Note: Descriptions are shown in the official language in which they were submitted.
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This invention relates to planographic printing inks.
It particularly concerns novel inks, especially adaptable
for use in a planographic printing process known as Driography,
which comprise a basic planographic printing ink vehicle, a
pigment, a selective modifying varnish and a flow control agent,
and, advantageously, certain tack maskers.
BACKGROUND OF THE INVENTI_
In planographic printing, as the term implies, both the
image and non-image areas lie substantially in the same plane.
The non-image areas are made ink-repellent so that when ink is
applied by roller to the plate surface, only the image areas
accept the ink for transfer to a copy sheet. Lithography is
the best known form of planography and has heretofore been the
only known practical and successful process of planographic
printing. It works on the theory that water and oil are
immiscible. The non-image areas are made water-receptive
(hydrophilic), and when water-wet they repel the oily ink. The
image areas are ink-receptive (organophilic) and water-repellent
(hydrophobic). On the press, the plate conventionally is first
dampened with a fountain solution (which wets the background or
non-image areas), after which ink is rolled over the plate by
form rollers. The ink coats the image areas, but is repelled
from the dampened non-image areas.
In present times, most lithography is done by "offset",
wherein the plate does not itself contact the copy sheet, but
instead contacts a rubber-like blanket roller, or cylinder
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during each revolution. The blanket recelves the ink image
and, in turn, revolves and transfers ("offsets") it to the
copy sheet.
~ Lithography was well established as a separate branch
i of the printing industry in the early l9001s. ~ecause a
i number of advantages are realized by the planographic method
of printing, lithographic printing has been a well-recognized
and widely-accepted part of the printing art for many yearæ.
Despite numerous developments and improvements which have
; 10 been made over the years, and notwithstanding difficulties
inherent therein, lithography has retained its total reliance
on the original concept that water which is coated o-~er the
non-image areas of a printing surface, being irmmiscible with
oil, will reject an oil-based printing ink.
~ ne of the difficulties inherent ln having both ink and
fountain, or dampening, solutions present is that the dampening
solution applied to the plates flows back lnto the train of
lnking, or form rollers on the press, during the course of
the printing run, causing emulsification of the ink. In
addition to back flowing, the fountain solution also tends
to flow forward over the offset or blanket cylinder, moistening
the paper causing it to curl and change dimension. This
cr~ates special difficulties in securing accurate registration
ln color printlng where the paper undergoes multiple passes
through the presses. Control of the delicate balance between
ink and fountain solution, which is necessary to produce
image fidelity and uniformity, is difficult to maintain, and
must be constantly watched, especially as conditions change
on the press during the course of a printing run. This is
further complicated by the difficulty ln maintaining the
desired chemical consistency of the fountain solution on the
press, especially in long p~ess runs. The fountain solution
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is generally a mixture of water, acid, buffer an~ gum designed
to keep the non-image areas o~ the pla~e passivated and ink
repellent to prevent them from receiving lnk. The nature of
the fountain solution affects the working properties o~ the
lnk being used. Too m~ch acid causes image removal (sharpening),
retards drying and causes roller stripping. Too much gum
encourages emulsification. The lithographic process requires
that a balance be maintained between ink and fountain solution.
If the water layer on the plate falls below a certain poi~t,
the ink begins to catch up into the non-image areas and
scumming, or sensitization of the non-image areas, occurs.
Scumming can be eliminated by increasing the amount of water
reaching the plate or by lowering the temperature of the
fountain solution. This latter change lncreases the viscosity
of the ink on the plate and form rollers making it less
mobile and thereby less prone to water pick-up and mechanical
breakdown into the non-image areas. In an e~fort to minimize
these problems, the proper formulation of fountain solution
itsel~ has become a highly complex and demanding art since
the fountain solution in many cases determines the level of
artistic and commercially acceptable quality which can be
attained in li~hographic printing.
During the more than half-century in which lithography
has been an established commercial form of printing, in
which the desirability of eliminating the step of dampening
the plate with water has been recognized, no one was able to
develop a successful planographic printing plate having a
printing surface with background areas that are ink-repellent
without being pre-wet by an ink-immiscible liquid until the
recent advent of Driography. Driography provides for the
flrst time a substantially simplified planographic printing
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process wherein need for all the sophisticated dampening
systems has been obviated.
A Driography printing plate and process are described
in U.S. Patent 3,511,178 to J.L. Curtin. The Driography process
is based on the properties of the plate involving adhesion.
In general, Driography comprises a printing plate having a
background surface, or non-image area with a sufficiently low
adhesion to the printing ink so that, without pre-wetting
the plate, the ink that is applied to the plate in such areas
will not split away and transfer from the inking rollers to -
the plate. That is, the adhesion of the ink to the inking
roller and the cohesion forces between the ink particles are
both greater than the adhesion between the ink and the surface
of the plate and the ink will not transfer to the surface.
Although when a press utilizing Driography is started up,
the ink spreads over the entire printing plate, the non-
image areas of the plate are rapidly cleaned by the form `
rollers since the forces between the roller and the ink are
greater than the forces between the ink and non-image areas.
Driography has many advantages over conventional lithog-
raphy. The printing quality and cosmetic appeal of the
final product are better than conventional lithography
utilizing a wet offset process. The press can operate at
faster speeds. The makeready is shorter and easier, since
there is no need to achieve a balance between the ink and
fountain solution or the solution and the printing plate,
each of which balances, in conventional, wet lithographic
processes, requires a considerable amount of time to achieve,
as well as constant monitoring to maintain them for successful
printing. Furthermore, the absence of the fountain solution
system makes the process more economical.
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~ lthough Drio~raphy has these and other adv~ntages, it
results in the provision of new problems which require
resolution if the apparent advantages provlded by Driography
are to be utilizable in a practical manner. An evaluation
of planographic inks can be divided into three categories,
(1) those which evaluate the handling characteristics of the
ink under ambient conditions, (2) those which relate to hou
the ink will perform on a press; and (3) those which relate
to the quality (e.g., the physical, optical and chemical
properties) of the printing produced.
An example of the new problems created involves the
absence of the fountain solution system which results ln the
press heating up and the printing plate reaching higher
temperatures than in conventional, wet lithography where
approximately 40% of the water of the fountain solution
evaporates from the press and in doing so, cools the rollers
an~ the printing plate. In a conventional, wet lithographic
pro~ess, the press will normally run at temperatures up to
about 90 to 100F., depending upon ambient conditions, air-
conditioning ln the press room, etc., and the printing plateto which the ink is applied will typlcally be about 10F.
below this press temperature. In Driography, the printing
press will normally be about lO~F., or more, higher than the
wet press temperature due to the absence of the fountain
solution. Because of this extra heat in Driography, and the
loss of the acid present in the fountain solution which
lmmobilizes part of the ink drying system to provide a
retarding effect upon ink drying, conventional lithographic
lnks tend to dry on the press faster ln Driography than in
conventional, wet lithography. For example, a lO~C. rise in
press temperature in general doubles the lnk drying rate so
that the lnk dries on the press in approximately one-half
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the time. Since the te~peratures in the press are approximately
20F. hlgher in Driography than in wet lithography, conventlonal
lithographic inks tend to dry on the press when used ln
Driography and do not move through the press properly to
transfer to the copy sheet.
Press stabllity is, therefore, not as good with Driography
as it is with conventional wet lithography. By press stability
is meant the ability of the ink, under press-operating
conditions (e.g., temperatures and shear rates), to move
through the press (e.g., through the rollers, plate and
blanket and transfer to and from the printing plate) and the
tendency of the ink not to dry in the roller train, plate
and blanket. The application and form rollers in the printing
process both supply ink and keep the printing plate clean by
removing ink from the non-image areas of the plate. ~n ink
has low press stability when the ink dries in the roller
train, on the printing plate or blanket~ or if the ink fails
to transfer ~rom the form rollers to the printing plate.
~onin~ is another example of a problem with Driography.
Toning occurs when ink is not refused by the non-image areas
of the printing plate. The result of toning is the application
of ink to the copy sheet in the non-image areas. Toning may
be ln the form of a light background color in the non-image
areas of the copy sheet so that the copy sheet appears
dlrty. In severe toning, the background, or non-image areas
of the copy sheet, merge into the printed, or i~age, areas.
Toning can be related to temperature. The toning
temperature of an ink is that temperature at which the in~,
under gi~en shear rates, loses internal cohesion and becomes
pseudoplastic in behavior. At this te~peratur~, control of
ink application, i.e., ink being picked up from the printing
plate by the form rollers, is lost. Toning is, accordingly,
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analogous to scummi~g in co~ventional, wet lithography.
Conventional lithbgraphic inks have very low ~oning temperatures
when used ln Driography, wor~ing well in Driography at about
75F., and below. Although some conventional lithographic
; inks will function at slightly higher temperatures, e.g., up
to 85F., ~eir utility is limited by uncertainty of operation
and limitations on color.
Conventional planographic inks do not perform well in
Driography printing. They are not press-stable, partlcu~arly
under the high temperatures and shear rates occurring in
Driography printing, which does not have the advantages
provided by a fountain solution. In addition, toning ~s
produced and the quality of the printing itself is less than
that desired.
It is considered that at low shear rates, typically rhe
Driography ink system should be near Newtonian and at hlgh
shear rates, it should move into the dilatant zone. This
accounts for the plate/form roller behavior to give a wipe
action of the form roller oVer the plate with the ink tending
to break clean from the low energy surface. In this type o~
syste~, the faster the roller movement~ the more resistant
to movement there is from the system. In addition, the
Driography ink system tends to heat up and is, therefore,
temperature sensitive.
DESCRIPTION OF THE INVENTION
The present inventlon is directed to improved planographic
printing inks~ especially suitable for use in Driography
processes.
An ob~ect of the present invention is the pr~vision of
planographic ink which are suitable for use in a Priography
prlnting system. Another ob~ect is the provision of such
lnks which exhibit viscosities suitable for handling under
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ambient condltions. Still another ob~ect is the provision
of such inks having rheological properties (e.g., viscosity~
flow, adhesion, and tack) whlch result ln advantageous
performance under the conditions of temperature and stress
encountered on a Drio~raphic press, particularly across a
broad range of press-operating temperatures, e.g., 85 to
140F., which range involves temperatures higher than
temperatures suitable for use with conventional wet lithographic
inks~ while exhibiting high press stabillty and with the
avoidance of toning.- The non-image area of the dry plate
used in Driography is usually a layer of silicone rubber
having a low energy surface. Still another ob;ect is the
provision of such inks ha~ing such rheology which are not
deleteriously affected significantly by interactlon between
the vehicle-pigment ingredients of the ink. Another object
i8 the provision of such inks which exhibit high viscosities
and internal cohesion, and, low yield value and surface
energy, and thus are able to flow, transfer and lay down
across the broad range of press-operating conditions including
the range of temperatures mentioned above, and at low and
high shear rates (e.g., those produced by high press speeds,
e.g., up to 1000 fpm, or more), while maintaining high
viscosities and internal cohesion, ~nd avoid pseudoplasticity.
Another ob~ect, is the provision of such an ink having a low
tack while avoiding substantial syneresis in both the stressed
and unstressed state. Syneresis further deleteriously
; affects the flow of the ink through, transferability of the
ink within, and trapping recovery of overprint a-~ng, the
printing operation.
Still another ob~ect is the provision of such an ink
which provides high quality printing, e.g., printings which
are sharp and exhibit fidelity, excellent reproducibility in
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~epth of color tone, absence of toning and are rub reslstant.
These and other advani,ageous ob~ects are accompllshed
by the inks of the present invention whlch exhlbit a unique
balance of rheological propert~es and advantageous performance
characteristics, particularly under the severe press-operating
conditions encountered in Driography, and which provide
high-quality printings.
The unique balance of rheological properties and advantag-
eous performance characteristics and high quality printings
are provided by a novel combination of components, co-acting
with one another, to enhance each of their beneficial effects
and, simultaneously, to alleviate their deleterious ef~cts,
to the novel planographic inks.
The novel inks of the present invention comprise a
ba~ic planographic printing ink vehicle, a pigment, conventional
ink ingredients, a selected modifying varnish, and a flow
control additive, and, advantageously, certain tack maskers.
The basic ink vehicle may be designed for use in a heat-~et
printing system ~here the inks are dried by heat or may be
designed for use in a sheet-Ped printing system where the
inks set and dry by oxidation. The basic vehicle can be a
gelled (either chemically- or physically-gelled) or a non-
gelled vehicle. A "chemically-gelled vehicle" is one wherein
the vehicle has been gelled as a result of chemical reaction
with a "chemical-gelling agent", as distinguished from a
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"physlcally-gelled vehicle", which is a vehicle basically
gelled as a result of physical interaction between the
vehicle and a "physical-gelling agent". The gelling of the
vehicle is another aspect of the present inventlon since it
enhances the thermal stability of the ink and diminishes the
prospect of toning. ~hemically-gelled vehicles are preferred.
In another aspect o~ the present invention, a non-reactive
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,lyamide is employed wlth chemlcally-gelled vehicles to
further increase the viscosity of the inks.
The selected modifying varnish is incorporated in
amounts sufficient to impart certain desired rheological
properties to the ink, e.g., a high viscosity and internal
cohesion, low yield value, and the maintenance of a high
viscosity at the elevated press temperatures and high press
speeds (shear rates) encountered in Driography, and thus
good transference and flow characteristics of the ink through
the press. The particular modifying varnish employed is
from a certain selective group of such varnishes and within
that group, is selected, depending upon the composition of
the basic planographic vehicle and the particular pigment
used, to "modify" and provide the desired vehicle-containing
ink.
The flow control additive is added to impart certain
rheological properties. e.g., to contribute to the high
vlscosity and internal cohesion of the ink, provide some
flow or low yleld value, and decrease the surface energy of
the ink with respect to the non-image area, and thus assist
in keeping the ink off the non-image areas. It is added in
amounts which do not deleteriously alter the viscosity
characteristics imparted by the modifying varnish. The
internal cohesion is sufficient to maintain wetting and
transference of the ink to the image areas of a printing
plate whereas the surface energy is sufficiently low that
the ink-does not wet the non-image areas of the printing
plate within the plate operating range of temperatures.
~ The use of the basic vehicle, selected modifying varnish,
and flow control additive, provide novel inks having hig~l
viscosity and internal cohesion with some flow or low yield
value, increase the toning temp2rature of the ink, and
thereby reduce the prospect of toning on the copy sheet at
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the high press temperatures and high press speeds used ln
Driography.
The inks of this invention have a high viscosity,
generally above 300 poise at 40C. for an ink designed to be
used in a sheet-fed system and above 100, typically in the
range of about 125 to 175 poise at 40C., for an ink to be
used in a heat-set system. The viscosity is measured with a
cone and plate type viscometer. It has a low yield value,
generally below about 5000 dynes/cm , preferably below about
300G dynes/cm2 as measured on the Laray viscometer. Ar ink
having a zero yield value is preferred. Conventional wet
lithographic inks have yield values of about 10,000 to
20,000 dynes/cm2. Many inks having such hi~h yield values
do not work well in Driography because droplets tend to
break off in contact with the plate and not be drawn back
onto the form rollers.
The desired viscosities O1 the inlcs of this inver.tion
are high in relation to the viscosities normal for conventional
inks designed for use in other lithographic systems. Conventional
lithographic inks for use in a sheet-fed system typically
have a viscosity at 40C. of about 90 tc 100 poise and such
inks for use in a heat-set system typically have a viscosity
at 40C. of 40 to 50 poise, or less.
A high viscosity system is, however, usually accompanied
by high tack, i.e.j 25 to 40 as measured on an Inkometer at
1200 RPM and 90~. over 1 minute, and a flying tendency,
i.e., where a fine mist of charged particles is thrown off
by the fast moving rollers. A11 tack measurements referred
to herein are similarly obtained unless otherwise stated.
The high tack associatëd with the system is advantageously
reduced by the addition of tack masking amounts of a vehicle-
modifying varnish, tack masker which is compatible with, and
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~oes not deleteriously a~fect, the novel ink~ Or the present
inventlon.
The basic planographic printlng ink vehicle is the
pigmer.t carrier and provides such charac~eristics as drying,
hardness, gloss, chemical resistance and printing qualities.
It is employed in amounts sufficient to carry the pigment,
as a dispersion, for instance, during the printing operation
and conventional vehicles include drying oil and synthetic
drying oil; natural or modified resins such as rosin, copal,
dammer, shellac, ha~dened rasin and rosin esters; synthetic
reslns ~uch as phenol resin, rosin modified phenol resin,
100% phenol resin, maleic acid resin, alkyd resin, petroleum
resin, vinyl resin, acrylic resin, polyamide resin, epoxy
resin, aminoalkyd resin, polyurethane resin and aminoplastic
resin; cellulose derivatives such as nitrocellulose and
ethyl cellulose; rubber derivatives such as chlorinated
rubberJ cyclized rubber; and others such ac glue, casein,
dextrin and zeln.
The preferred basic vehicles include the phenolic and
malelc resins. The resin can be used in making an oil-based
vehicle and is advantageously modi~ied by incorporating it
lnto an oil. The modi~ied resin is preferably gelled with a
chemical gelling agent, such as a metallo-organo one, e.g.,
an aluminum complexing agent. A solvent can also be added
to ad~ust the viscosity and tack, if desired. Oils suitable
for use in preparlng the basic vehicle system include linseed
oll, lithographic varnishes which are heat-bodied linseed
oils, and long oil, linseed alkyd resins which are commercially
available. Linseed oil will have a viscosity of abou~ 0.5
poise and the linseed lithographic varnishes will have a
viscosity in excess of 150 poise. Suitable alkyd resins for
use as an oil component in the printing ink vehicle are
formed by condensation of polybasic acids, e.g., phthalic t
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anhydride, terephthalic acid, isophthalic acid, etc., with
polyhydric alcohol, e.g., glycerol, and modified with drying
oils such as linseed oil. For printing ink use, they are
modified to give a long oil system, e.g., in excess of 70%
oil length. Commercially available alkyd resins include
*Iovite I-57, *Iovite I-llO, and *Iovite C-428, sold by Iovite
Chemicals, Inc., and *Terlc,n 3, sold by Lawter Chemicals and
are available in viscosities from about 5 to 500 poise. The
resin is modified by the oil which lacks hardness and gloss
when used alone. Suitable resins include the commercially
available esterified, rosin modified, phenolic resins and
esterified, rosin modified, maleic resins. These phenolic
resins are generally made by esterifying a rosin such as
polypale rosin or dimerized rosin with an esterifying polyhydric
alcohol such as pentaerithritol, glycerine or sorbitol and
reacting the product with a substituted phenol which can be
- paraoctylphenol, bis-phenol A, o-phenylphenol, xylenols,
cresols, etc. There will normally be about 20 to 30% phenolic
modification of the resin. Commercially available phenolic
resins include *M-93, *M-88 and *Ameberol F-7 of Union Camp Co.
and *Krumbaar K-1387 of Lawter Chemicals Company. The maleic
resins are typically produced by forming an adduct of a
rosin, e.g., gum rosin, and maleic anhydride and esterifying
with a polyhydric alcohol such as glycerine or pentaerithri-
tol. The maleic content of the resin is typically about 7
to 14%. *Arochem 532 and 533 of Ashland Chemicals are suitable
maleic resins. A high boiling, low aromatic and olefinic
content, hydrocarbon solvent is generally used in combination
with the oil and resin. The parafinic, saturated cyclic -
solvents such as *Magie 470, *Magie 500 or *Magie 535 are
suitable. These solvents boil above 450F. and contain less
than 15~ aromatics and olefins.
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The basic vehicle viscosity typically should be about
the same as the ink system, i.e., above about 300 poise at
40C. for an ink to be used in a sheet-fed system and above
lO0 to 125 poise at 40C. for an ink to be used in a web
system. These initial viscosities, however, are generally
lowered upon the addition of additives during the formulation
of the ink. The viscosity may be varied by varying the
proportions of oil, rosin and solvent in the vehicle, use of
a complexing or gelling agent, amount of gelling agent,
addition of polyamide, etc. Generally, the vehicle will
contain about 40 to 60% by weight resin, about 15 to 40~ oil
and about 15 to 35% solvent. For a sheet fed printing
system, the vehicle preferably contains about 45 to 55%
resin, about 20 to 30% oil and about 20 to 30% solvent,
whereas for a heat set printing system, the vehicle will
contain less oil and more resin, e.g., about 50 to 60%
resin, about 10 to 20% oil and about 25 to 35% solvent. The
preferred basic vehicle system of the novel inks of this
invention is a high viscosity oleoresinous vehicle comprising
a high melting point, esterified, rosin modified, phenolic,
gelled with an aluminium complexing agent. The phenolic is
oiled out into either vegetable oils or long oil alkyds to
solubilize the resin and let down with high boiling aliphatic
hydrocarbons.
A particularly suitable non-gelled basic vehicle system
for use in an ink designed for use in a sheet-fed system is
supplied by Iovite Chemicals, Inc., as *Iovite 2-108 and
contains 40% of an esterified, rosin modified, phenolic
resin, 6~ of a lO0~ oil soluble, phenolic resin, 30% oil,
30 23% solvent and 1% of a bodying agent. A preferred gelled
vehicle system, also supplied as *Iovite 3-311-43, *XP585 or
2-178, comprises about 16 to 20% bodied linseed oil, ll to
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15.5% long oil l~nseed al~yd, 32.5 to 37.~% blsphenol modi~led
rosin ester, 29 to 33% Magie 535 oll and 1 to 2% ~lu~inu~
isopropoxide. Preferred ~ehlcles for use ln lnk deslgned
for use in a heat-set printlng system include Iovlte 3-236
which is a pentaerithritol ester phenol~c resln in isophthalic
alkyd, gelled and dissolved in Magie 500 oil. This vehicle
ls a hlghly structured gel containing 62% solids wh~ch has
a tack of 14 at 400 RPM.
Pigments suitable for use in the present invention
include colorlng agents such as inorganic and organic
pigments which are usable in a planographic ink. Typical
inorganic and organic pigment~ include diarylide yellow of
the AAA, AAOA and AAOT type, phthalo-cyanide Blue GS, green
shade beta type, permanent red 2B calcium, lithol rubine
(4B), rhodamine YS, carbon black metal modi~led furnace type
(with alkali blue toner) chrome yellow, iron blues, iron
oxlde~, tltanlum dioxide, alumina hydrate, blanc fixe,
calcium carbonate, lake pigments, PMTA colors, fluorescent
pigments, metallic pigments, clayæ, naphthols, and other
organic plgments.
The pigments are employed in vehicle-dispersable amounts.
In general, it is desired to carry as much pigment ln the
ink as possible. A range of typical pigment amounts used
would be approxlmately 12 to 50% by weight Gf the ink. A
preferred manner of adding an organic pigment is as a Plushed
dispersion. This dispersion is prepared by treating a
pigment press cake with the basic vehicle components which
will preferentially flush out or eliminate the watex from
the plgment surface. The pigment loading of the dispersion
; 3 is as high as possible and still permit ease of handling of
the dispersion. Generally, about 30 to 45% of thls dlsperslon
will be pig~ent. A pre~erred vehicle for use in preparing
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the vehicle for use in an ink for a sheet-fed system is a
1:1:1 ratio of *Iovite 2-108, *Iovite I-llO and *Iovite I-102.
The use of a pigment dispersion has led to better flow
characteristics and ease ofhandling on the press. Drying
on the sheet is also faster. Further, ink performance at
low temperatures, e.g., 70F., is improved. A suitable
vehicle for preparing a pigment flush for use in an ink
designed for a heat-set system is a dimerized rosin ester
such as *Iovite 102 which is 53% *Pentalyn K is *Magie 535 oil
and has 50 to 55~ solids. *Magie 500 oil can also be used.
The selected modifying varnish is basically added to
adjust the rheological properties of the ink and, in general,
sufficient amounts are added to provide the high viscosity,
and internal cohesion and low yield value over the broad
range of press operating conditions including temperatures
; ranging from room temperature to 104 or 125F., and high
shear rates resulting from high press speeds, e.g., up to
1000 fpm, or more. The flow control agent is basically
added in an amount effective to provide the desired surface
energy over the operating range of press conditions. The
internal cohesion is sufficient to maintain wetting and
transference of the ink to the image areas of a printing
plate whereas the surface energy is sufficiently low that
the ink does not wet the non-image areas of the printing
plate within the plate operating range of temperatures. An
ink designed for use in a sheet-fed system will desirably
have a viscosity of above about 300 poise at 40C. measures
with a cone and plate type viscometer. The viscosity of the
inks designed for use in a heat-set system is desired to be
above 100 poise, typically in the range of about 125 to 175
poise, at 40C. The ink viscosity measurements herein,
unless otherwise stated, are made on a *Haake viscometer at
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40C. using a PKII cone drl~en at a constant speed of 16 RPM
representlng a 318.4 sec 1 shear rate. The initlal peak ls
taken as the vlscosity. T~e maxlmum viscosity suitable for
the lnk is that at which the ink will not move through the
roller train when it is maint~ined at roo~ temperature,
e.g., 70F., or about 700 poises. The desired vlscosities
of the inks of this invention are high in relation to the
viscosities normal for conventional inks designed for use in
other lithographic systems. Conventional lithographic inks
for use in a sheet-fed system typically have a viscosity at
40C. of about 90 to 100 poise and such inks for use in a
heat-set system typically have a viscosity at 40C. of 40 to
50 poise, or less. Sufficient modifying varnish is, therefore,
incorporated into the ink vehicle to provide an ink having
preferred rheological properties for the end use desired.
An addition o~ the flow control agent, polyamide or gelling
agent will tend to further increase the ink viscosity.
Generally, the modifying varnish will comprise about 3 to
35% by weight of the ink system, although preferably it will
be less than 20% by weight of the ink. The specific amount
of modifying varnish used in a given ink will not only be
determined by the basic vehicle system but also will be
determined in part by the pigment used since the ink viscosity
and flow is related to the specific basic vehicle-pigment
relationships. The selected modifying varnishes also improve
the performance of the ink system for both printing performance,
e.g., transfer through the press and setting, and end use
requirements, e.g., rub resistance.
A chemically gelled vehicle is preferred for the sheet-
3 fed ink systems since it further improves the thermal stabilityof the basic vehicle-modifying varnish ink system and pr~vides
an ink having a low tack. A physical gelling agent can also
-18-
,
be added to the ink system to improve the thermal stability
of an ink made from a non-gelled basic vehicle. However, it
is preferred to make the basic vehicle-modifying varnish
system the control on stability. The modifying varnish, as
well as the chemically-gelled vehicle, or a vehicle physically
gelled with a gelling agent, change the response of the ink
viscosity to temperature. Whereas, without use of modifying
varnish and the chemically- or physically-gelled vehicle as
a generalization, the ink viscosity changes about 10% for
each 1C. variation; the use of the modifying varnish,
gelled vehicle or the gelling agent slows down this viscosity
change. Further control of the viscosity, particularly when
using a gelled vehicle, can be accomplished by incorporating
a small, but sufficient amount of a polyamide, e.g., of the
*Versamid type, such as *Versamid 2950, in the vehicle to
increase the viscosity. Such polyamides are non-reactive
condensation products of dimerized fatty acids and have
amine values of about 3 to 8 and a softening point of about
90 to 100C.
The selective modifying varnishes for use with the
basic ink vehicle include cyclised rubber; dimerized rosin
esters; alkyds and rosin modified alkyds; esterified, rosin
modified, phenolic oleoresinous gels; and hydrocarbon resin
solutions. The modi~ying varnish, since it is changing the
rheology of the basic vehicle, is different from the basic
ink vehicle. A cyclised rubber of relatively low molecular
weight, such as *Alpex C8415 of American Hoescht Corp., is
desirable to improve setting properties of the inks. The
cyclised rubber is typically added as a solution in a high
boiling aliphatic hydrocarbon solvent such as a *Magie Oil
and is preferred for use in gelled ink systems. *Magie 470,
a petroleum oil having 85~ saturates, 10~ aromatics and 5
* Trade Mark
--19--
, ,,-,;, .. ., , ~ .
~ 5~
olefins can be used. Dimerized rosin esters are esterification
products of dimerized rosin and pentaerithritol and are
commercial available, such as *Iovite I-102 or 3-103 which
is 53~ *Pentalyn K produced by Hercules, Inc., in *Magie Oil
535. *Iovite 3-105 is an example of a rosin modified alkyd
suitable for use as a modifying varnish. This alkyd comprises
70% polyester resin, 30% tall oil and 0.03% aluminum isopropylate
cut to 60% solids with *Magie 535. The phenolic oleoresinous
gel is a heat-set phenolic resin, as described above, gelled
with a gelling agent, generally an aluminum complex such as
aluminum isopropylate. A number of these gels are commercially
available such as *LV-322 of Lawter Chemicals Company. *Lawter
931 is a suitable modifying varnish for use in combination with a
*Iovite 3-236 vehicle. *Lawter 931 is a low structure modified
pentaerithritol ester in alkyd comprising 67% solids in
*Magie 470; it has a tack of 20 at 400 RPM. Hydrocarbon resins,
such as *Nevchem 140 of Nevill Chemicals, melting above about
140C. (Ball and Ring) are suitable. Resin solutions containing
about 60% resin solids in a solvent such as *Magie 535 are ;
particularly suitable.
The flow control additives of this invention used with
both the sheet-fed and heat-set ink systems are, advantageously,
polysiloxanes, e.g., essentially linear polysiloxanes, having
chemically reactive radicals which polysiloxanes are chemically-,
or physically-, combined with organic surfactants, preferably
polyether surfactants. The polysiloxanes generally have a
viscosity ranging from about 25 to 150 centistokes at 25C. and
the chemically reactive radicals are generally a chain-terminating
radical, e.g., radicals such as hydrogen; hydroxyl; -OR, where
R can be lower alkyl, e.g., methyl or ethyl, or aryl, e.g., phenyl;
or halogen, e.g., chloro; preferably hydroxyl or -OR radicals;
* Trade Mark
-20-
. .,' - .
~'73~
but most preferably, a hydroxyl radical. One group of such
polysiloxanes has the general formula
R ¦ R
7 _ o si __x
R R n
wherein X is the chemically reactive radical, R has the same
meaning as set forth in the previous sentence and different
R radicals can be the same or different, and n is from about
3 to 100. Preferably, R is methyl.
Polysiloxanes chemically-combined with surfactants
include silicone polymers, e.g., resins including silicone
block copolymers such as silicone alkylene block copolymers,
silicone phenyl block copolymers, silicone chlorophenyl block
copolymers and, preferably, silicone alkylene oxide block -
copolymers, which can contain differing polyalkylene oxide
units, e.g., the alkylene oxide units including those having 2
; to 4 carbon atoms, and further, the differing units can be
connected by a suitable connecting (linking) organic functional
group, e.g., carboxyl, alkylene, amine, ester or ether group.
The preferred include silicone-polyether copolymers, e.g.,
silicone-ethylene oxide, silicone-propylene oxide, and silicone-
ethylene oxide-propylene oxide copolymers. They can be terminated
with an end-blocking radical, such as, for instance, a hydroxyl
or a lower alkoxy, e.g., butoxy, radical.
It is convenient and advantageous to add these flow
control materials (additives) as a 10 to 60% by weight solution
in a hydrocarbon, preferably aromatic, solvent, e.g., xylene
or toluene. These materials function to change the surface
energy of the ink as well as increase the viscosity.
; 30 A chemically-, or physically-, combined group of
-21-
~ 3~
preferred polyethers include polypropylene oxide polyethers
and polyethylene oxide-polypropylene oxide polyethers having
a wt. ratio of C2 to C3 ranging generally from about 1:1 to 1:12,
preferably from about 1:1.2 to 1:10. A particular material
suitable for use is S-30 of Union Carbide which is a silicone-
polyether combination containing about 20 wt. percent dimethyl
polysiloxane component and substantially the balance polypropylene
oxide component, incorporated as a 12 wt. percent solution in
xylene.
Another material suitable for use is DC-ll of Dow
Corning which is a toluene solution of a silicone-polyether
combination containing ethylene oxide and propylene oxide units
in a wt. ratio of C2 to C3 of about 43:57. Another example of
such a silicone-polyether has the structure
CH3Si ~ [Si(CH3)2]7_l2 (C3H6)10-15 4 9] 3
An amount of the flow control additive is used which
is sufficient to increase the toning temperature of the ink to
a temperature at which the toning does not occur in the printing
operation. The minimum amount of addition is that required to
provide an ink which does not become Newtonian, i.e., reach its
toning temperature, at temperatures at or below the printing
plate temperature. Preferably, the toning temperature is at
least 5F. above the expected plate temperature. Since plate
temperatures of 90F. to 125F., or higher, are to be expected
in Driography, inks having toning temperatures of 85 to 125F.,
preferably 140F., are desired. Obviously, for operations during
the winter and in air-conditioned facilities, a lower toning
temperature can be tolerated than during the summer, or in non-air-
` conditioned facilities. In general, the flow control additive
will comprise about 0.25 to 1.5%, or 2% by weight of the ink.
The amount of flow control additive preferably used is about
0.50 to 1%, by weight of the ink. A higher amount has no
apparent increased effect, although it does not hurt the ink
-22-
10~3S74
unless the amount added begins to act as a dll~ent and
reduce~ the effectiveness of the overall lnk system.
Complexing or che~cal-gelllng agents suitable ~or use
in this invention to chemically gell the preferred basic
vehlcle include metallo-organo chelating compounds, e.g.,
the alumlnum alkyoxylates such as the commercially available
methoxylated, ethoxylated and butoxylated aluminum derivatives.
Aluminum octoate can be used. Aluminum isopropoxide is
particularly suttable. The complexing agent is rap~dly and
thoroughly dispersed in the basic vehicle system under heat,
e.g., 350 to 450F., in an amount sufficient to produce the
desired increased viscosity. Amounts of about 1 to 5% by
weight of the basic vehicle, preferably a~out 1 to 3%, are
suitable. If desired, dispersion of the complexing agent
can be alded by incorporating it in the vehicle using a
carrier such as the ~olvent in the vehicle. In contrast to
use of a gellir.g agent ln the non-gelled basic ~rehicle nk
system, the complexing agent complexes the resin in the
; vehlcle rather than physically gelling the ink system.
A polyamide, as described above, can also be used with
the complexing agent to increase the viscosity of the ink
prepared from a gelled basic vehicle. Its action is a
physical effect and the polyamide is added in an amount
effective to increase the viscosity the desired amount. In
general, the polyamide is used in amounts of about 1 to 3%
by weight of the basic vehicle. The use of about 2% poly-
amide with an ink system having a viscosity of about 300
poise at 40~. will increase the viscosity to about 450
poise.
Physical-gelling agents for thermally stab~lizing the
inks of this lnvention prepared from non-gelled vehicles
include clay gellants such as montmorillonlte clay gellants
- 2 3 -
... .
and *Bentone 38 gellant, an organically modified montmorillon-
ite; fumed silica gellants, particularly the fumed, colloidal,
amorphous silica gellants having particles of submicroscopic
size, i.e., surface area of 200 to 400 square meters per
gram, such as *Cab-O-Sil M-5 and M-7 which are made by vapor
phase hydrolysis of silicon tetrachloride; and aluminum
gelling agents such as aluminum stearate or aluminum isopro-
pylate. The gelling agent is added in an amount sufficient
to provide the ink with the desired thermal stability, i.e.,
with a toning temperature above that desired, and in the
range of 85F. to 125F., or 140F., or higher. If too much
gelling agent is included in the ink, however, the viscosity
of the ink will be increased too much, i.e., to above 700
poise at 70F., and the ink will not move through the press.
If too little gelling agent is used, it has no effect on the
ink. Approximately 1 to 4%, preferably 1 to 2% by weight,
of the ink will generally be gelling agent.
A consequence of obtaining the high viscosity of the
inks of this invention, however, is that the ink also has a
high tack. The high tack of both the sheet-fed and web ink
systems is masked by the addition of an organo-silicone oil
which lowers the surface energy of the ink but also masks
the tack. An effective tack masking, organo-silicone oil in
effective amounts is used, frequently and advantageously in
combination with solvent, e.g., a gelled solvent, hydrocarbon
solvent or vegetable oil. If, however, too much of this
tack masking agent is included in the ink, syneresis will
occur and the ink will not transfer through the roller train
and to the printing plate. In general, approximately 0.5 to
2% by weight, preferably about 1 to 2%, of the tack masking
agent is used in the inks of this invention. Low molecular
weight, low viscosity, dimethyl polysiloxanes, i.e., of 10
* Trade Mark
-24-
.
- : . . .. .. . . .
~LO'~35~4
.
to 100 centistokes, have been used in Priographic inks
heretofore to achieve image/non-image contrast, but up ~o
now larger amounts, e.g., orer 5% b~ weight, have been
necessary and have given side effects such as syneresis both
in the stressed and unstressed state. This manifests itself~
with respect to the ink, in a fallure o~ the ink to transfer
through the roller train an~ refusal to trap on overprinting.
By using smaller amounts, generally below 2% by weight, of a
higher molecular weight and viscosity dimethyl polysiloxane,
which is compatible in the inks of thls invention, these
side effects do not occur.
Organo-si'~cone oils usable as tack maskers in the
novel inks of the present invention are water-insoluble,
substantlally non-volatile, liquid polysiloxanes having a
viscosity greater than 200 centistokes at 25C. and any of
the commonly known compounds of this type which are compatible
with, nGt deleteriGus to, and provide tack-maskirlg propeities
in~ the novel inks can be used. Essentially linear polysiloxanes
whereln the organic radical is a low molecular weight aliphatic
group, e.g., lower alkyl such as methyl or ethyl, or wherein
a high percentage of low molecular weight aliphatic groups
are present, are preferred. The particularly preferred
polysiloxanes are end-blocked with chemically non-reactive
radicals, ~or instance, with organic radicals such as trialkyl~
e.g., trimethyl, radicals. Others include aryl, e.g.,
phenyl and substituted (e.g., chloro-substituted) phenyls,
and alkyl-aryl, e.g., methyl-phenyl, sillcone oils. The
organo-silicone oils employed ~enerally have a viscosity
~ ~ro~ abDut 200 to 600, preferably 200 to 500, centlstokes at
3 25C. ~n inter~ediate molecular weight, intermediate viscosity,
dimethylpolysiloxane is particularly preferred. The materials
sold by Unlon Carbide as L-45 silicone fluids and Dow Corning
. .
-25-
.. . .. . . . .......... . .
. ...
3~
*DC-200 are suitable for use in the present in~ention. These
materials are available in a range of standard viscosities.
A material with a viscosity of about 350 centistokes, or
slightly higher, e.g., up to about 500 centistokes as measured
on a U-tube capillary viscometer, is particularly appropriate.
A gelled basic vehicle is preferred because the tack of the
ink system prepared from this vehicle is generally less than
the tack of an ink system prepared from the non gelled
vehicle.
The tack is also advantageously controlled by the
inclusion of a tack reducer such as a solvent, e.g., *Magie
470 oil, *Magie 500 oil, gelled *Magie 470, etc. Vegetable -
oil, e.g., tung oil, or a very low viscosity, long oil linseed
alkyd, such as *Lawter Solvar, are suitable tack reducers for
use in a sheet-fed system. Amounts from about 5 to 10~,
preferably 5 to 8% by weight of the ink are typical for the
tack reducer. The linseed alkyd will generally have a
viscosity of 0.75 to 1 poise, or less. In general, it is
desired that the tack of the ink be below about 20, preferably
below 16, as measured on an Inkometer at 1200 RPM and 90F.
over 1 minute and the tack masking agent and tack reducer
are advantageously added in combination in amounts selected
to reduce the tack and meet this objective. For instance,
the use of tack reducers generally involve a solvent-type
action which, while reducing tack, also tend to reduce
viscosity, and the tack masker, a non-solvent type, effects
a lowering of tack without deleteriously reducing viscosity.
Accordingly, the combination is particularly advantageous in
lowering tack with a minimum, if any, lowering of viscosity.
Additives which are added to the basic vehicle system,
conventional in the art, include wax compounds, driers, and
anti-oxidants. The wax compound, or combinations of wax
* Trade Mark
-26- -
~ 3~
compounds, provide slip and rub resistance. Printing ink
grade polyethylene such as *AC-6 of Allied Chemicals Co., or
*Epolene N-10 of Eastman Chemical Co. and waxes commercially
available may be used in the present invention. The polyethylene
wax is of a low density, medium crystallinity and the form
sold as a dispersion, such as *Iovite XP107 or *Lawter 697, in
an alkyd resin is suitable for use in a sheet-fed ink whereas
the form sold in 440 *Magie oil is suitable for use in a
heat-set ink system. The Fisher Tropsch (FT) waxes, generally
available in aliphatic hydrocarbon solvents, such as *Texolon
of Lawter Chemicals Company, are also suitable. Generally,
less than about 10~ by weight, preferably less than about 8%
of the wax compound is used in the ink because it reduces
the ink viscosity and gloss. The drier can be one of the
commercially available cobalt/manganese combinations. A
number of cobalt/manganese driers are commercially available
as cobalt/manganese linoleate, hexadeconate or octoate.
*Lin-all printing ink drier of Mooney Chemicals is a suitable
drier. *HEX-CEM lead-free drier of Mooney is also suitable.
Any conventional antioxidant that will not react in the ink
system may be used. Specific examples would include the
commercially available butylated hydroxy toluene, *Eugenol,
and *Bartyl. Also, greases can be used to improve transfer
of the ink through the press. Orange solid oil, a common
printing ink grease, is suitable.
Typical ink formulations in accordance with this inven-
tion using an organic pigment would be as follows (percent
by weight);
* Trade Mark
~735~4
Ge~eral Pre~erre~
.
organic
pigment10-18p 10~18% 12-18% 12-18%
non-gelled
vehicle25-60% -- 35-50% --
gelled
vehicle -- 40_55% __ 45 50%
modifying
- varnish3-35% 5-25% 3-20% 5-20%
gelling
agent 1-4% -- 1-2% --
wax
compound5-10% 5-10% 5-8% 5-8%
reducer5-10% 4-10% 5-8% 4-8%
flow con-
trol a~ent
(50% s~lu-
tion) 0. 5-3% 0.5-3% 1-2% 1-2%
tack mask-
ing agent0. 5-2% 0.5-2% 1-2% 1-2%
drier 0.5-2.5% 0.5-2.5% 0.5-1.5% 0.5-1.5%
antioxl-
dant 0. 25-0.5~ 0.25-0.5% 0.25-0.5~ 0.5-1.5
grease o-3% o-3% 0-3% o-3%
solvent o-4% 0-4% 0-4% o-4%
.~ When a-black pigment is used, a blue toner is desirable and
it replaces a portion ol the vehicle. Also, in using a
pigment flush, a substantial portion of the vehicle is first
used to prepare this dispersion. Furthermore, formulations
using inorganic pigments, because o~ their high specific
gravity, will be used at higher pigment loadings with the
neces~ary reductlon in vehicle component. The use of grease
and solvent ls particularly desirab~e ln a heat-set ink
system and with such a system the drier and antioxidant may ! -
be omitted ~n m~ny applications.
The invention may be further ll].ustrated by the foll~owing L
examples: I
-28-
f
~L0735
EX PLE I
The following materials were used in the ~e~uislte
amounts by weig~t to produce inks of the colors described in
Table I. Materials 7 to ~0 were separately weighed and
mixed. Materials 1 to 6 were weighed and milled. The two
parts were combined and giVen a canning pass. The ink had a
uni~orm consistency and a particle size of less than 2 as
measured by NPIRI Grindometer. The viscosities were 800 to
900 polse at 70F. as measured by Laray viscometer.
-29-
'
10~357~
~* .. ...
o o o o o o ~ o o ~ o
. . . . . . . . . .
m ~ ~ , O
~ ~ ~ ~ O
~_
~ OC> O O OU~ O O L~ o
m . . . . ,. . . . .
CO ~ ~ ~ ~~U O O
O
~> ~
~_
a) o o o o ou~ ~ o ~ o
. . . . I . . . . . .-
~ ~o : O
_. Ln ~I ~, O
~ : ~ . .
., ~ .
H
.~ ~ ~1 ~
.
,_1 o o o o o In o o In o
a~ . . . . . . . . .
~( ~ J a~ ~ N C`J O O
~ 1~ r~l
.
~_
O
t~ ~ q) ~ o a>~t~ x
h J~ ~ Qo 1::
o ~ a~ o co ,~ s~ Q)
O ~ ~ X
O O ~--H a~ ~I D rl OlSe a~ ,C Q
H H H ~ :1 O h ~ h 00
O .~: ~ U ~ C~
C~ rl ~ P~ ~ ~1 ~ O O h 8 ~1 ~
O ~ -
'` O
V H
3 0
. ;
* ~ ~3
H ~. n
(D ~D ~ O ~ ~ r~
~D
* ~ ~ pJ ~ (D ~
o Pl ~3~
a~ ~
~n
o
o
o (D It 1
~ W
o ~ 3 ~ *
~D * ~ o ~ o
~s u~ I' ~ I
W H~
3 o~ I o~
~ o ~ o
~
(D ~3 `~(3D ~ ~
3 n ~ ~. t~
~ rD ~ n _ H
~ rt It 3 K~ _
O ~ . ~ o
I Z
~3
~ 3 X ~ 1
1--3 pl t~)
(1) 1~.
U~ ~
~n O
~ ~,
g '~
~,' ~ .
~ . .
W
O
. ~ .
.' ~ ''~
--31--
- :. . . - - . ~ .. , . :.
1~35~
The ink w~s run with 3M driographlc plates, de~cribed
- in U. S. Patent No. 3,511~178, supra, in a Driography process
using a 4 color, sheet-~ed 38 lnch, Miller press. No toning
occurred durlng the printing run. An infrared sensor was
used to monitor press temperatures. Running temperatures of
the press were deter~ined to be black, 91F.; yellow, 90F.;
red, 100F.; and blue, 91~ to 94~F. No toning occurred.
The black was subsequently found to ha~e a toning temperature
o~ 97F. on a dif~erent press. The drying and skinning
rates were 4 hours on an open press. The tack equates with
the wet offset process~
Acceptable color copies were made with a composite form
with 5 varied process sub~ects, standard GATF color bars and
stars on center sheet, full GAT~ color blocks, a set o~
multi-screen, multi blocks and a set of 0-100/single screen
bars. Four papers were used: Mountie offset smooth 80#,
Mountle Vellum, Shasta suede and letterpress gloss coated.
The 3equence of printing was blue, red, yelloti and black.
The setting rate and drying speed o~ the pa~er were:
Setting Drying
Mountie offset smooth; some setoff, overnight
Mountie vellum, slower t~lan
conventional
Shasta suede, equal to 4-6 hours
Letterpress gloss coated, con~entional
Trapping was good on all colors and the print quality
and lay were acceptable. The rub resistance was acceptable.
~;XAMPLE II
Four inks were r-m in a Driography process using a 4
color, sheet-fed 38 inch ~arris press. The plates consisted
of boolc covers printed on Kromecote and ~allantine coated
coverstocks. Table II sets ~orth the requisite amounts by
weight o~ materials used to formulate the inks. Acceptable
- . c
~ 35~
COp~2S were made wit~ all colors. T~e setting rate was
instantaneous on the Xromecote and good on the B~llantine
coverstock. The drying speed was 2 to 4 hours and sklnning
rate 2 to 4 hours (blue 2). Trapplng was good an~ prlnt
quality and lay were acceptable. The black gave some mottle.
All covers spirit lacquered witho~t problem. The plate
temperatures when running these lnks were:
yellow 97F.
red 98F.
blue 98F.
black 90F.
-33-
iO735~
o o o o o o U~ o C .f~ I ~
. ~ . . . . . , . . . . .
r1 ~r.-l rt N rt O O
~1
~ IQ O O O O OIS`~ Jt-- O
rt , , ~ . . I. . . . .
m rt ~ 1' S S I00r~ N O O O
~cs I O O c~ o o o u~ o o1~ asc
., . . . . I . . .
p:; N S S :~ ~ It~r-l N r-l O O
H If~r.{ r.~ ~ O
H . r-l
a:
E~ ~ ~ In 1
O Il~ O O O O O 11~ 0 ~J ~ O
r-l . . . I
rt ::t r~ H N O O r-l
U~
bD ~ O ~--' * O
~ _~.,!$ O * ~
rl r~ ~ Ul a) ~)r~l
O O J~
r-lr~l ~ C) O ~ ~'` ~
~ ~ ~rl S d ~~1~ r~l
Nl~)h ~rl bD r~l hX--' rtrt
p~ o 6 - X ~C
ID11) ~ ~ X p~ D ~ ,~ O r-l
~ ~I ~ D ~ O~rt ~ ~ O h
rl ~ 3 ~ O c
O O ~ Z a~ q o~ ,~
H H~ C) C.) X ~ O~rl h 0 a
_r-l ~a 0 ~ H C2, ~~. u~
tc .or~ N a) .
(I) SS h ~ ~ ~ rl~ au O
r-l tq~ bO-rl E~ rl O S
~C) ~a) ~ ~ o H J~ h ~D r-l a
h Q~ O r1 E~ cdbD a~ o :~ q3 ~
O h S h ~ H l*.~ O ~ J ~ X
O ~ _ o o ~-1 r-l ~ ~I tYt r-l h
H
..
: ~, 34
: ~ -
: ' ` ~ ` :
10~3S~
N
N
N
N
~_ ~
,~
V
N
H N
H H
N
H
~t .
. H H
. a~
E-l E~
. ~ ,
* a~
v~
e~ '*
Cd* *
: E~* * * :
. ` . . _. .
-~ 2 e~ . -
V ~J .
; . . . .
0~3~
EXAMPLE III
An ink of the following for~ulation wa~ prepared: -
TA~LE III
Vehicle (Iovite 2-1~8) 1l~.o%*
Varnish 13.5
Polyethylene - printing 4.0
ink grade 45~ in alkyd
(Iovite CN-56M~
40% FT Wax in Magie 500 4.Q
Oil CLawter LV-1405~
Pigment l6.0
Alkali blue toner lO.~
Gelling agent l.O*
~, Tung oil 7.o
Dimethylpolysiloxane l.5
(L-45, 350 centistokes)
Flow Control Additive** 2.0
Drier (2.8% cobalt, 3.0%0.5
manganese)
Butylated hydroxy toluene 0.5
extended in alkyd
:
* The amount of gelling agent was varied and the amount of
Vehicle ad~usted when more, or less, than 1% gelling agent
was used.
** Same as Example I.
The plgment was furnace black. The modifying varnish was
cyclised rubber, Alpex ~8415, added as a solution in Magie
470 oil which contained 53% solids. Two gelling agents,
Bentone 38 and Cab-Q-Sil ~-5, were used to prepare a number
o~ inks and the inks were successfully printed using the
Priography process in a sheet-~ed syste~. T~ble IV sets
forth the amount of gelling ~gent used in the inks together
with the toning temperature and tack Or the ink. The viscosity
,
-36-
- '
~ 3C~
of the inks were 1000 to 1100 poise at 70F.
TABLE IV
Gelling Agent Bentone 38 Cab-O-Sil M-5
1/2% 1% 1 1/2% 2% 1% 2% 3%
Toning (F.) 105 115 104 108100 110 108
Tack* 20.2 21.2 6.6 15.221.8 21.4 17.9
* See Table I
Additional inks containing, respectively, 1~ Bentone 38 and
2% Cab-O-Sil M-5 were prepared substituting for the black
pigment and blue toner, 16% of a pigment listed in Table I
and 10% vehicle. The toning temperature and tack of these
inks were:
Bentone 38 Cab-O-Sil M-5
Toning (F.) TackToning (F.) Tack
Yellow107 20.5 107 22
Red 104 17.5-20.5 101 15.8-20
Blue 98 21.4 96 21.7
EXAMPLE IV
A blue ink was prepared as described in Example I as
follows:
Vehicle (Iovite 2-108)36% (by weight)
Varnish (Iovite 3-105) 36
Polyethylene (Iovite CN-56M) 5
Phthalocyanine Blue GS10
Tung oil 7
S-30 3 ~-
L-45 (350 centistokes)
Drier (2.8% cobalt/3.0%
manganese) 2
100%
:
-37-
~ ~,
~0'~3S~
This ink printed successfully in a sheet-~ed system and ~ad
a tonlng temperature of 121F. T~e tack ~as 2I-22 on ~he
Inkometer at 1200 RPM and 90F. over l minute and the ~ls-
cosity was about lO00 at 70~.
EXAMPLE V
The ink of Ex&mple III, replacing the gelling agent
with additional vehicle successfully printed and had a
toning temperature o~ 85F.
~XAMPLE VI
Inks having the formulae set forth in Table V in percent
by weight were prepared and successfully used in sheet-fed
press runs using the Driographic plate and process. The
viscosity, tack and toning temperature are stated. The
toning temperature is the plate surface temperature measured
by a contact pyrometer. The press was a water-cooled
temperature-controlled ATF Chief press.
The modifying varnish was a solution comprising 52%
Alp~x C8415 cyclised rubber, 2% Tridecanol and 46% Magie
470. ~The basic vehicle was the same except that in one
vehicle 1.5% polyamide (Versamid 2950) was added after
~elling. The basic vehicle comprised 16 to 20% bodied
linseed oil, 11 to 15.5% long oil linseed alkyd, 32.5 to
37~5% bisphenol modified rosin ester, 29 to 33% Magie 535
oil gelled with about 1% aluminum isopropoxide and l to 3%
aluminum octoate at 350 to 450~F.
.
-3~-
. .
iO~3574
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- .~0~.~357~
EXAMPLE VII
Inks were prepared acco.ding to the ~ormulae o~ Table
VI in percent by weight and successf~lly printed in a sheet-
fed system. The basic vehicle w~s the same as Example VI
except that the gel.ing was accomplished wlth about 1 to 2%
aluminum isopropoxide at 350 to 450F. and no polyamide was
included. The modi~ying varnish was the sa~e as i~ Example
V~. :
~-
.
- ,
5~
TABLE VI
Red Blue Yellow Black
Bas~c vehicle 53.25 53.25 49.25 42.00
Modify~ng
varnish 10.00 14.00 14.00 12.00
#6 linseed
alkyd (Modifying
Varnish) 6.00 3.00 7.00 5.00
Polyethylene
wax (LV563) 8.00 8.00 8.oo 8.00
Solvent (gelled
Magie 470) 2.00 1.00 3.00 __
Dry yellow ~ 14.00 --
Dry red 16.00 -- -- --
Dry blue -- 16.00 -- --
Dry black -- -- -- 18.00
Blue toner
base -- -- -- 10.00
Dimethyl-
arl~
(L45) 1.00 1.00 1.00 1.00
i ' 20 Flow control
additlve (same
as Example VI)2.00 2.00 2.00 2.00
Butylated
hydroxytoluene0.50 0.50 0.50 0.50
Drier (2.8% Co,
3 Mn) 0.75 0.75 0.75 1.00
Mn ~eeder drier
(hexcemLFD) 0.50 0.50 0.50 0.50
Viscosity (p)* 350 345 431 352
i 30 Tack (IR + 0.5)16.00 16.00 14.50 18.50
Toning temper-
ature (F.) 115 114 114 110
~ ~ At 40C. Haake PK II
.
.
.' ~,
-~l2-
.
iot~357~
- EXAMPLE VIII
50 lbs. of each lnk formula set forth in Table VII in
percent by weIght were made and printed in a sheet-fed
Miller 38 inch system. No problems in running, drying or
back-up were experienced in a 37,000 copy run in four colors.
The color pigments used were prepared from pigment flushes
using a vehicle comprising equal parts of Iovite 2-108, I-
110 and I-102. The pigments were:
% Pigment in
Pigment Pigment Flush
yellow AAA diarylide 30
red lithol rubine 36
blue phthalo blue GS 33
The remaining 0.250 percent of the yellow ink was an orange
base used to adj~st the color.
Runs of 6,000 to 67,000 impressions were also successfully
made with inks of t~e formulae set forth in Table VII using
a four-color Harris 38 inch system.
3-
.. , .. ....... , , . - . . . . . ............. - . - - ~ . . - .. - -
..... . . . . , .. - ~ . .: . ~ . . .
TABLE VII
Color Yellow Red B _Black
Iovite XP585 33.5 33.5 35.542.5
Modifying Varnish
(same as Example
VI) 5.0 5.0 5.06.0
Modifying Varnish
(Iovite I~112) ~ -- 6.0
Polyethylene Wax
(Lawter LV563) 6.0 8.0 6.08.0
Pigment base 46.0 46.0 46.0 --
Furnace black -- -- --16.0
Blue toner -- -- --10.0
FT Wax (Lawter
FT300) 2.0 2.0 2.02.0
Dimethylpoly-
siloxane (L45) 1.0 1.0 1.01.0
Flow Control
Additive (DCll, 27%
in toluene 2.0 2.0 2.02.0
Orange Solid Oil
(Famous Lubricants,
l-S) 2.0 -- -- 4.0
Drier (HEX-CEM LFD) 0.5 0.5 0.5 0.5
Butylated hydroxy-
toluene 0.5 0.5 0.50.5
Drier (2.8% Co,
3% Mn) 1.5 1.5 1.51.5
Viscosity (p)* 300 325 305346
Tack (IR 0.5 at
800 RPM) 16.0 17.5 15.716.5
Toning Temp. (F.) 112 110 107 100
* at 40C.
-44-
.~'~
- : . . :.: - . ~ . -
. .
0'~3574
EXAMPLE IX
Inks o~ the f~rmulae set ~orth ln Table VIII ln perce~t
by weight were successfully printed ln a heat-set press, -~
Hantscho MKII blanket to blanket press in which the compres-
sible bIankets were replaced with a ~oft top conventlonal
type. The drying was at 675 FPM at 425F. ln an Offenaire
drler.
The pigment flushes used were:
% Plgment
Pi~ment Vehicle in FIush
yeIlow AAA diarylide 53% Pentalyn K . 28
in Magie 500.
Oil
red lithol rubine 53% Pentalyn K 33
in Magie 535
0~1
blue phthalo blue 53~ Pentalyn K 33
GS in Magie 500
011
.:. .. , . .. , -,
-4~-
~0~3574
T~BLE VIII
Colo~ Yellow Red Blue Bl~ck
Vehicle (Iovite
3-236) 28.5 30.25 35.2533.25
Modlfying Varnish
(Lawter 931) 10.0 8.o 5.0 27.0
Polyethylene Wax
(Iovite XP107) 6.0 6.o 6.o 6.0
FT Wax (Lawter
LV1405)* 4.0 4.0 2.0**2.0**
Pigment 46.0 46.0 46.0 16.0
Blue toner -- -- -- 8.o
Dimethyl Polysiloxane
(L45) 1.0 1.0 1.0 1.0
Flow Control Additive
(DCll) 2.0 2.0 2.0 2.0
Orange Solid Oil (l-S) 2.0 2.0 2.0 2.0
Drier (2.8% Co, 3% Mn) 0.5 0.5 0.5 0.5
Butylated hydroxy
toluene 0.250 0.25 0.250.25
301verl~*** -- -- -- 2.û
Viscosity ~p~*** 120-140 120-1~0 130-150130-150
Tack (IR - 0.5) 17.5 15.5 17.5 16.0
* Lawter LV1405
** Lawter Texalon
; *** Magie 500
**** at 40~-
EXAMPLE X
The ink is essentially the same as the ink set rorth in
.~ Example I, except that instead of the flow control additive
set forth in Example I, the flow control additive ls composed
of a polysiloxane of the formula
-46-
-. . . . .. . . .. ...
35~
IH3 CH3
: CH3 S.i - _ o Si -
CH3 CH3 - n
where X is hydroxyl and n is 50, and the polysiloxane is
physically combined with a polyether having a wt. ratio of .
ethylene oxide to propylene oxide units of about 1:9.
EX~PLE XI
The ink is essentially the same as the ink of Example X
except that the polysiloxane is chemically combined with a
polyether having a wt. ratio of ethylene oxide to propylene
oxide units of about 1:1.4. :
EXAMPLES XII - XVI
The inks are essentially the same as the ink of Example
XI except that the chemically reactive group (X) of the
polysiloxane is as indicated for the respective example:
Example
XII hydrogen
~ XIII -O methyl
I XIV -O phenyl
XV chloro
XVI -O butyl
Planographic printing plates particularly suitable for
use with the novel inks of the present invention include
those described in U.S. Patent No. 3,511,178, supra.
They include those which are imaged with an image which is
oleophilic and oleo ink-receptive when dry, and when so
imaged, and in the absence of dampening, suitable for accepting ~-.
oleo-ink only in the image areas and printing therefrom, while
rejecting the oleo ink in the non-image areas, comprising a
backing having bonded thereover a highly adhesive layer adapted
to form the
: . ~
~ -47-
:
i~35~4
non-image areas which is oleo ink repellent when dry, chara,c-
terized b~ an adhesive release value when dry of less than
about 100 grams per inch. The plate can be pre-sensltized
and capable of being imaged by light exposure through a
photographic transparency and development.
The abheslve layer can co~prise a cured, solid, essentially
linear elastomeric organopolysiloxane, for instance, one
having a ratio of organo gro~ps to silicone a~oms of about
1.95 to 2.1.
A light-sensitive material having one solubility state
in r~lation to aqueous media before exposure to light and
another solubility state, in relation to aqueous media after
exposure to light and bei.ng soluble in one of said states
and insoluble in its other state, can be placed over and in
contact with the backing with the highly abhesive layer
overlying the light-sensitive material and being firmly
bonded to the underlying layer wher~ the latter is in its
in~oluble state.
The light-sensitive material is a light-sensitive diazo
resin characterized in being water-solub].e in lts light-
sensltive state, and becoming water-insoluble in its light-
exposed state. It can be an lnsoluble light-sensitive poly-
complex oxygenated anion diazonium salt characterized in
that it is insoluble prior to light exposure, and upon light
exposure ls decomposed and readily washed away. An in situ
~ormed decomposed diazo primer can be interposed between the
light-sensitive material and the overlying highly abhesive
surface layer.
An imaged planographic printing plate suitable for
3 printing in the absence of dampenlng, and upon being rolled
with oleo-ink on a prlnting press, of acceptlng said ink
only in the image areas and printing therefrom, while reJecting
-48-
10~3~4
the ink ln the non-image areas, can adv~n~a~eous~y. ~omprlse .
a backing ha~ing thereover an essentially planar surface, .
the portion of sald surface in the image areas being oleophilic
and oleo ink-receptive when dry, the non-image portions of
said surface be~ng highly abhesive and oleo ink repellent
when dry. The non-image portlons can comprise ~ cured,
solld, llnear sllicone elastomer characterized by an adhesive .
release value when dry of less than about 100 grams per inch
and the image areas can comprise a radiation modified,
cured, solid silicone elastomer having an adhesive release
value when dry greater than about 100 grams per inch.
_1~9_
