Note: Descriptions are shown in the official language in which they were submitted.
2160619
A GLOSSY INR JET RE~ vlr~G PAPER
Field of the Invention
This invention relates to a glossy ink jet receiving
paper that can be used for high resolution color ink jet
printing applications.
Backqround of the Invention
Recently, ink jet printing technology has been used
for presentation, graphic art, engineering drawing and home
office applications. The performance requirements for ink
jet media that are used for these applications are quite
stringent. These include fast ink drying, low ink
migration, large color gamut, good color fidelity, minimal
ink offset, high image resolution and good performance
under varied environmental conditions. Another important
requirement for ink jet media in commercial applications is
high surface gloss. This is particularly important for
graphic art applications. Current commercial ink jet media
cannot meet these performance requirements. For example,
plastic substrate based ink jet media cannot offer high
image resolution and fast drying, and most commercial ink
jet papers cannot overcome low gloss and poor color
fidelity.
Although many ink jet receiving paper designs have
been proposed in the field, none of them provides a
satisfactory solution to the problem of providing a glossy
ink jet receiving sheet. For example, U.S. Patent
5,141,599 discloses a glossy ink jet receiving material
2160~1g
~ 2 Docket No. 84-140P
based on a polyolefin coated paper, but the coated paper
performs more like a plastic film than a paper. Similarly,
U.S. Patent 4,092,457 disclosed an ink receiving material
based on synthetic fibers that do not offer desired paper
properties. Further, U.S. Patents 5,141,797, 5,279,885,
5,213,873, 5,207,824, 5,180,624, 4,542,059, 5,281,467,
5,302,437, 5,126,010, 5,013,603, a,952,943, 4,900,620 all
discuss ink jet receiving papers, but all of these designs
ignored two important performance parameters, namely, gloss
and ink migration. The provision of an ink jet receiving
paper which can satisfy both of these performance
requirements would be an important achievement in the art.
SummarY of the Invention
An objective of the present invention is to provide an
ink jet receiving sheet which overcomes the above-mentioned
drawbacks and problems which previously existed in the art.
The present invention provides an ink jet receiving
paper for use in applications wherein high gloss, good
image resolution and color fidelity are required. More
specifically, the present invention provides an ink jet
receiving paper with improved gloss, image resolution,
color fidelity, ink migration, dry time and environmental
tolerance. The present invention offers an ink jet
receiving paper giving optimal performance in this respect,
through the provision of unique combinations of ink
receptive coatings and paper substrates having specified
properties, wherein the resulting ink jet receiving paper
- fully meets the physical and performance requirements of
commercial ink jet recording media.
More specifically, the present invention provides for
a glossy ink jet receiving paper which comprises:
(1) a paper substrate having:
a gloss greater than about 20 and preferably greater
than about 30 as measured at a 60 degree angle,
a Sheffield smoothness of less than about 80 and
preferably less than about 60,
2~ 60619
3 Docket No. 84-140P
an opacity of greater than about 70~ and preferably
greater than about 80~, and
a brightness of greater than about 70~ and preferably
greater than about 80~; and
(2) an ink receptive coating containing one or more
water-soluble components in a total amount of abou~
4 to about 100 weight ~, based on the total weight of
solids in the coating.
Additionally, the prepared glossy ink jet receiving
paper media encompassed by the present invention should
possess the following characteristics:
a gloss of greater than about 50, as measured at a 60
degree angle on a surface of the paper coated with the ink
receptive coating,
a Sheffield smoothness of less than about 300 as
measured on a surface of the paper coated with the ink
receptive coating,
an opacity of greater than about 70% as measured on a
surface of the paper coated with the ink receptive coating,
and
a brightness of greater than about 70~ as measured on
a surface of the paper coated with the ink receptive
coating.
In the glossy ink jet receiving papers provided
herein, the ink receptive coating provides an image forming
layer, and the paper substrate provides a base for handling
as well as a reservoir for an ink vehicle.
Detailed Descri~tion of the Invention
In the present invention, any kind of paper can be
used as the paper substrate, so long as it meets the above
described parameters for gloss, Sheffield smoothness,
opacity and brightness. However, a clay-coated paper
meeting such parameters is thought to be preferred.
Exemplary of suitable paper substrates which may be
used in the present invention are clay-coated papers, such
as Reflections II grade paper (Consolidated Paper Inc.),
2160619
4 Docket No. 84-140P
MultiArt Gloss grade paper (Stora Papyrus Newton Falls,
Inc.), Tahoe Gloss grade paper (Simpson Paper Company),
Evergreen Gloss paper (Simpson Paper Company) and the like.
The base weight of the paper is not particularly
restricted, but should generally be in the range of about
30 g/m2 to about 250 g/m2, preferably about 50 g/m2 to about
150 g/m2. The paper substrate may be pretreated to enhance
adhesion of the ink receptive coating thereto or increase
the gloss level of the finished glossy ink jet receiving
paper product.
The paper substrate used in the present invention
preferably also contains at least one element selected from
the group consisting of silicon, aluminum, titanium,
potassium, iron, magnesium, sodium and calcium. These
elements are important to paper appearance and physical
properties. They also sometimes reduce ink migration and
dye fading.
The gloss of the paper used in the present invention
is important. This is because high gloss is required in
many ink jet imaging applications, particularly in the
areas of graphic art, pre-press proof reading, display and
presentation. Further, gloss is also a key factor that
affects color gamut.
The gloss is the characteristic of the paper surface
that causes it to reflect light at a given angle of
reflection in excess of the diffuse reflection at that
angle. The paper used in the present invention should have
gloss greater than about 20, and preferably greater than
about 30 as measured at a 60 degree angle. The gloss
values are obtained from a Micro Tri-Gloss Meter (BYK-
Gardner), according to the procedure described in the
product manual. The test procedure for determining gloss
more specifically entails the following steps: cut paper
sample into an 8.5 inch by 11 inch size sheet; calibrate
the Micro Tri-Gloss meter at 60 degrees using the standard
supplied with the unit; place sample on a flat surface and
2160619
Docket No. 84-140P
measure the gloss at 60 degrees; repeat the measurement on
five samples; and report the average value.
The ink receptive coatings utilized to prepare the
glossy ink jet receiving papers should not reduce the gloss
of the paper substrates utilized. Preferably the ink
receptive coating utilized should be capable of increasing
the gloss of the paper substrate at least 10~.
The opacity of the paper substrate used in the
invention should be greater than about 70%, and preferably
greater than about 80~. The opacity is measured on a BNL-3
Opacimeter (Technidyne Corp.), according to the procedure
described in the product manual. The test procedure for
determining opacity more specifically entails the following
' steps: cut paper sample into a 10 cm by 10 cm square;
calibrate the opacimeter according to the standard
procedure; and measure 5 samples and report the average
value.
The smoothness of the paper substrate is a property
that affects the paper's appearance and surface property.
The smoothness is also associated with gloss. For the
applications described herein, the Sheffield smoothness of
the paper should be below about 80 Sheffield Units and
preferably below about 60 Sheffield Units. The Sheffield
smoothness is measured on a Hagerty Smoothness Tester
(Model 538, Hagerty Technologies, Inc.), according to the
procedure described in the product manual. The test
procedure for determining smoothness more specifically
entails the following steps: cut sample into an 8.5 inch
by 11 inch size sheet and select Sheffield Units (SU) from
the Hagerty Smoothness Tester console; set test zones at 3
centimeters apart; start measurements and report average
smoothness values in SU units.
The brightness refers to the lightness or overall
spectral reflectance of the paper substrate. The
brightness of the paper used in this invention should be
greater than about 70~ and preferably greater than about
80~. The brightness is measured on a Photovolt Model 575
~tr~
- 6 619 Docket No. 84-140P
Reflection and Gloss Meter (Seragen Inc.), according to the
procedure described in the product manual. The test
procedure for determining brightness more specifically
entails the following steps: cut paper sample into a 10 cm
by 10 cm square; calibrate the meter by placing a standard
white enamel plaque over the search unit and adjust the
sensitivity knobs to set the meter to standard value; place
the sample to be measured over the search unit and back it
with the white standard enamel plaque; read the brightness
values; and repeat with five samples and report average
value.
The ink receptive coating layers present in the glossy
ink jet receiving paper of the present invention are coated
on a surface of the paper substrate and can exist as either
a single layer, or alternatively they may be a multi-layer
coating structure. However, it is required that at least
one ink receptive coating containing one or more water-
soluble components in a total amount of about 4 to about
100 weight %, based on the total weight of solids in the
coating, must be present in the provided ink jet recording
receiving papers encompassed hereby. The water soluble
components are preferably present in the ink-receptive
coating in a total amount of about 20 to about 100 weight
%, and most preferably in a total amount of about 30 to
about 100 weight ~, based on the total weight of solids in
the coating.
The ink receptive coatings used in the glossy ink jet
receiving papers of the present invention contain at least
one water-soluble component and may contain more than one
if so desired.
The chosen water-soluble components are preferably
soluble in an amount of about at least 1 wt%, and more
preferably about at least 3 wt~, in water at a temperature
in the range of about 5C to about 100C.
The coating materials used to prepare the ink
receptive coatings have to be carefully selected so that
the resulting ink jet receiving sheet has a gloss of about
2160619
~ 7 Docket No. 84-140P
50 or above as measured at a 60 degree angle, a Sheffield
smoothness of less than about 300 Sheffield units as
measured on a surface of the paper coated with the ink
receptive coating, an opacity of greater than about 70% as
measured on a surface of the paper coated with the ink
receptive coating, and a brightness of greater than about
70~ as measured on a sur.face of the paper coated with the
ink receptive coating.
Exemplary of suitable water-soluble components which
may be used in such coatings are poly(vinyl alcohol),
poly(vinyl pyrrolidone), poly(2-ethyl-2-oxazoline),
polyacrylamide, gelatins, poly(vinyl acetate), poly-
(ethylene glycol), poly(ethylene oxide), cellulose esters,
proteins, alginates, poly(acrylic acid), water-soluble
gums, and mixtures thereof. The water-soluble component
- may be a component of a homopolymer, a copolymer or a
polymer blend.
In addition, the ink receptive coating should be
soluble or swellable in the ink to be used for the intended
application. The term "soluble" when used in this context
means that the coating is soluble in the ink in an amount
of about at least 1~ on a wt/wt basis. The term
"swellablell when used in this context means the coating
increases in volume in the ink as a function of time before
reaching a saturated state. These properties are important
to achieving good image quality, since coating materials
that do not possess these properties cannot receive ink
satisfactorily.
If desired, inorganic and/or organic particulates may
be incorporated in the coating layer to provide proper
handling properties, increase brightness, provide high
surface gloss to the ink receiving paper, as well as
mixtures of these properties. Another function of the
particulates is to prevent sheet to sheet ink transfer when
imaged sheets are stacked for long term storage and in such
instances the particulates can be incorporated in either
~7
-8 ~0619 Docket No. 84-140P
the ink receiving side or backing side of the prepared
glossy ink jet receiving media.
Examples of inorganic particulates which may be used
in the glossy ink jet receiving media are silica, titanium
oxide, alumina, glass beads, barium sulfate, diatomaceous
earth and zinc oxide. Examples of organic particulates
which may be used include poly(methyl methacrylate),
pol yet hyle ne, p olyp rop yle ne, s t a rc h,
polytetrafluoroethylene and polystyrene.
To achieve optimal performance, the coat weight of the
coating should be well controlled. The coat weight of the
ink receiving coating should be within the range of about
lg/m2 to about 30 g/m2, and preferably from about 2 g/m2 to
about 20 g/m2.
The side of the substrate which does not bear the ink
- receptive coating may need a backing material in order to
reduce electrostatic charge and to reduce sheet-to-sheet
friction and sticking. The backing may either be a
polymeric coating or polymeric film.
Any of a number of coating methods may be employed to
coat the coating composition onto the paper base, such as
roller coating, wire-bar coating, dip coating, extrusion
coating, air knife coating, curtain coating, slide coating,
blade coating, doctor coating, or gravure coating. Such
techniques are well know in the art.
In practice, various additives may be employed in the
coatings of both sides of the paper. These additives
include surface active agents which control wetting or
spreading action of the coatings, antistatic agents,
suspending agents, and compounds with acidic groups to
control the pH, among other properties, of the coated
paper.
It is noted that the same apparatuses used for
measuring the gloss, Sheffield smoothness, opacity and
brightness of the paper substrate can also be used to
measure such properties of the finished ink jet receiving
papers disclosed herein.
21 6 061 9Docket No. 84-140P
The following general procedures were used for the
preparation of the ink jet recording sheets according to
the examples. All the examples are given merely as
illustrative of the invention in order to aid those
desiring to practice the present invention, and are not to
be considered as limiting.
E~ca~p l e
Substrate:
MultiArt Gloss 80#
Coatinq Composition:
PVP K9o2 6.8 parts
Acrylic Copolymer3 1.2 parts
PMMA Particulate (20 um) 4 0.04 parts
--- 15 DOWANOL PM5 20 parts
MEK5 30 parts
1. Stora Papyrus Newton Falls, Inc.
2. Poly(vinyl pyrrolidone) K90, ISP, Inc.
3. Copolymer of methyl methacrylate and 2-hydroxyethyl
methacrylate.
4. Poly(methyl methacrylate) particulate.
5. Propylene glycol monomethyl ether, Dow Chemical
Corporation.
6. Methyl ethyl ketone.
The coating was coated on the following paper
substrates using a No. 24 Meyer rod. The coating is dried
in a circulating hot air oven at 110C for 2 minutes. The
dry coat weight of the finished coating is about 7 g/m2.
The same procedure was used for Examples 2-6 and
Comparative Examples 1-3. A No. 36 Meyer rod was used for
Example 7.
. ~?`~
` 2160619
Docket No. 84-140P
Example 2
Substrate:
Reflections II go#l
Coatina Com~osition:
Same as in Example 1
1. Consolidated Papers, Inc.
Example 3
Substrate:
Excellence 100
Coatinq Composition:
Same as in Example 1
1. Repap Sales Corporation
Example 4
20 Substrate:
Warren Flo 80# Text
Coatinq Composition:
Same as in Example 1
2 5 1. S. D. Warren Company
Example 5
Substrate:
Tahoe Gloss 80#
Coatina Composition:
Same as in Example 1
l. Simpson Paper Company
~, " . .. , . . , , ,, . ~,
- 1121 6061 9Docket No. 84-140P
Example 6
Substrate:
CH~OMOLUX 60#l
Coatinq Com~osition:
Same as in Example 1
1. Zanders Feinpapiere, A. G.
Example 7
Substrate:
MultiArt 100# Gloss
Coatinq Composition:
PVP K90 4.62 parts
~ AIRVOL 6032 4.62 parts
Methocel A4M3 0.25 parts
Isopropyl Alcohol 2.00 parts
Water 88.51 parts
1. Stora Papurus Newton Falls, Inc.
2. Polyvinyl Alcohol, Air Products and Chemicals, Inc.
3. Dow Chemical Company
Comparative Example 1
Substrate:
Ardor Offset 50#1
Coatin~ ComPosition:
Same as in Example 1
1. Georgia Pacific
21 60ffl9D
- 12 ocket No. 84-140P
Comparative Example 2
Substrate:
Gilbert 20# Bond (25~Cotton)
Coatina Com~osition:
Same as in Example 1
1. Gilbert Paper Company
10Comparative Example 3
Substrate:
XEROX 4200DP 20# Bond
Coatinq Composition:
15Same as in Example 1
1. Xerox Corporation
The gloss values are presented in Table I. The paper
substrate disclosed in Examples 1-7 are superior to those
shown in Comparative Examples 1-3.
TABLE I
GLOSS VAL~ES
Substrate S~mple
Example Gloss Gloss Image Quality
(60 deg) (60 deg)
1 38 73 Good
2 57 83 Good
3 45 76 Good
4 24 62 Good
32 67 Good
6 62 84 Good
7 38 72 Good
C1 4.0 7.0 Poor
C2 3.7 6.5 Poor
C3 5.0 9.Q Poor
Z1 60619
- 13 Docket No. 84-140P
*Image quality was visually inspected on samples
printed on a HP DESKJET 1200C with a full page color
graphic pattern. Good: High color brightness and imagery
gloss. Poor: Poor imagery brightness and gloss.
In Examples 8-10, a multilayered coating structure
consisting of an underlayer and a surface layer is applied
to a paper substrate, to produce the desired glossy ink-jet
receiving paper.
Example 8
Substrate:
MultiArt Gloss 100# Paper
Underlayer:
PVP-Kg02 6.8 parts
Copolymer A3 1.2 parts
Quaternary polymer4 3.2 parts
Starch particulateS 0.2 parts
DOWANOL pM6 120 parts
Surface laYer:
Methocel F-50' 1.5 parts
Methanol 5.0 parts
~ater 93.5 parts
1. Stora Papyrus Newton Falls, Inc.
2. Poly(~inyl pyrrolidone) K90, ISP, Inc.
3. Copolymer of methyl methacrylate and 2-hydroxyethyl
methacrylate.
4. Quaternized copolymer of methylmethacrylate and
dimethylaminoethyl methacrylate.
5. Corn starch.
6. Propylene glycol monomethyl ether, Dow Chemical
Corporation.
7. Hydroxypropyl methylcellulose, Dow Chemical
Corporation.
2160619
_ 14 Docket No. 84-140P
The coating was coated on the paper base using a No.
42 Meyer rod. After drying the underlayer coating at 110C
for about 2 minutes, the surface layer coating was coated
using a No. 10 Meyer rod at the same condition. The dry
coat weight of the finished coating is about 7 g/m2. The
same procedure was used for Examples 9-10 and Comparati~e
Examples 4-7.
Example 9
Substrate:
MultiArt Gloss 100# Paper
Underlayer:
- Samé composition as that in Example 8
Surface laYer:
~ 15 Hydroxyethyl Cellulose blend2 1.75 parts
.Citric acid3 0.25 parts
Water 98.00 parts
1. Stora Papyrus Newton Falls, Inc.
2. Union Carbide Corporation
3. Pfizer Inc.
Example 10
' -
Substrate:
MultiArt Gloss 100# Paper
UnderlaYer:
Same composition as that in Example 8
Surface laYer:
AIRVOL 5232 3.87 parts
ACRYLIDON ACP10053 1.00 parts
Isopropyl alcohol 4.00 parts
Water 91.13 parts
1. Stora Papyrus Newton Falls, Inc.
2. Polyvinyl Alcohol, Air Products and Chemicals, Inc.
2160619
I5 Docket No. 84-140P
3. Copolymer of vinyl pyrrolidone and acrylic acid, ISP,
Inc.
Comparative Example 4
Substrate:
MELINEX 339 White Polyester Film
UnderlaYer:
Same as that in Example 8
Surface laYer:
Same as that in Example 8
1. ICI Films
Comparative Example 5
-
lS Substrate:
Schoeller VRH polyolefin coated paper
Underlayer:
Same as that in Example 8
Surface laYer:
Same as that in Example 8
1. Schoeller Technical Papers, Inc.
Comparative Example 6
Substrate:
. MELINEX 339 White Polyester Film
Underlayer:
Same as that in Example 8
Surface layer:
Same as that in Example 9
1. ICI Films
16 9 Docket No. 84-140P
Comparative Example 7
Substrate:
Schoeller VRH polyolefin coated paper
S Underlayer:
Same as that in Example 8
Surface laYer:
Same as that in Example 9
1. Schoeller Technical Papers, Inc.
The ink migration results are present in Table II.
The glossy ink jet receiving papers disclosed in Examples
8-10 are clearly superior to the other ink jet receiving
papers shown in Comparative Examples 4-7.
_ 15
- TABLE II
INg MIGRATION PERFORM~NCE COMPARISON
Migration Migration %
(Blue/Red) (Blue/Red)
Example 8 2.17 mil 5.4
Example 9 1.50 mil 3.8
Example 10 2.17 mil 5.4
Comparative
Example 4 8.83 mil 22.1
Comparative
Example 5 7.67 mil 19.2
Comparative
Example 6 14.17 mil 35.4%
Comparative
Example 7 12.33 mil 30.8~
Ink migration (sometimes called color to color bleed)
measurements were performed as follows: color prints with
a 40 mil solid blue line in a red background were printed
with a HP DESKJET 1200C printer. The prints were
conditioned for 30 minutes at 73F/50~ RH (RH=relative
humidity). Then the samples were stored in an controlled
2160619
- 17 Docket No. 84-140P
environment chamber at 86F/80~ RH for 48 hrs. The blue
line width was measured with an ACU-RITE travelling
microscope (Automation Components, Inc). The differential
line width of the initial and final line was reported in
the above table. Ink migration (~) was calculated as
follows.
Ink Migration (~) = (Lwf - Lwi) /LWi X 100
wherein:
LWi is the initial blue line width (40 mil), and
LWf is the blue line width after 48 hours at 86F/80
RH .
The above detailed disclosure, including the Examples
set forth herein, has been provided as an aid to those
- desiring to practice the present invention. Accordingly,
the same is not to be construed as unduly limiting to the
present invention, since those skilled in the art will
readily recognize that various changes may be made in the
procedures and materials referred to herein without
departing from the spirit or scope of the present
inventive discovery.
Each of the publications, product manuals and patent
documents referred to herein is incorporated by reference
in its entirety.
