[0001] The present invention relates to a porous ink jet recording element and a printing
method using the element.
[0002] In a typical ink jet recording or printing system, ink droplets are ejected from
a nozzle at high speed towards a recording element or medium to produce an image on
the medium. The ink droplets, or recording liquid, generally comprise a recording
agent, such as a dye or pigment, and a large amount of solvent. The solvent, or carrier
liquid, typically is made up of water and an organic material such as a monohydric
alcohol, a polyhydric alcohol or mixtures thereof.
[0003] An ink jet recording element typically comprises a support having on at least one
surface thereof an ink-receiving or image-receiving layer, and includes those intended
for reflection viewing, which have an opaque support, and those intended for viewing
by transmitted light, which have a transparent support.
[0004] An important characteristic of ink jet recording elements is their need to dry quickly
after printing. To this end, porous recording elements have been developed which provide
nearly instantaneous drying as long as they have sufficient thickness and pore volume
to effectively contain the liquid ink. For example, a porous recording element can
be manufactured by cast coating, in which a particulate-containing coating is applied
to a support and is dried in contact with a polished smooth surface.
[0005] When a porous recording element is printed with dye-based inks, the dye molecules
penetrate the coating layers. However, there is a problem with such porous recording
elements in that the optical densities of images printed thereon are lower than one
would like. The lower optical densities are believed to be due to optical scatter
which occurs when the dye molecules penetrate too far into the porous layer.
[0006] EP 1,002,660 relates to a porous ink jet recording element comprising fine particles,
hydrophilic binder and a water-soluble, cationic polymer. However, there is a problem
with this element in that the density of an image printed on such an element using
a water-soluble cationic polymer is lower than one would like.
[0007] U.S. Patent 6,089,704 relates to a nonporous ink jet recording element comprising
cationic polymeric vinyl latex and a hydrophilic polymer. However, there is a problem
with this nonporous recording element in that it images printed thereon dry too slowly.
[0008] U.S. Patent 6,096,469 relates to an ink jet recording element comprising mesoporous
particles dispersed in an organic binder. In column 8, it is disclosed that the organic
binder can be a cationic latex polymer "having less than 10 mole percent of a copolymerizable
monomer having a tertamino or quaternary ammonium functionality." However, there is
a problem with this element in that the density of an image printed on such an element
with a binder having less than 10 mole percent of a cationic mordant functionality
is lower than one would like.
[0009] It is an object of this invention to provide a porous ink jet recording element that,
when printed with dye-based inks, provides superior optical densities, good image
quality and has an excellent dry time.
[0010] Another object of the invention is to provide a printing method using the above-described
element.
[0011] These and other objects are achieved in accordance with the invention which comprises
an ink jet recording element comprising a support having thereon a porous image-receiving
layer comprising:
(a) particles having a mean particle size of from greater than 0.04 µm to 5 µm; and
(b) water insoluble, cationic, polymeric particles comprising at least 20 mole percent
of a cationic mordant moiety.
[0012] By use of the invention, a porous ink jet recording element is obtained that, when
printed with dye-based inks, provides superior optical densities, good image quality
and has an excellent dry time.
[0013] Another embodiment of the invention relates to an ink jet printing method comprising
the steps of
I) providing an ink jet printer that is responsive to digital data signals;
II) loading the printer with the porous ink jet recording element described above;
III) loading the printer with an ink jet ink composition; and
IV) printing on the image-receiving layer using the ink jet ink composition in response
to the digital data signals.
[0014] In a preferred embodiment, the (a) particles useful in the invention include alumina,
boehmite, hydrated aluminum oxide, clay, calcium carbonate, titanium dioxide, calcined
clay, aluminosilicates, silica, barium sulfate, or organic particles such as polymeric
beads. Examples of organic particles useful in the invention are disclosed and claimed
in U.S. Patent Application Serial Numbers: 09/458,401, filed Dec. 10, 1999; 09/608,969,
filed June 30, 2000; 09/607,417, filed June 30, 2000; 09/608,466 filed June 30, 2000;
09/607,419, filed June 30, 2000; and 9/822,731, filed March 30, 2001. The (a) particles
may be porous or nonporous. In a preferred embodiment of the invention, the particles
are inorganic oxides. In another preferred embodiment, the (a) particles have a mean
particle size of from 0.05 µm to 1 µm.
[0015] While many types of inorganic and organic particles are manufactured by various methods
and commercially available for an image-receiving layer, porosity of the ink-receiving
layer is necessary in order to obtain very fast ink drying. The pores formed between
the particles must be sufficiently large and interconnected so that the printing ink
passes quickly through the layer and away from the outer surface to give the impression
of fast drying.
[0016] The (b) water insoluble, cationic, polymeric particles comprising at least 20 mole
percent of a cationic mordant moiety useful in the invention can be in the form of
a latex, water dispersible polymer, beads, or core/shell particles wherein the core
is organic or inorganic and the shell in either case is a cationic polymer. Such particles
can be products of addition or condensation polymerization, or a combination of both.
They can be linear, branched, hyper-branched, grafted, random, blocked, or can have
other polymer microstructures well known to those in the art. They also can be partially
crosslinked. Examples of core/shell particles useful in the invention are disclosed
and claimed in U.S. Patent Application Serial No. 09/772,097, of Lawrence et al.,
Ink Jet Printing Method, filed January 26, 2001. Examples of water dispersible particles
useful in the invention are disclosed and claimed in U.S. Patent Application Serial
No. 09/770,128, of Lawrence et al., Ink Jet Printing Method, filed January 26, 2001;
and U.S. Patent Application Serial No.09/770,127, of Lawrence et al., Ink Jet Printing
Method, filed January 26, 2001. In a preferred embodiment, the water insoluble, cationic,
polymeric particles comprise at least 50 mole percent of a cationic mordant moiety.
[0017] The (b) water insoluble, cationic, polymeric particles useful in the invention can
be derived from nonionic, anionic, or cationic monomers. In a preferred embodiment,
combinations of nonionic and cationic monomers are employed. In general, the amount
of cationic monomer employed in the combination is at least 20 mole percent.
[0018] The nonionic, anionic, or cationic monomers employed can include neutral, anionic
or cationic derivatives of addition polymerizable monomers such as styrenes, alpha-alkylstyrenes,
acrylate esters derived from alcohols or phenols, methacrylate esters, vinylimidazoles,
vinylpyridines, vinylpyrrolidinones, acrylamides, methacrylamides, vinyl esters derived
from straight chain and branched acids (e.g., vinyl acetate), vinyl ethers (e.g.,
vinyl methyl ether), vinyl nitriles, vinyl ketones, halogen-containing monomers such
as vinyl chloride, and olefins, such as butadiene.
[0019] The nonionic, anionic, or cationic monomers employed can also include neutral, anionic
or cationic derivatives of condensation polymerizable monomers such as those used
to prepare polyesters, polyethers, polycarbonates, polyureas and polyurethanes.
[0020] The (b) water insoluble, cationic, polymeric particles employed in this invention
can be prepared using conventional polymerization techniques including, but not limited
to bulk, solution, emulsion, or suspension polymerization.
[0021] The amount of (b) water insoluble, cationic, polymeric particles used should be high
enough so that the images printed on the recording element will have a sufficiently
high density, but low enough so that the interconnected pore structure formed by the
aggregates is not filled. In a preferred embodiment of the invention, the weight ratio
of (b) water insoluble, cationic, polymeric particles to (a) particles is from 1:2
to 1:10, preferably 1:5.
[0022] Examples of (b) water insoluble, cationic, polymeric particles which may be used
in the invention include those described in U.S. Patent 3,958,995. Specific examples
of these polymers include:
Polymer A. Copolymer of (vinylbenzyl)trimethylammonium chloride and divinylbenzene
(87:13 molar ratio)
Polymer B. Terpolymer of styrene, (vinylbenzyl)dimethylbenzylamine and divinylbenzene
(49.5:49.5:1.0 molar ratio)
Polymer C. Terpolymer of butyl acrylate, 2-aminoethylmethacrylate hydrochloride and
hydroxyethylmethacrylate (50:20:30 molar ratio)
Polymer D. Copolymer of styrene, dimethylacrylamide, vinylbenzylimidazole and 1-vinylbenzyl-3-hydroxyethylimidazolium
chloride (40:30:10:20 molar ratio)
Polymer E. Copolymer of styrene, 4-vinylpyridine and N-(2-hydroxyethyl)-4-vinylpyridinium
chloride (30:38:32 molar ratio)
Polymer F. Copolymer of styrene, (vinylbenzyl)dimethyloctylammonium chloride), isobutoxymethyl
acrylamide and divinylbenzene (40:20:34:6 molar ratio)
[0023] In a preferred embodiment of the invention, the image-receiving layer also contains
a polymeric binder in an amount insufficient to alter the porosity of the porous receiving
layer. In another preferred embodiment, the polymeric binder is a hydrophilic polymer
such as poly(vinyl alcohol), poly(vinyl pyrrolidone), gelatin, cellulose ethers, poly(oxazolines),
poly(vinylacetamides), partially hydrolyzed poly(vinyl acetate/vinyl alcohol), poly(acrylic
acid), poly(acrylamide), poly(alkylene oxide), sulfonated or phosphated polyesters
and polystyrenes, casein, zein, albumin, chitin, chitosan, dextran, pectin, collagen
derivatives, collodian, agar-agar, arrowroot, guar, carrageenan, tragacanth, xanthan,
rhamsan and the like. In still another preferred embodiment of the invention, the
hydrophilic polymer is poly(vinyl alcohol), hydroxypropyl cellulose, hydroxypropyl
methyl cellulose, gelatin, or a poly(alkylene oxide). In yet still another preferred
embodiment, the hydrophilic binder is poly(vinyl alcohol). The polymeric binder should
be chosen so that it is compatible with the aforementioned particles.
[0024] The amount of binder used should be sufficient to impart cohesive strength to the
ink jet recording element, but should also be minimized so that the interconnected
pore structure formed by the aggregates is not filled in by the binder. In a preferred
embodiment of the invention, the weight ratio of the binder to the total amount of
particles is from 1:20 to 1:5.
[0025] In addition to the image-receiving layer, the recording element may also contain
a base layer, next to the support, the function of which is to absorb the solvent
from the ink. Materials useful for this layer include (a) particles, (b) particles,
polymeric binder and/or crosslinker.
[0026] Since the image-receiving layer is a porous layer comprising particles, the void
volume must be sufficient to absorb all of the printing ink. For example, if a porous
layer has 60 volume % open pores, in order to instantly absorb 32 cc/m
2 of ink, it must have a physical thickness of at least 54 µm.
[0027] 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 resin-coated paper, 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 biaxially oriented support laminates. Biaxially 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 biaxially 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. In a preferred embodiment, polyethylene-coated paper is employed.
[0028] 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.
[0029] In order to improve the adhesion of the ink-receiving layer to the support, the surface
of the support may be subjected to a corona-discharge treatment prior to applying
the image-receiving layer.
[0030] Coating compositions employed in the invention may be applied by any number of well
known techniques, including dip-coating, wound-wire rod coating, doctor blade coating,
rod coating, air knife coating, gravure and reverse-roll coating, slide coating, bead
coating, extrusion coating, curtain coating and the like. Known coating and drying
methods are described in further detail in Research Disclosure no. 308119, published
Dec. 1989, pages 1007 to 1008. Slide coating is preferred, in which the base layers
and overcoat may be simultaneously applied. After coating, the layers are generally
dried by simple evaporation, which may be accelerated by known techniques such as
convection heating.
[0031] In order to impart mechanical durability to an ink jet recording element, crosslinkers
which act upon the binder discussed above may be added in small quantities. Such an
additive improves the cohesive strength of the layer. Crosslinkers such as carbodiimides,
polyfunctional aziridines, aldehydes, isocyanates, epoxides, polyvalent metal cations,
and the like may all be used.
[0032] To improve colorant fade, UV absorbers, radical quenchers or antioxidants may also
be added to the image-receiving layer as is well known in the art. Other additives
include pH modifiers, adhesion promoters, rheology modifiers, surfactants, biocides,
lubricants, dyes, optical brighteners, matte agents, antistatic agents, etc. In order
to obtain adequate coatability, additives known to those familiar with such art such
as surfactants, defoamers, alcohol and the like may be used. A common level for coating
aids is 0.01 to 0.30 % active coating aid based on the total solution weight. These
coating aids can be nonionic, anionic, cationic or amphoteric. Specific examples are
described in MCCUTCHEON's Volume 1: Emulsifiers and Detergents, 1995, North American
Edition.
[0033] The coating composition can be coated either from water or organic solvents, however
water is preferred. The total solids content should be selected to yield a useful
coating thickness in the most economical way, and for particulate coating formulations,
solids contents from 10-40% are typical.
[0034] Ink jet inks used to image the recording elements of the present invention are well-known
in the art. The ink compositions used in ink jet printing typically are liquid compositions
comprising a solvent or carrier liquid, dyes or pigments, humectants, organic solvents,
detergents, thickeners, preservatives, and the like. The solvent or carrier liquid
can be solely water or can be water mixed with other water-miscible solvents such
as polyhydric alcohols. Inks in which organic materials such as polyhydric alcohols
are the predominant carrier or solvent liquid may also be used. Particularly useful
are mixed solvents of water and polyhydric alcohols. The dyes used in such compositions
are typically water-soluble direct or acid type dyes. Such liquid compositions have
been described extensively in the prior art including, for example, U.S. Patents 4,381,946;
4,239,543 and 4,781,758.
[0035] The following example is provided to illustrate the invention.
[0036] The following comparative cationic polymers used are water-soluble:
C-1 Poly(vinylbenzyl)trimethylammonium chloride, available as Chemistat® 6300H from
Sanyo Chemical Industries.
C-2 Polypropylene oxide-based triamine, available as Jeffamine® T-5000 from Huntsman,
Corp.
Element 1 of the Invention
[0037] A coating solution for a base layer was prepared by mixing 100 dry g of precipitated
calcium carbonate Albagloss-s® (Specialty Minerals Inc.) as a 70% solution and 8.5
dry g of silica gel Gasil® 23F (Crosfield Ltd.) with 0.5 dry g of a poly(vinyl alcohol)
Gohsenol® GH-17 (Nippon Gohsei Co., Ltd.) as a 10% solution and 5 dry g of styrene-butadiene
latex CP692NA® (Dow Chemical) as a 50% solution. The solids of the coating solution
was adjusted to 35% by adding water.
[0038] The base layer coating solution was bead-coated at 25°C on a base paper, basis weight
185 g/m
2, and dried at 60°C by forced air. The thickness of the base coating was 25 µm or
27 g/m
2.
[0039] A coating solution for the image-receiving layer was prepared by combining alumina
Dispal® 14N4-80 (Condea Vista Co.), poly(vinyl alcohol) Gohsenol® GH-17 (Nippon Gohsei
Co.) and Polymer A illustrated above in a ratio of 86:4:10 to give an aqueous coating
formulation of 15% solids by weight. Surfactants Zonyl® FS-300 (DuPont Co.) and Silwet®
L-7602 (Witco Corp.) were added in small amounts as coating aids.
[0040] The image-receiving layer coating solution was coated on top of this base layer.
The recording element was then dried at 60°C by forced air to yield a two-layer recording
element. The thickness of the image-receiving layer was 8 µm or 8.6 g/m
2.
Element 2 of the Invention
[0041] Element 2 was prepared the same as Element 1 except that Polymer B was used instead
of Polymer A.
Element 3 of the Invention
[0042] Element 3 was prepared the same as Element 1 except that both Polymer A. and Polymer
B were used.
Comparative Element 1 (no water-insoluble, cationic polymeric particles)
[0043] This element was prepared the same as Element 1 except that water-soluble Polymer
C-1 was used instead of Polymer A.
Comparative Element 2 (no water-insoluble, cationic polymeric particles)
[0044] This element was prepared the same as Element 1 except that water-soluble Polymer
C-2 was used instead of Polymer A.
Comparative Element 3 (no cationic polymeric particles)
[0045] This element was prepared the same as Element 1 except that the image-receiving layer
contained only alumina and poly (vinyl alcohol) in the ratio 96:4.
Density Testing
[0046] Test images of cyan, magenta, yellow, red, green and blue patches at 100% ink laydown
were printed using a Hewlett-Packard DeskJet 970 printer and ink cartridge with catalogue
number HP C6578D.
[0047] After drying for 24 hours at ambient temperature and humidity, the Status A D-max
densities were measured using an X-Rite® 820 densitometer (for each of the red, green
and blue densities, the two component color densities were measured and averaged).
The following results were obtained:
Table 1
Recording Element |
Status A D-max Density |
|
Cyan |
Magenta |
Yellow |
Red |
Green |
Blue |
1 |
0.9 |
2 |
1.6 |
1.5 |
1.2 |
1.6 |
2 |
0.9 |
2 |
1.6 |
1.5 |
1.2 |
1.6 |
3 |
0.9 |
1.9 |
1.6 |
1.5 |
1.2 |
1.6 |
C-1 |
0.6 |
1.6 |
1.2 |
1.2 |
1.0 |
1.2 |
C-2 |
0.7 |
1.7 |
1.3 |
1.2 |
1.1 |
1.3 |
C-3 |
0.9 |
1.2 |
1.2 |
1.2 |
1.1 |
1.4 |
[0048] The above results show that Status A D-max densities for the recording element of
the invention are higher in all colors as compared to the comparative elements.