[0001] This invention relates to an ink jet recording element which when printed with a
water-soluble dye has improved Dmax density and light stability and a printing method
using the element.
[0002] 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 that 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 ink jet, 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.
[0003] The inks used in the various ink jet printers can be classified as either dye-based
or pigment-based. A dye is a colorant that 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 ink jet inks, such inks still suffer
from deficiencies such as low optical densities on plain paper and poor light-fastness.
When water is used as the carrier medium, such inks also generally suffer from poor
water-fastness.
[0004] 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 that swells to absorb the ink or a porous layer that imbibes the
ink via capillary action.
[0005] 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 or fade induced by
atmospheric ozone.
[0006] WO 99/26935 relates generally to the use of amido or carbamate substituted trisaryl-1,3,5-triazines
to protect against degradation. However, there is no disclosure in this patent for
use of these materials in an ink jet recording system.
[0007] U.S. Patent 6,045,917 relates to the use of cationic mordants in an ink jet image-recording
layer. However, there is a problem with this element in that images formed in the
image-receiving layer have poor light stability, as will be shown hereafter.
[0008] It is an object of this invention to provide an ink jet recording element which when
printed with a water-soluble dye has improved Dmax density and light stability.
[0009] Another object of the invention is to provide a printing method using the above-described
element.
[0010] These and other objects are achieved in accordance with this invention which relates
to an ink jet recording element comprising a support having thereon the following
layers in order:
a) a base layer comprising a polymeric binder and a polymeric mordant; and
b) an overcoat layer comprising a trisaryl-1,3,5-triazine ultraviolet light absorbing
material.
[0011] It has been found that the above recording element provides excellent Dmax density
and light stability.
[0012] Another embodiment of the invention relates to 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 an ink jet recording element as described above;
C) loading the printer with an ink jet ink composition comprising water, a humectant,
and a water-soluble dye; and
D) printing on the overcoat layer using the ink jet ink in response to the digital
data signals.
[0013] Any water-soluble dye may be used in the ink jet ink composition employed in printing
the element 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. Patent 5,482,545.
Other dyes which may be used are found in EP 802246-A1 and JP 09/202043. 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 that may be used in the invention is
as follows:
[0014] 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 0.2 to 5 % by weight of the ink jet ink composition, preferably from
0.3 to 3 % by weight. Dye mixtures may also be used.
[0015] In a preferred embodiment of the invention, the trisaryl-1,3,5-triazine ultraviolet
light absorbing material has the formula:
wherein:
each R independently represents hydrogen; hydrocarbyl group, such as alkyl, cycloalkyl,
aryl, aralkyl, alkaryl, alkenyl, cycloalkenyl or alkynyl groups having up to 24 carbon
atoms; or a hydrocarbyl group substituted with hydroxyl, amino, carboxyl, thio, amido,
carbamoyl, activated methylene, isocyanato, cyano, epoxy, allyl, methallyl, acryloyl,
methacryloyl, maleate, or maleimido; and
R1 represents R, OR, -SR, halogen, -SO2R, -SO3R, -COOR, - COR, -OCOR, -NRR or cyano.
[0016] Specific examples of trisaryl-1,3,5-triazine ultraviolet light absorbing materials
useful in the invention include the following:
[0017] The trisaryl-1,3,5-triazine ultraviolet light absorbing materials employed in the
invention can be used in an amount of from 0.05 to 4.0 g/m
2, preferably from 0.20 to 1.5 g/m
2.
[0018] Any polymeric mordant can be used in the invention. In a preferred embodiment, the
mordant can be a cationic protonated amine-containing polymer or a polymer that contains
a quaternary ammonium group. Examples of these mordants include poly(1-vinylimidazole),
poly(4-vinylpyridine), poly(styrene-co-N-benzyl-N,N-dimethyl-N-vinylbenzyl-ammonium
chloride-co-divinylbenzene) (49:49:2 mole ratio), poly(N,N,N-tributyl-N-vinylbenzyl-ammonium
chloride), poly(N,N-dimethyl-N-benzyl-N-vinylbenzyl-ammonium chloride), poly(styrene-co-N,N,N-trimethyl-N-vinylbenzyl-ammonium
chloride) (1:1 mole ratio), poly(N,N,N-trimethyl-N-vinylbenzyl-ammonium chloride-co-divinylbenzene)
(87:13 mole ratio), poly(N,N-dimethyl-N-octadecyl-N-vinylbenzyl-ammonium chloride),
poly(styrene-co-1-vinylimidazole-co-3-hydroxyethyl-1-vinylimidazolium chloride) (5:4:1
mole ratio), poly(styrene-co-1-vinylimidazole-co-3-benzyl-1-vinylimidazolium chloride)
(5:4:1 mole ratio), poly(styrene-co- 1-vinylimidazole-co-3-hydroxyethyl-1-vinylimidazolium
chloride) (2:2:1 mole ratio), poly(styrene-co-4-vinylpyridine-co-1-hydroxyethyl-4-vinylpyridinium
chloride) (5:4:1 mole ratio), poly(diallydimethylammonium chloride) and chitosan.
[0019] The polymeric mordant employed in the invention can be used in an amount of from
0.2 to 16 g/m
2, preferably from 0.4 to 8 g/m
2.
[0020] The binder employed in the base layer is preferably a hydrophilic polymer. Examples
of hydrophilic polymers useful in the invention include polyvinyl alcohol, polyvinyl
pyrrolidone, 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/vinyl alcohol), poly(acrylic acid),
poly(1-vinyl pyrrolidone), 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).
[0021] The hydrophilic polymer may be present in an amount of from 0.1 to 30 g/m
2, preferably from 0.2 to 16 g/m
2 of the base layer.
[0022] The weight ratio of polymeric mordant to binder is from 1:99 to 8:2, preferably from
1:9 to 4:6.
[0023] Latex polymer particles and/or inorganic oxide particles may also be used in the
binder in the base 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. Preferably, the latex polymer particles are porous. 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 70 to 98%, preferably from 80 to 95%.
[0024] The pH of the aqueous ink compositions employed with the element of the invention
may be adjusted by the addition of organic or inorganic acids or bases. Useful inks
may have a preferred pH of from 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 tetramethylethylenediamine.
[0025] A humectant is employed in the ink jet composition employed with the element of 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.
[0026] Water-miscible organic solvents may also be added to the aqueous ink employed with
the element of 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.
[0027] 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.
[0028] A biocide may be added to the composition employed with the element of 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®
GXL (Zeneca Specialties Co.) at a final concentration of 0.0001-0.5 wt. %.
[0029] A typical ink composition employed with the element of 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%).
[0030] Additional additives, which may optionally be present in the ink jet ink composition
employed with the element of the invention, include thickeners, conductivity enhancing
agents, anti-kogation agents, drying agents, and defoamers.
[0031] The ink jet inks employed with the element of the 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.
[0032] The image-recording layer used in the element of the 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; antifoaming 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.
[0033] The support for the ink jet recording element used in the invention can be any of
those usually used for ink jet receivers, such as paper, resin-coated paper, polyesters,
or microporous materials such as polyethylene polymer-containing material sold by
PPG Industries, Inc., Pittsburgh, Pennsylvania under the trade name of Teslin ®, Tyvek
® synthetic paper (DuPont Corp.), and OPPalyte® films (Mobil Chemical Co.) and other
composite films listed in U.S. Patent 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. Patents 5,853,965; 5,866,282; 5,874,205; 5,888,643;
5,888,681; 5,888,683; and 5,888,714. 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.
[0034] The support used in the invention may have a thickness of from 50 to 500 µm, preferably
from 75 to 300 µm. Antioxidants, antistatic agents, plasticizers and other known additives
may be incorporated into the support, if desired. In a preferred embodiment, paper
is employed.
[0035] 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.
[0036] 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
2 µm.
[0037] The image-recording layer may be present in any amount that is effective for the
intended purpose. In general, good results are obtained when it is present in an amount
of from 2 to 60 g/m
2, preferably from 6 to 40 g/m
2, which corresponds to a dry thickness of 2 to 50 µm, preferably 6 to 40 µm.
[0038] The overcoat layer may be present in any amount that is effective for the intended
purpose. In general, good results are obtained when it is present in an amount of
from 1.1 to 10.7 g/m
2, preferably from 1.6 to 5.4 g/m
2, which corresponds to a dry thickness of 1.0 to 10 µm, preferably 1.5 to 5 µm.
[0039] The following examples illustrates the utility of the present invention.
[0040] The following mordants were used as controls in the image-recording layer:
MP-1: poly(N-vinylbenzyl-N,N,N-trimethylammonium chloride-co-divinylbenzene) (about
90/10 mol%) (U.S. Patent 6,045,917)
MP-2: poly(styrene-co-N-vinylbenzyl-N,N,N-trimethylammonium chloride-co-divinylbenzene)
(about 49/49/2 mol%) (U.S. Patent 6,045,917)
MP-3: poly(styrene-co-N-vinylimidazole-co-3-hydroxyethyl-1-vinylimidazolium chloride)
(about 50/40/10 mol%)
Example 1- Preparation of UVD-1 Dispersion
[0041] 600.0 g of triazine UV absorber compound UV-1 was added to 360.0 g of tris-2-ethylhexyl
phosphate and heated to 100 °C with stirring to form an organic composition. An aqueous
composition was prepared by combining 480.0 g of a deionized bone gelatin with 4131.4
g of deionized water, 8.6 g of a 0.7 weight percent solution of Kathon LX® biocide
and 420.0 g of a 10.0 weight percent solution of Alkanol XC ® (DuPont Corp.) surfactant.
The aqueous composition was heated to 80 °C.
[0042] The organic composition was added to the aqueous composition while shearing with
a Brinkman rotor-stator mixer and the resulting premix was passed one time through
a high energy multiple orifice homogenizer to form a dispersion.
Example 2-Preparation of UVD-2 Dispersion
[0043] 225.0 g of triazine UV absorber compound UV-1 and 75.0 g of triazine UV absorber
compound UV-2 was added to 180.0 g of tris-2-ethylhexyl phosphate and heated to 100
°C with stirring to form an organic composition. An aqueous composition was prepared
by combining 240.0 g of a deionized bone gelatin with 2065.7 g of deionized water,
4.3 g of a 0.7 weight percent solution of Kathon LX ® biocide and 210.0 g of a 10.0
weight percent solution of Alkanol XC ® (DuPont Corp.) surfactant. The aqueous composition
was heated to 80°C.
[0044] The organic composition was added to the aqueous composition while shearing with
a Brinkman rotor-stator mixer and the resulting premix was passed one time through
a high energy multiple orifice homogenizer to form a dispersion.
Example 3-Light Stability in Gelatin Based Coatings
Preparation of a water soluble, anionic dye ink composition, I-1
[0045] 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 ® biocide (Zeneca
Specialties) at 0.003 wt %, and a surfactant, Surfynol 465 ® (Air Products Co.) at
0.05 wt. %.
[0046] 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.
Preparation of a water soluble, anionic dye ink composition, I-2
[0047] Ink I-2 containing Dye 2 identified above (Reactive Red 31, CAS-12237-00-2) was composed
of Novajet Magenta Ink (Lyson Inc.) prepared by mixing 100 g of the commercial ink
with 0.5 g of Surfynol 465 ® surfactant (Air Products Inc.).
Preparation of Control Ink Recording Elements C-1 through C-3
[0048] The composite side of a polyethylene resin-coated photographic grade paper based
support was corona discharge treated prior to coating. Control Ink Recording Elements
were composed of a mixture of 0.86 g/m
2 of control polymers MP-1 through MP-3, 7.75 g/m
2 of gelatin and 0.09 g/m
2 of S-100 12 µm polystyrene beads (ACE Chemical Co.), and coated from distilled water
on the above mentioned paper support. In the preparation of C-3, a 60:40 mixture of
distilled water to methanol was used in place of distilled water to dissolve MP-3.
Preparation of Invention Ink Recording Elements E-1 through E-3
[0049] Recording elements E- 1 through E-3 of the invention were prepared by overcoating
C-1 through C-3 prepared above with a mixture of 20 g of UVD-1 dispersion prepared
in Example 1 above, 86 g of a 11.6% solution of gelatin, 2 g of a 10% solution of
Olin 10G® surfactant and 298 g of distilled water yielding a dry layer thickness after
coating of 1.51 g/m
2.
Preparation of Invention Ink Recording Elements E-4 through E-6
[0050] Recording elements E-4 through E-6 of the invention were prepared analogous to E-1
through E-3 above except UVD-2 dispersion from Example 2 was used in place of UVD-1.
Printing
[0051] Elements E-1 through E-6 and control elements C-1 through C-3 were printed using
an Epson 200 ® printer and inks I-1 and I-2 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® densitometer. The Dmax densities at step 11 were
recorded for I-1 and I-2 in Table 1 below.
[0052] The images were then subjected to a high intensity daylight fading test for 2 weeks,
50Klux, 5400°K., approximately 25% RH. The Status A blue or green reflection density
nearest to 1.0 was compared before and after fade and a percent density retained was
calculated for the yellow and magenta dyes with each receiver element. The results
can be found in Table 1 below.
Table 1
Recording Element |
Dmax Density, I-1 |
% Retained After Fade, I-1 |
Dmax Density, I-2 |
% Retained After Fade, I-2 |
E-1 |
1.70 |
76 |
2.01 |
77 |
E-2 |
1.48 |
90 |
1.83 |
86 |
E-3 |
1.49 |
91 |
1.87 |
89 |
E-4 |
1.57 |
81 |
2.02 |
72 |
E-5 |
1.47 |
85 |
1.84 |
80 |
E-6 |
1.56 |
91 |
1.87 |
90 |
C-1 |
1.50 |
70 |
1.82 |
61 |
C-2 |
1.40 |
63 |
1.83 |
60 |
C-3 |
1.59 |
67 |
2.19 |
68 |
[0053] The above results show that the recording elements E-1 through E-6 of the invention,
as compared to the control recording elements C-1 through C-3 gave higher Dmax densities
and % retained densities after high intensity daylight fading with both inks.