanolamine 00.50
Reactive Red 120 3.09
Acid Red 52 l.20
C4 Ink DI Water 86.06%
2 Pyrrolidone l0.00
GIV-GARD DXN~ 00.20
COBRATEC~ 99 00.l0
Triethanolamine 00.50
Reactive Red 120 1.54
Acid Red 52 1.60
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The above inks were fade tested with the following
results.
5 Inks Without Additives
Ink ID# 63H
t1E* OH*
Al 47.8 7.5
A2 57.5 21.6
A3 60.7 33.8
A4 62.1 43.2
B 1 38 -0.54
B2 46.4 l4.8
B3 56.3 28.4
B4 64.7 39.1
Cl 69.4 2.6
C2 64.3 11.3
C3 72.4 20.~-
C4 83.9 22.7
The inks were prepared with about 0.5% CuTPPS4
stabilizing additive and fade tested on HP paper and HP Y CD
paper with the following results.
SU9STITUTE SHEET (RULE 26)
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Inky made with 0.5 % CuTPPSd on HP premium naner
Samples 15H 78H 94H
ID#
DE* OH* DE* OH* DE* OH*
A1 9.6 4.8 34.7 12.l 41.6 l2.8
A2 14.7 12.8 41.8 23.8 48.8 24.9
A3 l9.6 18.7 42.7 31.9 47 32.7
A4 29.6 28.9 51.8 42.4 55.5 42.1
Bl 8.2 1.8 30.6 8.8 38.2 9.2
B2 8.3 6.3 32.3 17.8 37.8 l8.8
B3 l4.9 13.8 39.0 27.5 44.5 28.6
B4 25.2 24.6 47.7 38.3 51.6 38.5
C 1 14. 3 -7.71 41. 8 8 .9 N/A N/A
C2 7.9 -2.7 33.7 13.9 N/A NIA
C3 9.2 6.9 37.9 23.6 N/A N/A
C4 23.l 22.2 48.6 37.7 N/A N/A
SUBSTITUTE SHEET (RULE 26)
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Tnkc with 0.5~h CuTPPSd on Hvdroxv-Pronvl v-CD saner
Samples 15H 78H 94H
ID#
DE* OH* DE* ~H* DE* ~H*
A1 1.5 -0.2 6.6 -3.2 8 -4.1
A2 1.2 0.28 4.1 -0.8 5 .4 -1.3
A3 2.8 2.14 5 4.3 5.2 4.3
A4 4.9 4.7 l0.4 9.8 l0.2 9.5
B 1 3.1 -1.5 9.4 -5.5 11.2 -6.9
B2 2.3 -2.4 7.7 -5.2 8.3 -5.7
B3 1.2 1.1 4.1 0.13 4.7 -0.79
B4 2.9 2.6 7.2 6.3 7.7 6.5
C 1 4 -3 .3 17 . -13. N/A N/A
l 8
C2 3 -2.6 3.4 -2.8 NIA N/A
C3 1.6 -1.5 5.2 -3 .3 NIA N/A
C4 1.4 I.1 4.7 3.5 N/A N/A
Additionally, HP-1600 magenta ink was prepared with
about 0.5% CuTPPS4 stabilizing additive and fade tested on HP
paper and HP y-CD paper with the following results.
SUBSTITUTE SHEET (RULE 26)
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15 Hour Multiple Samules
Sam les ID# DE* OH*
HP#1 l4.68 13.l3
HP#2 20.86 19.50
HP#3 17.01 1 S.SS
HP#4 13.04 11.15
HP#S l3.11 10.57
HP#6 13.09 11.10
HP -CD #1 2.66 -l.47
HP -CD #2 1.20 -. S 3
HP -CD #3 2.44 -.S3
HP -CD #4 1.30 -.47
HP -CD #5 l.74 -.30
HP -CD #6 1.3S -.34
The HP-1600 magenta ink was also prepared with about
O.S% CuTMPS4 stabilizing additive and fade tested on-HP
S paper and HP y-CD paper with the following results.
15 Hour Multiple Samples
HP#1 13.94 1 l.39
HP#2 13.S8 11.11
HP#3 l3.98 11.S7
HP#4 14.16 11.S6
HP -CD #1 2.32 -.99
HP -CD #2 1.44 -1.0S
HP -CD #3 2.17 -.67
HP -CD #4 1.98 -1.21
HP -CD #S 2.14 -1.38
HP -CD #6 1.79 -.8S
HP CD #7 .36 .1 S
SUBSTITUTE SHEET (RULE 28)
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EXAMPLE 2
Preparation and Testing of Inks Containing Porphine and
Lanthanide Colorant Stabilizers
This example reports the results of fade testing of
various inks, either with or without the stabilizing additives of
the present invention, on untreated paper. More particularly,
the paper is untreated QIS Photo Glossy paper.
The stabilizing additives of this example are porphines
and europium salts. Specifically, the porphine Cu-meso-tetra-
(4-sulfanatophenyl)-porphine (designated CuTPPS4) (available
from Porphyrin Products, Inc., Logan, UT) is used, as in
Example 1 above. The europium salt, europium nitrate
(designated EuN) (Strem Chemical Co., Newburyport, MA) is
used.
A forty-eight hour accelerated fade test of various
magenta ink composition was performed. A magenta control
without stabilizing additives was applied to the QIS paper
medium. After subjecting the ink composition and paper
medium to the forty-eight hour test, DE* and ~H* values were
measured. Similar measurements were taken using the
following ink formulations:
a) magenta + 0.5 wt% CuTPPS4
b) magenta + 0.05 wt% EuN
c) magenta + 0.5 wt% CuTPPS4 + 0.05 wt% EuN.
The resulting measurements are given below.
Ink Formulation Media OE'~ OH*
Ma enta Control IS Photo Gloss 31.8 24.5
Ma enta + CuTPPS4 QIS Photo Gloss 16.4 -3.7
Ma enta + EuN IS Photo Gloss l9.6 l7.3
Magenta + CuTPPS4 QIS Photo Glossy 7.8 2.8
+
EuN
SUBSTITUTE SHEET (RULE 26)
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EXAMPLE 3
A coating composition was formulated by adding 7.0
parts polyvinylpyrrolidone (PVP K-90, International Specialty
5 Products) to 63.4 part deionized water. The composition was
heated and agitated to dissolve the PVP. To this solution was
added: 1.4 parts Triton X-100 (Rohm and Haas), 0.1 parts
SURFYNOL~ 420 (Air Products), and 3.5 parts glycerol
(Fisher Scientific). Beta-cyclodextrin, (3-CD, and
10 hydroxypropyl-beta-cyclodextrin, hp-(3-CD, (Cerestar) were
added to the composition as 1.8 parts and 22.9 parts,
respectively. The composition was agitated and heated, as
necessary, to obtain a clear solution. The solution was allowed
to cool to room temperature before being applied to a
15 substrate.
EXAMPLE 4
A coating composition was formulated by placing 2.8
parts of a poiy(sodium acrylate) solution (Polysciences,
20 140,000 M.W. 25~lo in water) in a container and diluting with
61.2 parts deionized water. To this solution, 6.3 parts
polyvinylpyrrolidone (PVP K-90, International Specialty
Products) was added. The composition was heated and agitated
to dissolve the PVP. To this solution was added: 1.4 parts
25 Triton X-l00 (Rohm and Haas), 0.1 parts SURFYNOL~ 420
(Air Products), and 3.5 parts glycerol (Fisher Scientific).
Beta-Cyclodextrin, 13-CD, and hydroxypropyl-beta-
cyclodextrin, hp- f3-CD, (Cerestar) were added to the
composition as 1.8 parts and 22.9 parts, respectively. The -
30 composition was agitated and heated, as necessary, to obtain a
clear solution. The solution was allowed to cool to room
temperature before being applied to a substrate.
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EXAMPLE 5
A coating composition was formulated by placing 3.~
parts of a poly(sodium acrylate) solution (Polysciences,
225,000 M.W. 20% in water) in a container and diluting with
60.5 parts deionized water. To this solution 6.3 parts
polyvinylpyrrolidone (PVP K-90, International Specialty
Products) was added. The composition was heated and agitated
to dissolve the PVP. 1.4 parts Triton X-l00 (Rohm and Haas),
0.1 parts SURFYNOL~ 420 (Air Products), and 3.5 parts
glycerol (Fisher Scientific) were added to the composition.
Beta-Cyclodextrin, 13-CD, and hydroxypropyl-beta-
cyclodextrin, hp-f3-CD, (Cerestar) were added to the
composition as 1.8 parts and 22.9 parts, respectively. The
composition was agitated and heated, as necessary, to obtain a
clear solution. The solution was allowed to cool to room
temperature before being applied to a substrate.
EXAMPLE 6
A coating composition was formulated as in Example 4,
except that 2.0 parts Dow Corning Super Wetter (Dow
Corning, Q2-5211) was substituted for Triton X-100 (Rohm
and Haas).
EXAMPLE 7
A coating composition was formulated by dissolving 3.3
parts poly(vinylalcohol) (Airvol 523, Air Products) in 62.0
parts hot deionized water. 3.7 parts of a poly(sodium acrylate)
solution (Polysciences, 225,000 M.W. 20% in water) was
added, followed by 6.3 parts polyvinylpyrrolidone (PVP K-90,
International Specialty Products). The composition was heated
and agitated to dissolve the PVP. 1.4 parts Triton X-100
(Rohm and Haas) and 0.1 parts SURFYNOL~ 420 (Air
Products) were added to the composition. Beta-cyclodextrin,
13-CD, and hydroxypropyl-beta-cyclodextrin, hp-(3-CD,
(Cerestar) were added to the composition as 1.$ parts and 22.9
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parts, respectively. The composition was agitated and heated,
as necessary, to obtain a clear solution. The solution was
allowed to cool to room temperature before being applied to a
substrate.
EXAMPLE 8
A coating composition was formulated as in Example 7,
substituting polyvinylpyrrolidone (PVP K-l20, International
Specialty Products) for polyvinylpyrrolidone (PVP K-90).
EXAMPLE 9
A coating composition was formulated as in Example 7,
substituting poly(sodium acrylate) solution (PARAGUM~ 231,
Para-Chem Southern Inc.) for poly(sodium acrylate) solution
(Polysciences, 225,000 M.W. 20% in water).
EXAMPLE 10
A coating composition was formulated by mixing 500 g
of a 10% solution of poly(vinylalcohol) (Airvol 523, Air
Products) and 250 g of a 20% solution of
polyvinylpyrrolidone (PVP K-90, International- Specialty
Products). 3.0 g of a 33% solution of Triton X-100 (Rohm
and Haas) and 1.0 g of ORGASOL~ polyamide particles ( 18
microns) were added to the composition. l50 g of a 50%
solution of Hydroxypropyl-beta-cyclodextrin, hp-13-CD,
(Cerestar) was added to the composition. The composition was
agitated and heated, as necessary, to obtain a clear solution.
The solution was allowed to cool to room temperature before
being applied to a substrate.
EXAMPLE 11
A coating composition was formulated by mixing 2S0 g
of a 10% solution of poly(vinylalcohol) (Airvol 523, Air
Products); 6.1 g of a 33% solution of Triton X-100 (Rohm
and Haas); and 0.5 g of SURFYNOL~ 420 (Air Products).
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l500 g of a 5% solution of Sodium carboxymethyi cellulose
- (Catalog No. 41927-3, Aldrich Chemicals, Inc.) and 1~0 g of a
~0% solution of Hydroxypropyl-beta-cyclodextrin, hp-f3-CD,
(Cerestar) was added to the composition. The composition was
agitated and heated, as necessary, to obtain a clear solution.
The solution was allowed to cool to room temperature before
being applied to a substrate.
EXAMPLE 12
A coating composition was formulated by mixing 1500 g
of a 10% solution of poly(vinylalcohol) (Airvol 523, Air
Products); 4 g of Triton X-l00 (Rohm and Haas); and 1:0 g of
SURFYNOL~ 420 {Air Products). 1000 g of a 5% solution of
Sodium carboxymethyl cellulose (Catalog No. 41927-3,
Aldrich Chemicals, Inc.) and 300 g of a 50% solution of
Hydroxypropyl-beta-cyclodextrin, hp-f3-CD, (Cerestar) was
added to the composition. The composition was agitated and
heated, as necessary, to obtain a clear solution. The solution
was allowed to cool to room temperature before being applied
to a substrate.
EXAMPLE 13
Preparation of Inks Containing Porphine Colorant Stabilizers
This example reports the preparation of various inks,
with one of the stabilizing additives of the present invention.
More particularly, the stabilizing additive of this example is
the porphine, Cu-meso-tetra-(4-sulfanatophenyl)-porphine
(designated CuTPPS4) (available from Porphyrin Products,
Inc., Logan, UT), which is represented by the following
structure:
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H03 O~H
H03S S03H
In this example, an ink set comprising cyan, magenta,
yellow and black inks was prepared using one or more of the
following components: deionized water; borax, hydrochloric
acid and/or sodium hydroxide as buffer/pH adjusters; EDTA
or sodium salts thereof as a chelating agent; ethylene glycol
and/or glycerine as wetting agents; GIV-GARD DXN~ as a
biocide; COBRATEC~ 99 as a corrosion inhibitor; and Projet
Cyan I, DB l68 Liquid, Reactive Red I87, Acid Red 52 and/or
Acid Yellow 17 as dyes. In addition to the CuTPPS4
porphine, a lanthanide salt, europium nitride (EuN03) was
also used as a colorant stabilizer. The ink compositions
prepared are given below, each component being given in
weight percent.
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Cyan Black Red Yellow
(Blue)
DI Water 54.73 50.23 81.49 C3.83
Borax 1.90 1.90 1.90 1.90
HCL( 1 N) 1.57 1.57 1.57 1.57
EDTA 2Na 0.00 0.00 0.10 0.00
EuN03 6H20 0.00 0.00 0.05 0.00
NaOH (2N) 3.00 0.00 0.00 0.00
CuTPPS4 0.00 0.00 0.50 0.10
EG 10.00 3.50 5.00 5.00
Gl cerine I0.00 3.50 5.00 5.00
GIV-GARD 0.20 0.20 0.20 0.20
DXN~
COBRATEC~ 0.l0 0.10 0.10 0.l0
99
Pro'et C an 18.50 1.00 0.00 0.00
I
DB l68 Li uid 0.00 38.00 0.00 0.00
Reactive Red 0.00 0.00 2.89 0.00
l87
Acid Red 52 0.00 0.00 l.20 0.00
Acid Yellow 0.00 0.00 0.00 22.30
17
t std)
EXAMPLE 14
Effect of Cyclodextrin on Coatings Made With Various
5 Binders
In order to determine the effect of cyclodextrin (CD)
content on the fading characteristics of images printed with the
inks of Example 13 on photoglossy coatings made with
different polymer binders, the following experiment was
10 conducted.
Stock aqueous solutions of four binders: ( 1 ) CMC
(sodium salt of carboxymethyl cellulose, catalog no. 42,927
from Aldrich Chemical Company) at 5 wt%; (2) PVOH
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(polyvinyl alcohol, Airvol 523 from ~4ir Products and
Chemicals, Inc.) at 10 wt%; (3) PAA (sodium polyacrylate =
sodium salt of polyacrylic acid, PARAGUM~ I31 from
Polysciences, Inc.) at 5 wt%; and (4) PVP (polyvinyl
pyrolidone, PVP-K90 from ISP Technologies) at 10 wt% were
prepared. To each stock solution was added 3 wt% Triton X-
100 (from Union Carbide Chemicals). In addition a stock
aqueous solution of hydroxypropyl-beta-cyclodextrin, hp-f3-
CD) (Cerestar) at 50 wt% and 3 wt% Triton X-100 was
prepared. The cyclodextrin and binder solutions were
combined in the appropriate ratios to yield solutions containing
a solid fraction of cyclodextrin, fcd = Mcd/(Mcd+Mpolymer),
where Mcd and Mpolymer are respectively the weights of
cyclodextrin and polymer solids in the combined solution.
1 S The solutions were rod-coated onto 7 mil Jen-coat ink-
jet photoglossy base sheets and oven dried. The rods used
were chosen so as to obtain a relatively fixed dry coat weight
of about 4 lbs/144.3 yd2. For example, by using a #20 Meyer
rod, a fcd=100% (no polymer binder) coating of about 4.5
lbs/144.3 yd2 was achieved. Similarly, by using a #68 Meyer
rod, a fcd=50% carboxymethyl cellulose coating of about 4.5
lbs/144.3 yd2 was achieved. By using a #60 Meyer rod, a
fcd=50% polyvinyl alcohol coating of 3.9 lbs/144.3 yd2 was
achieved. By using a #58 Meyer rod, a fcd=50% polyvinyl
pyrolidone coating of 3.7 lbs/144.3 yd2 was achieved. In order
to achieve a coat weight of 3.8 lbs/144.3 yd2 for a sodium
polyacrylate coating, two passes were required, wherein, the
first was with a #34 Meyer rod and the second pass was with a
double-wound #60 Meyer rod.
The above-prepared photoglossy media were then
printed using the inks of Example I3. In particular, solid
squares of the primary colors, magenta, cyan and yellow, were
printed. The printed samples were then faded by irradiating
with ultraviolet light from a xenon lamp in an Atlas Ci35
Weather-ometer (Atlas Electric Devices) for--43 hours at a
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nominal irradiance of 1.10 W/m2 at 340 nm and a temperature
of 63~C. Spectradensitometer (X-Rite) measurements were
made before and after fading. Fading was quantified by c~E
values for the primary colors (magenta, cyan and yellow). The
results are given below.
Binder fcd(%) ~Emagenta DEcyan DEyellow
PVP 0 43.9 34.3 16.5
10 27.4 34.4 16.1
20 22.3 32.6 12.3
30 2l.5 3l.6 l3.4
40 l6.1 28.3 l0.9
50 12.5 25.3 9.6
60 9.0 22.6 9.9
70 4.9 18.6 S.7
80 2.9 16.1 4.6
90 1.8 1l.5 4.1
100 3.7 5.1 3.0
CMC 0 - - -
10 22.1 5.5 32.7
20 30.7 4.6 - 14.7
30 22.3 4.3 14.6
40 l4.6 3.5 l0.4
50 7.9 2.0 6.7
60 6.8 1.9 6.7
70 7.6 1.5 3.2
80 5.1 3.5 5.5
90 4.3 2.6 5.5
l00 3.7 5.1 3.0
35
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Binder fcd(%) DEmagenta DEcyan ~Eyellow
PVOH 0 5.0 3.3 21.7
10 10.1 3.3 l6.6
20 5.9 2.6 l3.3
30 5.5 3.1 11.0
40 5.5 2.4 8.7
50 4.5 2.5 6.5
60 3.9 3.0 4.8
70 4.6 2.8 3.~
80 4.6 3.2 3.6
90 4.4 3.4 3.5
100 3.7 5.1 3.0
PAA 0 - - -
10 66.1 4.2 45.5
70.1 3.1 50.2
- - -
20 40 59.4 2.9 23.l
50 48.1 2.9 15.6
60 4l.9 2.7 8.6
70 23.4 2.7 9.9
80 7.8 2.3 7.2
25 90 7.1 4.2 4.8
100 3.7 5.1 3.0
For the magenta, fading was suppressed in the PVOH
binder, irrespective of CD content. CMC and PVP behaved
30 similarly, with increased CD content inhibiting fading up to
about 60%. Fading was most pronounced in the PAA binder,
with large (80 %) amounts of CD necessary to inhibit fading.
For the cyan, fading was suppressed for CMC, PVOH and
PAA binders, irrespective of CD content. Fading was only
significant in the PVP binder, with CD suppressing the fading
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most likely by displacing the PVP. For the yellow, PVOH and
PVP behaved similarly, with increased CD content inhibiting
fading up to about 60%. CMC was a little worse, while again
fading was most pronounced in the PAA.
Having thus described the invention, numerous changes
and modifications thereof will be readily apparent to those
having ordinary skill in the art, without departing from the
spirit ~r scope of the invention.
