U.S. patent application number 09/770128 was filed with the patent office on 2002-10-10 for ink jet printing method.
This patent application is currently assigned to Eastman Kodak Company. Invention is credited to Lawrence, Kristine B., Teegarden, David M..
Application Number | 20020145652 09/770128 |
Document ID | / |
Family ID | 25087570 |
Filed Date | 2002-10-10 |
United States Patent
Application |
20020145652 |
Kind Code |
A1 |
Lawrence, Kristine B. ; et
al. |
October 10, 2002 |
INK JET PRINTING METHOD
Abstract
An inkjet printing method, comprising the steps of: A) providing
an ink jet printer that is responsive to digital data signals; B)
loading the printer with ink-receptive elements comprising a
support having thereon an image-receiving layer comprising a
cationic, water-dispersible, partially quaternized
pyridine-containing polymer; C) loading the printer with an inkjet
ink composition comprising water, a humectant, and a water soluble
anionic dye; and D) printing on said image-receiving layer using
said ink jet ink in response to said digital data signals.
Inventors: |
Lawrence, Kristine B.;
(Rochester, NY) ; Teegarden, David M.; (Pittsford,
NY) |
Correspondence
Address: |
Patent Legal Staff
Eastman Kodak Company
343 State Street
Rochester
NY
14650-2201
US
|
Assignee: |
Eastman Kodak Company
|
Family ID: |
25087570 |
Appl. No.: |
09/770128 |
Filed: |
January 26, 2001 |
Current U.S.
Class: |
347/100 |
Current CPC
Class: |
B41M 5/5245 20130101;
C09D 11/30 20130101 |
Class at
Publication: |
347/100 |
International
Class: |
G01D 011/00 |
Claims
What is claimed is:
1. An ink jet printing method, comprising the steps of: A)
providing an ink jet printer that is responsive to digital data
signals; B) loading the printer with ink-receptive elements
comprising a support having thereon an image-receiving layer
comprising a cationic, water-dispersible, partially quaternized
pyridine-containing polymer; C) loading said printer with an ink
jet ink composition comprising water, a humectant, and a
water-soluble anionic dye; and D) printing on said image-receiving
layer using said ink jet ink in response to said digital data
signals.
2. The method of claim 1 wherein said cationic, water-dispersible,
partially quaternized pyridine-containing polymer has the formula:
4wherein: each A independently represents a carbonyl group or a
direct link; each B independently represents O, NH or a direct
link; each R.sub.1 independently represents H or CH.sub.3; each
R.sub.2 independently represents an alkyl, cyclic alkyl or alkoxy
group having from 1 to about 10 carbon atoms or a direct link;
R.sub.3 represents a substituted or unsubstituted pyridine ring;
R.sub.4 represents a substituted or unsubstituted pyridinium ring;
R.sub.5 represents a linear, branched or cyclic alkyl, alkoxy or
aryl group having from 1 to about 24 carbon atoms; X represents an
anion or a mixture of anions; Z represents at least one
ethylenically unsaturated monomer; a represents a mole % of from
about 0 to about 98; b represents a mole % of from about 5 to about
98; and c represents a mole % of from about 75 to about 2.
3. The method of claim 2 wherein each R.sub.1 represents H, each A,
B and R.sub.2 represents direct links, R.sub.3 is pyridine and
R.sub.4 is pyridinium.
4. The method of claim 2 wherein Z is a styrenic monomer, an
acrylate ester, a methacrylate ester, an acrylamide, a
methacrylamide, a vinylpyrrolidone, a vinyl ester derived from
straight chain and branched acids, a vinyl ether, a vinyl nitrile,
a vinyl ketone, a halogen-containing monomer or an olefin.
5. The method of claim 2 wherein Z is styrene.
6. The method of claim 2 wherein R.sub.5 is hydroxyethyl, a linear
alkyl group having from about 12 to about 18 carbon atoms or
benzyl.
7. The method of claim 2 wherein X is chloride.
8. The method of claim 1 wherein said humectant is diethylene
glycol, glycerol or diethylene glycol monobutylether.
9. The method of claim 1 wherein said image-receiving layer also
contains a binder.
10. The method of claim 9 wherein said binder is a hydrophilic
polymer.
11. The method of claim 10 wherein said hydrophilic polymer is
gelatin or poly(vinyl alcohol).
12. The method of claim 1 wherein said image-receiving layer
contains particulates.
13. The method of claim 12 wherein said particulates are inorganic
oxides or organic latex polymers.
14. The method of claim 12 wherein said particulates are barium
sulfate, calcium carbonate, clay, silica or alumina.
15. The method of claim 1 wherein said anionic dye comprises about
0.2 to about 5% by weight of said ink jet ink composition.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] Reference is made to commonly assigned, co-pending U.S.
Patent Applications:
[0002] Serial Number______ by Bermel et al., (Docket 81820) filed
of even date herewith entitled "Ink Jet Recording Element";
[0003] Serial Number______ by Bermel et al., (Docket 82109) filed
of even date herewith entitled "Ink Jet Recording Element";
[0004] Serial Number______ by Bermel et al., (Docket 82110) filed
of even date herewith entitled "Ink Jet Recording Element";
[0005] Serial Number______ by Bermel et al., (Docket 82111) filed
of even date herewith entitled "Ink Jet Recording Element";
[0006] Serial Number______ by Bermel et al., (Docket 82133) filed
of even date herewith entitled "Ink Jet Printing Method";
[0007] Serial Number______ by Bermel et al., (Docket 82134) filed
of even date herewith entitled "Ink Jet Printing Method";
[0008] Serial Number______ by Bermel et al., (Docket 82138) filed
of even date herewith entitled "Ink Jet Printing Method";
[0009] Serial Number______ by Bermel et al., (Docket 82139) filed
of even date herewith entitled "Ink Jet Printing Method";
[0010] Serial Number______ by Lawrence et al., (Docket 81817) filed
of even date herewith entitled "Ink Jet Printing Method";
[0011] Serial Number______ by Lawrence et al., (Docket 81818) filed
of even date herewith entitled "Ink Jet Printing Method";
[0012] Serial Number______ by Lawrence et al., (Docket 81821) filed
of even date herewith entitled "Ink Jet Printing Method";
[0013] Serial Number______ by Lawrence et al., (Docket 81893) filed
of even date herewith entitled "Ink Jet Printing Method";
[0014] Serial Number______ by Lawrence et al., (Docket 81894) filed
of even date herewith entitled "Ink Jet Printing Method"; and
[0015] Serial Number______ by Lawrence et al., (Docket 81983) filed
of even date herewith entitled "Ink Jet Printing Method".
FIELD OF THE INVENTION
[0016] This invention relates to an inkjet printing process for
improving the light stability and waterfastness of a printed image
containing an ink jet ink containing a water-soluble anionic dye
and a cationic receiver.
BACKGROUND OF THE INVENTION
[0017] Ink jet printing is a non-impact method for producing images
by the deposition of ink droplets in a pixel-by-pixel manner to an
image-recording element in response to digital signals. There are
various methods which may be utilized to control the deposition of
ink droplets on the image-recording element to yield the desired
image. In one process, known as continuous ink jet, a continuous
stream of droplets is charged and deflected in an imagewise manner
onto the surface of the image-recording element, while unimaged
droplets are caught and returned to an ink sump. In another
process, known as drop-on-demand inkjet, individual ink droplets
are projected as needed onto the image-recording element to form
the desired image. Common methods of controlling the projection of
ink droplets in drop-on-demand printing include piezoelectric
transducers and thermal bubble formation. Ink jet printers have
found broad applications across markets ranging from industrial
labeling to short run printing to desktop document and pictorial
imaging.
[0018] The inks used in the various ink jet printers can be
classified as either dye-based or pigment-based. A dye is a
colorant which is molecularly dispersed or solvated by a carrier
medium. The carrier medium can be a liquid or a solid at room
temperature. A commonly used carrier medium is water or a mixture
of water and organic co-solvents. Each individual dye molecule is
surrounded by molecules of the carrier medium. In dye-based inks,
no particles are observable under the microscope. Although there
have been many recent advances in the art of dye-based inkjet inks,
such inks still suffer from deficiencies such as low optical
densities on plain paper and poor light-fastness.
[0019] When water is used as the carrier medium, such inks also
generally suffer from poor water-fastness.
[0020] An ink jet recording element typically comprises a support
having on at least one surface thereof an ink-receiving or
image-forming layer. The ink-receiving layer may be a polymer layer
which swells to absorb the ink or a porous layer which imbibes the
ink via capillary action.
[0021] Ink jet prints, prepared by printing onto ink jet recording
elements, are subject to environmental degradation. They are
especially vulnerable to water smearing, dye bleeding, coalescence
and light fade. For example, since ink jet dyes are water-soluble,
they can migrate from their location in the image layer when water
comes in contact with the receiver after imaging. Highly swellable
hydrophilic layers can take an undesirably long time to dry,
slowing printing speed, and will dissolve when left in contact with
water, destroying printed images. Porous layers speed the
absorption of the ink vehicle, but often suffer from insufficient
gloss and severe light fade.
[0022] U.S. Pat. No. 5,942,335 discloses an ink jet recording sheet
comprising a support carrying an ink-receiving layer comprising a
hydrophilic polymer and a polyvinylpyridine. However, there is a
problem with this recording sheet in that images formed in the
image-receiving layer have poor waterfastness.
[0023] U.S. Pat. No. 6,045,917 relates to the use of poly(N-vinyl
benzyl-N, N, N-trimethyl ammonium chloride-co-ethyleneglycol
dimethacrylate) particles in an inkjet image-recording layer.
However, there is a problem with these particles in that images
formed in the image-receiving layer have poor light stability, as
will be shown hereafter.
[0024] It is an object of this invention to provide an ink jet
printing method using anionic dyes suitable for use in aqueous inks
for ink jet printing that will provide images with better light
stability and waterfastness using certain receiver elements.
SUMMARY OF THE INVENTION
[0025] This and other objects are achieved in accordance with this
invention which relates to an inkjet printing method, comprising
the steps of:
[0026] A) providing an ink jet printer that is responsive to
digital data signals;
[0027] B) loading the printer with ink-receptive elements
comprising a support having thereon an image-receiving layer
comprising a cationic, water-dispersible, partially quaternized
pyridine-containing polymer,
[0028] C) loading the printer with an ink jet ink composition
comprising water, a humectant, and a water soluble anionic dye;
and
[0029] D) printing on the image receiving layer using the ink jet
ink in response to the digital data signals.
[0030] It has been found that use of the above dyes and
image-receiving layer provides excellent light stability and
waterfastness.
DETAILED DESCRIPTION OF THE INVENTION
[0031] Any anionic, water-soluble dye may be used in composition
employed in the method of the invention such as a dye having an
anionic group, e.g., a sulfo group or a carboxylic group. The
anionic, water-soluble dye may be any acid dye, direct dye or
reactive dye listed in the COLOR INDEX but is not limited thereto.
Metallized and non-metallized azo dyes may also be used as
disclosed in U.S. Pat. No. 5,482,545, the disclosure of which is
incorporated herein by reference. Other dyes which may be used are
found in EP 802246-A1 and JP 09/202043, the disclosures of which
are incorporated herein by reference. In a preferred embodiment,
the anionic, water-soluble dye which may be used in the composition
employed in the method of the invention is a metallized azo dye, a
non-metallized azo dye, a xanthene dye, a metallophthalocyanine dye
or a sulfur dye. Mixtures of these dyes may also be used. An
example of an anionic dye which may be used in the invention is as
follows: 1
[0032] The dyes described above may be employed in any amount
effective for the intended purpose. In general, good results have
been obtained when the dye is present in an amount of from about
0.2 to about 5% by weight of the ink jet ink composition,
preferably from about 0.3 to about 3% by weight. Dye mixtures may
also be used.
[0033] In a preferred embodiment of the invention, the cationic,
water-dispersible, dispersible, partially quaternized
pyridine-containing polymer has the formula: 2
[0034] wherein:
[0035] each A independently represents a carbonyl group or a direct
link, i.e., a bond;
[0036] each A independently represents O, NH or a direct link,
i.e., a bond;
[0037] each R.sub.1 independently represents H or CH.sub.3;
[0038] each R.sub.2 independently represents an alkyl, cyclic alkyl
or alkoxy group having from 1 to about 10 carbon atoms or a direct
link, i.e., a bond;
[0039] R.sub.3 represents a substituted or unsubstituted pyridine
ring;
[0040] R.sub.4 represents a substituted or unsubstituted pyridinium
ring;
[0041] R.sub.5 represents a linear, branched or cyclic alkyl,
alkoxy or aryl group having from 1 to about 24 carbon atoms;
[0042] X represents an anion or a mixture of anions, such as halide
(e.g., chloride or bromide), alkylsulfate (e.g. methylsulfate),
alkylsulfonate (e.g. methylsulfonate), or arylsulfonate (e.g.
benzenesulfonate or toluenesulfonate);
[0043] Z represents at least one ethylenically unsaturated
monomer;
[0044] a represents a mole % of from about 0 to about 98;
[0045] b represents a mole % of from about 5 to about 98; and
[0046] c represents a mole % of from about 75 to about 2.
[0047] In a preferred embodiment of the invention, each R.sub.1
represents H, each A, B and R.sub.2 represents direct links,
R.sub.3 is pyridine and R.sub.4 is pyridinium. In another preferred
embodiment, R.sub.5 is hydroxyethyl, a linear alkyl group having
from about 12 to about 18 carbon atoms or benzyl.
[0048] As noted above, Z in the formula represents at least one
ethylenically unsaturated, nonionic monomer. Examples of these
include a styrene or an alpha-alkylstyrene, where the alkyl group
has 1 to 4 carbon atoms and the aromatic group may be substituted
or part of a larger ring system. Other examples of Z include
acrylate esters derived from aliphatic alcohols or phenols;
methacrylate esters; acrylamides; methacrylamides;
N-vinylpyrrolidone or suitably substituted vinylpyrrolidones; vinyl
esters derived from straight chain and branched acids, e.g., vinyl
acetate; vinyl ethers, e.g., vinyl methyl ether; vinyl nitrites;
vinyl ketones; halogen-containing monomers such as vinyl chloride;
and olefins, such as butadiene. The ethylenically unsaturated,
nonionic monomer may contain more than one polymerizable group. In
a preferred embodiment, Z represents styrene.
[0049] Specific examples of the cationic, water-dispersible,
partially quaternized pyridine-containing polymer useful in the
invention include the following:
1 3 Polymer m (mol %) n (mol %) p (mol %) P-1 45 42 13 P-2 50 44 6
P-3 50 38 12 P-4 45 50 5 P-5 45 45 10
[0050] The cationic, water-dispersible, partially quaternized
pyridine-containing polymer employed in the invention may be used
in an amount of from 0.2 to about 32 g/m.sup.2, preferably from
about 0.4 to about 16 g/m.sup.2.
[0051] The polymers employed in this invention can be prepared
using conventional polymerization techniques including, but not
limited to bulk, solution, emulsion, or suspension polymerization.
They also can be partially crosslinked.
[0052] A binder may also be employed in the image-receiving layer
in the invention. In a preferred embodiment, the binder is a
hydrophilic polymer. Examples of hydrophilic polymers useful in the
invention include poly(vinyl alcohol), polyvinylpyrrolidone,
poly(ethyl oxazoline), poly-N-vinylacetamide, non-deionized or
deionized Type IV bone gelatin, acid processed ossein gelatin, pig
skin gelatin, acetylated gelatin, phthalated gelatin, oxidized
gelatin, chitosan, poly(alkylene oxide), sulfonated polyester,
partially hydrolyzed poly(vinyl acetate-co-vinyl alcohol),
poly(acrylic acid), poly(1-vinylpyrrolidone), poly(sodium styrene
sulfonate), poly(2-acrylamido-2-methane sulfonic acid),
polyacrylamide or mixtures thereof. In a preferred embodiment of
the invention, the binder is gelatin or poly(vinyl alcohol).
[0053] If a hydrophilic polymer is used in the image-receiving
layer, it may be present in an amount of from about 0.02 to about
30 g/m.sup.2, preferably from about 0.04 to about 16 g/m.sup.2 of
the image-receiving layer.
[0054] The weight ratio of cationic, water dispersible partially
quaternized pyridine-containing polymer to binder is from about
1:99 to about 8:2, preferably from about 1:9 to about 4:6.
[0055] Latex polymer particles and/or inorganic oxide particles may
also be used as the binder in the image-receiving layer to increase
the porosity of the layer and improve the dry time. Preferably the
latex polymer particles and/or inorganic oxide particles are
cationic or neutral. Examples of inorganic oxide particles include
barium sulfate, calcium carbonate, clay, silica or alumina, or
mixtures thereof. In that case, the weight % of particulates in the
image receiving layer is from about 80 to about 95%, preferably
from about 85 to about 90%.
[0056] The pH of the aqueous ink compositions employed in the
invention may be adjusted by the addition of organic or inorganic
acids or bases. Useful inks may have a preferred pH of from about 2
to 10, depending upon the type of dye being used. Typical inorganic
acids include hydrochloric, phosphoric and sulfuric acids. Typical
organic acids include methanesulfonic, acetic and lactic acids.
Typical inorganic bases include alkali metal hydroxides and
carbonates. Typical organic bases include ammonia, triethanolamine
and tetramethylethlenediamine.
[0057] A humectant is employed in the inkjet composition employed
in the invention to help prevent the ink from drying out or
crusting in the orifices of the printhead. Examples of humectants
which can be used include polyhydric alcohols, such as ethylene
glycol, diethylene glycol, triethylene glycol, propylene glycol,
tetraethylene glycol, polyethylene glycol, glycerol,
2-methyl-2,4-pentanediol 1,2,6-hexanetriol and thioglycol; lower
alkyl mono- or di-ethers derived from alkylene glycols, such as
ethylene glycol mono-methyl or mono-ethyl ether, diethylene glycol
mono-methyl or mono-ethyl ether, propylene glycol mono-methyl or
mono-ethyl ether, triethylene glycol mono-methyl or mono-ethyl
ether, diethylene glycol di-methyl or di-ethyl ether, and
diethylene glycol monobutylether; nitrogen-containing cyclic
compounds, such as pyrrolidone, N-methyl -2-pyrrolidone, and
1,3-dimethyl-2-imidazolidinone; and sulfur-containing compounds
such as dimethyl sulfoxide and tetramethylene sulfone. A preferred
humectant for the composition employed in the invention is
diethylene glycol, glycerol, or diethylene glycol
monobutylether.
[0058] Water-miscible organic solvents may also be added to the
aqueous ink employed in the invention to help the ink penetrate the
receiving substrate, especially when the substrate is a highly
sized paper. Examples of such solvents include alcohols, such as
methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol,
n-butyl alcohol, sec-butyl alcohol, t-butyl alcohol, iso-butyl
alcohol, furfuryl alcohol, and tetrahydrofurfuryl alcohol; ketones
or ketoalcohols such as acetone, methyl ethyl ketone and diacetone
alcohol; ethers, such as tetrahydrofuran and dioxane; and esters,
such as, ethyl lactate, ethylene carbonate and propylene
carbonate.
[0059] Surfactants may be added to adjust the surface tension of
the ink to an appropriate level. The surfactants may be anionic,
cationic, amphoteric or nonionic.
[0060] A biocide may be added to the composition employed in the
invention to suppress the growth of microorganisms such as molds,
fungi, etc. in aqueous inks. A preferred biocide for the ink
composition employed in the present invention is Proxel.RTM. GXL
(Zeneca Specialties Co.) at a final concentration of 0.0001-0.5 wt.
%.
[0061] A typical ink composition employed in the invention may
comprise, for example, the following substituents by weight:
colorant (0.05-5%), water (20-95%), a humectant (5-70%), water
miscible co-solvents (2-20%), surfactant (0.1-10%), biocide
(0.05-5%) and pH control agents (0.1-10%).
[0062] Additional additives which may optionally be present in the
ink jet ink composition employed in the invention include
thickeners, conductivity enhancing agents, anti-kogation agents,
drying agents, and defoamers.
[0063] The ink jet inks employed in this invention may be employed
in ink jet printing wherein liquid ink drops are applied in a
controlled fashion to an ink receptive layer substrate, by ejecting
ink droplets from a plurality of nozzles or orifices of the print
head of an ink jet printer.
[0064] The image-recording layer used in the process of the present
invention can also contain various known additives, including
matting agents such as titanium dioxide, zinc oxide, silica and
polymeric beads such as crosslinked poly(methyl methacrylate) or
polystyrene beads for the purposes of contributing to the
non-blocking characteristics and to control the smudge resistance
thereof; surfactants such as non-ionic, hydrocarbon or fluorocarbon
surfactants or cationic surfactants, such as quaternary ammonium
salts; fluorescent dyes; pH controllers; anti-foaming agents;
lubricants; preservatives; viscosity modifiers; dye-fixing agents;
waterproofing agents; dispersing agents; UV- absorbing agents;
mildew-proofing agents; mordants; antistatic agents, anti-oxidants,
optical brighteners, and the like. A hardener may also be added to
the ink-receiving layer if desired.
[0065] The support for the ink jet recording element used in the
invention can be any of those usually used for inkjet receivers,
such as paper, resin-coated paper, polyesters, or microporous
materials such as polyethylene polymer-containing material sold by
PPG Industries, Inc., Pittsburgh, Pa. under the trade name of
Teslin .RTM., Tyvek .RTM. synthetic paper (DuPont Corp.), and
OPPalyte.RTM. films (Mobil Chemical Co.) and other composite films
listed in U.S. Pat. No. 5,244,861. Opaque supports include plain
paper, coated paper, synthetic paper, photographic paper support,
melt-extrusion-coated paper, and laminated paper, such as biaxally
oriented support laminates. Biaxally oriented support laminates are
described in U.S. Pat. Nos. 5,853,965; 5,866,282; 5,874,205;
5,888,643; 5,888,681; 5,888,683; and 5,888,714, the disclosures of
which are hereby incorporated by reference. These biaxally oriented
supports include a paper base and a biaxially oriented polyolefin
sheet, typically polypropylene, laminated to one or both sides of
the paper base. Transparent supports include glass, cellulose
derivatives, e.g., a cellulose ester, cellulose triacetate,
cellulose diacetate, cellulose acetate propionate, cellulose
acetate butyrate; polyesters, such as poly(ethylene terephthalate),
poly(ethylene naphthalate), poly(1,4-cyclohexanedimethylene
terephthalate), poly(butylene terephthalate), and copolymers
thereof; polyimides; polyamides; polycarbonates; polystyrene;
polyolefins, such as polyethylene or polypropylene; polysulfones;
polyacrylates; polyetherimides; and mixtures thereof. The papers
listed above include a broad range of papers, from high end papers,
such as photographic paper to low end papers, such as
newsprint.
[0066] The support used in the invention may have a thickness of
from about 50 to about 500 .mu.m, preferably from about 75 to 300
.mu.m. Antioxidants, antistatic agents, plasticizers and other
known additives may be incorporated into the support, if desired.
In a preferred embodiment, paper is employed.
[0067] In order to improve the adhesion of the image-recording
layer to the support, the surface of the support may be subjected
to a corona-discharge-treatment prior to applying the
image-recording layer.
[0068] In addition, a subbing layer, such as a layer formed from a
halogenated phenol or a partially hydrolyzed vinyl chloride-vinyl
acetate copolymer can be applied to the surface of the support to
increase adhesion of the image recording layer. If a subbing layer
is used, it should have a thickness (i.e., a dry coat thickness) of
less than about 2 .mu.m.
[0069] The image-recording layer may be present in any amount which
is effective for the intended purpose. In general, good results are
obtained when it is present in an amount of from about 2 to about
44 g/m.sup.2, preferably from about 6 to about 32 g/m.sup.2, which
corresponds to a dry thickness of about 2 to about 40 .mu.m,
preferably about 6 to about 30 .mu.m.
[0070] The following examples illustrates the utility of the
present invention.
EXAMPLES
[0071] The following polymers were used as controls in the
image-receiving layer:
[0072] CP-1: poly(styrene-co-4-vinylpyridine) (about 50:50 mole %)
(U.S. Pat. No. 5,942,335)
[0073] CP-2: poly(N-vinylbenzyl-N,N,N-trimethylammonium
chloride-co-divinylbenzene) (about 90/10 mole %) (U.S. Pat. No.
6,045,917)
[0074] Synthetic Preparation
[0075] Preparation of
poly(styrene-co-4-vinylpyridine-co-1-(2-hydroxyethyl-
)4-vinylpyridinium chloride) (P-1)
[0076] A 1-L 3-necked round-bottomed flask fitted with a mechanical
stirrer, reflux condenser, and N.sub.2 inlet was charged with 395 g
of tetrahydrofuran, 74.6 g of styrene, and 74.4 g of
4-vinylpyridine. The solution was sparged with N.sub.2 for approx.
15 min, 1.53 g of 2,2'azobisisobutryonitrile was added, and the
solution was stirred and sparged an additional 15 min. The reaction
mixture was heated at 60.degree. C. with stirring under a slight
positive pressure of N.sub.2 for 18 hr, cooled, concentrated to
approximately 1/2 the initial volume, and precipitated into a large
excess of ether. The precipitate was dried in a vacuum oven at
35-40.degree. C. overnight. The polymer was dissolved in methanol
and reprecipitated into ether, filtered, and dried in vacuo.
[0077] To a 250-mL 3-necked round-bottomed flask fitted with a
mechanical stirrer, reflux condenser, and N.sub.2 inlet was added a
solution of 20.0 g of the copolymer above in 80 g of
dimethylformamide. After the solution had been sparged with N.sub.2
for 20 min, 3.84 g of 2-chloroethanol was added and the solution
stirred and heated at 100.degree. C. for 24 hr under a slight
positive pressure of N.sub.2. The clear, brown solution was
precipitated into 1500 mL of ether and the precipitate dried at
35.degree. C. in a vacuum oven overnight. Tg 135-136.degree. C.
Example 1
[0078] Light Stability
[0079] Preparation of a water soluble, anionic dye ink composition,
I-1
[0080] Ink I-1 containing Dye 1 identified above was prepared by
mixing the dye concentrate (3.1%) with de-ionized water containing
humectants of diethylene glycol (Aldrich Chemical Co.) and glycerol
(Acros Co.), each at 6%, a biocide, Proxel GXL .RTM. biocide
(Zeneca Specialties) at 0.003wt %, and a surfactant, Surfynol 465
.RTM. (Air Products Co.) at 0.05wt. %.
[0081] The dye concentration was based on solution absorption
spectra and chosen such that the final ink when diluted 1:1000,
would yield a transmission optical density of approximately
1.0.
[0082] Preparation of Control Ink Recording Elements C-1 and
C-2
[0083] The composite side of a polyethylene resin-coated
photographic grade paper based support was corona discharge treated
prior to coating. Ink receptive layers were composed of a mixture
of 0.86 g/m.sup.2 of polymer CP-1 or CP-2, 7.75 g/m.sup.2 of pig
skin gelatin and 0.09 g/m.sup.2 of S-100 12 .mu.m polystyrene beads
(ACE Chemical Co.), and coated from distilled water on the above
mentioned paper support.
[0084] Preparation of Invention Ink Recording Elements E-1 through
E-5
[0085] Recording elements E-1 through E-5 of the invention were
coated the same as described above, using P-1 through P-5 instead
of CP-1 or CP-2.
[0086] Printing
[0087] Elements E-1 through E-5 and control elements C-1 and C-2
were printed using an Epson 200 .RTM. printer using I-1 ink
described above. After printing, all images were allowed to dry at
room temperature overnight, and the densities were measured at all
steps using an X-Rite 820.RTM. densitometer. The images were then
subjected to a high intensity daylight fading test for 2 weeks,
50Klux, 5400.degree. K., approximately 25% RH. The Status A blue
reflection density nearest to 1.0 was compared before and after
fade and a percent density retained was calculated for the yellow
dye with each receiver element. The results can be found in Table 1
below.
2TABLE 1 Recording Blue Density Blue Density % Retained Element
Polymer Before Fade After Fade After Fade E-1 P-1 1.09 0.84 77 E-2
P-2 1.01 0.84 84 E-3 P-3 1.02 0.73 71 E-4 P-4 0.97 0.97 90 E-5 P-5
0.99 0.72 73 C-1 CP-1 1.0 0.88 88 C-2 CP-2 1.04 0.72 69
[0088] The above results show that the recording elements E-1
through E-5 of the invention, as compared to the control recording
elements C-2, gave higher % retained density after high intensity
daylight fading. Although control receiving element C-1 gave higher
% retained densities than several of the recording elements of the
invention, C-1 exhibits poor dye fixation as will be shown in
Example 2 below.
Example 2
[0089] Waterfastness
[0090] Preparation of a water soluble, anionic dye ink composition,
I-2
[0091] Ink I-2 was prepared as described in Example 1 except Dye 2
(0.58%) was added in place of Dye 1.
[0092] Printing
[0093] Elements E-1 and E-5 and control elements C-1 through C-2
were printed as described in Example 1 except I-2 was used instead
of I-1. After printing, all images were allowed to dry at room
temperature overnight.
[0094] The images were then subjected to a waterfastness test (WF)
which involves soaking each imaged receiver in room temperature,
distilled water for 5 minutes and then allowing the image to dry at
room temperature overnight. The image quality of each print was
then visually ranked and assigned a value between 0 and 5. The
visual ranking is an indirect measure of how well the dye is fixed
(dye fixation) to the receiver layer. Zero represents no image
degradation (better dye fixation) and 5 represents severe image
degradation (poor dye fixation) and the results are summarized in
Table 2 below.
3TABLE 2 Recording Element Polymer WF Rank E-1 P-1 2 E-2 P-2 3 E-3
P-3 2 E-4 P-4 3 E-5 P-5 2 C-1 CP-1 4 C-2 CP-2 1
[0095] The above results show that the recording elements E-1
through E-5 of the invention, as compared to the control recording
element C-1, gave better dye fixation after the waterfastness test.
Although control receiver element C-2 gave better dye fixation than
the recording elements of the invention, the light stability was
worse as illustrated in Example 1 above.
Example 3
[0096] Light Stability Using Particulates
[0097] Preparation of Control Ink Recording Element C-3
[0098] Control recording element C-3 was prepared the same as C-2
in Example 1 except the ink receptive layer was composed of two
layers. The bottom layer was composed of a mixture of 37.9
g/m.sup.2 of fumed alumina (Cabot Corp.), 4.3 g/m.sup.2 of GH-23
.RTM. poly(vinyl alcohol) (Nippon Gohsei); 0.9 g/m.sup.2 of
dihydroxydioxane (Clariant) hardener, and 0.04 g.m.sup.2 of Olin
10G .RTM. (Olin Co.) surfactant coated from distilled water.
[0099] On top of the above layer was then coated a mixture of 2.68
g/m.sup.2 of fumed alumina, 0.06 g/m.sup.2 of GH-23 poly(vinyl
alcohol), and 0.48 g/m.sup.2 of CP-2 coated from distilled
water.
[0100] Preparation of Invention Ink Recording Element E-6
[0101] Recording element E-6 of the invention was coated the same
as described for control receiver element C-3, except P-2 was used
in place of CP-2.
[0102] Printing
[0103] The recording element E-6 of the invention and control
recording element C-3 were printed and evaluated as described in
Example 1 above and the results are summarized in Table 3
below.
4TABLE 3 Recording Blue Density Blue Density % Retained Element
Polymer Before Fade After Fade After Fade E-6 P-2 1.08 0.57 53 C-3
CP-2 0.98 0.31 31
[0104] The above results show that the recording element E-6 of the
invention, as compared to the control recording element C-3, gave
higher % retained density after high intensity daylight fading.
[0105] The invention has been described in detail with particular
reference to certain preferred embodiments thereof, but it will be
understood that variations and modifications can be effected within
the spirit and scope of the invention.
* * * * *