Sartomer Products
For Inks
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TABLE OF CONTENTS
INTRODUCTION ........................................................................................ 4
LITHO GRAPHIC INKS .............................................................................. 5
FLEXOGRAPHIC INKS ............................................................................. 9
SCREEN INKS .......................................................................................... 13
SMA® RESINS IN HIGH P/B DISPERSIONS & STABLE INKS ................... 16
INTRODUCTION
Sartomer offers several product lines for use in inks. SMA resins, acrylate oligomers, and acrylate monomers are all used
in the ink industry for lithographic, flexographic and screen printinks.
Sartomer’s acrylate monomers and oligomers provide all necessary reactive ingredients yielding the higher quality
flexographic, lithographic, and screen inks. Sartomer’s products are excellent pigment dispersives, let down materials for
optimizing adhesion, cure response enhancers and cured ink durability providers.
SMA® resins are low molecular weight styrene/maleic anhydride copolymers. They are available both as base resins and as
partial mono esters. Commercial products are supplied in solid form, either as flake or powder, and as aqueous ammonia
solutions. SMA® resins typically are harder, have higher glass transition temperatures, and offer higher acid numbers than
conventional styrene acrylic copolymers.
SMA® resins deserve recognition as effective agents for pigment wetting, grinding, and dispersing in waterborne inks and
coatings. Their outstanding performance in these applications facilitates the preparation of stable aqueous pigment dispersions
which have higher pigment/binder (P/B) ratios and higher pigment loadings than are recommended for competitive styrene/
acrylic systems. Despite their higher total solids, these dispersions exhibit lower viscosities and equal or better color
strength (when diluted to equal pigment loading) than do the styrene/acrylic dispersions.
4
Lithographic Inks
Lithographic Ink Formulating Lithographic inks are very viscous to the point that
The lithographic printing process is one in which the they are paste-like. Litho inks are generally very strong
image to be printed is rendered on a flat surface and in color value to compensate for the smaller amount
treated to retain ink while the non-image areas are typically applied. The various tones and shading are
treated to repel ink. Based on the principle that oil and achieved by overlaying the four basic shades of ink.
water do not mix, a plate is coated with a photopolymer
film or ink that is exposed to light through a Ultraviolet (UV) and Electron Beam (EB) curable inks
photographic mask. The exposed areas are chemically are available for litho printing. The use of UV curable
“hardened,� and the unexposed areas are dissolved inks is on the rise, particularly for the application of
when the plate is put through a chemical process during overprint coatings.
the next stage. When printing a page, the plate is
dampened, and the water adheres only to the One advantage in using UV and EB curable inks is the
unexposed, non-image areas, which repel the greasy low VOC content which allows printers to operate
ink that is applied to the plate immediately thereafter. presses at comparable speeds to conventional inks,
versus the slow drying and slow press speeds associ-
The most common lithographic printing uses the offset ated with water-based coatings.
method, in which the ink is “offset� onto a rubber-
coated cylinder that is pressed against the paper. In A schematic of the lithographic process is presented
commercial printing the term is used synonymously with below.
offset printing.
Lithographic Press
Setup Process
Lithographic
Ink De liv ery Ro lls
Ink Trough
Damping Rolls
Plate Cylinder
W ater Fountain
Impression Cylinder
Rubber Blanket Cylinder
W eb
5
The goal of the litho ink is to provide properties such SR355 and SR399 work well for EB litho inks
as
The table shows the physical properties of these
- a wide window for press operation monomers.
- water balance
- minimized tack loss after fountain solution addition
- high print quality Viscosity (25? Acrylates / Health Structure
C) Molecule Rating
- fast cure speed
SR355 500 4 1 DiTMPTA
- good final film properties
SR399 12000 4 2 DiPETA
- adhesion SR454 60 3 2 3 EO TMPTA
- scratch and scuff resistance SR492 90 3 2 3 PO TMPTA
CD564 23 2 1 3 PO HDDA
Sartomer Materials for Lithographic SR349 1500 2 2 3 EO BPADA
Formulations SR9003 15 2 2 2 PO NPGDA
Sartomer provides materials for UV curable SR9020 95 3 2 GPTA
lithographic formulations. These materials include
SMA resins, monomers, oligomers, and photoinitiators. Health Ratings are listed on the product MSDS.
Acrylates / molecule is an average.
Monomers
UV and EB curable lithographic inks contain Oligomers
monomers at 0 � 20% by weight of a formulation. Oligomers provide pigment wetting, dispersion, film
Monomers lower viscosity and tack. They increase toughness, scratch resistance, and adhesion. They are
cure rates and the crosslink density. Too much or the used at 60 - 80% of formulation. Some of the more
wrong kind of monomer can lead to poor water common oligomers used and their properties are listed
balance. Some of the more common monomers used below.
and their properties are listed below.
CN133
CD564 and SR9003 - Very fast epoxy acrylate
- Low viscosity - Low cost replacement for SR399
- Cut tack quickly
- Too much leads to water balance issues CN750 and CN790
- Promote adhesion when used up to 40%
SR492 and SR9020 - Good for lamination
- Hydrophobic - Good litho properties
- Excellent litho properties - CN750 is chlorinated
- Some pigment wetting CN2203
- Produce high viscosity inks with low tack
SR355, SR399 and SR454 - Very low or no misting inks
- Greatly increase cure speed - Excellent cure speed
- Increase film hardness - Works well in EB inks
SR349 CN293 and CN2295
- Very fast cure speed - Hydrophobic
- Toughness and scratch resistance of an - Good pigment wetting
oligomer - Very fast cure
- Good solubility with resins used in hybrid
SR9020 is the workhorse monomer for litho inks. litho inks
6
CN294 Photoinitiators
Sartomer uses Esacure® photoinitiators such as
- Similar backbone to CN293 and CN2295
Esacure® KS300, Esacure® TZT, and Esacure® ITX.
- Excellent pigment wetting
- Good litho properties
Esacure ® KS300 1 is 1-hydroxy-cyclohexyl-
- High viscosity with low tack
phenylketone. It is a highly reactive photoinitiator de-
CN2282 signed for UV coatings and inks based on epoxy acry-
- Fast cure lates, urethane acrylates, polyester acrylates, and mix-
- Yields tough films tures. The melting point is 62-64 °C and it soluble in
- Flexibility despite being tetrafunctional organic solvents & monomers. It provides fast cure
- Works well with CN790 for adhesion response, good through cure, and low color in cured
- Good litho properties films.
Esacure® TZT1 is a eutectic mixture of 2,4,6-
CN111US
- Used at up to 10% to increase flow of trimethylbenzophenone and 4-methylbenzophenone. It
inks is practically insoluble in water, but completely soluble
in most organic solvents, monomers, oligomers, and
CN118 resins. It provides high reactivity, is highly soluble, yields
- Very fast cure low odor and color in cured films. It also provides
- Hydrophobic good surface cure, fast cure response, good through
- Excellent litho properties cure, and adhesion. Its suggested use level is 0.2
percent by weight.
CN9167
Esacure® ITX1 is a photoinitiator that is used in
- High impact
- Resilient combination with a suitable coinitiator, e.g., ethyl 4-
- Water resistant (dimethylamino) benzoate (EDB), to initiate UV free
radical polymerization. Esacure® ITX1 is used in inks,
The table discusses the physcial properties of these varnishes, and decorative coatings. It provides fast cure
oligomers. response, good surface cure, good through cure, and
low odor in both clear and pigmented coatings. The
suggested use level is 0.25 - 1.5 weight percent.
1
supplied by Lamberti USA, Inc.
Viscosity Acrylates / Health Structure
Molecule Rating
25?C (60?C)
CN111US 26000 2.5 1 Epoxy Acrylate
CN118 (3090) 2 2 Epoxy Acrylate
CN133 18000 3 2 Epoxy Acrylate
CN293 7700 6 3 Polyester Acrylate
CN294 (4000) 4 3 Polyester Acrylate
CN750 (1750) 3 2 Polyester Acrylate
CN790 (2800) 3 2 Polyester Acrylate
CN2203 (1800) 4 2 Polyester Acrylate
CN2282 80000 4 2 Polyester Acrylate
CN2295 58000 6 2 Polyester Acrylate
7
Lithographic Ink Formulation starting point formulation. Properties were tested and
Sartomer has developed the following lithographic ink data is presented.
Sartomer Litho Ink Formulation
CN790 40.0% Polyester Acrylate, Adhesion to plastics
Black Pigment 20.0% Degussa Special Black 250
CN2282 13.0% Polyester Acrylate, Grinding Vehicle, Cure Speed, Film Properties
SR355 10.0% Di-TMPTA, Cure speed
Irgacure® 907 3.5% PI for curing dark inks supplied by Ciba Specialty Chemicals
Esacure® KS300 3.0% PI for curing the bulk supplied by Lamberti USA, Inc.
Esacure® TZT 1.0% PI for curing the surface supplied by Lamberti USA, Inc.
Esacure® ITX 0.5% PI sensitizer supplied by Lamberti USA, Inc.
Talc 3.0% Luzenac America Artic Mist
Polyethylene Wax 1.0% Shamrock S394-SD4
The graph below presents the adhesion and surface Brookfield DVIII+ Rheometer using a CP52 spindle.
energy of the litho ind formulation on various substrates. Rheology 2
Plastic Viscosity
71,558 cps
100 39
90 38
80 37
Surface Energy (D/cm)
Yield Stress
70 36
% Adhesion
784 D/cm2
60 35
50 34
40 33
Cure Speed 4
30 32
20 31
400 W/in H bulb
10 30
200 fpm
0 29
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Cure Speed
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Cure Speed was run with a Fusion 400 W/in H bulb.
cr
A
The peak irradiance was determined using an EIT
Power Puck at 30 fpm.
Sartomer Litho Ink Formulation Properties
Properties essential to developing a good lithographic
250-260 nm � 110 mW/cm2
ink - tack, yield stress, plastic viscosity, yield stress,
280-320 nm � 620 mW/cm2
cure speed, and water pickup were analyzed for the
320-390 nm � 850 mW/cm2
formulation descirbed previously.
395-445 nm � 740 mW/cm2
Tack
.
Water Pickup
Tack was run on a Thwing-Albert Inkometer.
Water Pickup was tested on a Duke Emulsification
400 rpm � 10.8
Tester using Emerald Green fount. Water Pickup
800 rpm � 15.2
31.2%
1200 rpm � 19.5
Very low misting
Yield Stress and Plastic Viscosity
Yield Stress and Plastic Viscosity were run on a
8
Flexographic Inks
Flexographic Ink Formulating Sartomer Materials for Flexographic
In the typical flexo printing process, the substrate is Formulations
fed into the press from a roll. The image is printed as Sartomer provides materials for UV curable
the substrate is pulled through a series of stations or flexographic formulations. These materials include
print units where each print unit is printing a single color. SMA resins, monomers, oligomers, and photoinitiators.
As with gravure and lithographic printing, the various
tones and shading are achieved by overlaying the four Monomers
basic shades of ink. Flexography is the major process Monomers are typically used in flexographic
used to print packaging materials. Flexography is used formulations at 30 - 60 weight percent of the
to print corrugated containers, folding cartons, multiwall formulation. Chosing the correct monomers for use is
sacks, paper sacks, plastic bags, milk and beverage critical. The incorrect type of monomer can lead to
cartons, disposable cups and containers, labels, plate swell and registration issues. Monomers provide
adhesive tapes, envelopes, newspapers, and wrappers lower viscosity, increased cure rates, adhesion, and
(candy and food). lower crosslink density. Some suggested monomers
are reviewed along with the performance properties
UV flexo inks are commonly used for top coats and they provide.
lacquers. The use of UV curable colored inks is rising
within the flexographic printing industry because UV SR531
is responsible for many improvements in the image qual- - Increases flexibility of system without
ity of flexographic printing. decreasing toughness
- Allows for thermoformability
UV curable flexographic printing operations require
low viscosity inks which are generally 500 � 1200 cps SR492
in voscosity depending on color and substrate. They - Increase cure speed
must have excellent adhesion to plastic films, fast cure - Pigment grinding capabilities
( generally running on 300 fpm printing lines), excel-
lent stability, no flocculation of pigments which will SR601
leads to viscosity and color strength change, and no - Very fast cure speed
polymerization. - Toughness and scratch resistance of an
exographic Press oligomer
A schematic of the flexographic process is presented
etup below. SR339
- Adhesion to polar plastics
Anilox Roll
SR355, SR399LV, SR454, and SR494
- Greatly increase cure speed
Plate Ro ll
- Increase film hardness
Impress ion Ro ll
SR508, CD562, and SR9003
- Low viscosity
Chambered Doctor Blade
Substrate
9
SR9003 Viscos ity Acrylates / Hea lth Structure
Molecule Rating
25Ëš C (60Ëš C)
- Has some pigment grinding capability
CN293 7700 6 3 Polyester Acrylate
- All are good diluents of other UV CN2284 320 2 3 Polyester Acrylate
components CN2282 80000 4 2 Polyester Acrylate
- Improved transfer CN2278 250 4 3 Polyester Acrylate
- Weatherability (in some instances)
Oligomer Letdowns for UV Flexo
Letdowns provide additional physical properties such
The physical properties of these monomers are
as weatherability, cure speed, and adhesion.
presented in the table.
Viscos ity Acrylates / Hea lth Structure Viscos ity Acrylates / Hea lth Structure
(25° C) Molecule Rating Mo lecule Rating
25Ëš C (60Ëš C)
CD562 15 2 2 2 EO HDDA CN131B 250 1 2 Epoxy Acrylate
SR238 10 2 2 HDDA CN132 900 2 2 Epoxy Acrylate
SR339 12 1 2 2-PEA CN133 18000 3 2 Epoxy Acrylate
CN371 1700 2 2 Amine Acry late
SR355 500 4 1 DiTMP TA
CN386 US 25 1 2 Amine Acry late
SR399LV 7000 4 2 DiPETA
CN929 (400) 3 2 AL Urethane Acrylate
SR454 60 3 2 3 EO TMP TA
CN991 (660) 2 2 AL Urethane Acrylate
SR492 90 3 2 3 PO TMP TA
CN2262 500 4 2 Polyester Acrylate
SR494 150 4 3 4EO PETA
CN2270 55 2 2 Polyester Acrylate
SR508 10 2 3 DPGDA
CN2281 1000 2 2 Polyester Acrylate
SR531 15 1 2 CTFA
CN9006 (1800) 6 2 AL Urethane Acrylate
SR601 1080 2 2 4 EO BP ADA
SR9003 15 2 2 2 PO NP GDA
Health Ratings were pulled from the product MSDS
Acrylates / molecule is an average
Viscosities in red are at 60 °C
Grinding Vehicles for UV Flexo
Oligomers for UV Flexo Cure
Grinding vehicles are essential in the development of
Oligomers provide an ink with physical property
flexographic inks. These vehicles will efficiently break
enhancements which improve performance. Listed are
down pigment agglomerates and will allow for efficient
oligomers which are used in UV curable flexo inks.
stabilization. Using these vehicles will increase flow,
stability, and color development of the ink.
CN132 and CN133
- Increase cure speed
CN293
- Hard films
- Contains PETA
- CN132 increase opacity of white
- Excellent pigment dispersion
pigmented inks
- Very fast cure speed
CN131B
CN2278
- Low viscosity
- Low viscosity
- Enhances adhesion to plastics
- Fast cure
- Flexible and thermoformable
- Good pigment dispersion
- Good cure rate
CN2282
CN9006, CN991, and CN929
- New for pigment dispersion
- Aliphatic urethane acrylates
- Good cure speed
- Used to formulate weatherable flexo inks
- Excellent toughness
CN9006
CN2284
- Is very hard and fast curing
- Designed for UV flexo dispersions
CN991 and CN929
- Flexibility
Grinding verhicle properties are shown in the table.
10
CN2281 CN2270
- Low viscosity - Low viscosity
- Excellent cure rate - Excellent flow properties
CN2282 - Some pigment wetting
- Higher viscosity CN2262
- Good flexibility - Good toughness
- Excellent cure - Low cost
- Enhances film toughness CN371
- Higher viscosity
- Fastest surface cure speed
- Very low extractables
CN386US
- Lower viscosity
CMYK Millbases
- Fast surface cure
The millbase is the first step, and most crucial, in
- Higher extractables
making a UV flexo ink. The millbase contains
- Higher yellowing
pigment, oligomer, monomer, and a dispersant.
The dispersant is needed to provide long term
flocculation stability.
Black Cyan Yellow Magenta
Pigment PBk 7 PB 15:4 PY 14 PR 57:1
Special Black 250 Irgalite GLVO Irgalite AXL Rubine L6B05
Supplier Code
Degussa Ciba Ciba Clariant
Supplier
% Pigment 40.0 40.0 35.0 35.0
% CN2282/monomer 53.0 53.0 60.4 20.0
blend
% SR492 38.0
1
% Solsperse 39000 7.0 10.0 4.6 7.0
Particle Size 0.4 0.3 0.3 0.2
Yield Stress 2 10 4 2
Plastic Viscosity 1450 2200 1570 1300
11
CMYK Flexo Inks the letdowns, many different inks can be made from
The millbases are let down with monomer, oligomer, the same millbase.
photoinitiator, and additives into the final ink. by varying
Black Cyan Yellow Magenta
% Millbase 50.0 50.0 57.0 57.0
% SR355 22.0 22.0 15.0 15.0
% CN386US 10.0 10.0 10.0 10.0
% CN2262 8.0 8.0 8.0 8.0
Irgacure® 3691 3.5 3.5 3.5 3.5
Esacure® KS3002 3.0 3.0 3.0 3.0
Esacure® TZT2 1.0 1.0 1.0 1.0
Esacure® ITX2 0.5 0.5 0.5 0.5
Everglide® UV6363 1.0 1.0 1.0 1.0
Byk®-UV35004 0.5 0.5 0.5 0.5
Byk®-088 0.5 0.5 0.5 0.5
1
supplied by Ciba Specialty Chemicals
2
supplied by Lamberti USA, Inc.
3
supplied by Shamrock Technologies
4
supplied by Byk Chemie
Magenta Flexo Ink 100 46
90
Properties 44
80
Cure Speed
42
Surface Energy (D/cm)
Cure Speed was run with a Fusion 400 W/in H bulb 70
at 650 fpm. Prints were made with a 600 line/in anilox 40
% Adhesion
60
Cavanaugh hand proofer. 11 mJ/cm2 was the energy.
50 38
40
Yield Stress and plastic viscosity 36
Yield Stress and Plastic Viscosity were run on a 30
34
Brookfield DVIII+ Rheometer with a CP42 spindle. 20
Yield stress was 2.0 D/cm2 and plastic viscosity was 605 32
10
cps.
0 30
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Surface Energy
12
Screen Inks
Screen printing inks are moderately viscous inks which Oligomers
exhibit different properties when compared to other Give the cured ink the main attributes
printing inks such as offset, gravure and flexographic Toughness
inks though they have similar basic compositions. There Weatherability
are five different types of screen inks but the focus in Scratch resistance
this bulletin is on UV curable screen inks. Some provide adhesion
The screen printing process uses a porous mesh Monomer Properties for UV Screen
stretched tightly with proper tension for to accurate
Viscos ity Acrylates / Health Structure
color registration over a frame made of wood or metal.
(25Ëš C) Mo lecule Rating
The mesh is made of porous fabric or stainless steel
SR238 10 2 2 HDDA
mesh. A stencil is produced on the screen photochemi- SR285 6 1 3 THF A
cally and defines the image to be printed. SR339 12 1 2 2-PEA
SR368 Solid 3 3 THEICTA
Screen printing ink is applied to the substrate by plac- SR399LV 7000 4 2 DiPETA
ing the screen onto which ink with a paint-like consis- SR454 60 3 2 3 EO TMPTA
SR506 9 1 1 IBOA
tency has been placed. Ink is then forced through the
SR531 15 1 2 CTF A
fine mesh openings using a squeegee that is drawn
SR601 1080 2 2 4 EO BPADA
across the screen, applying pressure thereby forcing
the ink through the open areas of the screen. Ink will
Health Ratings were pulled from the product MSDS
pass through only in areas where no stencil is applied,
Acrylates / molecule is an average
thus forming an image on the printing substrate. The
diameter of the threads and the thread count of the
Suggested Monomers
mesh will determine how much ink is deposited onto
SR531
the substrates.
Increases flexibility of system without
decreasing toughness
Screen Ink Formulation Goals
Allows for thermoformability
SR399LV and SR454
Excellent adhesion to many substrates
Increase cure speed
Flow under shear stress
Pigment grinding capabilities
Good printability through screen
SR601
Good resolution
Very fast cure speed
Excellent color fastness
Toughness and scratch resistance of
Balance of cure speed and flexibility
an oligomer
Possible weatherability
SR238 and SR285
Adhesion to difficult substrates
Monomers
High Draize value limits use
Lower the viscosity of the formulation
SR506
Provide adhesion through substrate swelling
Common diluent used in screen inks
Allow for adjustment of hardness or softness
High Tg
of the cured ink
Odor issue
Increase cure speed
SR339
Increase solvent resistance with crosslink
Adhesion to polar plastics
density
SR368
Increase scratch and abrasion resistance
13
Oligomer Properties for UV Screen CN710
New oligomer for adhesion to plastics
Designed for choroplast
Viscosity Acrylates / Health Structure
Mo lecule Rating
Works well on many plastics
25Ëš C (60Ëš C)
CN131B 250 1 2 Epoxy Acrylate
CN991
CN133 18000 3 2 Epoxy Acrylate
Weatherable
CN371 1700 2 2 Amine Acrylate
CNUVE151 150000 2 2 Epoxy Acrylate
Flexible
CN710 (1740) 1 2 Polyester Acrylate
Low viscosity
CN963B80 (1100) 2 2 AL Uretha ne Acrylate
CN966B85 (5810) 2 2 AL Uretha ne Acrylate
CN963B80
CN981 (10900) 2 1 AL Uretha ne Acrylate
CN991 (660) 2 2 AL Uretha ne Acrylate
Weatherable
CN2262 500 4 2 Polyester Acrylate
Very hard
CN9001 (46500) 2 1 AL Uretha ne Acrylate
CN9893 (25000) 2 1 AL Uretha ne Acrylate
CN981
Good combination of flexibility and
Suggested Oligomers toughness
Good adhesion to plastics such as
CN131B polyesters
Increases flexibility of system
CN966B85
Allows for thermoformability
Very flexible oligomer
CN133
Also available in IBOA and EOEOEA cuts
Increase cure speed
to change properties
Increases hardness
Excellent adhesion
CN371
Poor scratch resistance
Aids in surface cure
CN9001
CN2262
Thermoformable
Low cost oligomer
Excellent toughness with good elongation
Good toughness and abrasion resistance
weatherable
CNUVE151
CN9893
Flexible epoxy acrylate
Very flexible oligomer
Screen Ink Formulation
CN710 60.0% Experimental Polyester Acrylate for adhesion
SR531 14.5% CTFA
CN371 5.0% Amine acrylate for promoting surface cure
Cyan Pigment 4.0% Sun 249-2083
Irgacure® 3691 3.5% Red shifted PI for dard colors
Esacure® KS3002 3.0% Bulk cure
Esacure® TZT2 1.0% Surface cure
Esacure® ITX2 0.5% PI sensitizer
Aerosil 200 5.0% Degussa fumed silica
CN307 2.0% Acrylated Poly Bd for improved flow and release
394-SD4 1.0% Shamrock polyethylene wax
Byk®-088 0.5% Byk defoamer
1
supplied by Ciba Specialty Chemicals
2
supplied by Lamberti USA, Inc.
14
Bi
% Adhesion
ax
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ly
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0
10
20
30
40
50
60
70
80
90
100
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Adhesion Properties
C cC s
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C F in l as
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26
28
30
32
34
36
38
40
42
44
46
% Adhesion
Surface Energy (D/cm)
Surface Energy
SMA® Resins in High P/B Dispersions and Stable Inks
SMA® resins are low molecular weight styrene/maleic rise over time or with heat aging. The loss of stability
anhydride copolymers. They are available both as base can be due to inadequate adsorption of the polymer
resins and as partial mono esters. Commercial products onto the pigment surface, or orientational phenomena
are supplied in solid form, either as flake or powder, related to the pigment:polymer association that limit
and as aqueous ammonia solutions. SMA® resins the adsorption layer thickness.
typically are harder, have higher glass transition
With phthalo blue pigments, SMA ® 17352H
temperatures, and offer higher acid numbers than
conventional styrene acrylic copolymers. demonstrated better color stability in the dispersion
over time than did some competitive acrylic resins.
SMA® resins deserve recognition as effective agents
for pigment wetting, grinding, and dispersing in With various metallized azo red pigments, dispersions
made from these pigments follows: SMA® 17352H
waterborne inks and coatings. Their outstanding
performance in these applications facilitates the will produce more viscosity stable dispersions at
preparation of stable aqueous pigment dispersions higher pigment to binder ratios than typical styrene
which have higher pigment/binder (P/B) ratios and acrylic resins. Examples of dispersions made from
higher pigment loadings than are recommended for these pigments are as follows:
competitive styrene/acrylic systems. Despite their
Dispersion of Lithol Rubine with SMA® 17352
higher total solids, these dispersions exhibit lower
viscosities and equal or better color strength (when
diluted to equal pigment loading) than do the styrene/ Dispersion Preparation:
The RD 5721(1) pigment was dispersed at 6:1 p/b ratio
acrylic dispersions.
and 38% loading for the SMA® formulas, and 4:1 p/b
This bulletin will describe the preparation of some at 38% pigment loading for the Competitive Acrylic
typical SMA® dispersions with various pigments and formulas. A 50:50 blend of a Competitive Acrylic and
SMA® 17352H was also used to make one of the
will show how these dispersions can be used to prepare
stable inks with a variety of commercial emulsions. The dispersions.
SMA®s were used as aqueous ammoniacal solutions,
indicated by the “H� which follows their identifying Premixes were made using a blender. All liquid
number. ingredients (with the exception of 28 g of water, which
is retained by the mill media from a prior rinse and
Typical Properties of SMA® 17352H becomes part of the batch) were weighed into the
% Solids 24.0 - 26.0 blender and mixed for 30 seconds to homogenize. The
Acid Number (of Solid Resin) 270 pigment was weighed into the blender and allowed to
pH 8.0 - 9.5
mix at slow speed for two minutes to begin the process
Tg (glass transition temperature
of wetting it out. The sides of the blender were scraped
124 °C
of the solid resin)
down, and the pigment subsequently premixed at high
Surface Tension (1% solution) 36.9 dynes/cm
speed for fifteen minutes.
SMA® Demonstrates Excellent Color and
After the premix step, the dispersions were milled for
Viscosity Stability
various grind times based on their viscosity/amperage
Color and viscosity stability are important parameters
draw (see below) on an Eiger Mini-100 mill using 0.8-
of any dispersion formulation. Color stability refers to
1.0 mm zirconium silicate beads and 5000 rpm.
the retention of color strength as the dispersion ages,
either at ambient or elevated temperature conditions.
The first 30 ml of liquid was removed from the mill on
Viscosity stability refers to the minimization of viscosity
recirculation and discarded.
16
Lithol Rubine Dispersions with SMA® 17352H
FORMULA 1 FORMULA 2 FORMULA 3
Uhlich RD 5721(1) 171.00 171.00 171.00
Competitive Acrylic 142.50 —â?? 52.78
SMA 17352H(11) —â?? 118.75 52.78
Dehydran® 4100(2) 3.15 3.15 3.15
Water 133.35 157.10 170.29
TOTAL 450.00 450.00 450.00
Pigment Loading 38% 38% 38%
P/B 4 6 6
Resin % 9.5 6.33 6.33
The SMA®-containing dispersion was much lower in account for this.
viscosity and therefore exhibited only about half the
amperage draw on the mill as the did the Competitive No scratches were seen on the gauge; “pepper� or
Acrylic dispersion. The grind times were adjusted to speckle frequency noted as follows:
FORMULA 1 Competitive Acrylic, 10 minutes slight speckle 4 amps
SMA® 17352H, 20 minutes
FORMULA 2 moderate speckle between 4-10 NPIRI 2.5 amps
FORMULA 3 50:50 Comp. Acrylic/17352, 20 min. moderate speckle between 4-10 NPIRI 2.0 - 2.5 amps
The purpose in adjusting the grind times was to Brookfield LVF viscometer. Tint strengths of the
equalize, as much as possible, the amount of work original dispersions as well as their 35% counterparts
being done on the pigment. Lower viscosity bases are were measured.
advantageous but may produce erroneous results when
compared to higher viscosity bases milled for the same Results and Discussion:
amount of time. This is because the higher viscosity The reductions of these dispersions to 35% produced
bases may develop more color than the lower viscosity the following viscosities (60 rpm, Brookfield LVF):
bases due to higher shear forces generated in the mill,
Formula 1 Competitive Acrylic 1062 cps
rather than due to any specific interactions between
Formula 2 17352H 125 cps
the pigment and the resin.
Formula 3 17352/Competitive Acrylic 756 cps
The SMA®-containing dispersions were much lower
Inks were made from these dispersions per the
in viscosity, which explains why it took longer to
formulas below and proofed on Leneta 3NT-3. These
achieve acceptable grind. The conclusion here is that
inks were prepared by making the vehicle first (all
they could ultimately be loaded higher in pigment (to
components except pigment dispersion) and then
about 40% pigment loading by weight).
adding this vehicle to the pigment dispersion with
mixing. Brookfield viscosities of the inks were
After milling, the dispersions were reduced to 35%
subsequently measured.
pigment loading and their viscosities measured on a
17
INK FORMULATIONS FROM SMA®-BASED DISPERSIONS
INK A INK B INK C
17352H dispersion —â?? 34.29 —â??
Competitive Acrylic dispersion 34.29 —â?? —â??
Comp. Acryl./17352H dispersion —â?? —â?? 34.29
Competitive Acrylic 13.33 —â?? 7.40
SMA® 17352H —â?? 12.50 7.41
XHD 47J(4) 0.50 0.50 0.50
ECO 2177(3) 47.92 52.08 50.00
Water 3.96 0.63 0.40
TOTAL 100.00 100.00 100.00
Pigment Loading 12.00 12.00 12.00
Solution resin % 7.00 5.00 6.00
Emulsion resin % 23.00 25.00 24.00
TOTAL SOLIDS, % 42.00 42.00 42.00
24 hour and 1 month 60 rpm viscosities of the inks were as follows :
24 hr 1 month
INK A Competitive Acrylic/2177 system 157.0 cps 235 cps
INK B 17352/SMA 172.5 cps 199 cps
INK C 50/50 [Competitive Acrylic/17352]/ 2177 250 cps 165 cps
The inks which contained 17352 were the most shock rhodamine (Pigment Red 81), which, due to its inherent
stable. Inks made from the competitive solution resin chemistry, tends to be unstable in alkaline waterbased
exhibited some shocking. All the inks printed at higher media. SMA® 17352H makes a thin and stable
color density than the Competitive Acrylic control, yet dispersion at 6/1 pigment:binder ratio that is compatible
were at comparable (or lower) viscosity at one month. with acrylic letdown resins:
The combination of SMA® 17352H and Competitive
Acrylic produced dispersions and inks that were the Example formulation at 38% pigment loading:
lowest in viscosity upon aging.
RD 8181(5) 171.00
Color strength (tint) measurements of the dispersions SMA 17352H 118.75
showed all SMA® containing formulas to have slightly DeeFo XHD 47J 5.00
higher strength (4 � 5%) than the Competitive Acrylic Water 155.25
controls. The 17352 containing dispersions showed
the highest color strength and stability overall. TOTAL 450.00
In general, many reds showed better color and viscosity This can be media milled in accordance with the above
stability when dispersed with SMA® 17352H vs. procedures, taking care that the millbase temperature
typical styrene acrylics. Another example is that of does not exceed 120°F, as the pigment is sensitive to
color changes upon prolonged heating.
18
An equivalent formula made with the Competitive Dispersion of Calcium Lithol with
SMA® 17352H
Acrylic at its recommended use level of 4:1 P/B
produced a dispersion which became solid in 2�3 days. Another metallized azo red that has the tendency to
Rhodamine dispersions at 4:1 and 6:1 P/B with SMA® be unstable in aqueous systems is Pigment Red 48:2.
17352 remained fluid and low in viscosity (< 200 cps The dispersions below were prepared in accordance
for 6/1) even after two months aging. with the same procedure described above:
Calcium Lithol Dispersions with SMA® 17352H
Formula A Formula B Formula C
Competitive acrylic @ 36.6% solids 33.30 17.30 —â??
SMA® 17352H @ 24.3% solids —â?? —â?? 26.10
Permanent Red 2B(12) 33.00 38.00 38.00
Surfynol® DF-70(13) 1.00 1.00 1.00
Dee Fo® 1144A/75(10) —â?? —â?? 0.50
Water 32.70 43.70 34.40
TOTAL 100.00 100.00 100.00
Pigment 33.00% 38.00% 38.00%
Resin 12.10% 6.33% 6.33%
P/B 2.7 6.0 6.0
Viscosities of the dispersions were measured and compared at ambient and with heat aging (7 days at 60°C):
24 hr. ambient 7 days ambient 7 days heat aged
Formula A B C A B C A B C
RPM
0.5 1600 6000 128 5058 3988 182 4808 23500 320
2.5 640 3300 126 2138 1715 141 1920 9100 256
5 416 2300 102 1517 1203 109 1382 6300 205
10 278 1500 98 1101 861 93 1050 4450 186
50 119 520 60 408 64 1990 93
Formula A - Competitive acrylic dispersion, 33% pigment
Formula B - Competitive acrylic dispersion, 38% pigment
Formula C - SMA® 17352H dispersion, 38% pigment
19
Calcium Lithol Dispersion Viscosities, 38% pigment
loading
10000
9000
8000
7000
6000
Viscosity, cps
5000
4000
3000
2000
1000
0
0 10 20 30 40 50 60
Brookfield RPM
Formula B, 24 hr. ambient Formula B, 7 days ambient
Formula B, 7 days heat aged Formula C, 24 hr. ambient
Formula C, 7 days ambient Formula C, 7 days heat aged
Inks made from SMA® 17352 dispersion showed
It is apparent from the dispersion viscosity data that
the SMA® 17352 dispersion is much lower in viscosity. similar low shear viscosity but higher high shear
This holds true at equal pigment solids or lower pigment viscosity, which is conducive to better ink transfer
solids to the acrylic-containing dispersion, whether (lower pseudoplasticity):
ambient or heat-aged.
INK FORMULAS:
CALCIUM LITHOL INKS
SMA® 17352H
Comp. Acrylic
Competitive acrylic @ 36.6% solids 6.40 —â??
SMA® 17352H —â?? 19.20
Pigment Dispersion* 42.40 36.80
Surfynol DF-70 0.20 0.20
Lucidene® 605(15) 42.80 42.80
Water 8.20 1.00
TOTAL 100.00 100.00
Pigment 14.00% 14.00%
TOTAL SOLIDS 42.00% 42.00%
* 33% pigment loading dispersion used for acrylic formula, 38% pigment loading dispersion used for SMA® 17352 formula.
20
Red 48:2 Inks - Lucidene 605 emulsion letdown
after 7 days ambient aging
SMA® 17352
Comp. Acrylic
RPM
0.5 992 960
2.5 422 736
5 298 630
10 221 534
50 122 354
Ink Viscosities, 7 day am bient aging
1200
1000
800
600
400
200
0
0 10 20 30 40 50 60
B r ookf i el d R P M
Comp. Acrylic SMA 17352
Dispersion of Phthalo Blue With SMA® 17352
Comparative tint strengths of these inks showed the
SMA®-containing ink to be 22% stronger than the all- These dispersions were prepared at 6/1 pigment:
binder ratio and 41% pigment loading, using the
acrylic ink. This is indicative of lower amounts of
procedures outlined above. The exception here is that
pigment flocculation, either on preparation or on aging
of the SMA® ink. all the dispersions were milled for 15 minutes.
BLUE Dispersion A BLUE Dispersion B
Competitive acrylic @ 34% solids 20.4 —â??
SMA® 17352 @ 24% solids —â?? 28.5
PB 15:3 (Aarbor International) 41.0 41.0
Dee Fo XHD 47J(4) 0.5 —â??
Dee Fo PI-35(6) —â?? 0.5
Water 38.1 30.0
TOTAL 100.0 100.0
21
The viscosity of the SMA®-based dispersion was dispersion lost more color strength ( ~ 10+%) over
time than did the SMA® dispersion (~ 3%).
higher than that of the Competitive acrylic standard
(2150 cps @ 60 rpm vs. 652 cps @ 60 rpm).
Similarly, with Daicolor Pope DC 3127, but at optimal
Color development for both dispersions was equal pigment:binder ratios for the resins:
initially, but it was noted that the Competitive acrylic
BLUE Dispersion C BLUE Dispersion D
Competitive acrylic @ 34% solids —â?? 27.9
SMA® 17352H @ 24% solids 28.5 —â??
DC 3127(9) 41.0 38.0
Dee Fo XHD 47J —â?? 0.5
Dee Fo PI-35 0.5 —â??
Water 30.0 33.6
TOTAL 100.0 100.0
P/B: 6/1 4/1
The SMA® dispersion was able to be prepared at 41% dispersion can be added to the vehicle, but a small
pigment loading, whereas the competitive acrylic degree of pigment flocculation can occur. Adding the
dispersion could only be prepared at 38% pigment dispersion with agitation can mitigate this, though not
loading. This was still too viscous for an adequate totally prevent it.
viscosity measurement to be taken. The SMA®-
containing dispersion was 3700 cps at 60 rpm on a Though all pigment dispersions demonstrate slight
flocculation when added in this manner, SMA® 17352
Brookfield LVF, however.
has demonstrated more resistance to this effect in many
Again, in measuring color strength, both dispersions pigment systems at high pigment: binder than do typical
when adjusted to equal pigment loading exhibited styrene-acrylics at lower pigment: binder levels.
similar color development, but over time, the Susceptibility to this behavior is dependent not only
Competitive acrylic dispersion lost 10% color strength. on the dispersant system and p:b ratio, but also on the
components of the letdown vehicle and the nature of
A Note Regarding Ink Preparation: the pigment in question.
A difficulty which is often encountered when preparing
In summary, SMA® 17352 provides:
inks from pigment dispersions (especially those which
have high pigment loading) is “shocking�. This
�
destabilization of the dispersion, caused by flocculation Stable dispersions with high pigment:binder
of the pigment, can occur during the introduction of ratiosthis allows for a higher solids content and
the letdown vehicle to the pigment dispersion. It is consequent increase in throughput. Also, this
especially a problem with mechanical ink blending/ reduces binder level, giving more formulation
metering systems in which the ingredients of the ink flexibility.
are introduced together without continuous mixing.
� Lower viscosity dispersions with reduced
The best way to avoid pigment flocculation when using pseudoplastic behavior vs. dispersions made with
any pigment dispersion is to prepare the let down conventional acrylic dispersing resins.
vehicle separately and add it to the pigment
�
dispersionwith mixing. If this is not practical, the Stable inks with improved long-term shear and
color stability.
22
Products Mentioned
(1) RD 5721 Pigment Red 57:1 Uhlich Color
(2) Dehydran® 4100 Defoamer Henkel KGAA
(3) ECO 2177 Acrylic Emulsion Johnson Polymer
(4) XHD 47J Defoamer Ultra Additives, Inc.
(5) RD 8181 Pigment Red 81 Uhlich Color
(6) Dee Fo® PI-35 Defoamer Ultra Additives, Inc.
(8) XJH 123 Defoamer Ultra Additives, Inc.
(9) DC 3127 Pigment Blue 15:3 Daicolor Pope
(10) Dee Fo 1144 A/75 Defoamer Ultra Additives
(11) SMA® 17352H Styrene/Maleic Anhydride Copolymer Sartomer Company
(12) Permanent Red 2B Pigment Red 48:2 Engelhard
(13)Surfynol® DF-70 Defoamer Air Products & Chemicals, Inc.
(14) SCX 2660 Acrylic Emulsion Johnson Polymer
(15)Lucidene® 605 Acrylic Emulsion Rohm and Haas Company
Dehydran® is a registered trademark of Henkel KGAA
Dee Fo® is a registered trademark of Ultra Additives, Inc.
SMA® is a registered trademark of Sartomer Company.
Surfynol® is a registered trademark of Air Products and Chemicals, Inc
Lucidene® is a registered trademark of Rohm and Haas Company
23
Sales Offices
Sartomer Company, Inc.
Oaklands Corporate Center
502 Thomas Jones Way
Exton, PA 19341
Tel: 610-363-4100
Fax: 610-363-4140
E-mail: contact@sartomer.com
Cust. Serv.: 800-SARTOMER
Web: www.sartomer.com
For updated contact information world wide, please refer to Sartomer's web-site at:
http://www.sartomer.com/sales.asp
The information in this bulletin is believed to be accurate, but all recommendations are made without warranty since the conditions of use are beyond SARTOMER Company's
control. The listed properties are illustrative only, and not product specifications. SARTOMER Company disclaims any liability in connection with the use of the information,
and does not warrant against infringement by reason of the use of its products in combination with other material or in any proces
1540 02/08
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