Heat fusible polyester and polyamide dispersions

It has been discovered that pastes of particulate thermoplastic polymers dispersed in a soft resinous phase can be prepared which heat-set by fusion of the thermoplastic binder. Polyesters and polyamides have been found to be particularly useful. When pigmented or otherwise colored, these formulations have utility as printing inks. When uncolored, they can be used as clear overprint coatings. In addition, these fusible pastes have utility as specialty coatings in adhesives and can be fabricated into self-supporting shapes.

BACKGROUND OF THE INVENTION 
Printing processes require that printing inks be both fluid and capable of 
subsequent ready conversion to a dry, smudge-resistant film once in place 
on paper or another substrate. One common type of printing ink consists 
primarily of a pigment and a binder which are suspended or dissolved in a 
volatile diluent. The binder serves the purpose of adhering the pigment to 
the printed substrate. the diluent must subsequently be removed by 
allowing it to evaporate either at room temperature, or for higher 
printing speeds, by heating. Large amounts of heat are needed to vaporize 
the ink diluent, which requires that substantial quantities of fuel be 
consumed. Since large volumes of air must be drawn over the drying ink 
film to remove the diluent vapor, frequently much heat is wasted. Further, 
the evaporation of the ink diluent into the open atmosphere can be a 
source of pollution. In many instances, it is necessary or desirable to 
burn off or otherwise remove the solvent vapor from the drying air before 
discharging it to the atmosphere. Additional fuel is consumed and special 
equipment must be installed for this purpose. 
A second common type of printing ink consists of mixtures containing 
oleoresinous varnishes and/or drying oils which set by air oxidation. 
These inks set slowly so it is necessary to take precautions to avoid 
set-off (transfer) or ink between printed sheets. 
Inks may also be formulated which contain drying oils or the like together 
with some binder and volatile diluent. In the usual printing operation, 
heat is applied to such an ink immediately after it is printed onto the 
substrate. At this stage, the diluent is driven off, reducing or 
minimizing problems of ink set-off. However, the ink is not fully set and 
rub resistance is inadequate. A subsequent drying stage is necessary in 
which the drying oil or the like hardens, as by oxidation and/or 
polymerization. 
While it is necessary that a printing ink set rapidly and conveniently 
after printing, it is equally necessary that it not set or dry on the 
press. Inks containing volatile components may thicken on the press as the 
solvent evaporates, making it difficult or impossible to control the 
printing process. Air oxidizing varnished, drying-oils, and the like, may 
thicken or gum on the press on exposure to the atmosphere. Such inks are 
especially inclined to "skin over" when the press is shut down during a 
run. An ink which is not subject to such changes while on the printing 
press is said to "stay open". 
Ink technologists have sought to achieve inks which set rapidly with a low 
level of energy input to initiate setting, which do not release polluting 
materials to the atmosphere, and which stay open to on press, while at the 
same time meeting the physical and mechanical requirements of the printing 
process. Much attention has been directed to highly chemically reactive 
formulations. After printing, such inks are set by polymerization and/or 
cross-linking which is initiated by heat or radiation. A typical 
chemically reactive system contains polyfunctional acrylate esters (often 
in combination with other unsaturated materials), one or more ultraviolet 
photoinitiators, pigment and a variety of secondary components to control 
ink physical properties. See U.S. Pat. No. 3,804,640 and U.S. Pat. No. 
3,881,942, both to Buckwalter. In normal use, such inks are printed on 
presses equipped with ultraviolet lamps which expose the film on the paper 
or other substrate immediately after printing. The inks set rapidly and 
with essentially no emission of polluting materials. Inks based on such 
highly reactive materials, however, have limited storage stability. The 
acrylates and other reactive materials in common use have been found to be 
chemically incompatible with some pigments which are desirable in printing 
inks. They present toxicity hazards, or are dangerous eye irritants, and 
are frequently skin sensitizers. When the inks are designed to be set by 
an ultraviolet light initiated reaction, the ultraviolet radiation itself 
and the high voltages necessary to power the ultraviolet lamps are 
additional health and safety hazards. 
U.S. Pat. No. 3,024,213 to Ludlow discloses a heat drying ink vehicle based 
on polyvinyl chloride plastisols, more particularly finely divided 
polyvinyl chloride polymer dispersed in liquid plasticizers, all of which 
have low viscosity and solubility parameters closely matched to polyvinyl 
chloride, and containing a compatible thermoplastic resinous binder to 
increase ink cohesion and tack. Further improvements in inks based on 
polyvinyl chloride and vinyl chloride copolymer plastisols are disclosed 
in U.S. Pat. No. 3,760,724 to Budzinski. These inks are set by applying 
heat which causes the liquid plasticizers and polyvinyl chloride or vinyl 
chloride copolymer to co-dissolve. Thus, such polyvinyl chloride 
plastisol-based inks are readily heat-settable without significant release 
of volatile materials to the atmosphere. These inks, however, do not have 
good press running characteristics. Undesirable build-up of material on 
the blanket of lithographic offset presses occurs when polyvinyl chloride 
plastisol inks are used. Further, both Ludlow and Budzinski require the 
use of at least one plasticizer in such polyvinyl chloride plastisol inks. 
Such plasticizers may, as Ludlow discloses, damage ordinary natural rubber 
rolls on printing presses. It is thus necessary that ink rolls of 
polyurethane rubber or other plasticizer resistant compositions be used. 
SUMMARY OF THE INVENTION 
The present invention provides nonvolatile, heat-set pastes. It has been 
discovered that pastes of particulate polyesters or polyamides dispersed 
in a soft resinous phase can be prepared which heat-set by the fusion of 
the polyester or polyamide binder. When pigmented or otherwise colored, 
these formulations have utility as printing inks. When uncolored, they can 
be used as clear over-print coatings. In addition, these fusible pastes 
have utility as specialty coatings and adhesives and can be fabricated 
into self-supporting shapes. 
DESCRIPTION OF THE PREFERRED EMBODIMENTS 
According to this invention, nonvolatile, heat-set vehicles for printing 
inks can be made by dispersing particulate polyester or polyamide polymer 
binder in a soft resinous phase. More particularly, the printing ink 
vehicles of this invention contain particular polyester or polyamide 
dispersed in a tackifying, cohesion-increasing material which may be a 
resin or mixture of resins whose softening point is either at or below 
room temperature, or has been lowered by dilution with an oil. 
The binder materials used in this invention comprise particulate polyesters 
and polyamides having a crystallinity below about 20%, most preferably 
10%. The glass transition temperature (Tg), or crystalline melting point, 
must be above room temperature. 
Suitable polyester binder materials comprise the polyesterification 
products of one or more dicarboxylic acid (or the corresponding ester) and 
one or more diols with a weight average molecular weight of greater than 
5000. 
Suitable dicarboxylic acids may be aliphatic, aromatic, or alicyclic and 
may be saturated or unsaturated. These acids have the general formula 
##STR1## 
wherein R represents an alkylene radical, arylene radical, alkylene 
arylene alkylene radical, or cycloalkylene radical having from 1 to 36 
carbon atoms. Throughout this specification the expression dicarboxylic 
acid is intended to include anhydrides of such acids where such anhydrides 
exist. Typical dicarboxylic acids include: malonic acid, succinic acid, 
glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, 
sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, itaconic 
acid, maleic acid, maleic acid anhydrides, fumaric acid, phthalic acid 
anhydride, hexahydroterephthalic acid, and the like, and further include 
dimers of unsaturated fatty acids such as oleic acid, linoleic acid, and 
linolenic acid. 
Suitable diols may be aliphatic, aromatic, or alicyclic. These diols have 
the general formula: 
##STR2## 
wherein R' and R" represent hydrogen or alkyl radicals having 1 to 3 
carbon atoms, and R"' represents an alkylene radical, arylene radical, 
alkylene arylene alkylene radical, cycloalkylene radical, alkylene 
cycloalkylene alkylene radical, or alkylene oxy alkylene radical having 
from 1 to 36 carbon atoms and n is 0 or 1. Typical diols include: ethylene 
glycol, propylene glycols, butylene glycols, diethylene glycol, 
dipropylene glycols, triethylene glycol, 1,4- dihydroxymethylcyclohexane, 
isopropylidene bis (p-phenyleneoxypropanol-2), 1,4-dihydroxymethyl 
benzene, and the like. 
Minor amounts of polyfunctional carboxylic acids or polyfunctional alcohols 
may be included to increase molecular weight, to modify crystallinity, or 
to modify melt flow properties, but in no case should they be included at 
such a level as to cause cross-linking of the polymer. Similarly, small 
amounts of monofunctional carboxylic acid or alcohols may be added to 
control the molecular weight of the products. 
Suitable polyamide binder materials comprise the polycondensation product 
of one or more dicarboxylic acid (or the corresponding ester) and one or 
more diamine. 
Suitable dicarboxylic acids are as specified for inclusion in polyester 
binder materials. 
Piperazine is a suitable diamine as are other diamines which may be 
aliphatic, aromatic, or alicyclic. These diamines have the following 
general formula: 
EQU H.sub.2 N--R"".sub.n --NH.sub.2 
wherein R"" represents an alkylene radical, arylene radical, alkylene 
arylene alkylene radical, cycloalkylene radical, or alkylene cycloalkylene 
alkylene radical having from 1 to 36 carbon atoms, where n is 0 or 1. 
Typical diamines include piperazine, hydrazine, ethylene diamine, 
tetramethylene diamine, hexamethylene diamine, pentamethylene diamine, 
octamethylene diamine, decamethylene diamine, p-xylylene diamine, 
1,4-diaminocyclohexane, and the like. 
Minor amounts of polyfunctional carboxylic acids or polyfunctional amines 
may be included to increase molecular weight, modify crystallinity or to 
modify melt flow properties, but in no case should they be included at 
such a level as to cause cross-linking of the polymer. Similarly, small 
amounts of monofunctional carboxylic acids or amines may be added to 
control the molecular weight of the products. 
While the particle size of the polyester or polyamide binder is not 
critical, for lithographic or letterpress inks particles about 0.05 to 
about 2.0 microns in cross-section are preferred, with particles of about 
0.5 micron in cross-section being most preferable. Larger particles may 
give poor uniformity and press performance. In screen printing, much 
heavier ink films are printed so much larger particle sizes may be 
tolerated. The limit in particle size for inks used in screen printing is 
fixed by the mesh size of the printing screen and the thickness of the ink 
film desired. For use with coarse mesh screens and heavy ink films, 
particle sizes as high as about 50 microns can be used. 
Polyester or polyamide particles of a size useful in this invention may be 
prepared by emulsifying the water immiscible solution of the desired 
polymer in water and stripping the solvent. 
Dispersions of polyester or polyamide in a soft resinous phase can be 
achieved by blending into an aqueous polymer emulsion one or more of the 
liquid components of the soft resinous phase and stripping the water from 
the mix at a temperature low enough to avoid fusion of the polyester or 
polyamide. It is also possible to prepare these dispersions by 
freeze-drying or spray drying the emulsion in order to isolate the 
particulate polyester or polyamide and dispersing the dry polymer powder 
in the soft resinous phase. 
Alternatively, particles may be prepared by grinding or milling the 
polyester or polyamide, or by controlled precipitation from solution. In 
many cases, a particle size classification process may be necessary to 
obtain the optimum size of the material. 
In some cases, it may be desirable to include additives such as 
plasticizers, resins, pigments, dyes, flameproofing agents, etc. in the 
polyester or polyamide. This may be conveniently accomplished by 
dispersing or dissolving the additive in the polymer or polymer solution 
before converting it to small particle form. 
The continuous soft resinous phase of the paste is comprised of a 
tackifying, cohesion-increasing material which may be a resin or mixture 
of resins with a softening point at or below room temperature, or which 
has been diluted with an oil to suitably lower the softening point. The 
term "resin" is here restricted to amorphous organic solids, semi-solids 
and viscous liquids with room temperature viscosities above about 2000 
centipoise. Such resins are commonly polymeric, but number average 
molecular weight must be under about 5000. Typical classes of resins which 
may be used are hydrocarbon resins, including naturally occurring coal tar 
and other fossil resins, synthetic aliphatic and aromatic hydrocarbon 
resins prepared from petroleum- or coal-derived feedstocks, and resins 
based on pure hydrocarbon monomers and combination of monomers, such as 
styrene and alkyl-substituted styrenes, indene and dicyclopentadiene; 
terpene resins; rosin and rosin esters such as hydrogenated methyl ester 
of rosin and phenolic modified pentaerythritol ester of rosin; ketone 
formaldehyde thermoplastic resins; condensed ketone thermoplastic resins; 
and resins based on acrylate esters and alkyl substituted acrylate esters; 
and transesterification products of alcohols with dimethyl terephthalate 
process residues. 
Diluent oils may be aliphatic, aromatic, or naphthenic in character, and 
may contain polar functionality, but must be compatible with and dissolve 
in the resin system. Typically, they have solubility parameters between 
about 7.0 and 8.5. They must be substantially nonvolatile at the 
temperature at which the ink is set, typically 75.degree. C. or higher. It 
is important to choose diluents which do not rapidly solvant the 
particulate thermoplastic phase at room temperature. This may be 
accomplished by avoiding those diluent oils which closely match the 
solubility parameter of the particulate polymers. 
There is no such restriction on the solubility parameter of the resin 
itself. The rate of solvation is slow enough that even inks containing 
resins which closely match the solubility parameter of the particulate 
thermoplastic may be prepared and printed. in extreme cases, solvation may 
proceed at a rate that would limit certain combinations of resin and 
thermoplastic polymers to applications where inks are prepared as needed, 
and are not stored longer than a day or so. Printing inks are commonly 
prepared as needed in larger printing plants. 
The particulate polyester and polyamide and soft resin of this invention 
should be used in proportions such that the ratio of polymer to resin will 
preferably be between about 1:6 and about 1:1. Also, the ratio of soft 
resin to diluent oil may range from those cases in which the formulation 
is oil-free (i.e., where the soft resin is naturally thin enough to 
achieve the desired rheology in the final fusible past formulation) to 
about 1:15 ratio of resin to oil. 
In addition to the above-described essential ingredients, when the pastes 
are used as printing inks surface active agents, pigment dispersing aids, 
waxes, slips aids, tack modifiers and the like may be included. 
The primary mechanism by which the pasts of this invention set appears to 
be the fusion of the particulate thermoplastic binder to form a continuous 
film on heating the paste, in which the soft resinous phase is largely 
dissolved and/or entrapped. In some circumstances, it may be desirable for 
the paste film to harden further. This can be achieved by choosing for the 
soft resinous phase, either in whole or in part, materials capable of 
undergoing polymerization or cross-linking during the thermal fusion of 
the particulate thermoplastic material or subsequent to it. In such cases, 
it may be appropriate to include suitable catalysts, driers, accelerators, 
or other additives which are necessary or desirable to initiate or promote 
the desired polymerization or cross-linking reaction. Such subsequent 
hardening of the thermally set paste film may be achieved by including one 
or more unsaturated alkyd resins as part of the resinous phase, such as 
alkyds based on phthalic, isophthalic, adipic, azelaic, sebacic, 
terephthalic, hydrophthalic, maleic, fumaric, and benzoic acids and 
anhydrides modified with unsaturated fatty acids; rosin modified alkyds; 
phenolic modified alkyds; epoxy alkyds; polyamide alkyds; isocyanate 
alkyds; and styrene or substituted styrene alkyds, such as styrene and 
acrylonitrile modified alkyds. The unsaturated isophthalic alkyds are 
preferred. 
Similarly, drying oils or semi-drying oils such as linseed oil, tung oil, 
oiticica oil, dehydrated caster oil, soya oil, safflower oil, fish oil, 
tall oil, or the like may be used as hardening agents in the resinous 
phase. These oils may be used in the natural state or may be bodied to 
increase viscosity by heating or other partial polymerization. 
When such oxidation drying materials are included in the paste, suitable 
driers or catalysts which promote oxidative cross-linking and 
polymerization may be included, typically salts of complexes of metals 
capable of existing in more than one valence state, such as vanadium 
oxyacetylacetonate, vanadium oxysulfate, vanadium 
oxy-1,1,1-tri-fluoroacetylacetonate, vanadium oxy-1-phenylacetylacetonate, 
ferric acetylacetonate-benzoin, manganese octoate, lead naphthenate, 
cobaltic acetylacetonate, titanyl acetylacetonate, cobaltous naphthenate, 
cobaltous 2-ethylhexanoate, cobaltous sterate, cobaltic sterate, cobaltous 
acetyl-acetonate, manganous sterate, manganic sterate, manganous 
acetylacetonate, manganic acetylacetonate, manganese naphthenate, 
zirconium acetylacetonate, vanadyl naphthenate, ferrous sulfate, ferrous 
pyrophosphate, ferrous sulfide, the ferrous complex of 
ethylenedinitrilotetraacetic acid, ferrous o-phenanthroline, ferrous 
ferrocyanide, ferrous acetylacetonate and the corresponding nickel, 
copper, mercury and chromium compounds. 
The use of a colorant is not critical to the invention. The fusible paste 
dispersion can be used unpigmented as a clear overprint varnish. When a 
colorant is desired, it may be a pigment or dye. The colorant normally may 
be most conveniently dispersed in the continuous soft resinous phase of 
the ink. However, it may be desirable in some circumstances to include the 
colorant within the particulate thermoplastic material. 
When used as printing inks, the pastes of this invention may be printed by 
any of the printing processes which require a paste type ink. Common 
printing processes in which paste inks are used include letterpress, 
lithography, and screen printing. Printing may be sheet-fed or web-fed, 
and may be on paper, board, fabric, metal, glass, plastic, wood, leather, 
rubber, or other substrates. Variations in ink rheology and tack 
properties are required for optimum performance for any chosen printing 
process and substrate. Inks based on the pastes of this invention can be 
suitably formulated to meet these specific requirements by appropriate 
choice and relative concentration of materials used in the resinous phase. 
This will be readily apparent to those skilled in printing ink 
formulation. 
In addition to printing, pastes may be applied to substrates by 
roll-coating, doctoring, screening, dipping, or the like, especially for 
the preparation of specialty coatings or for use as heat-set thermoplastic 
adhesives. Self supporting shapes may be prepared by cavity molding, dip 
molding, rotational molding, slush molding or the like. Variations in 
paste rheology and tack properties are required for optimum performance 
for any chosen fabrication process. The pastes can be formulated to meet 
these requirements by appropriate choice and relative concentration of 
materials used in the resinous phase. This will be readily apparent to 
those skilled in the art of materials fabrication. 
After printing, coating or forming, the pastes of this invention may be set 
by heating to at least about 75.degree. C. and preferably to at least 
about 150.degree. C. to fuse the particulate thermoplastic resin. This may 
be done in a conventional forced-air drying oven, in common use in the 
printing industry. However, since no air flow is necessary to remove 
volatile material, it is frequently advantageous to heat the paste film by 
irradiation, typically in the infrared spectral region. At 150.degree. C., 
the paste may be fused by heating for from about 0.01 second to about 2 
minutes, longer times being required for those pastes which do not contain 
pigments than for those which do contain pigment. Also, the duration of 
the heating may vary depending upon the thickness of the paste coating, 
substrate, or purpose for which the paste is used (e.g., adhesive, 
molding, material, etc.).

EXAMPLE 1 
An amorphous polyester is prepared which consists of 47.5 mole percent 
isophthalate, 2.5 mole percent succinate and 50 mole percent of 
isopropylidene bis(p-phenyleneoxy-propanol-2) (i.e., the condensation 
product of bisphenol A and propylene oxide in a mole ratio of 1 to 2). The 
polyester has a Tg=67.degree. C., and a weight average molecular weight 
Mw=8580. The polyester is ground to a particle size ranging from about 1 
micron to 20 microns by milling in a ball mill with ceramic balls covered 
with heptane for about 17 hours. A printing ink is prepared by blending 
together the following materials using a Hoover Automatic Muller to 
achieve a uniform paste: 
______________________________________ 
Ingredients Parts by Weight 
______________________________________ 
Polyester 25 
Phenolic modified pentaerythritol 
5 
ester of rosin* 
Hydrogenated methyl ester of 
55 
rosin - with a viscosity of 
about 5500 centipoise* 
Carbon black 15 
______________________________________ 
*Dissolved together before blending with other ingredients 
The ink is printed on an offset proof press. The printed sheets are passed 
at about 65 meters/minute under two successive near IR lamps, subjecting 
the printed sheets to radiation peaking at about 1.2 microns wavelength at 
an average energy density of about 6.9 W/cm.sup.2. The surface of the 
sheet reaches a temperature above 75.degree. C. After setting, the ink is 
dry and resistant to smudging or smearing. 
The above ink is screen printed onto paper, and infrared set as above. 
After setting, the ink is dry and resistant to smudging or smearing. 
EXAMPLE 2 
Using the particulate polyester of Example 1, a printing ink is prepared by 
blending together the following materials using an automatic muller 
achieving a uniform paste: 
______________________________________ 
Ingredients Parts by Weight 
______________________________________ 
Polyester 25 
Hydrocarbon resin - largely based on 
5 
styrene with a ring and ball softening 
point of 30.degree. C. and number average 
molecular weight below 5000.* 
Extending oil - petroleum derived; 
55 
solubility parameter of about 7.8; 
less than 0.1% volatility at 150.degree. C.* 
Carbon black 15 
______________________________________ 
*Dissolved together before blending with other ingredients 
The ink is printed on an offset proof press. The printed sheets are passed 
at about 65 meters/minute under two successive near IR lamps, subjecting 
the printed sheets to radiation peaking at about 1.2 microns wavelength at 
an average energy density of about 6.9 W/cm.sup.2. After setting, the ink 
is dry and resistant to smudging or smearing. 
The above ink is screen printed onto paper, and infrared set as in Example 
1. After setting, the ink is dry and resistant to smudging or smearing. 
EXAMPLE 3 
An amorphous polyester is chosen which consists of the condensation product 
of terephthalic acid and a small amount of isophthalic acid with neopentyl 
glycol. The polyester has a Tg=60.degree. C., and a weight of 21,100. The 
polyester is ball milled as in Example 1 to a particle size ranging from 
about 1 micron to 20 microns. A printing ink is prepared by blending 
together the following materials using an automatic muller achieving a 
uniform paste: 
______________________________________ 
Ingredients Parts by Weight 
______________________________________ 
Polyester 25 
Phenolic modified pentaerythritol 
5 
ester of rosin* 
Hydrogenated methyl ester of 
55 
rosin - with a viscosity of 
about 5500 centipoise* 
Carbon black 15 
______________________________________ 
*Dissolved together before blending with other ingredients 
The ink is printed on an offset proof press. The printed sheets are passed 
at about 65 meters/minute under two successive near IR lamps, subjecting 
the printed sheets to radiation peaking at about 1.2 microns wavelength at 
an average energy density of about 6.9 W/cm.sup.2. After setting, the ink 
is dry and resistant to smudging or smearing. 
The above ink is screen printed onto paper, and infrared set as in Example 
1. After setting, the ink is dry and resistant to smudging or smearing. 
EXAMPLE 4 
Using the particulate polyester of Example 3, a printing ink is prepared by 
blending together the following materials using an automatic muller 
achieving a uniform paste: 
______________________________________ 
Ingredients Parts by Weight 
______________________________________ 
Polyester 25 
Phenolic modified pentaerythritol 
5 
ester of rosin* 
Extending oil - petroleum derived; 
55 
solubility parameter of about 7.8; 
less than 0.1% volatility at 150.degree. C.* 
Carbon black 15 
______________________________________ 
*Dissolved together before blending with other ingredients 
The ink is printed on an offset proof press. The printed sheets are passed 
at about 65 meters/minute under two successive near IR lamps, subjecting 
the printed sheets to radiation peaking at about 1.2 microns wavelength at 
an average energy density of about 6.9 W/cm.sup.2. After setting, the ink 
is dry and resistant to smudging or smearing. 
The above ink is screen printed onto paper, and infrared set as in Example 
1. After setting, the ink is dry and resistant to smudging or smearing. 
EXAMPLE 5 
Using the particulate polyester of Example 3, a printing ink is prepared by 
blending together the following materials using an automatic muller 
achieving a uniform paste: 
______________________________________ 
Ingredients Parts by Weight 
______________________________________ 
Polyester 25 
Hydrocarbon resin - largely based on 
5 
styrene with a ring and ball softening 
point of 30.degree. C. and number average 
molecular weight below 5000.* 
Extending oil - petroleum derived; 
55 
solubility parameter of about 7.8; 
less than 0.1% volatility at 150.degree. C.* 
Carbon black 15 
______________________________________ 
*Dissolved together before blending with other ingredients 
the ink is printed on an offset proof press. The printed sheets are passed 
at about 65 meters/minute under two successive near IR lamps, subjecting 
the printed sheets to radiation peaking at about 1.2 microns wavelength at 
an average energy density of about 6.9 W/cm.sup.2. After setting, the ink 
is dry and resistant to smudging or smearing. 
The above ink is screen printed onto paper, and infrared set as in Example 
1. After setting, the ink is dry and resistant to smudging or smearing. 
EXAMPLE 6 
A polyester is selected with a crystallinity of about 6.5%, consisting of 
the condensation product of iso- and terephthalates with ethylene glycol. 
The polyester had a Tg=22.degree. C., a crystalline melting point of about 
91.degree. C. and a molecular weight above 5000. The polyester is 
dissolved in methylene chloride to give a 20% by weight solution. The 
solution is mixed with water in the weight ratio 3 to 2, in which is 
dissolved 3 parts per hundred by weight based on polyester of sodium 
lauryl sulfate. The mix is subjected to high shear resulting in a stable 
emulsion. The methylene chloride is vacuum stripped from the emulsion and 
the resulting polyester in water emulsion is freeze dried, resulting in 
polyester particles of about 3 to 10 microns. A printing ink is prepared 
by blending together the following materials using an automatic muller 
achieving a uniform paste: 
______________________________________ 
Ingredients Parts by Weight 
______________________________________ 
Polyester 25 
Phenolic modified pentaerythritol 
5 
ester of rosin* 
Hydrogenated methyl ester of 
55 
rosin - with a viscosity of 
about 5500 centipoise* 
Carbon black 15 
______________________________________ 
*Dissolved together before blending with other ingredients 
The ink is printed on an offset proof press. The printed sheets are passed 
at about 65 meters/minute under two successive near IR lamps, subjecting 
the printed sheets to radiation peaking at about 1.2 microns wavelength at 
an average energy density of about 6.9 W/cm.sup.2. After setting, the ink 
is dry and resistant to smudging or smearing. 
The above ink is screen printed onto paper, and infrared set as in Example 
1. After setting, the ink is dry and resistant to smudging or smearing. 
EXAMPLE 7 
A polyamide is selected with a crystallinity of about 10.degree. C., 
consisting of two condensation products of dimerized vegetable fatty acids 
and ethylene diamine containing a small amount of diethylene triamine. The 
polyamide has a Tg=-9.degree. C., a crystalline melting point of about 
75.degree. C. and a molecular weight above 5000. The polyamide is ball 
milled as in Example 1 to a particle size of about 1 micron. A printing 
ink is prepared by blending together the following materials using an 
automatic muller achieving a uniform paste: 
______________________________________ 
Ingredients Parts by Weight 
______________________________________ 
Polyamide 25 
Phenolic modified pentaerythritol 
5 
ester of rosin* 
Extending oil - petroleum derived; 
55 
solubility parameter of about 7.8; 
less than 0.1% volatility at 150.degree. C.* 
Carbon black 15 
______________________________________ 
*Dissolved together before blending with other ingredients 
The ink is printed on an offset proof press. The printed sheets are passed 
at about 65 meters/minute under two successive near IR lamps, subjecting 
the printed sheets to radiation peaking at about 1.2 microns wavelength at 
an average energy density of about 6.9W/cm.sup.2. After setting, the ink 
is dry and resistant to smudging or smearing. 
The above ink is screen printed onto paper, and infrared set as in Example 
1. After setting, the ink is dry and resistant to smudging or smearing. 
EXAMPLE 8 
Using the particulate polyamide of Example 7, a printing ink is prepared by 
blending together the following materials using an automatic muller 
achieving a uniform paste: 
______________________________________ 
Ingredients Parts by Weight 
______________________________________ 
Polyamide 25 
Phenolic modified pentaerythritol 
5 
ester of rosin* 
Hydrogenated methyl ester of 
55 
rosin - with a viscosity of 
about 5500 centipoise* 
Carbon black 15 
______________________________________ 
*Dissolved together before blending with other ingredients 
The ink is printed on an offset proof press. The printed sheets are passed 
at about 65 meters/minute under two successive near IR lamps, subjecting 
the printed sheets to radiation peaking at about 1.2 microns wavelength at 
an average energy density of about 6.9 W/cm.sup.2. After setting, the ink 
is dry and resistant to smudging or smearing. 
The above ink is screen printed onto paper, and infrared set as in Example 
1. After setting, the ink is dry and resistant to smudging or smearing. 
EXAMPLE 9 
Using the particulate polyamide of Example 7, a printing ink is prepared by 
blending together the following materials using an automatic muller 
achieving a uniform paste: 
______________________________________ 
Ingredients Parts by Weight 
______________________________________ 
Polyamide 25 
Hydrocarbon resin - largely based on 
5 
styrene with a ring and ball softening 
point of 30.degree. C. and a number average 
molecular weight below 5000.* 
Extending oil - petroleum derived; 
55 
solubility parameter of about 7.8; 
less than 0.1% volatility at 150.degree. C.* 
Carbon black 15 
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*Dissolved together before blending with other ingredients 
The ink is printed on an offset proof press. The printed sheets are passed 
at about 65 meters/minute under two successive near IR lamps, subjecting 
the printed sheets to radiation peaking at about 1.2 microns wavelength at 
an average energy density of about 6.9 W/cm.sup.2. After setting, the ink 
is dry and resistant to smudging or smearing. 
The above ink is screen printed onto paper, and infrared set as in Example 
1. After setting, the ink is dry and resistant to smudging or smearing.