[0001] This invention relates to an ink jet recording element and a printing method using
the element. More particularly, this invention relates to a subbing layer for an ink
jet recording 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, 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-forming 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] It is well known that in order to achieve and maintain photographic-quality images
on such an image-recording element, an ink jet recording element must:
- Be readily wetted so there is no puddling, i.e., coalescence of adjacent ink dots,
which leads to non-uniform density
- Exhibit no image bleeding
- Exhibit the ability to absorb high concentrations of ink and dry quickly to avoid
elements blocking together when stacked against subsequent prints or other surfaces
- Exhibit no discontinuities or defects due to interactions between the support and/or
layer(s), such as cracking, repellencies, comb lines and the like
- Not allow unabsorbed dyes to aggregate at the free surface causing dye crystallization,
which results in bloom or bronzing effects in the imaged areas
- Have an optimized image fastness to avoid fade from contact with water or radiation
by daylight, tungsten light, or fluorescent light
[0005] An ink jet recording element that simultaneously provides an almost instantaneous
ink dry time and good image quality is desirable. However, given the wide range of
ink compositions and ink volumes that a recording element needs to accommodate, these
requirements of ink jet recording media are difficult to achieve simultaneously.
[0006] Ink jet recording elements are known that employ porous or non-porous single layer
or multilayer coatings that act as suitable image receiving layers on one or both
sides of a porous or non-porous support. Recording elements that use non-porous coatings
typically have good image quality but exhibit poor ink dry time. Recording elements
that use porous coatings typically contain colloidal particulates and have poorer
image quality but exhibit superior dry times.
[0007] While a wide variety of different types of porous image-recording elements for use
with ink jet printing are known, there are many unsolved problems in the art and many
deficiencies in the known products which have severely limited their commercial usefulness.
A major challenge in the design of a porous image-recording layer is to be able to
obtain good quality, crack-free coatings with as little non-particulate matter as
possible. If too much non-particulate matter is present, the image-recording layer
will not be porous and will exhibit poor ink dry times.
[0008] U.S. Patent 4,877,686 relates to a recording sheet for ink jet printing wherein boric
acid or its derivative is used to cause gelling in a polymeric binder containing hydroxyl
groups and a filler comprising particles. However, there is a problem with this element
in that the amount of boric acid used does not provide an element which, when printed
with an ink jet printer, will have a fast dry time without cracking.
[0009] It is an object of this invention to provide an ink jet recording element that has
a fast dry time when used in ink jet printing. It is another object of this invention
to provide a porous recording element that has good coating quality, especially reduced
cracking. It is still another object of this invention to provide an ink jet recording
element that exhibits good image quality after printing.
[0010] Still another object of the invention is to provide a printing method using the aobve-described
element.
[0011] These and other objects are achieved in accordance with the invention which comprises
an ink jet recording element comprising a substrate having thereon:
a) a subbing layer comprising a polymeric binder and a borate or a borate derivative,
the borate or borate derivative being present in an amount of from up to 3 g/m2, and the weight ratio of the polymeric binder to the borate or borate derivative
is from 0.2:1 to 3:1; and
b) an image-receiving layer comprising inorganic particles and a cross-linkable polymer
containing hydroxyl groups, the cross-linkable polymer being present in an amount
of less than 50 g/m2, and the weight ratio of the cross-linkable polymer to the inorganic particles is
from 5:95 to 30:70.
[0012] The ink jet recording element of the invention has good coating and image quality
and a fast dry time when printed in an ink jet printer.
[0013] 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; and
D) printing on the image-receiving layer using the ink jet ink in response to the
digital data signals.
[0014] The polymeric binder in the subbing layer employed in the invention is preferably
a water soluble or water dispersible polymer such as poly(vinyl alcohol), poly(vinyl
pyrrolidone), gelatin, a cellulose ether, a poly(oxazoline), a poly(vinylacetamide),
partially hydrolyzed poly(vinyl acetate/vinyl alcohol), poly(acrylic acid), poly(acrylamide),
poly(alkylene oxide), a sulfonated or phosphated polyester or polystyrene, casein,
zein, albumin, chitin, chitosan, dextran, pectin, a collagen derivative, collodian,
agar-agar, arrowroot, guar, carrageenan, tragacanth, xanthan, rhamsan and the like;
a latex such as poly(styrene-co-butadiene), a polyurethane latex, a polyester latex,
or a poly(acrylate), poly(methacrylate), poly(acrylamide) or copolymers thereof. In
a preferred embodiment, the polymeric binder is poly(vinyl alcohol), a sulfonated
polyester dispersion, such as AQ29® (Eastman Chemical Co.), gelatin, a polyurethane
or poly(vinyl pyrrolidone).
[0015] The polymeric binder for the subbing layer is preferably used in an amount of up
to 3 g/m
2.
[0016] The borate or borate derivative employed in the subbing layer of the ink jet recording
element of the invention may be, for example, borax, sodium tetraborate, boric acid,
phenyl boronic acid, or butyl boronic acid. As noted above, the borate or borate derivative
is used in an amount of up to 3 g/m
2. It is believed that upon coating, the borate or borate derivative in the subbing
layer diffuses into the image-receiving layer to cross-link the cross-linkable binder
in the image-receiving layer.
[0017] The inorganic particles which may be used include, for example, comprise metal oxides,
hydrated metal oxides, boehmite, clay, calcined clay, calcium carbonate, -aluminosilicates,
zeolites or barium sulfate. In a preferred embodiment, the metal oxide is silica,
alumina, zirconia or titania. In another preferred embodiment, the metal oxide is
fumed silica, fumed alumina, colloidal silica or boehmite. In still another preferred
embodiment, the inorganic particles are present in the image-receiving layer in an
amount of up to 50 g/m
2.
[0018] When the inorganic particles are fumed silica or fumed alumina, they preferably have
a primary particle size up to 50 nm, but can be aggregated to give an aggregate size
of less than 300 nm. When the inorganic particles are colloidal silica or boehmite,
they preferably have a particle size of less than 150 nm.
[0019] The cross-linkable polymer containing hydroxyl groups employed in the image-receiving
layer may be, for example, poly(vinyl alcohol), partially hydrolyzed poly(vinyl acetate/vinyl
alcohol), copolymers containing hydroxyethylmethacrylate, copolymers containing hydroxyethylacrylate,
copolymers containing hydroxypropylmethacrylate, hydroxy cellulose ethers such as
hydroxyethylcellulose, etc. In a preferred embodiment, the cross-linkable polymer
containing hydroxyl groups is poly(vinyl alcohol) or partially hydrolyzed poly(vinyl
acetate/vinyl alcohol).
[0020] An additional polymeric binder, such as any of the polymeric binders listed above
for the subbing layer, may also be added to the image-receiving layer along with the
cross-linkable polymer, if desired.
[0021] The amount of binder used in the image-receiving layer 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 particles is not filled in by
the binder.
[0022] In addition to the image-receiving layer, the recording element of the invention
may also contain a layer on top of the image-receiving layer, the function of which
is to provide gloss. Materials useful for this layer include submicron inorganic particles
and/or polymeric binder.
[0023] 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.), impregnated paper such as Duraform®, 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.
[0024] 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.
[0025] In order to improve the adhesion of the image-receiving layer to the support, the
surface of the support may be subjected to a corona-discharge treatment prior to applying
the subbing layer.
[0026] The above 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 wt. % are typical.
[0027] 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,
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.
[0028] The coating composition may be applied to one or both substrate surfaces through
conventional pre-metered or post-metered coating methods such as blade, air knife,
rod, roll coating, etc. The choice of coating process would be determined from the
economics of the operation and in turn, would determine the formulation specifications
such as coating solids, coating viscosity, and coating speed.
[0029] The image-receiving layer thickness may range from 1 to 60 µm, preferably from 5
to 40 µm.
[0030] After coating, the ink jet recording element may be subject to calendering or supercalendering
to enhance surface smoothness. In a preferred embodiment of the invention, the ink
jet recording element is subject to hot soft-nip calendering at a temperature of 65°C
and a pressure of 14000 kg/m at a speed of from 0.15 m/s to 0.3 m/s.
[0031] In order to impart mechanical durability to an ink jet recording element, additional
crosslinkers that further act upon the cross-linkable 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 maybe used. A common level for coating
aids is 0.01 to 0.30 wt. % 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] 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.
[0034] In order to obtain the best results, the materials and amounts in the image-receiving
layer and the thickness of the image-receiving layer are selected to that the pore
volume of the image-receiving layer is greater than about 22 cc/m
2 and it has a median pore diameter between about 20 and about 50 nm.
[0035] The following examples are provided to illustrate the invention.
Example 1
Subbing Layer 1
[0036] Sulfonated polyester dispersion AQ29® (Eastman Chemical Co.) and borax (sodium tetraborate
decahydrate), at a 70:30 ratio, were used to prepare a coating solution. The coating
solution was bead-coated at 25°C on polyethylene-coated paper base that had been previously
subjected to corona discharge treatment. The recording element was then dried by forced
air at 43 °C for 4 minutes. The thickness of the subbing layer was 3.8 g/m
2.
Subbing Layer 2
[0037] This subbing layer was prepared the same as for Subbing Layer 1 except that the ratio
of AQ29® to borax was 50:50.
Subbing Layer 3
[0038] This subbing layer was prepared the same as for Subbing Layer 1 except that Witco
240® (Uniroyal Chemical Co.) was used in place of AQ29®.
Subbing Layer 4
[0039] This subbing layer was prepared the same as for Subbing Layer 2 except that poly(vinyl
alcohol) Airvol® 103 (Uniroyal Chemical Co.) was used in place of AQ29®. The thickness
of the subbing layer was 0.26 g/m
2.
Element 1 of the Invention
[0040] A coating solution for the image-receiving layer was prepared by mixing 74 g of fumed
silica Cab-O-Sperse® PG022 (Cabot Corp.) as a 20% solution, 25.1 g of poly(vinyl alcohol)
Gohsenol® GH-17 (Nippon Gohsei Co. Ltd.) as a 10% solution, and 0.9 g of Olin® 10G
(Dixie Chemical Co.) as a 10% solution. The solid of the coating solution was 17.4
wt. %. The coating solution was bead-coated at 25 ° C on Subbing Layer 1 and dried
by forced air at 21 ° C. The thickness of the image-receiving layer was 50 g/m
2.
Element 2 of the Invention
[0041] This element was prepared the same as Element 1 except that 75.8 g of fumed silica
Cab-O-Sperse® PG022 (Cabot Corp.) as a 20% solution, 27.2 g of poly(vinyl alcohol)
Gohsenol® GH-17 (Nippon Gohsei Co. Ltd.) as a 10% solution, and 0.95 g of Olin® 10G
(Dixie Chemical Co.) as a 10% solution were used.
Element 3 of the Invention
[0042] This element was prepared the same as Element 1 except that 75.8 g of fumed silica
Cab-O-Sperse® PG022 (Cabot Corp.) as a 20% solution, 33.4 g of poly(vinyl alcohol)
Gohsenol® GH-17 (Nippon Gohsei Co. Ltd.) as a 10% solution, and 0.95 g of Olin® 10G
(Dixie Chemical Co.) as a 10% solution were used.
Element 4 of the Invention
[0043] A coating solution for the image-receiving layer was prepared by mixing 449.5 g of
fumed alumina W440® (DeGussa Corp.) as a 40% solution, 220g of poly(vinyl alcohol)
Gohsenol® GH-17 (Nippon Gohsei Co. Ltd.) as a 10% solution, and 2 g of Olin® 10G (Dixie
Chemical Co.) as a 10% solution. The solids concentration of the coating solution
was adjusted to 17.4 wt. % by adding water. The coating solution was bead-coated at
25 °C on Subbing Layer 1 and dried by forced air at 21 °C. The thickness of the image-receiving
layer was 53 g/m
2.
Element 5 of the Invention
[0044] A coating solution for the image-receiving layer was prepared by mixing 75.8 g of
Cab-O-Sperse® PG002 (Cabot Corp.) as a 20% solution, 33.4 g of poly(vinyl alcohol)
Gohsenol® GH-17 (Nippon Gohsei Co. Ltd.) as a 10% solution, and 0.95 g of Olin® 10G
(Dixie Chemical Co.) as a 10% solution. The coating solution was bead-coated at 25°C
on Subbing Layer 1 and dried by forced air at 21°C. The thickness of the image-receiving
layer was 50 g/m
2.
Element 6 of the Invention
[0045] This element was prepared the same as Element 1 except that 75.8 g of fumed silica
Cab-O-Sperse® PG022 (Cabot Corp.) as a 20% solution, 43.4 g of poly(vinyl alcohol)
Gohsenol® GH-17 (Nippon Gohsei Co. Ltd.) as a 10% solution, and 0.95 g of Olin® 10G
(Dixie Chemical Co.) as a 10% solution were used.
Element 7 of the Invention
[0046] This element was prepared the same as Element 1 except that 19.9 g of colloidal silica
Nalco® 1056 (Nalco Corp.) as a 30% solution, 15 g of poly(vinyl alcohol) Gohsenol®
GH-17 (Nippon Gohsei Co. Ltd.) as a 10% solution, and 0.38 g of Olin® 10G (Dixie Chemical
Co.) as a 10% solution were used.
Element 8 of the Invention
[0047] This element was prepared the same as Element 4 except that the solution was coated
on Subbing Layer 2.
Element 9 of the Invention
[0048] This element was prepared the same as Element 4 except that the solution was coated
on Subbing Layer 3.
Element 10 of the Invention
[0049] This element was prepared the same as Element 4 except that the solution was coated
on Subbing Layer 4.
Comparative Element 1 (no subbing layer)
[0050] A coating solution for the image-receiving layer was prepared by mixing 42.25 g of
Cab-O-Sperse® PG022 (Cabot Corp.) as a 20% solution, 15 g of poly(vinyl alcohol) Gohsenol®
GH-17 (Nippon Gohsei Co. Ltd.) as a 10% solution, and 0.5 g of Olin® 10G (Dixie Chemical
Co.) as a 10% solution. The coating solution was bead-coated at 25°C on polyethylene-coated
paper base that had been previously subjected to corona discharge treatment, and dried
by forced air at 21°C. The thickness of the image-receiving layer was 50 g/m
2.
Comparative Element 2 (no subbing layer)
[0051] This element was prepared the same as Comparative Element 1 except that 37.25 g of
fumed silica Cab-O-Sperse® PG022 (Cabot Corp.) as a 20% solution and 25 g of poly(vinyl
alcohol) Gohsenol® GH-17 (Nippon Gohsei Co. Ltd.) as a 10% solution were used.
Comparative Element 3 (no subbing layer)
[0052] This element was prepared the same as Comparative Element 1 except that 32.25 g of
fumed silica Cab-O-Sperse® PG022 (Cabot Corp.) as a 20% solution and 35 g of poly(vinyl
alcohol) Gohsenol® GH-17 (Nippon Gohsei Co. Ltd.) as a 10% solution were used.
Comparative Element 4 (no subbing layer)
[0053] This element was prepared the same as Comparative Element 1 except that 29.75 g of
fumed silica Cab-O-Sperse® PG022 (Cabot Corp.) as a 20% solution and 40 g of poly(vinyl
alcohol) Gohsenol® GH-17 (Nippon Gohsei Co. Ltd.) as a 10% solution were used.
Comparative Element 5 (no subbing layer)
[0054] This element was prepared the same as Comparative Element 1 except that 19.9 g of
fumed silica Naico® 1056 (Nalco Corp.) as a 30% solution, 15 g of poly(vinyl alcohol)
Gohsenol® GH-17 (Nippon Gohsei Co. Ltd.) as a 10% solution, and 0.38 g of Olin® 10G
(Dixie Chemical Co.) as a 10% solution were used.
Comparative Element 6
[0055] This element was prepared the same as Element 4, except that no borax was used in
the subbing layer.
Comparative Element 7
[0056] This element was prepared the same as Element 4, except that no AQ29® was used in
the subbing layer.
Coating Quality
[0057] The above dried coatings for visually evaluated for cracking defects. The results
are tabulated in Table 1.
Table 1
Recording Element |
Subbing Layer |
Ratio Particles:Polymer |
Coating Quality |
1 |
1 |
85:15 |
Good |
2 |
1 |
85:15 |
Good |
3 |
1 |
82:18 |
Good |
4 |
1 |
89:11 |
Good |
5 |
1 |
82:18 |
Good |
6 |
1 |
78:22 |
Good |
7 |
1 |
80:20 |
Good |
8 |
2 |
90:10 |
Good |
9 |
3 |
90:10 |
Good |
10 |
4 |
90:10 |
Good |
Comparative 1 |
none |
85:15 |
Bad |
Comparative 2 |
none |
75:25 |
Bad |
Comparative 3 |
none |
65:35 |
Bad |
Comparative 4 |
none |
60:40 |
Good |
Comparative 5 |
none |
80:20 |
Bad |
Comparative 6 |
AQ29® only |
90:10 |
Bad |
Comparative 7 |
borax only |
90:10 |
Bad |
[0058] The results show that the elements of the invention had better coating quality than
all but one of the comparative elements. While Comparative Element 4 had good coating
quality, it contained 40 wt. % binder as compared to less than 25 wt. % binder for
the elements of the invention., and was worse for coalescence as will be shown in
Example 2.
Example 2
Preparation of Inks
Cyan Ink
[0059] A cyan ink was prepared using Pigment Blue15:3 at 1.4 wt. %, sulfonated polyester
dispersion AQ55® (Eastman Chemical Co.) at 1.1 wt. %, glycerol at 6.0 wt. %, Surfynol®
465 at 0.2 wt. %, Dowanol® EB (Dow Chemical Co.) at 2.5 wt. % and diethylene glycol
at 24.0 wt. %. Small amounts of triethanol amine and lactic acid were used to adjust
the pH to 8.
Magenta Ink
[0060] A magenta ink was prepared using Pigment Red 122 at 2.2 wt. %, sulfonated polyester
dispersion AQ55® (Eastman Chemical Co.) at 2.0 wt %, glycerol at 6.0 wt. %, Surfynol®
465 at 0.2 wt. %, Dowanol EB (Dow Chemical Co.) at 2.5 wt.% and diethylene glycol
at 19.4 wt.%. Small amounts of triethanol amine and lactic acid were used to adjust
the pH to 8.
Yellow Ink
[0061] A yellow ink was prepared using Pigment Yellow 155 at 2.2 wt. %, sulfonated polyester
dispersion AQ55® (Eastman Chemical Co.) at 2.0 wt. %, glycerol at 6.0 wt. %, Surfynol®
465 at 0.2 wt. %, Dowanol® EB at 2.5 wt. % and diethylene glycol at 20 wt.%. Small
amounts of triethanol amine and lactic acid were used to adjust the pH to 8.
Black Ink
[0062] A black ink was prepared using Pigment Black 7 at 1.6 wt. % of the ink composition,
sulfonated polyester dispersion AQ55® (Eastman Chemical Co.) at 1.485 wt. %, glycerol
at 6.0 wt. %, Surfynol® 465 at 0.2 wt. %, Dowanol® EB at 2.5 wt. % and diethylene
glycol at 23 wt. %. Small amounts of triethanol amine and lactic acid were used to
adjust the pH to 8.
Printing
[0063] The above inks were filtered through a 0.2 µm polytetrafluoroethylene filter, degassed
using ultrasonic treatment with an applied vacuum of 559 mm of mercury and placed
in a clean empty cartridge used for printing with a Mutoh 4100 ink jet printer. The
above inks were printed on Recording Elements1-10 and Comparative Element 4 using
a Mutoh 4100 ink jet printer without color correction at 283 dots per centimeter (720
dpi) bi-directional printing, with "microdot on" setting giving a droplet size of
about17 picoliters.
[0064] The test image consisted of a block 9.2 cm by 19.4 cm, divided into equally sized
patches 0.7 cm by 0.4 cm to give 40 rows of patches and 12 columns of patches. The
rows were numbered from 10 to 400 in increments of 10 to indicate the increasing percentage
of ink laydown. Thus, patches 10 to 100 were printed with one ink, patches 110 to
200 were printed with two inks, patches 210 to 300 were printed with three inks and
patches 310 to 400 were printed with four inks. The columns were labeled with the
order of ink laydown for cyan, magenta, yellow and black inks as shown in Table 2.

Coalescence
[0065] Coalescence varies depending on the order in which inks are printed. Coalescence
was evaluated by visual inspection of each of the printed recording elements. The
first row in which puddling on the surface appears was recorded. Values greater than
about 150 are desirable. The results are shown in Table 3.
Table 3
Printed Recording Element |
Subbing Layer |
Ratio Particles:Polymer |
Coalescence |
1 |
1 |
85:15 |
400 |
2 |
1 |
85:15 |
280 |
3 |
1 |
82:18 |
290 |
4 |
1 |
89:11 |
380 |
5 |
1 |
82:18 |
220 |
6 |
1 |
78:22 |
200 |
8 |
2 |
90:10 |
390 |
9 |
3 |
90:10 |
260 |
10 |
4 |
90:10 |
180 |
Comparative 4 |
none |
60:40 |
130 |
[0066] The results show that the elements of the invention were better for coalescence than
Comparative Element 4.