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Description  |
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FIELD OF INVENTION
This invention relates to non-pigmented jet ink compositions that dry
opaque, particularly to compositions that dry opaque white, or opaque
yellow, and to their application onto non-porous substrates. The ink
compositions, which are suitable for use in high speed jet ink printing
systems, contain a cellulose ester film former and a resin binder in a
solvent blend. It is believed that the resulting film, obtained upon
evaporation of the solvent blend, has a reticulated structure containing a
multiplicity of microvoids, the microvoids scattering light incident
thereupon, whereby the white opaque image is produced.
BACKGROUND OF THE INVENTION
Jet ink printing systems discharge discrete droplets of ink through a fine
jet nozzle to the substrate. In this method of printing, unlike letter
press, gravure, silk screen and comparable printing techniques, there is
no contact between the printer and article to be printed. The ink droplets
have a defined resistivity so that they can be deflected by an electric
field when discharged from the nozzle. The jet ink printing system is of
considerable importance in applying decorative and identifying indicia to
a variety of substrates, including glass, metal and synthetic polymeric
surfaces. U.S. Pat. Nos. 3,465,350 and 3,465,351 are exemplary of these
systems.
Ink to be used with jet printing means have specific viscosity and
resistivity limitations, should provide good wettability of the substrate,
and must be quick drying and smear resistant. Further, the ink must be
compatible both with the jet printing equipment and in the eventual end
use application. With regard to the former it is critical that the ink
flow through the fine jet nozzles without clogging same.
Typically, jet inks consist of three basic components--a colorant such as a
dye or pigment; a resin binding agent which serves to secure or adhere the
colorant to the substrate surface, and a carrier fluid or solvent for the
colorant or binding agent, the carrier fluid evaporating upon application
of the ink. In jet printing inks, an electrolyte is often employed to
ensure that the droplets can be adequately charged whereby proper
deflection is achieved. U.S. Pat. No. 4,021,252 issued to Banczak et al is
representative of this genre of jet printing inks. Banczak uses from one
to 25% by weight shellac as the binding agent, between 0.5 and 5% by
weight of a basic dye as the colorant, and a solvent blend consisting of
water and alcohol. Optionally the solvent blend may be modified by the
addition of a glycol ether to solubilize colorants of limited solubility.
Other prior art patents reflective of the Banczak approach are listed
below, some of which are for specific end use applications:
______________________________________
U.S. Pat. No.
4,024,096 Wachtel
4,070,322 Hwang et al
4,155,767 Specht et al
4,155,895 Rohowetz et al
4,168,254 Fell
4,168,662 Fell
4,177,075 Mansukhani
4,186,020 Wachtel
4,196,006 Mansukhani
4,196,007 Mansukhani
German Offenlegungsschrift
28 12 364 M & T Chemicals
(Published
October 1978)
______________________________________
To produce an opaque white image utilizing the ink formulations of the
above identified prior art references, it would be necessary to use a
pigment such as rutile titanium dioxide. However, this opacifying agent is
present in the solvent as a dispersed solid, and tends to settle out of
solution thereby clogging the jet nozzle. This drawback is even more
pronounced in low viscosity jet inks which are preferred. Other
disadvantages of conventional pigmented inks are that they usually require
curing at elevated temperatures, and/or have extended drying times. The
goal of the present invention, then, is to provide non-pigmented jet inks
that produce opaque white images on non-porous substrates, and which can
be applied to said substrates in a single operating step.
As is well known in the art, a solution of certain compounds, particularly
the cellulose esters, when applied to a surface will dry opaque white. See
generally, Jerome Seiner, Microvoids As Pigments. A Review, Industrial and
Engineering Chemistry, Product Research & Development, Vol. 17, pp.
302-317 (Dec. 12, 1978) and J. J. Clancy, Microvoid Coatings in Graphic
Art Application. A Patent Survey, Industrial and Engineering Chemistry,
Product Research & Development, Vol. 13, No. 1, pp. 30-34 (March 1974). A
sampling of patents issued with respect to such compositions follows:
______________________________________
U.S. Pat. No.
1,449,157 Wilkie
2,296,337 Cummings
2,519,660 James
2,739,909 Rosenthal
2,927,039 Vander Weel
3,020,172 Mohnhaupt
3,031,328 Larsen
3,654,193 Seiner
3,655,591 Seiner
______________________________________
The above inventions are related to paints, paper coatings, and recording
materials.
More recently, U.S. Pat. No. 4,207,577 to Mansukhani applied this
technology to jet inks. The Mansukhani patent discloses a two-step
procedure for obtaining opacity, the second step being either an
adjustment of the temperature of the applied film to the ambient dew
point, or by applying moisture thereto. In an alternate embodiment a basic
dye is used in the ink formulation, the film then being moistened with
water. The method above is applied to a general ink composition consisting
of cellulose esters, binding agents and a solvent blend. The two step
approach of Mansukhani represents a serious limitation in the use of his
ink in certain applications. For example, some products are sensitive and
can not undergo the second "moisturing" step. Other products are humidity
sensitive. Similarly, printing on a hot surface will drive off the
solvents before the second step can be accomplished. Finally, the
Mansukhani method requires the addition of a second step treatment zone to
existing product conveying systems.
SUMMARY OF INVENTION
It is an object of this invention to provide improved non-pigmented jet ink
compositions, suitable for use with jet ink printing techniques, that
provide opaque films.
It is another object of this invention to provide improved non-pigmented
jet ink compositions that dry opaque white and which are suitable for use
on metal, glass and other non-porous substrates.
Yet another object of this invention is to provide a jet ink that dries
opaque white which has good stability and shelf life.
A related aspect of this invention is to provide a method for obtaining
substrates having identifying indicia, said indicia derived by application
of the jet ink compositions of the present invention by means of jet ink
printing techniques. In this regard, the indicia as applied to non-porous
substrates exhibit ready adhesion thereto, are abrasion and fade
resistent, and can withstand post application conditions of moisture and
elevated temperature.
It is a primary object of this invention to obtain substrates having said
identifying indicia by means of a one step method not involving a post
cure treatment of the film to render it opaque.
A further object of the invention is to provide a method for reconstituting
cycled ink used in the printing operation.
These and other objects of the invention will be better understood from a
reading of the detailed description of the invention, a summary of which
follows.
The jet ink formulations disclosed herein comprise a film forming cellulose
ester having a hydroxyl content between 2 to 8%, a resin binding agent,
and a solvent blend. Preferred cellulose esters are cellulose acetate
propionates, cellulose acetate butyrates and cellulose acetates, while the
binding agent may be selected from a wide range of alkali soluble resins
of the rosin ester and meleic types as well as polyvinyl acetate and
acrylic resins. The solvent blend consists essentially of at least one
volatile organic solvent within which the film forming cellulose ester is
soluble in combination with one or more non-solvents of reduced volatility
within which the film forming cellulose ester is essentially insoluble,
and which is miscible with the organic solvent. Volatile components of the
solvent blend comprise from about 70 to 90% by weight of the ink
composition, and are selected from the group consisting of aliphatic
alcohols of one to three carbon atoms, ketones of three to seven carbon
atoms, and acetates of four to seven carbon atoms. The non-solvent is
present in concentration from about 2 to 10% by weight of the ink
composition, the preferred non-solvent being water.
In use, the ink is fed from a supply reservoir to the nozzle of the jet
printing apparatus and then dispensed as a coded series of droplets onto
the substrate. Evaporation of the solvent blend from the droplets is
achieved rapidly, the indicia turning opaque thereupon. Because the amount
of ink actually printed is quite small, most printers transfer ink from
the supply reservoir in a larger, more controllable volume, apply only the
small quantity needed to the substrate, and send the excess to a return
tank. However, the entire flow of ink from the supply reservoir discharges
through the nozzle at atmospheric conditions, the resulting flash
vaporization causing a change in the cycled ink composition present in the
return tank. For this reason it is preferred to reconstitute the cycled
ink with make-up solution consisting essentially of the organic solvent,
but also including if necessary non-solvent and ink solids. The make-up
ink is formulated specifically to re-attain approximately the supply
reservoir composition for subsequent re-use of the cycled ink.
DETAILED DESCRIPTION OF THE INVENTION
The non-pigmented jet ink compositions of the present invention contain a
film forming cellulose ester, a resin binding agent and a solvent blend
therefor hereinafter described. The composition may optionally contain
other ink solids such as dyes, optical brighteners, surfactants,
hygroscopic salts, and electrolytes. As used herein, pigment and dyes
comprise the class of compounds defined as colorants. Pigments, generally
being insoluble, dry powders, are incompatible with the invention; dyes,
typically being soluble organic compounds, may be included to provide
enhanced visibility of the opaque image on a particular substrate.
Each of the primary constituents must be in proper proportion to achieve
both suitability for the jet ink printing apparatus and for coating a
particular substrate. To meet these use requirements, the following
standards should be attained:
(1) inks should dry essentially instantly or be smear resistant upon
application with subsequent complete drying in about 60 seconds,
preferably in less than 30 seconds, without a post cure;
(2) ink viscosity should be between from about 1.5 to about 25 centipoise,
preferably between 1.5 and 18 centipoise;
(3) indicia printed on glass must exhibit ready adhesion thereto, be
abrasion and fade resistant, and have the ability to withstand conditions
of moisture and elevated temperature encountered generally during
conventional pasteurization operations;
(4) as applied to metal or synthetic polymer coating surfaces, the indicia
must exhibit resistance to fading and be able to maintain adhesion under
pasteurization conditions when immersed in an aqueous solution for 15
minutes at 150.degree. F.;
(5) indicia printed on bottles must exhibit resistance to removal by
lubricant soaps conventionally used by commercial bottlers on conveying
lines, and
(6) inks should have a minimum shelf life of about one month.
Fade resistance as used herein means that indicia should remain opaque on
the substrate for a period of not less than three months. Shelf life is
defined as the ability of the ink itself to render opaque white films upon
use after storage at ambient conditions for no less than one month.
COMPONENTS OF THE COMPOSITION
Investigations into the many film formers, the large array of binding
agents, and the broad spectrum of solvent species and concentrations that
can be hypothecated by a reading of the prior art revealed that the
aforesaid properties of the ink, the characteristics of the indicia, and
the one-step approach to film formation could be achieved only with the
proper combination of compatible prime constituents. Thus, for example,
adhesion to the substrate was poor unless the proper resin were used. The
selection of resin, however, was a function of solvent blend employed and
film former chosen. The ability to form an opaque film was likewise
dependent on the compatibility of the constituents. Similarly, suitable
shelf life was obtained by using the appropriate solvent blend--film
former--resin ingredients.
The Film Former and Binding Agent
The film former used in the ink composition must be a cellulose ester whose
percent hydroxyl content ranges from between 2.0% to about 8.0%,
preferably between 4.0% to 6.0%. The ester is present in concentrations
from about 2.0 to 15.0% by weight of the composition, preferably from
between 3.0 to 10.0% by weight of the ink formula. It is critical that the
film former be gellable in the non-solvent as will be more extensively
described below. Hence, while the film former is soluble in the volatile
organic solvent constituents of the solvent blend, it is essentially
insoluble in the less volatile non-solvent. Furthermore, the ink system
should have a viscosity between 1.5 to 25 cp., preferably between 1.5 and
18 cp. at the ester concentrations stated above for use with jet printing
equipment. Preferred film formers are cellulose acetate propionate,
cellulose acetate butyrate, cellulose acetate and combinations of same,
each having a preferred hydroxyl content between 4.0 and 6.0% of the
ester, and are available commercially from Eastman Chemical Company.
The resin binding agent is used to improve the adhesion of the film to the
substrate. It is believed that the ester film has a planar structure
providing few sites for attachment to a surface. The binding agent
apparently provides molecular projections which attach to the substrate.
One class of appropriate binding agents are rosin based ester resins or
maleic resins soluble in the ink solvent system and also soluble in the
non-solvent. Dissolution of these resins in the non-solvent in many
instances is enhanced by a somewhat basic environment. Therefore, it is
often preferred to adjust the pH of the ink to between 8 and 9 when they
are used by the addition of an effective amount of dilute ammonium
hydroxide or the equivalent. Examples of such compounds are Alresat KM140,
a rosin modified maleic anhydride resin (American Hoescht); UniRez 757, a
maleic resin (Union Camp), and Filtrez 5001, a fumaric rosin based resin
(FRP Company).
Preferred binding agents that can be used are polyvinyl acetate resins,
acrylic type resins, and their copolymers. Commercially available resins
of this type are Synthacryl VSC 75/1, an acrylic resin (American Hoescht);
Gelva #264 and Gelva #V1 1/2, polyvinyl acetate resins (Monsanto), and
NS26-1314, a carboxylated polyvinyl acetate resin copolymer (National
Starch). As with the rosin and maleic resins, the preferred resins should
be soluble in the ink solvent, and should also be soluble in water or
dilute alkali solutions. In commercial form many of these binding agents
themselves are in solution, the solvents therefor necessarily being
compatible with the ink itself.
The binding agent is present in the ink composition in an amount between
1.5 to 15% by weight, although the preferred range is between 2 and 8% by
weight. Necessarily, the agent must be compatible with the cellulose ester
film former, and generally has a viscosity in a 50% by weight solution of
dilute aqueous alkali of less than 15,000 cps., preferably less than 2000
cps. The melting point should be above 150.degree. F. Binding agent
percentages stated herein are on a resin solvent free basis.
The Solvent Blend
In the description of the solvent blend, the following definitions are
employed:
Solvent Blend--the mixture of a more volatile solvent and a less volatile
non-solvent.
Solvent--the more volatile portion of the solvent blend within which the
film former and resin is soluble. Where more than one solvent is used, the
term solvent system has been employed.
Non-solvent--the less volatile portion of the solvent blend within which
the film former is essentially insoluble.
The solvent blend consists essentially of at least one or more volatile
solvents and at least one less volatile non-solvent. The amount of solvent
in the blend must be sufficient to completely dissolve the film former
notwithstanding the diminution of solvating power of the blend by the
addition of non-solvent thereto. Its volatility should be such that
substantial evaporation of the solvent takes place rapidly, preferably
within 2 to 3 seconds, upon application of the ink composition to the
substrate. However, the solvent must also be compatible with the jet ink
printer. For example, ethers such as ethyl ether have been found to be
suitable solvents yet are not preferred because they are incompatible with
gaskets and seals typically used in the printing equipment and form
dangerous reaction products with oxygen. Another requirement of the
solvent is that it should evaporate uniformly from the film former and
binder. That is, the solvent should be present in solution with the
non-solvent and dissolved solid constituents throughout the initial
evaporation period and at least until the onset of gellation as will
hereinafter be described.
Conversely, the non-solvent, which is present in concentration ranging
between 2 and 10% by weight of the composition, should be less volatile so
that the non-solvent remains subsequent to the evaporation of the solvent.
Of course, the rate of evaporation of individual constituents of the blend
will be dependent on their relative volatilities, and as evaporation takes
place the solvent blend will become increasingly non-solvent rich. It is
also preferable that the solvent blend constituents not form an azeotrope
that will solubilize the film former.
Water is the preferred non-solvent, although glycerin has also been found
to be a suitable substitute. Water is preferred not only because it forms
the desired gel with the film former, but also because its viscosity is
low relative to its vapor pressure. Thus, when used in proper amounts, the
viscosity of the ink composition ranges between 1.5 and 25 cp. as noted
above.
Solvents acceptable for use in the blend are aliphatic alcohols having from
one to three carbons, aliphatic ethers having from four to ten carbons,
aliphatic ketones of three to seven carbons, and aliphatic acetates of
three to seven carbons, none of which form an azeotrope that will dissolve
the film former. In addition, two or more solvents can be combined within
the blend, and such combinations are preferred in balancing the
volatility, viscosity, density and resistivity properties of the ink
composition. For example, methanol is a suitable solvent. However, solvent
systems comprising methanol-acetone, methanol-methyl ethyl ketone, and
methanol-acetone-methyl ketone have been found more effective. Similarly,
the methanol-ethyl acetate and methanol-acetone-ethyl acetate solvent
systems have been used with success. Generally, however, alkyl acetates
and ketones should not be present in amounts above about 50% by weight of
the solvent. As parameters for achieving a usable solvent system for
incorporation into the solvent blend, it is desirable for the relative
drying time of the solvent system to be in the range between one and nine
as compared with ethyl ether having an arbitrary drying time of 1.0 (quick
drying), and for the viscosity to be between from about 0.2 and 1.2 cp.
Preferably, the ink composition contains at least 30% by weight methanol.
The remaining solvent blend constituents are, as a weight percent of the
ink composition, preferably between 20 and 50% acetone, from 0 to about
25% methyl ethyl ketone, and from 0% to about 25% ethyl acetate. The
solvent system is between 70% and 90% by weight of the ink composition.
The solvent blend, including nonsolvent and solvent, in combination with
the film former and the binding agent, comprises the ink composition,
except for minor concentrations of miscellaneous additives hereinafter
described.
Other Ingredients
In general the resistivity of the ink should be between 100 and 3500
ohm/cm., preferably between 500 and 2000 ohm/cm. In some instances the
solvent blend or the resin binding agent used will satisfy this
requirement. However, electrolytes can be added optionally to maintain the
specific resistivity of the ink within desired limits for use in video jet
printing equipment. Satisfactory compounds include dimethylamine
hydrochloride, sodium propionate, sodium acetate, and the like. In
addition, it has been found that the addition of a hygroscopic salt and
preferably a deliquescent salt such as dimethylamine hydrochloride or
lithium chloride in an amount between 0.05 and 3%, preferably between 0.1
and 1.0%, by weight of the composition also enhances the opacity of the
dried film. Hence, such hygroscopic/deliquescent salts are the preferred
electrolytes, and may be included even though the resistivity is within an
acceptable range without their addition.
Finally, small amounts, generally no more than 2.0% each by weight, of
conventional basic dyes, surfactants, and optical brighteners, can be
included in the composition. A dye is useful when a white image does not
show up clearly on a particular substrate. However, the film produced is
still opaque, and relies on the mechanism described below for visibility.
Particularly advantageous dyes for use herein are yellow. Typical yellow
dyes are Morfast Yellow 101, an azo-type dye and Morfast yellow 102, a
metal-complexed azo-type dye, both avaiable from Morton-Norwich Company.
The above dyes are supplied as a 50% solution, with isopropanol as the
solvent. When used, these dye solutions typically comprise 0.5% to 4% by
weight of the ink composition.
Another acceptable yellow dye is Neozapon Yellow GG, also a metal-complexed
azo-type dye, available from BASF Wyandotte Company.
MECHANISM FOR PRODUCING WHITE OPAQUE IMAGES
It is believed that the following events take place to form the film which
produces the opaque images.
Upon deposition of the ink on the substrate, the solvent blend evaporates
rapidly. Because of the difference in relative volatility between the
solvent and non-solvent, the cellulose ester film former and binding agent
remain behind in a progressively non-solvent rich residuum of the solvent
blend. As the concentration of non-solvent increases, the film former,
which is insoluble in the non-solvent, forms a gel with but a portion of
the remaining solvent blend. The surplus of solvent blend not entrapped
within the gel is present as microdroplets amid the gel. Upon subsequent
complete evaporation of the solvent blend, now principally the non-solvent
species therein, a reticulated film is produced over the substrate, the
microdroplets having produced a network of microvoids both within and on
the surface of the film, said microvoids scattering incident light thereby
making the film opaque.
USE OF THE INK COMPOSITION
A continuous stream of ink is transferred from a pressurized supply
reservoir for discharge as droplets from a printing nozzle at ambient
conditions. The pressure in the reservoir is sufficient to overcome
transfer line and nozzle pressure drops, said pressure being about 10 to
50 psia. The disposition of the droplets exiting the nozzle is dependent
on whether a coded message is to be printed on a substrate. Assuming that
the coded message is not to be printed, the droplets are recaptured
proximate to the nozzle and cycled back to a return tank. Because the
nozzle discharges to atmosphere, it is necessary that the return tank be
under vacuum, the return tank pressure being about 4-6 psia.
When an article to be encoded passes beneath the printer nozzle, a portion
of the droplet stream is deflected by a pre-set series of electric signals
thereby causing the coded message to be printed. The bulk of the droplets,
however, continue to be recaptured for transfer to the return tank. This
system is used because the actual amount of ink necessary for printing the
coded messages is substantially smaller than the volumetric flow rate
through the printing equipment required for meaningful control. Droplets
applied to the substrate turn opaque rapidly, generally within a few
seconds, by means of the mechanism postulated above.
Make-up Solution
Because of the flash vaporization which occurs at the nozzle, and the
reduction in pressure in the return tank, the composition of the ink in
the return tank is different than the ink in the supply reservior. For
this reason it is necessary to reconstitute the former for eventual re-use
by the addition of make-up solution. The make-up formulation is a function
of the rate of loss of the ink constituents, and consists essentially of
the volatile solvent species, but may also include non-solvent and ink
solids. In general, make-up is added intermittently. The return tank is
mounted on a weigh scale, and as evaporation occurs, an automatic valve is
actuated to allow make-up solution to be transferred from a make-up
reservoir to the return tank. Alternately, a property of the ink could be
monitored, e.g., specific gravity, to actuate the transfer. Because the
rate of loss is dependent upon the actual ink composition and operating
conditions, the make-up solution composition should be determined a priori
by a trial and error procedure.
The examples below further illustrate the teachings of this disclosure:
EXAMPLE 1
The ink formulation which follows was used successfully to print white
opaque videojet codes on glass and black cable:
______________________________________
pbw
______________________________________
Cellulose Acetate Propionate
Film Former 4.32
(Eastman CAP 504-0.2)
Polyvinyl Acetate Binding Agent:
(Monsanto Gelva #264)
Resin 2.14
Ethanol 2.61
Methanol Solvent 86.4
Water Non-Solvent 4.32
Dimethylamine Hydrochloride
Electrolyte;
0.20
(DMA.HCl) Opacifier
Total 99.99
______________________________________
The use of cellulose acetate propionate has been found to be the most
preferred film former of those tested. Publication No. E-169D from Eastman
indicates that CAP 504-0.2 has the following properties:
______________________________________
Viscosity 0.2 seconds (ASTM D-1343 with
Formula A, D-817)
Specific Gravity
1.263 25.degree./4.degree. C.
Melting Range 188-210.degree. C.
Hydroxyl Content
5.0 wt. % (avg.)
Propionyl Content
40.0 wt. % (avg.)
Acetyl Content 2.5 wt. % (avg.)
______________________________________
Gelva #264 is a vinyl type resin whose viscosity is between 7000 and 11000
cps. in a 55-57% ethanol solution by weight. For computing solvent blend
constituent concentrations, the resin solvent should be taken into
account. Conversely, resin concentrations defined herein are on a dry
basis.
The ink produced according to this formulation had a Brookfield viscosity
of 4.0 centipoises at 24.5.degree. C. and a resistivity of 800 ohm/cm. at
24.5.degree. C.
EXAMPLE 2
In this example, the solvent comprises a mixture of methanol and acetone,
the acetone being used to reduce the viscosity of the ink composition.
______________________________________
pbw
______________________________________
Cellulose Acetate Propionate
(Eastman CAP 504-0.2)
Film Former 8.0
Acrylic Resin (American
Binding Agent:
Hoescht Synthacryl VSC 75/1)
Resin 2.8
Isopropanol 2.8
Water 1.4
Methanol Solvent 40.0
Acetone Solvent 50.0
Water Non-Solvent 6.0
Dimethylamine Hydrochloride
Electrolyte; 0.2
Opacifiers
Total 111.20
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This composition had a Brookfield viscosity of 6.11 centipoises at
24.5.degree. C., and produced a smear resistent printed code about two
seconds after application to the substrate.
EXAMPLE 3
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pbw
______________________________________
CAP 504-0.2 7.0
Synthacryl VSC 75/1
6.0
Methanol 44.5
Acetone 26.5
Methyl Ethyl Ketone
9.0
Water 5.8
Surfactant 1.0
DMA.HCl 0.2
Total 100.0
______________________________________
The Brookfield viscosity was 5.6 cps. and the resistivity was 800 ohm-cm.,
each at 24.5.degree. C. This ink was life tested and produced opaque
images upon use after 1000 hours of storage at ambient conditions.
In conjunction with the use of this ink on the jet printing apparatus, the
following make-up solution was employed:
______________________________________
ml. (25.degree. C.)
______________________________________
Acetone 1425
Methanol 1110
Methyl Ethyl Ketone
230
Ink (as stated above)
234
2999.
______________________________________
EXAMPLES 4-9
Table I provides further examples of the use of cellulose acetate
propionate in combination with various resin compounds and solvent blends.
TABLE I
__________________________________________________________________________
Constituent,
Example No.
pbw 4* 5 6 7 8 9
__________________________________________________________________________
CAP 504-0.2
60 6.0 6.0 8.0 7.0 4.5
Binding Agent:
Resin 60 Resin 5.0 Resin 2.4
Resin 2.6
Resin 2.4
Resin 2.0
Ethanol 3.6
Isopropanol 0.4
Isopropanol
Ethanol 2.5
Water 4.0
Water 1.2
(Resin modified
(Maleic resin,
(Carboxylated
(Acrylic resin,
(Syntharcyl
(Gelva #264)
maleic resin,
UniRez 7083,
polyvinyl acetate,
Acrysol 1-100,
VSC 75/1)
Alresat KM140,
Union Camp Corp.)
NS - 26 - 1314,
Rohm and
American Hoescht) National Starch)
Haas)
Methanol
805 82.0 84.0 40.0 57.5 85.5
Acetone 30.0
MEK 20.0
Ethyl Acetate 25.0
Water 65 7.0 5.0 6.0 4.0 4.5
DMA.HCl 0.2 0.5
Optical 15
Brigthener
(HM-35,
DayGlo Corp.)
Surfactant
20 1.0 0.5
(FC 170C, (FC 170C)
(Arquad 2C-75,
3M Corp.) Armak Chemicals)
Dye 2
(Yellow GG, BASF
Wyandotte)
TOTAL, pbw
1027 100.0 101.0 111.2 100.5 99.5
__________________________________________________________________________
*Sufficient NH.sub.4 OH to raise pH to 8.5
EXAMPLE 10
This ink composition shows the use of cellulose acetate butyrate, which has
a hydroxyl content of 4.3%.
______________________________________
pbw
______________________________________
Cellulose Acetate Butyrate
6.0
(Eastman CAP 533-0.4)
Acrylic Resin (Synthacryl
7.0
VSC 75/1)
Methanol 45.0
Acetone 20.0
Methyl Ethyl Ketone 9.0
Water 7.0
DMA.HCl 0.2
Total 94.2
______________________________________
The examples above are intended to be illustrative only, and are not to be
construed as in any way limiting the invention defined by the claims which
follow.
* * * * *
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