U.S. patent application number 13/453916 was filed with the patent office on 2013-10-24 for phase change ink compositions and sulfonated compounds for use in the same.
This patent application is currently assigned to XEROX CORPORATION. The applicant listed for this patent is Biby Abraham, C. Geoffrey Allen, Mihaela Maria Birau, James D. Mayo, Peter G. Odell, Salma Falah Toosi. Invention is credited to Biby Abraham, C. Geoffrey Allen, Mihaela Maria Birau, James D. Mayo, Peter G. Odell, Salma Falah Toosi.
Application Number | 20130276666 13/453916 |
Document ID | / |
Family ID | 49229799 |
Filed Date | 2013-10-24 |
United States Patent
Application |
20130276666 |
Kind Code |
A1 |
Birau; Mihaela Maria ; et
al. |
October 24, 2013 |
PHASE CHANGE INK COMPOSITIONS AND SULFONATED COMPOUNDS FOR USE IN
THE SAME
Abstract
A phase change ink composition, comprising an anti-drool
additive to prevent and/or reduce printhead and nozzle
contamination in ink jet printers caused by drooling and fouling of
the faceplate by the ink. In particular, there is provided
sulfonated small molecules for use in phase change ink compositions
and which are compatible with phase change ink components.
Inventors: |
Birau; Mihaela Maria;
(Mississauga, CA) ; Toosi; Salma Falah;
(Mississauga, CA) ; Allen; C. Geoffrey;
(Waterdown, CA) ; Abraham; Biby; (Mississauga,
CA) ; Mayo; James D.; (Mississauga, CA) ;
Odell; Peter G.; (Mississauga, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Birau; Mihaela Maria
Toosi; Salma Falah
Allen; C. Geoffrey
Abraham; Biby
Mayo; James D.
Odell; Peter G. |
Mississauga
Mississauga
Waterdown
Mississauga
Mississauga
Mississauga |
|
CA
CA
CA
CA
CA
CA |
|
|
Assignee: |
XEROX CORPORATION
Norwalk
CT
|
Family ID: |
49229799 |
Appl. No.: |
13/453916 |
Filed: |
April 23, 2012 |
Current U.S.
Class: |
106/31.13 ;
524/157; 524/159 |
Current CPC
Class: |
C08K 5/42 20130101; C08K
5/19 20130101; C09D 11/34 20130101; C09D 11/38 20130101 |
Class at
Publication: |
106/31.13 ;
524/157; 524/159 |
International
Class: |
C09D 11/12 20060101
C09D011/12; C09D 11/10 20060101 C09D011/10 |
Claims
1. A phase change ink composition comprising: a colorant; an ink
vehicle; and an anti-drool additive, wherein the anti-drool
additive is a sulfonated compound having one or more sulfonic acid
groups and a NH.sub.4 or a N-alkyl or N-aryl quaternary ammonium
counterion that is selected from the group consisting of
tetramethylammonium, tetraethylammonium, tetrapropylammonium,
tetrabutylammonium, tetrapentylammonium, tetrahexylammonium,
tetraheptylammonium, tetraoctylammonium, tetranonylammonium,
tetradecylammonium, tetradodecylammonium,
tetraoctadecylammonium,N,N-dimethyl dioctadecyl, N,N-dimethyl
dioctyl, N,N-dimethyl didecyl, and mixtures thereof, and further
wherein the anti-drool additive is soluble in the wax ink
vehicle.
2. The phase change ink composition of claim 1, wherein the
sulfonated compound is a naphthalene or anthraquinone.
3. The phase change ink composition of claim 1, wherein the
anti-drool additive contains two to three aromatic rings.
4. (canceled)
5. The phase change ink composition of claim 1, wherein the N-alkyl
or N-aryl counterion is selected from one of the following:
##STR00006## wherein R.sub.1, R.sub.2 and R.sub.3 can be identical
or different from one another and each is selected from the group
consisting of alkyl, alkoxy, aryl, and alkylaryl, and X is any
halogen atom.
6. The phase change ink composition of claim 1, wherein the alkyl,
alkoxy, aryl, and alkylaryl groups have equal to or greater than 4
carbon atoms.
7. The phase change ink composition of claim 1 having a drool
pressure in a printer of at least about 1.5 inches of water.
8. The phase change ink composition of claim 6 having a drool
pressure in a printer of from about 1.5 inches of water to about
4.0 inches of water.
9. The phase change ink composition of claim 1 exhibiting little to
no staining through visual observation.
10. The phase change ink composition of claim 1, wherein the
anti-drool additive is present in the phase change ink composition
in an amount of from about 0.1 to about 20 percent by weight of the
total weight of the phase change ink composition.
11. The phase change ink composition of claim 9, wherein the
anti-drool additive is present in the phase change ink composition
in an amount of from about 0.2 to about 20 percent by weight of the
total weight of the phase change ink composition.
12. The phase change ink composition of claim 10, wherein the
anti-drool additive is present in the phase change ink composition
in an amount of from about 0.5 to about 10 percent by weight of the
total weight of the phase change ink composition.
13. The phase change ink composition of claim 1 further comprising
a dispersant selected from the group consisting of
polyethyleneimines, polymers containing quaternary ammonium salts,
polymers containing polyalkylated succinimides, and mixtures
thereof.
14. The phase change ink composition of claim 12, wherein the
dispersant is present in the phase change ink composition in an
amount of from about 0.1 to about 25 percent by weight of the total
weight of the phase change ink composition.
15. The phase change ink composition of claim 13, wherein the
dispersant is present in the phase change ink composition in an
amount of from about 0.5 to about 10 percent by weight of the total
weight of the phase change ink composition.
16. The phase change ink composition of claim 14, wherein the
dispersant is present in the phase change ink composition in an
amount of from about 1 to about 6 percent by weight of the total
weight of the phase change ink composition.
17. A phase change ink composition comprising: a colorant; an ink
vehicle; and an anti-drool additive, wherein the anti-drool
additive is a compound selected from the group consisting of
##STR00007## and mixtures thereof.
18. A phase change ink composition comprising: a colorant; an ink
vehicle; and an anti-drool additive being soluble in the wax ink
vehicle, wherein the anti-drool additive is a sulfonated compound
having one or more sulfonic acid groups and a N-alkyl or N-aryl
counterion that is quaternary ammonium a NH.sub.4 or a N-alkyl or
N-aryl quaternary ammonium counterion that is selected from the
group consisting of tetramethylammonium, tetraethylammonium,
tetrapropylammonium, tetrabutylammonium, tetrapentylammonium,
tetrahexylammonium, tetraheptylammonium, tetraoctylammonium,
tetranonylammonium, tetradecylammonium, tetradodecylammonium,
tetraoctadecylammonium,N,N-dimethyl dioctadecyl, N,N-dimethyl
dioctyl, N,N-dimethyl didecyl, and mixtures thereof, and further
wherein the phase change ink has a .DELTA.(Drool Pressure) in a
printer of from about 1.5 inches of water to about 6.0 inches of
water.
19. The phase change ink composition of claim 18, wherein the
anti-drool additive contains two to three aromatic rings.
20. The phase change ink composition of claim 18 further including
additives selected from the group consisting of an isocyanate
derived material, antioxidant, defoamer, slip and leveling agents,
clarifier, viscosity modifier, adhesive, plasticizer and mixtures
thereof.
Description
BACKGROUND
[0001] The present embodiments relate generally to phase change ink
compositions, and in particular, sulfonated small molecules for use
in phase change ink compositions to prevent and/or reduce printhead
and nozzle contamination in ink jet printers caused by drooling and
faceplate staining. Phase change ink or solid ink compositions are
characterized by being solid at room temperature and molten at an
elevated temperature at which the molten ink is applied to a
substrate. These phase change ink compositions generally comprise
an ink vehicle and a colorant, and can be used for ink jet
printing.
[0002] Phase change ink or solid ink printers conventionally
receive ink in a solid form, which is sometimes referred to as ink
sticks. The ink sticks are typically inserted through an insertion
opening of an ink loader for the printer and are moved by a feed
mechanism and/or gravity toward a heater plate. The heater plate
melts the phase change ink impinging on the plate into a liquid
that is delivered to a printhead assembly for jetting onto a
recording medium. The recording medium is typically paper or a
liquid layer supported by an intermediate imaging member, such as a
metal drum or belt.
[0003] A printhead assembly of a phase change ink printer typically
includes one or more printheads each having a plurality of ink jets
from which drops of melted phase change ink are ejected towards the
recording medium. The ink jets of a printhead receive the melted
ink from an ink supply chamber, or manifold, in the printhead
which, in turn, receives ink from a source, such as a melted ink
reservoir or an ink cartridge. Each ink jet includes a channel
having one end connected to the ink supply manifold. The other end
of the ink channel has an orifice, or nozzle, for ejecting drops of
ink. The nozzles of the ink jets may be formed in an aperture, or
nozzle plate that has openings corresponding to the nozzles of the
ink jets. During operation, drop ejecting signals activate
actuators in the ink jets to expel drops of fluid from the ink jet
nozzles onto the recording medium. By selectively activating the
actuators of the ink jets to eject drops as the recording medium
and/or printhead assembly are moved relative to each other, the
deposited drops can be precisely patterned to form particular text
and graphic images on the recording medium.
[0004] One difficulty faced by fluid ink jet systems is that
organic pigments and dyes used in the phase change inks show
drooling behavior and faceplate staining in the printhead. Drooling
is defined as the burst of the ink out of the printhead when
pressure is applied and is expressed in inches water in the Low
Pressure Assist cycle (LPA). Staining represents the fouling of the
faceplate by the ink.
[0005] A synergist or a pigment stabilizer is a compound that
promotes the adsorption of the polymeric dispersant onto the
pigment. For example, in the case of a cationic dispersant, the
dispersant anchor is comprised of a positive charge and will
interact with an anionic group present on the synergist, exchanging
counter ions and promote an anchoring of the dispersant onto the
modified pigment surface. Solid inks containing a
pigment/dispersant package show drooling behavior and faceplate
staining in the printhead, even at low applied pressures and in
some cases, such pigmented inks show auto-drooling behavior which
is an extremely undesirable property of an ink. Changing pigments,
dispersants, and the use of synergist with the pigment to enable
dispersion stabilization did not successfully improve drooling and
staining.
[0006] Experimental trials indicated that one approach for solving
drool and staining of the faceplate by solid ink could be use of
compounds containing acid groups. Commercially available compounds,
however, tend to be very polar in nature and cannot be used as such
compounds exhibit a strong gelling behavior in solid ink. For
example inks prepared with commercially available synergists
SOLSPERSE 5000 (a derivatized sulfonated copper phthalocyanine) and
SOLSPERSE 22000 (a derivatized sulfonated analog of Pigment Yellow
12) at nominal ink loadings below 1% by weight (with no pigment
added) showed no drooling or staining behavior. However, when the
synergist loading was increased at or above 2.5% wt (with no
pigment added), the inks displayed strong gelling behavior.
[0007] Because these commercially available synergists cannot be
used as colorants or as anti-drooling additives, there is a need
for finding other compounds containing acid functional groups to
address the problems discussed above while being compatible for use
in phase change inks.
SUMMARY
[0008] According to embodiments illustrated herein, there is
provided a phase change ink composition comprising: a colorant; an
ink vehicle; and an anti-drool additive, wherein the anti-drool
additive is a sulfonated compound having one or more sulfonic acid
groups and a N-alkyl or N-aryl counterion that is quaternary
ammonium NH.sub.4 or an alkyl or aryl quaternary ammonium selected
from the group consisting of tetrabutylammonium,
tetraoctylammonium, tetradodecylammonium,
tetraoctadecylammonium,N,N-dimethyl dioctadecyl, N,N-dimethyl
dioctyl, N,N-dimethyl didecyl, and mixtures thereof, and further
wherein the anti-drool additive is soluble in the wax ink
vehicle.
[0009] In particular, the present embodiments provide a phase
change ink composition comprising: a colorant; an ink vehicle; and
an anti-drool additive, wherein the anti-drool additive is a
compound selected from the group consisting of
##STR00001##
and mixtures thereof.
[0010] In further embodiments, there is provided a phase change ink
composition comprising: a colorant; an ink vehicle; and an
anti-drool additive being soluble in the wax ink vehicle, wherein
the anti-drool additive is a sulfonated compound having one or more
sulfonic acid groups and a NH.sub.4 or a N-alkyl or N-aryl
quaternary ammonium counterion that is selected from the group
consisting of tetramethylammonium, tetraethylammonium,
tetrapropylammonium, tetrabutylammonium, tetrapentylammonium,
tetrahexylammonium, tetraheptylammonium, tetraoctylammonium,
tetranonylammonium, tetradecylammonium, tetradodecylammonium,
tetraoctadecylammonium,N,N-dimethyl dioctadecyl, N,N-dimethyl
dioctyl, N,N-dimethyl didecyl, and mixtures thereof, and further
wherein the phase change ink has a .DELTA.(Drool Pressure) in a
printer of from about 1.5 inches of water to about 6.0 inches of
water.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] For a better understanding of the present embodiments,
reference may be made to the accompanying figures.
[0012] FIG. 1 illustrates an example of a domesticated sulfonated
small molecule according to the present embodiments;
[0013] FIG. 2 illustrates a second example of a domesticated
sulfonated small molecule according to the present embodiments;
[0014] FIG. 3 illustrates a third example of a domesticated
sulfonated small molecule according to the present embodiments;
and
[0015] FIG. 4 illustrates a fourth example of a domesticated
sulfonated small molecule according to the present embodiments.
DETAILED DESCRIPTION
[0016] In the following description, it is understood that other
embodiments may be utilized and structural and operational changes
may be made without departure from the scope of the present
embodiments disclosed herein. Phase change ink technology broadens
printing capability and customer base across many markets, and the
diversity of printing applications will be facilitated by effective
integration of printhead technology, print process and ink
materials. The phase change ink compositions are characterized by
being solid at room temperature and molten at an elevated
temperature at which the molten ink is applied to a substrate.
However, phase change ink systems also experience problems during
performance at other temperatures including at jetting temperature.
For example, organic pigments and dyes used in phase change inks
can exhibit drooling behavior and faceplate staining on the front
face of the printhead.
[0017] Drooling is defined as the burst of the ink out of the
printhead whether pressure is applied or not. For purposes of
quantifying drool, it is convenient to express drool of a given
test ink sample against a non-drooling reference such as the ink
base without any colorant and/or dispersant. The relationship below
defines the level of drool for a given test ink.
.DELTA.(Drool Pressure)=Drool Pressure(sample)-Drool
Pressure(reference)
It is desirable to have as small as possible a delta drool pressure
of a given ink such that optimum jetting and print performance can
be realized.
[0018] The gauge pressure is that measured pressure realized in the
printer's Low Pressure Assist cycle above atmospheric pressure.
Drool pressure of a sample ink is the gauge pressure realized that
causes the ink to burst out of at least some of the nozzles in the
printhead which can be accurately measured by a micropressure
gauge. Drooling of inks in a printhead complicate the jetting
process due to undesirable inter-nozzle color mixing as well as
resulting in the undesirable depletion of ink from the ink loader.
Drool pressure of a reference ink is that gauge pressure realized
that causes the reference ink to burst out of at least some of the
nozzles in the printhead which can be measured by a micropressure
gauge. Typically this pressure value satisfies the requirements for
successful jetting over the many purge and wipe cleaning cycles
that occurs over the lifetime of the printer. Staining of the
printhead is the undesirable fouling of the faceplate by an ink, or
at least a portion of an ink, which can be qualitatively assessed
through visual observation. For example, staining can be seen as
ink smeared on the surface of the faceplate. Thus a desirable
observation is when little or no ink is observed on the faceplate.
A printhead that has been very undesirably compromised by staining
from an ink, or a portion of an ink, will likely be more prone to
ink drooling at even lower applied pressures during the course of
the printer's normal purge and wipe cleaning cycles. In the present
embodiments, there is provided a phase change ink composition that
has a drool pressure in a printer of at least 1.5 inches of water.
In further embodiments, the composition has a drool pressure in of
from about 1.5 inches of water to about 6.0 inches of water or of
from about 2.8 inches of water to about 6.0 inches of water.
[0019] The present embodiments address drooling and faceplate
staining by using a specific type of compound in the phase change
inks as anti-drool additives. Specifically, the present embodiments
provide for the use of certain small molecules containing two or
three aromatic rings and SO.sub.3M (M=metal) groups as anti-drool
additives, such as for example, disulfonated 3-hydroxy naphthalene.
In embodiments, M can be selected from the group consisting of
monovalent metals, such as Na, K, Li, divalent metals such as Ca,
Mg, Ba, Cu, Cd, Zn, Mn and/or trivalent metals such as Al, Cr, and
Co. These additives, however, need minor modifications before use
in the inks. The metal counterion from the SO.sub.3.sup.- group is
replaced by a quaternary ammonium salt that contains long greasy
chains to facilitate compatibility with the solid ink vehicle. More
specifically, the metal counterion is replaced by a quaternary
ammonium salt that contains long greasy chains to enable
compatibility with the solid ink vehicle. The sulfonic end groups
and the quaternary ammonium end groups interact, exchanging counter
ions and promoting an anchoring of the dispersant onto the modified
additive surface. The sulfonated modified compounds containing at
least two SO.sub.3 modifications had a .DELTA.(Drool Pressure) in
the range of from about -0.8 to about +0.8 inches of water, which
is satisfactory. The addition of these compounds also eliminated
fouling of the printhead faceplate. As such, the present
embodiments provide small molecules having two or three aromatic
rings and SO.sub.3Me groups which are used as anti-drool additives
after minor modification. Some examples of the sulfonated small
molecules used in the present embodiments are Sulfonated
Quinizarin, N,N-dimethyl-dioctadecyl salt (sulfonated quinizarin)
(FIG. 1), 2-Naphthalene N,N dimethyl-dioctadecyl (FIG. 2),
1,5-disulfonic naphthalene N,N dimethyl-dioctadecyl salt (FIG. 3),
and 3-hydroxy naphthalene-2,7 disulfonic N,N dimethyl-dioctadecyl
salt (FIG. 4).
[0020] Phase change inks prepared with the sulfonated compounds of
the present embodiments were tested for drooling and staining in a
Phaser 8860 printer (available from Xerox Corp.). The tested inks
demonstrated at least reduced drooling and staining behavior if not
complete elimination of such behavior. As such, the anti-drool
additive of the present embodiments offers major advantages by
preventing or reducing undesirable drooling and staining behavior,
thus improving stability of the ink in the printhead, and also
allows for the opportunity to use cheaper commercial dyes that
could be modified for improved performance in a phase change ink
jet printhead.
[0021] The sulfonated compounds of the present embodiments are
usually sold as sodium salts of the corresponding acid
functionality (COO.sup.- or SO.sub.3.sup.-). Because these
off-the-shelf colorants exhibit gelling behavior in phase change
ink, the colorants must be modified by replacing the metal
counterion with a more suitable N-alkyl/aryl counterion which will
allow much improved compatibility with phase change ink components.
Suitable N-alkyl/aryl counterions to be used in the modification
may be selected from the group consisting of quaternary ammonium
NH.sub.4, or any alkyl or aryl quaternary ammonium, such as
tetramethylammonium, tetraethylammonium, tetrapropylammonium
tetrabutylammonium, tetrapentylammonium, tetrahexylammonium,
tetraheptylammonium, tetraoctylammonium, tetranonylammonium,
tetradecylammonium, tetratradodecylammonium,
tetraoctadecylammonium,N,N-dimethyl dioctadecyl, N,N-dimethyl
dioctyl, N,N-dimethyl didecyl, N,N,N-trimethyl-1-docosanaminium,
behenyl trimethylammonium, N-octadecyltrimethylammonium, and other
quaternary ammonium compounds such as ARQUADs, and mixtures
thereof.
[0022] The quaternary ammonium compounds known as the ARQUADs are
primarily alkyltrimethylammonium chlorides and may be represented
by the formula R--N(CH.sub.3).sub.3Cl wherein R is a long chain
alkyl group having at least 8 carbon atoms. These particular
quaternary ammonium compounds are marketed by Akzo Nobel N.V. under
the trade-name ARQUAD. Examples of suitable ARQUAD materials are:
Arquad 316, cocoalkyltrimethylammonium from ARQUAD C-35,
didecydimethylammonium from ARQUAD 2.10-50, ARQUAD 2.10-70 HFP,
2.10-80, coco(fractionated) dimethylbenzylammonium from ARQUAD MCB
33, ARQUAD MCB 50, ARQUAD MCB 80, hexadecyltrimethylammonium from
ARQUAD 16-29, stearyltrimethylammonium from ARQUAD 18-50,
behenyltrimethylammonium from ARQUAD 20-80, or salts thereof. A
variety of compounds of this class are available varying as to the
length and number of long chain alkyl groups attached to the
nitrogen atom. In other embodiments, the N-alkyl or N-aryl
counterion is selected from one of the following:
##STR00002##
wherein R.sub.1, R.sub.2 and R.sub.3 can be identical or different
from one another and each is selected from the group consisting of
alkyl, alkoxy, aryl, and alkylaryl and X is any halogen atom. In
embodiments, the alkyl, alkoxy, aryl, and alkylaryl groups have
equal to or greater than 4 carbon atoms. The quaternary ammonium
counter ion can also include alkoxylates such as the following:
##STR00003##
Examples include Ethoquad C/12 where R=coco (a complex mixture of
unsaturated and saturated C6 to C18 acids from coconut oil) and
m+n=2, Ethoquad C/25 where R=coco and m+n=15, Ethoquad O/12 where
R=oleyl and m+n=2, all available from Lion Akzo Corporation. The
quaternary ammonium counter ion can also be an oligomer such as the
following
##STR00004##
Poly[oxy-1,2-ethanediyl(dimethyliminio)-1,2-ethanediyl(dimethyliminio)-1,-
2-ethanediylchloride (1:2)] available from Shijiazhuang Guhong
Chemicals Co., Ltd. Examples of counter ions containing aryl groups
include but are not limited to: benzyltributylammonium bromide,
benzyltributylammonium chloride, benzyltriethylammonium chloride,
benzyltriethylammonium bromide, benzyltriethylammonium iodide,
benzyltrimethylammonium iodide, benzyltrimethylammonium bromide,
benzyltrimethylammonium chloride (neat or in solution)]
[0023] Dispersants used in the phase change inks include, but are
not limited to, those selected from the group consisting of
MODAFLOW 2100, available from Cytec Surface Specialties, OLOA 1200,
OLOA 11000, OLOA 11001, available from Chevron Oronite Company LLC,
IRKASPERSE 2153, 2155, SOLSPERSE 9000, 16000, 17000, 17940, 18000,
19000, 19240, 20000, 36000, 39000, 41000, 54000, available from
Lubrizol Corporation) and mixtures thereof. Further, specific
dispersants that may be used of which are disclosed in U.S. Pat.
No. 7,973,186, which is incorporated herein in its entirety have
the following formulas:
##STR00005##
or a mixture thereof; wherein R and R' are the same or different,
and wherein R and R' are independently selected from an alkyl
group, an arylalkyl group, or an alkylaryl group, wherein the alkyl
group, the arylalkyl group, or the alkylaryl group has from about
18 to about 60 carbon atoms; and wherein m is an integer of from
about 1 to about 30. Exemplary ink compositions may include one or
more dispersants and/or one or more surfactants for their known
properties, such as controlling wetting properties of the ink
composition, and stabilizing pigmented colorants.
[0024] The anti-drool additive may be present in the phase change
ink in any desired or effective amount to prevent drooling and/or
staining, for example, at least from about 0.05 percent by weight
of the ink to about 20 percent by weight of the ink, at least from
about 0.2 percent by weight of the ink to about 10 percent by
weight of the ink, and at least from about 0.5 percent by weight of
the ink to about 5 percent by weight of the ink. The dispersant may
be present in the phase change ink in an amount of from about 0.1
to about 25 percent by weight of the total weight of the ink. In
further embodiments, the dispersant may be present in the phase
change ink in an amount of from about 0.2 to about 10, or from
about 0.5 to about 6 percent by weight of the total weight of the
ink.
[0025] The ink of the present embodiments may further include
conventional additives to take advantage of the known functionality
associated with such conventional additives. Such additives may
include, for example, at least one isocyanate derived material,
antioxidant, defoamer, slip and leveling agents, clarifier,
viscosity modifier, adhesive, plasticizer and the like.
[0026] The ink vehicle or carrier may also include at least one
isocyanate derived material. The isocyanate derived material may be
a urethane resin obtained by reacting two equivalents of an
alcohol, such as hydroabietyl alcohol and one equivalent of an
isocyanate or diisocyanate (isophorone diisocyanate), as disclosed
in, for example, Example 1 of U.S. Pat. No. 5,782,966, the
disclosure of which is totally incorporated herein by reference in
its entirety. The isocyanate derived material may be present in the
ink carrier in an amount of from about 2 to about 99 percent or
from about 2 to about 90 percent or from about 3 to about 80
percent by weight of the ink carrier. Other suitable
isocyanate-derived materials include a urethane resin that was the
adduct of three equivalents of stearyl isocyanate and a
glycerol-based alcohol, prepared as described in Example 4 of U.S.
Pat. No. 6,309,453, the disclosure of which is totally incorporated
herein by reference in its entirety.
[0027] The ink may optionally contain antioxidants to protect the
images from oxidation and also may protect the ink components from
oxidation while existing as a heated melt in the ink reservoir.
Examples of suitable antioxidants include (1) N,N'-hexamethylene
bis(3,5-di-tert-butyl-4-hydroxy hydrocinnamamide) (IRGANOX 1098,
available from Ciba Inc.), (2)
2,2-bis(4-(2-(3,5-di-tert-butyl-4-hydroxyhydrocinnamoyloxy))
ethoxyphenyl)propane (TOPANOL-205, available from ICI America
Corporation), (3) tris(4-tert-butyl-3-hydroxy-2,6-dimethyl
benzyl)isocyanurate (CYANOX 1790, 41, 322-4, LTDP, Aldrich D12,
840-6), (4) 2,2'-ethylidene bis(4,6-di-tert-butylphenyl)fluoro
phosphonite (ETHANOX-398, available from Ethyl Corporation), (5)
tetrakis(2,4-di-tert-butylphenyl)-4,4'-biphenyl diphosphonite
(ALDRICH 46, 852-5; hardness value 90), (6) pentaerythritol
tetrastearate (TCI America #PO739), (7) tributylammonium
hypophosphite (Aldrich 42,009-3), (8)
2,6-di-tert-butyl-4-methoxyphenol (Aldrich 25, 106-2), (9)
2,4-di-tert-butyl-6-(4-methoxybenzyl)phenol (Aldrich 23,008-1),
(10) 4-bromo-2,6-dimethylphenol (Aldrich 34, 951-8), (11)
4-bromo-3,5-didimethylphenol (Aldrich B6, 420-2), (12)
4-bromo-2-nitrophenol (Aldrich 30, 987-7), (13) 4-(diethyl
aminomethyl)-2,5-dimethylphenol (Aldrich 14, 668-4), (14)
3-dimethylaminophenol (Aldrich ID14, 400-2), (15)
2-amino-4-tert-amylphenol (Aldrich 41, 258-9), (16)
2,6-bis(hydroxymethyl)-p-cresol (Aldrich 22, 752-8), (17)
2,2'-methylenediphenol (Aldrich B4, 680-8), (18)
5-(diethylamino)-2-nitrosophenol (Aldrich 26, 951-4), (19)
2,6-dichloro-4-fluorophenol (Aldrich 28, 435-1), (20) 2,6-dibromo
fluoro phenol (Aldrich 26,003-7), (21) .alpha.-trifluoro-o-creso-1
(Aldrich 21, 979-7), (22) 2-bromo-4-fluorophenol (Aldrich 30,
246-5), (23) 4-fluorophenol (Aldrich F1, 320-7), (24)
4-chlorophenyl-2-chloro-1,1,2-tri-fluoroethyl sulfone (Aldrich
13,823-1), (25) 3,4-difluoro phenylacetic acid (Adrich 29,043-2),
(26) 3-fluorophenylacetic acid (Aldrich 24, 804-5), (27)
3,5-difluoro phenylacetic acid (Aldrich 29,044-0), (28)
2-fluorophenylacetic acid (Aldrich 20, 894-9), (29)
2,5-bis(trifluoromethyl) benzoic acid (Aldrich 32, 527-9), (30)
ethyl-2-(4-(4-(trifluoromethyl)phenoxy)phenoxy)propionate (Aldrich
25,074-0), (31) tetrakis (2,4-di-tert-butyl phenyl)-4,4'-biphenyl
diphosphonite (Aldrich 46, 852-5), (32) 4-tert-amyl phenol (Aldrich
15, 384-2), (33) 3-(2H-benzotriazol-2-yl)-4-hydroxy
phenethylalcohol (Aldrich 43,071-4), NAUGARD 76, NAUGARD 445,
NAUGARD 512, AND NAUGARD 524 (manufactured by Chemtura
Corporation), and the like, as well as mixtures thereof. The
antioxidant, when present, may be present in the ink in any desired
or effective amount, such as from about 0.25 percent to about 10
percent by weight of the ink or from about 1 percent to about 5
percent by weight of the ink.
[0028] The ink may further contain an optional viscosity modifier
such as FORAL 85, a glycerol ester of hydrogenated abietic (rosin)
acid (commercially available from Eastman), FORAL 105, a
pentaerythritol ester of hydroabietic (rosin) acid (commercially
available from Eastman), CELLOLYN 21, a hydroabietic (rosin)
alcohol ester of phthalic acid (commercially available from
Eastman), ARAKAWA KE-311 and KE-100 Resins, triglycerides of
hydrogenated abietic (rosin) acid (commercially available from
Arakawa Chemical Industries, Ltd.), synthetic polyterpene resins
such as NEVTAC 2300, NEVTAC 100, and NEVTACO 80 (commercially
available from Neville Chemical Company), WINGTACK 86, a modified
synthetic polyterpene resin (commercially available from Sartomer),
and the like. Viscosity modifiers may be present in the ink in any
effective amount, such as from about 0.01 percent by weight of the
ink to from about 98 percent by weight of the ink, from about 0.1
percent by weight of the ink to about 50 percent by weight of the
ink, from about 5 weight percent of the ink to about 10 weight
percent of the ink.
[0029] Adhesives, such as VERSAMID 757, 759, or 744 (commercially
available from Cognis) may be present in the ink from about 0.01
percent by weight of the ink to from about 98 percent by weight of
the ink, from about 0.1 percent by weight of the ink to about 50
percent by weight of the ink, from about 5 weight percent of the
ink to about 10 weight percent of the ink.
[0030] Plasticizers such as UNIPLEX 250 (commercially available
from Unitex), the phthalate ester plasticizers commercially
available from Ferro under the trade name SANTICIZER, such as
dioctyl phthalate, diundecyl phthalate, alkylbenzyl phthalate
(SANTICIZER 278), triphenyl phosphate (commercially available from
Ferro), KP-140, a tributoxyethyl phosphate (commercially available
from Great Lakes Chemical Corporation), MORFLEX 150, a dicyclohexyl
phthalate (commercially available from Morflex Chemical Company
Inc.), trioctyl trimellitate (commercially available from Sigma
Aldrich Co.), and the like. Plasticizers may be present in an
amount from about 0.01 percent by weight of the ink to from about
98 percent by weight of the ink, from about 0.1 percent by weight
of the ink to about 50 percent by weight of the ink, from about 5
weight percent of the ink to about 10 weight percent of the
ink.
[0031] When present, the optional additives may each, or in
combination, be present in the ink in any desired or effective
amount, such as from about 1 percent to about 10 percent by weight
of the ink or from about 3 percent to about 5 percent by weight of
the ink.
[0032] In embodiments, the ink carriers for the phase change inks
may have melting points of from about 60.degree. C. to about
150.degree. C., for example from about 80.degree. C. to about
120.degree. C., from about 85.degree. C. to about 110.degree. C.,
from about 100.degree. C. to about 110.degree. C., or from about
105.degree. C. to about 110.degree. C. as determined by, for
example, observation and measurement on a microscope hot stage,
wherein the binder material is heated on a glass slide and observed
by microscope. Higher melting points are also acceptable, although
printhead life may be reduced at temperatures higher than
150.degree. C. Furthermore, low energy inks have a jetting
viscosity of about 9 cP to about 13 cP, or such as from about 10 cP
to about 11 cP at melting points of about 107.degree. C. to about
111.degree. C.
[0033] The ink compositions can be prepared by any desired or
suitable method. For example, each of the components of the ink
carrier can be mixed together, followed by heating, the mixture to
at least its melting point, for example from about 60.degree. C. to
about 150.degree. C., 80.degree. C. to about 120.degree. C. and
85.degree. C. to about 110.degree. C. The colorant may be added
before the ink ingredients have been heated or after the ink
ingredients have been heated. When pigments are the selected
colorants, the molten mixture may be subjected to milling such as
in an attritor or ball mill apparatus or high speed shearing mill,
with or without milling media, to effect dispersion of the pigment
in the ink carrier. Where ink compositions contain colorants that
are pigments, the anti-drool additive may be added before, during
or after the pigment dispersion processing step. In those methods
where the anti-drool additive is added after the pigment dispersion
processing step, the resultant heated mixture may be further
processed such as by milling in an attritor, ball mill apparatus,
or high speed shearing mill, with or without milling media, or
simply stirred, with the addition of the anti-drool additive not
being limited by these methods. In embodiments, the heated mixture
is stirred for about 5 seconds, for about 2 minutes, for about 10
minutes or more, to obtain a substantially homogeneous, uniform
melt, followed by cooling the ink to ambient temperature (typically
from about 20.degree. C. to about 25.degree. C.). The inks are
solid at ambient temperature. In a specific embodiment, during the
formation process, the inks in their molten state are poured into
molds and then allowed to cool and solidify to form ink sticks.
Suitable ink preparation techniques are disclosed in U.S. Pat. No.
7,186,762, the disclosure of which is incorporated herein by
reference in its entirety.
[0034] The inks can be employed in apparatus for direct printing
ink jet processes and in indirect (offset) printing ink jet
applications. Another embodiment disclosed herein is directed to a
process which comprises incorporating an ink as disclosed herein
into an ink jet printing apparatus, melting the ink, and causing
droplets of the melted ink to be ejected in an imagewise pattern
onto a recording substrate. A direct printing process is also
disclosed in, for example, U.S. Pat. No. 5,195,430, the disclosure
of which is totally incorporated herein by reference. Yet another
embodiment disclosed herein is directed to a process which
comprises incorporating an ink as disclosed herein into an ink jet
printing apparatus, melting the ink, causing droplets of the melted
ink to be ejected in an imagewise pattern onto an intermediate
transfer member, and transferring the ink in the imagewise pattern
from the intermediate transfer member to a final recording
substrate. In a specific embodiment, the intermediate transfer
member is heated to a temperature above that of the final recording
sheet and below that of the melted ink in the printing apparatus.
In another specific embodiment, both the intermediate transfer
member and the final recording sheet are heated; in this
embodiment, both the intermediate transfer member and the final
recording sheet are heated to a temperature below that of the
melted ink in the printing apparatus; in this embodiment, the
relative temperatures of the intermediate transfer member and the
final recording sheet can be (1) the intermediate transfer member
is heated to a temperature above that of the final recording
substrate and below that of the melted ink in the printing
apparatus; (2) the final recording substrate is heated to a
temperature above that of the intermediate transfer member and
below that of the melted ink in the printing apparatus; or (3) the
intermediate transfer member and the final recording sheet are
heated to approximately the same temperature. An offset or indirect
printing process is also disclosed in, for example, U.S. Pat. No.
5,389,958, the disclosure of which is totally incorporated herein
by reference. In one specific embodiment, the printing apparatus
employs a piezoelectric printing process wherein droplets of the
ink are caused to be ejected in imagewise pattern by oscillations
of piezoelectric vibrating elements. Inks as disclosed herein can
also be employed in other hot melt printing processes, such as hot
melt acoustic ink jet printing, and the like. Phase change inks as
disclosed herein can also be used in printing processes other than
hot melt ink jet printing processes.
[0035] Any suitable substrate or recording sheet can be employed,
including plain papers such as XEROX 4200 papers, XEROX Image
Series papers, Courtland 4024 DP paper, ruled notebook paper, bond
paper, silica coated papers such as Sharp Company silica coated
paper, JuJo paper, HAMMERMILL LASERPRINT paper, and the like,
glossy coated papers such as XEROX Digital Color Gloss, Sappi
Warren Papers LUSTROGLOSS, specialty papers such as Xerox
DURAPAPER, and the like, transparency materials, fabrics, textile
products, plastics, polymeric films, inorganic recording mediums
such as metals and wood, and the like, transparency materials,
fabrics, textile products, plastics, polymeric films, inorganic
substrates such as metals and wood, and the like.
[0036] The inks described herein are further illustrated in the
following examples. All parts and percentages are by weight unless
otherwise indicated.
[0037] It will be appreciated that several of the above-disclosed
and other features and functions, or alternatives thereof, may be
desirably combined into many other different systems or
applications. Also, various presently unforeseen or unanticipated
alternatives, modifications, variations or improvements therein may
be subsequently made by those skilled in the art, and are also
intended to be encompassed by the following claims.
[0038] While the description above refers to particular
embodiments, it will be understood that many modifications may be
made without departing from the spirit thereof. The accompanying
claims are intended to cover such modifications as would fall
within the true scope and spirit of embodiments herein.
[0039] The presently disclosed embodiments are, therefore, to be
considered in all respects as illustrative and not restrictive, the
scope of embodiments being indicated by the appended claims rather
than the foregoing description. All changes that come within the
meaning of and range of equivalency of the claims are intended to
be embraced therein.
EXAMPLES
[0040] The examples set forth herein below and are illustrative of
different compositions and conditions that can be used in
practicing the present embodiments. All proportions are by weight
unless otherwise indicated. It will be apparent, however, that the
present embodiments can be practiced with many types of
compositions and can have many different uses in accordance with
the disclosure above and as pointed out hereinafter.
[0041] Several inks and ink bases containing various dispersants
with or without modified naphthalene compounds were evaluated for
drool in a Typhoon printhead. SOLSPERSE 17000 (available from
Lubrizol Corporation) and a dispersant resin as prepared in Example
1 of U.S. Pat. No. 7,973,186 were used as a dispersant for the
example data. The ink components are presented in Table 1. The
percentages in the ink formulation are based on weight.
TABLE-US-00001 TABLE 1 Ink Base Component Details Polymethylene wax
A fractionated polymethylene wax available from IGI Inc.
Polyethylene wax A fractionated polyethylene wax available from
Baker Petrolite Triamide wax As prepared in Example 1 of U.S. Pat.
No. 6,860,930 Kemamide S-180 .RTM. Stearyl stearamide available
from Witco Chemical Corporation KE-100 .RTM. Triglycerides of
hydrogenated abietic acid available from Arakawa Industries
Urethane resin As prepared in example 4 of U.S. Pat. No. 6,309,453
Naugard .RTM. 445 Antioxidant available from Uniroyal Chemical
Company
The following anti-drool materials (ADM), shown in Table 2, were
used in the Examples.
TABLE-US-00002 TABLE 2 Anti-Drool Material Anti-Drool Material
Composition Description Designation Example 1 N,N-dimethyl
dioctedecyl ADM-1 Sulfonated quinizarin Example 2 (2-naphthalene
N,N- ADM-2 dimethyl dioctedecyl) Example 3 (1,5-disulfonic ADM-3
napthtalene N,N- dimethyldioctadecyl) Example 4 (3-hydroxy
naphthalene ADM-4 2,7-disulfonated N,N- dimethyldioctadecyl)
Example 5 (3-hydroxy naphthalene ADM-4 2,7-disulfonated N,N-
dimethyldioctadecyl) Example 6 (3-hydroxy naphthalene ADM-4
2,7-disulfonated N,N- dimethyldioctadecyl) Example 7 (3-hydroxy
naphthalene ADM-4 2,7-disulfonated N,N- dimethyldioctadecyl)
Comparative Example 1
Preparation of Standard Ink Base
[0042] In a 500 mL beaker were introduced 84.9 g (54.16%)
polymethylene wax, 20.0 g (12.76%) triamide wax, 28.0 g (17.86%)
S180.RTM., 20 g (12.76%) KE-100.RTM., 3.52 g (2.25%) urethane
resin, 0.336 g (0.21%) Naugard.RTM. 445. The solids were allowed to
melt in an oven at 130.degree. C. until all components were molten.
The resultant ink base was filtered through a 5 .mu.m mesh.
Comparative Example 2
Preparation of Ink Base with Dispersant Resin
Example 1 of U.S. Pat. No. 7,973,186
[0043] In a 500 mL beaker were introduced 84.9 g (53.08%) a
polyethylene wax, 20 g (12.5%) triamide wax, 28 g (17.5%)
S180.RTM., 20 g (12.5%) KE-100.RTM., 3.52 g (2.2%) urethane resin,
0.336 g (0.21%) Naugard.RTM. 445 and 3.2 g (2%) dispersant resin
(Example 1 U.S. Pat. No. 7,973,186). The mixture was allowed to
melt in an oven at 130.degree. C. until all components were molten.
The resultant mixture was filtered through a 5 .mu.m mesh.
Comparative Example 3
Preparation of Pigmented Ink with Dispersant Resin
Example 1 of U.S. Pat. No. 7,973,186
[0044] The following materials were weighed in a 600 mL beaker such
that the accompanying weight percentages also include the pigment,
dispersant and pigment synergist that were added in subsequent
mixing step: 80.48 g (50.85%) polyethylene wax, 18.51 g (11.57%)
triamide wax, 26.66 g (16.66%) S-180.RTM., 18.66 g (11.66%)
KE-100.RTM., 1.712 g (1.07%) urethane resin, 0.224 g (0.14%)
Naugard.RTM. 445 (an antioxidant), and 8.0 g (5%) SOLSPERSE 17000.
The materials were melted in an oven at 120.degree. C., mixed well,
then transferred to a Szgevari 01 attritor, available from Union
Process, that was also heated to 120.degree. C., and charged with
1800 g 440 C type 1/8 inch diameter stainless steel balls available
from Hoover Precision Products. A heated impeller was attached to
the assembly whereupon the impeller speed was adjusted such that
the stainless steel balls at the top of the vessel began to tumble
gently over each other. To this stirring solution were added 4.032
g (2.52%) of Pigment Violet 19. The pigmented ink was allowed to
attrite at 300 RPM for 18 hours upon which the final attrited
mixture was isolated from the stainless steel balls and filtered
with a 5 micron stainless steel mesh using a KST-47 filtration
apparatus, commercially available from Advantec Corporation.
Comparative Example 4
Preparation of Pigmented Ink with Dispersant Resin
Example 1 of U.S. Pat. No. 7,973,186
[0045] The following materials were weighed in a 600 mL beaker such
that the accompanying weight percentages also include the pigment,
dispersant and pigment synergist that were added in subsequent
mixing step: 82.81 g (51.79%) polymethylene wax, 19.2 g (12.01%)
triamide wax, 28.09 g (17.57%) S-180.RTM., 19.2 g (12.01%)
KE-100.RTM., 1.712 g (1.07%) urethane resin, 0.224 g (0.14%)
Naugard.RTM. 445 (an antioxidant), and 3.824 g (2.39%) dispersant
resin (Example 1 U.S. Pat. No. 7,973,186). The materials were
melted in an oven at 120.degree. C., mixed well, then transferred
to a Szgevari 01 attritor, available from Union Process, that was
also heated to 120.degree. C., and charged with 1800 g 440 C type
1/8 inch diameter stainless steel balls available from Hoover
Precision Products. A heated impeller was attached to the assembly
whereupon the impeller speed was adjusted such that the stainless
steel balls at the top of the vessel began to tumble gently over
each other. To this stirring solution were added 4.032 g (2.52%) of
Pigment Mogul L, 0.8 g (0.5%) of Sunflo B124 (Synergist). The
pigmented ink was allowed to attrite at 250 RPM for 18 hours upon
which the final attrited mixture was isolated from the stainless
steel balls and filtered with a 5 micron stainless steel mesh using
a KST-47 filtration apparatus, commercially available from Advantec
Corporation.
Example 1
Preparation of the Phase Change Ink Base Containing Dispersant
Resin
(Example 1 of U.S. Pat. No. 7,973,186) and 2.0% wt Sulfonated
Quinizarin, N,N-dimethyl-dioctadecyl
[0046] In a 500 mL beaker were introduced 83.36 g (51.761%)
polymethylene wax, 20.48 g (12.72%) triamide wax, 27.84 g (17.29%)
S180.RTM., 20 g (12.42%) KE-100.RTM., 2.62 g (1.63%) urethane
resin, 0.336 g (0.21%) Naugard.RTM. 445 and 3.2 g (1.99%)
dispersant resin (Example 1 U.S. Pat. No. 7,973,186). The mixture
was allowed to melt in an oven at 130.degree. C. until all
components were molten. When the mixture looked homogenous, 3.2 g
(1.99%) of sulfonated quinizarin (N,N-dimethyl-dioctadecyl) was
added with stirring. The resultant mixture was filtered through a 5
.mu.m mesh.
Example 2
Preparation of the Phase Change Ink Base Containing Dispersant
Resin
(Example 1 of U.S. Pat. No. 7,973,186) and 2.0% 2-Naphthalene N,N
dimethyl-dioctadecyl
[0047] In a 500 mL beaker were introduced 83.36 g (51.76%)
polymethylene wax, 20.48 g (12.72%) triamide wax, 27.84 g (17.29%)
5180.RTM., 20 g (12.42%) KE-100.RTM., 2.62 g (1.63%) urethane
resin, 0.336 g (0.21%) Naugard.RTM. 445 and 3.2 g (1.99%)
dispersant resin (Example 1 U.S. Pat. No. 7,973,186). The mixture
was allowed to melt in an oven at 130.degree. C. until all
components were molten. When the mixture looked homogenous, 3.2 g
(1.99%) of Naphthalene N,N dimethyl-dioctadecyl was added with
stirring. The resultant mixture was filtered through a 5 .mu.m
mesh.
Example 3
Preparation of the Phase Change Ink Base Containing Dispersant
Resin
(Example 1 of U.S. Pat. No. 7,973,186) and 2.0% Naphthalene
1,5-disulfonic N,N dimethyl-dioctadecyl
[0048] In a 500 mL beaker were introduced 83.36 g (51.76%)
polymethylene wax, 20.48 g (12.72%) triamide wax, 27.84 g (17.29%)
S180.RTM., 20 g (12.42%) KE-100.RTM., 2.62 g (1.63%) urethane
resin, 0.336 g (0.21%) Naugard.RTM. 445 and 3.2 g (1.99%)
dispersant resin (Example 1 U.S. Pat. No. 7,973,186). The mixture
was allowed to melt in an oven at 130.degree. C. until all
components were molten. When the mixture looked homogenous, 3.2 g
(1.99%) of Naphthalene 1,5-disulfonic N,N dimethyl-dioctadecyl was
added with stirring. The resultant mixture was filtered through a 5
.mu.m mesh.
Example 4
Preparation of the Phase Change Ink Base Containing Dispersant
Resin
(Example 1 of U.S. Pat. No. 7,973,186) and 1.0% 3-hydroxy
naphthalene-2,7 disulfonic N,N dimethyl-dioctadecyl salt
[0049] In a 500 mL beaker were introduced 83.36 g (51.76%)
polymethylene wax, 20.48 g (12.72%) triamide wax, 27.84 g (17.29%)
S180.RTM., 20 g (12.42%) KE-100.RTM., 2.62 g (1.63%) urethane
resin, 0.336 g (0.21%) Naugard.RTM. 445 and 3.2 g (1.99%)
dispersant resin (Example 1 U.S. Pat. No. 7,973,186). The mixture
was allowed to melt in an oven at 130.degree. C. until all
components were molten. When the mixture looked homogenous, 3.2 g
(1.99%) of 3-hydroxy naphthalene-2,7 disulfonic N,N
dimethyl-dioctadecyl salt was added with stirring. The resultant
mixture was filtered through a 5 .mu.m mesh.
Example 5
Preparation of the Phase Change Ink Base Containing Dispersant
Resin
(Example 1 of U.S. Pat. No. 7,973,186) and 2.0% 3-hydroxy
naphthalene-2,7 disulfonic N,N dimethyl-dioctadecyl salt
[0050] In a 500 mL beaker were introduced 81.76 g (51.28%)
polymethylene wax, 20.48 g (12.85%) triamide wax, 27.84 g (17.46%)
S180.RTM., 20 g (12.54%) KE-100.RTM., 2.62 g (1.64%) urethane
resin, 0.336 g (0.21%) Naugard.RTM. 445 and 3.2 g (2.01%)
dispersant resin (Example 1 U.S. Pat. No. 7,973,186). The mixture
was allowed to melt in an oven at 130.degree. C. until all
components were molten. When the mixture looked homogenous, 3.2 g
(2.01%) of 3-hydroxy naphthalene-2,7 disulfonic N,N
dimethyl-dioctadecyl salt were added with stirring. The resultant
mixture was filtered through a 5 .mu.m mesh.
Example 6
Preparation of the Phase Change Pigmented Ink Containing Dispersant
Resin
(Example 1 of U.S. Pat. No. 7,973,186) and 2.0% 3-hydroxy
naphthalene-2,7 disulfonic N,N dimethyl-dioctadecyl salt
[0051] Repeat of the ink formulation in Comparative Example 3 with
3.2 g (1.98%) of 3-hydroxy naphthalene-2,7 disulfonic N,N
dimethyl-dioctadecyl salt added with stirring to the molten ink.
The resultant mixture was filtered through a 5 .mu.m mesh.
Example 7
Preparation of the Phase Change Pigmented Ink Containing Dispersant
Resin
(Example 1 of U.S. Pat. No. 7,973,186) and 2.0% 3-hydroxy
naphthalene-2,7 disulfonic N,N dimethyl-dioctadecyl salt
[0052] Repeat of the ink formulation in Comparative Example 4 with
3.2 g (1.96%) of 3-hydroxy naphthalene-2,7 disulfonic N,N
dimethyl-dioctadecyl salt added with stirring to the molten ink.
The resultant mixture was filtered through a 5 .mu.m mesh.
Drool Testing and Results
[0053] The drool pressure threshold of a given test ink was
determined by first applying the pressure at the range used for the
ink base. If drooling was observed, the drooling pressure threshold
of that test ink would be determined by applying graduated
decreases in pressure. The delta drool pressure of a given test ink
was also calculated by the difference of the measured drool
pressure thresholds of the reference ink base and the test ink
sample.
.DELTA.(Drool Pressure)=Drool Pressure(sample)-Drool
Pressure(reference)
[0054] Thus a test ink having a drool pressure of negative
differential inches of water, relative to the ink base from a
commercially available ink (serving as a control), drooled at a
lower applied pressure that was typically used in the printer.
[0055] To assess test ink resistance to drooling, the ink was
tested in a Typhoon print head. The print head was emptied by
printing 20 duplex solid fills. The channels were refilled with
molten ink from an oven, purged, emptied and re-filled until
printed solid fills on paper appeared uniform. A pressure of
approximately 2.8 inches water was set in the printer so that in a
purge/wipe cycle, a quantity of test ink was purged at that
pressure and then wiped off the front face from the printhead's
wiper blade in the printhead's cleaning or purge/wipe cycle. At
this point, the front face of the printer was visually observed as
to whether any drooling onto the printhead's front face was
initiated and/or persisted. If drooling of a test ink was observed
at a certain pressure, then the applied pressure was gradually
reduced to a level where drooling of a test ink was not visually
observed and this pressure level was recorded as the drool pressure
limit of the test ink.
[0056] At the completion of the test, the test ink is rinsed out
with clear base, usually requiring 4 to 6 fill/purge/empty
cycles.
[0057] The differential drool pressure, or .DELTA.(Drool Pressure),
of the respective test ink is reported as differential inches of
water, with respect to the drooling level of the ink base, and is
calculated as follows:
.DELTA.(Drool Pressure of test ink)=Pigmented Ink failure (inches
of water)-ink base failure (inches of water)
[0058] Thus a test ink having negative differential inches of
water, relative to the ink base, is drooling at a lower applied
pressure. Drool pressure of a sample ink is the gauge pressure
realized that causes the ink to burst out of at least some of the
nozzles in the printhead which can be accurately measured by a
micropressure gauge. The results of the drool test for ink bases
and inks are presented in Table 3 below:
TABLE-US-00003 TABLE 3 Drool Pressure .DELTA. (Drool Visual
Anti-Drool (gauge), Pressure), Fouling Dispersant Material inches
of inches of observed on Example Sample used Designation water
water printhead Comparative Ink base None Not 2.31 0.0 No 1 only
applicable Comparative Ink base .sup.1 Custom Not 1.59 -0.64 Yes 2
dispersing applicable compound Comparative Magenta ink SOLSPERSE
Not 0.37 -1.73 Yes 3 Pigment 17000 applicable Violet 19 Comparative
Ink Carbon .sup.1 Custom Not 1.50 -0.62 No 4 Black Mogul dispersing
applicable L pigment compound synegist SunFlo SFB 124 1 Ink base
.sup.1 Custom ADM-1 0.68 -1.42 Yes dispersing compound 2 Ink base
.sup.1 Custom ADM-2 1.29 -0.82 Yes dispersing compound 3 Ink base
.sup.1 Custom ADM-3 Not gelled Not dispersing applicable applicable
compound 4 Ink base .sup.1 Custom ADM-4 1.61 -0.49 No dispersing
compound 5 Ink base .sup.1 Custom ADM-4 2.11 0 No dispersing
compound 6 Magenta ink SOLSPERSE ADM-4 1.31 -0.80 No Pigment 17000
Violet 19 7 Ink Carbon .sup.1 Custom ADM-4 2.42 0.00 No Black Mogul
dispersing L pigment compound .sup.1 Custom dispersing compound
prepared according to Example 1 from U.S. Pat. No. 7,973,186
[0059] Differential drool pressure values of about -0.8 to about
+0.8 inches of water are desirable and indicate a normal range of
printhead values for optimum performance over purge/wipe cycles. As
can be seen from Table 3, many examples of the present embodiments
resulted in drool value of .DELTA.(Drool Pressure) of -0.8 to 0
inches of water which was a significant improvement over the
comparative examples which did not incorporate the small molecule
modified compound. For instance, Comparative Example 3, which
contains SOLSPERSE 17000, resulted in significant failure as
drooling of the printhead and severe fouling were evident. In
Example 6, the addition of only 2% modified small compound
(3-hydroxy naphthalene 2,7-disulfonated N,N-dimethyldioctadecyl)
reduced the .DELTA.(Drool Pressure) value in half. In Example 7,
the addition of only 2% modified small compound (3-hydroxy
naphthalene 2,7-disulfonated N,N-dimethyldioctadecyl) reduced the
.DELTA.(Drool Pressure) value to zero.
SUMMARY
[0060] In summary, the present embodiments provide for novel
anti-drool additives for use in phase change ink compositions.
These additives include several sulfonated small molecules modified
to be made compatible with solid ink and formulated in inks. The
inventive inks tested for drool showed remarkable improvement in
drool performance. For one example, remarkable improvement was seen
when the inks contained between from about 1 and about 2% by weight
of one of these additives, disulfonated compound 3-hydroxy
naphthalene.
[0061] The claims, as originally presented and as they may be
amended, encompass variations, alternatives, modifications,
improvements, equivalents, and substantial equivalents of the
embodiments and teachings disclosed herein, including those that
are presently unforeseen or unappreciated, and that, for example,
may arise from applicants/patentees and others.
[0062] Unless specifically recited in a claim, steps or components
of claims should not be implied or imported from the specification
or any other claims as to any particular order, number, position,
size, shape, angle, color, or material.
[0063] All the patents and applications referred to herein are
hereby specifically, and totally incorporated herein by reference
in their entirety in the instant specification.
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