Cray Valley Products For · PDF fileCray Valley Products For Inks Acrylate Oligomers ... have...

SMA® Resins

Cray Valley ProductsFor Inks

Acrylate Oligomers

Acrylate Monom

ers

Photoinitiators

TABLE OF CONTENTS

INTRODUCTION ........................................................................................ 4LITHO GRAPHIC INKS .............................................................................. 5FLEXOGRAPHIC INKS ............................................................................. 9SCREEN INKS .......................................................................................... 13SMA® RESINS IN HIGH P/B DISPERSIONS & STABLE INKS ................... 16

4

INTRODUCTION

Cray Valley offers several product lines for use in inks. SMA resins, acrylate oligomers, and acrylate monomers are all usedin the ink industry for lithographic, flexographic and screen printinks.

Cray Valley’s acrylate monomers and oligomers provide all necessary reactive ingredients yielding the higher qualityflexographic, lithographic, and screen inks. Cray Valley’s products are excellent pigment dispersives, let down materials foroptimizing 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 aspartial mono esters. Commercial products are supplied in solid form, either as flake or powder, and as aqueous ammoniasolutions. SMA® resins typically are harder, have higher glass transition temperatures, and offer higher acid numbers thanconventional styrene acrylic copolymers.

SMA® resins deserve recognition as effective agents for pigment wetting, grinding, and dispersing in waterborne inks andcoatings. Their outstanding performance in these applications facilitates the preparation of stable aqueous pigment dispersionswhich 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 colorstrength (when diluted to equal pigment loading) than do the styrene/acrylic dispersions.

5

Lithographic Inks

Plate CylinderPlate Cylinder

Rubber Blanket CylinderRubber Blanket Cylinder

Impression Cylinder

Web

Impression Cylinder

Web

Ink Trough Ink Delivery RollsInk Trough Ink Delivery Rolls

Water Fountain

Damping Rolls

Water Fountain

Damping Rolls

Lithographic Press Setup

Lithographic Ink FormulatingThe lithographic printing process is one in which theimage to be printed is rendered on a flat surface andtreated to retain ink while the non-image areas aretreated to repel ink. Based on the principle that oil andwater do not mix, a plate is coated with a photopolymerfilm or ink that is exposed to light through aphotographic mask. The exposed areas are chemically“hardened,” and the unexposed areas are dissolvedwhen the plate is put through a chemical process duringthe next stage. When printing a page, the plate isdampened, and the water adheres only to theunexposed, non-image areas, which repel the greasyink that is applied to the plate immediately thereafter.

The most common lithographic printing uses the offsetmethod, in which the ink is “offset” onto a rubber-coated cylinder that is pressed against the paper. Incommercial printing the term is used synonymously withoffset printing.

Lithographic inks are very viscous to the point thatthey are paste-like. Litho inks are generally very strongin color value to compensate for the smaller amounttypically applied. The various tones and shading areachieved by overlaying the four basic shades of ink.

Ultraviolet (UV) and Electron Beam (EB) curable inksare available for litho printing. The use of UV curableinks is on the rise, particularly for the application ofoverprint coatings.

One advantage in using UV and EB curable inks is thelow VOC content which allows printers to operatepresses at comparable speeds to conventional inks,versus the slow drying and slow press speeds associ-ated with water-based coatings.

A schematic of the lithographic process is presentedbelow.

Lithographic Process

6

GPTA2395SR9020

3 EO BPADA221500SR349

3 EO TMPTA2360SR454

3 PO TMPTA2390SR492

3 PO HDDA1223CD564

2 PO NPGDA2215SR9003

2

1

Health Rating

4

4

Acrylates / Molecule

DiPETA12000SR399

DiTMPTA500SR355

StructureViscosity (25?C)

The goal of the litho ink is to provide properties suchas

- a wide window for press operation - water balance - minimized tack loss after fountain solution addition - high print quality - fast cure speed - good final film properties - adhesion - scratch and scuff resistance

Cray Valley Materials for LithographicFormulationsSartomer provides materials for UV curablelithographic formulations. These materials includeSMA resins, monomers, oligomers, and photoinitiators.

MonomersUV and EB curable lithographic inks containmonomers at 0 – 20% by weight of a formulation.Monomers lower viscosity and tack. They increasecure rates and the crosslink density. Too much or thewrong kind of monomer can lead to poor waterbalance. Some of the more common monomers usedand their properties are listed below.

CD564 and SR9003 - Low viscosity - Cut tack quickly - Too much leads to water balance issues

SR492 and SR9020 - Hydrophobic - Excellent litho properties - Some pigment wetting

SR355, SR399 and SR454 - Greatly increase cure speed - Increase film hardness

SR349 - Very fast cure speed - Toughness and scratch resistance of anoligomer

Health Ratings are listed on the product MSDS.Acrylates / molecule is an average.

OligomersOligomers provide pigment wetting, dispersion, filmtoughness, scratch resistance, and adhesion. They areused at 60 - 80% of formulation. Some of the morecommon oligomers used and their properties are listedbelow.

CN133 - Very fast epoxy acrylate - Low cost replacement for SR399

CN750 and CN790 - Promote adhesion when used up to 40% - Good for lamination - Good litho properties - CN750 is chlorinated

CN2203 - Produce high viscosity inks with low tack - Very low or no misting inks - Excellent cure speed - Works well in EB inks

CN293 and CN2295 - Hydrophobic - Good pigment wetting - Very fast cure - Good solubility with resins used in hybridlitho inks

SR9020 is the workhorse monomer for litho inks.SR355 and SR399 work well for EB litho inksThe table shows the physical properties of thesemonomers.

7

CN294 - Similar backbone to CN293 and CN2295 - Excellent pigment wetting - Good litho properties - High viscosity with low tack

CN2282 - Fast cure - Yields tough films - Flexibility despite being tetrafunctional - Works well with CN790 for adhesion - Good litho properties

CN111US - Used at up to 10% to increase flow of

inks

CN118 - Very fast cure - Hydrophobic - Excellent litho properties

CN9167 - High impact - Resilient - Water resistant

The table discusses the physcial properties of theseoligomers.

PhotoinitiatorsCray Valley uses Esacure® photoinitiators such asEsacure® KS300, Esacure® TZT, and Esacure® ITX.

Esacure® KS3001 is 1-hydroxy-cyclohexyl-phenylketone. It is a highly reactive photoinitiator de-signed for UV coatings and inks based on epoxy acry-lates, urethane acrylates, polyester acrylates, and mix-tures. The melting point is 62-64 °C and it soluble inorganic solvents & monomers. It provides fast cureresponse, good through cure, and low color in curedfilms.

Esacure® TZT1 is a eutectic mixture of 2,4,6-trimethylbenzophenone and 4-methylbenzophenone. Itis practically insoluble in water, but completely solublein most organic solvents, monomers, oligomers, andresins. It provides high reactivity, is highly soluble, yieldslow odor and color in cured films. It also providesgood surface cure, fast cure response, good throughcure, and adhesion. Its suggested use level is 0.2percent by weight.

Esacure® ITX1 is a photoinitiator that is used incombination with a suitable coinitiator, e.g., ethyl 4-(dimethylamino) benzoate (EDB), to initiate UV freeradical polymerization. Esacure® ITX1 is used in inks,varnishes, and decorative coatings. It provides fast cureresponse, good surface cure, good through cure, andlow odor in both clear and pigmented coatings. Thesuggested use level is 0.25 - 1.5 weight percent.

Polyester Acrylate2480000CN2282

Polyester Acrylate23(1750)CN750





Epoxy Acrylate12.526000CN111US

Epoxy Acrylate22(3090)CN118

2

2

Health Rating

4

3


Polyester Acrylate(1800)CN2203

Epoxy Acrylate18000CN133

StructureViscosity 25?C (60?C)

1 supplied by Lamberti USA, Inc.

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Cray Valley Litho Ink Formulation PropertiesProperties essential to developing a good lithographicink - tack, yield stress, plastic viscosity, yield stress,cure speed, and water pickup were analyzed for theformulation descirbed previously.

.TackTack was run on a Thwing-Albert Inkometer.

400 rpm – 10.8800 rpm – 15.21200 rpm – 19.5

Yield Stress and Plastic ViscosityYield Stress and Plastic Viscosity were run on a

The graph below presents the adhesion and surfaceenergy of the litho ind formulation on various substrates.

Cray Valley Litho Ink Formulation

CN790 40.0% Polyester Acrylate, Adhesion to plasticsBlack Pigment 20.0% Degussa Special Black 250CN2282 13.0% Polyester Acrylate, Grinding Vehicle, Cure Speed, Film PropertiesSR355 10.0% Di-TMPTA, Cure speedIrgacure® 907 3.5% PI for curing dark inks supplied by Ciba Specialty ChemicalsEsacure® 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 MistPolyethylene Wax 1.0% Shamrock S394-SD4

Lithographic Ink FormulationSartomer has developed the following lithographic ink

starting point formulation. Properties were tested anddata is presented.

Brookfield DVIII+ Rheometer using a CP52 spindle.Rheology 2Plastic Viscosity71,558 cps

Yield Stress784 D/cm2

Cure Speed 4400 W/in H bulb200 fpm

Cure SpeedCure Speed was run with a Fusion 400 W/in H bulb.The peak irradiance was determined using an EITPower Puck at 30 fpm.

250-260 nm — 110 mW/cm2280-320 nm — 620 mW/cm2320-390 nm — 850 mW/cm2395-445 nm — 740 mW/cm2

Water PickupWater Pickup was tested on a Duke EmulsificationTester using Emerald Green fount. Water Pickup31.2%

Very low misting

9

Flexographic Ink FormulatingIn the typical flexo printing process, the substrate isfed into the press from a roll. The image is printed asthe substrate is pulled through a series of stations orprint units where each print unit is printing a single color.As with gravure and lithographic printing, the varioustones and shading are achieved by overlaying the fourbasic shades of ink. Flexography is the major processused to print packaging materials. Flexography is usedto print corrugated containers, folding cartons, multiwallsacks, paper sacks, plastic bags, milk and beveragecartons, disposable cups and containers, labels,adhesive tapes, envelopes, newspapers, and wrappers(candy and food).

UV flexo inks are commonly used for top coats andlacquers. The use of UV curable colored inks is risingwithin the flexographic printing industry because UVis responsible for many improvements in the image qual-ity of flexographic printing.

UV curable flexographic printing operations requirelow viscosity inks which are generally 500 – 1200 cpsin voscosity depending on color and substrate. Theymust have excellent adhesion to plastic films, fast cure( generally running on 300 fpm printing lines), excel-lent stability, no flocculation of pigments which willleads to viscosity and color strength change, and nopolymerization.

A schematic of the flexographic process is presentedbelow.

Flexographic Inks

Impression Roll

Substrate

Impression Roll

Substrate

Impression Roll

Substrate

Plate RollPlate Roll

Anilox Roll

Chambered Doctor Blade

Anilox RollAnilox Roll

Chambered Doctor Blade

lexographic Press etup

Cray Valley Materials for FlexographicFormulationsCray Valley provides materials for UV curableflexographic formulations. These materials includeSMA resins, monomers, oligomers, and photoinitiators.

MonomersMonomers are typically used in flexographicformulations at 30 - 60 weight percent of theformulation. Chosing the correct monomers for use iscritical. The incorrect type of monomer can lead toplate swell and registration issues. Monomers providelower viscosity, increased cure rates, adhesion, andlower crosslink density. Some suggested monomersare reviewed along with the performance propertiesthey provide.

SR531 - Increases flexibility of system without

decreasing toughness - Allows for thermoformability

SR492 - Increase cure speed - Pigment grinding capabilities

SR601 - Very fast cure speed - Toughness and scratch resistance of an

oligomer

SR339 - Adhesion to polar plastics

SR355, SR399LV, SR454, and SR494 - Greatly increase cure speed - Increase film hardness

SR508, CD562, and SR9003 - Low viscosity

10

DPGDA3210SR508

CTFA2115SR531


3 EO TMPTA2360SR454

3 PO TMPTA2390SR492

4EO PETA34150SR494


2 EO HDDA2215CD562

HDDA2210SR238

2

1

2

Health Rating

4

4

1


DiPETA7000SR399LV

DiTMPTA500SR355

2-PEA12SR339

StructureViscosity (25° C)

DPGDA3210SR508

CTFA2115SR531


3 EO TMPTA2360SR454

3 PO TMPTA2390SR492

4EO PETA34150SR494


2 EO HDDA2215CD562

HDDA2210SR238

2

1

2

Health Rating

4

4

1


DiPETA7000SR399LV

DiTMPTA500SR355

2-PEA12SR339

StructureViscosity (25° C)

Grinding Vehicles for UV Flexo

Grinding vehicles are essential in the development offlexographic inks. These vehicles will efficiently breakdown pigment agglomerates and will allow for efficientstabilization. Using these vehicles will increase flow,stability, and color development of the ink.

CN293 - Contains PETA - Excellent pigment dispersion - Very fast cure speed

CN2278 - Low viscosity - Fast cure - Good pigment dispersion

CN2282 - New for pigment dispersion - Good cure speed - Excellent toughness

CN2284 - Designed for UV flexo dispersions

Grinding verhicle properties are shown in the table.




3

Health Rating

4



StructureViscosity

25˚ C (60˚ C)




3

Health Rating

4



StructureViscosity

25˚ C (60˚ C)

Health Ratings were pulled from the product MSDSAcrylates / molecule is an averageViscosities in red are at 60 °C

Oligomers for UV Flexo CureOligomers provide an ink with physical propertyenhancements which improve performance. Listed areoligomers which are used in UV curable flexo inks.

CN132 and CN133 - Increase cure speed - Hard films - CN132 increase opacity of white

pigmented inksCN131B

- Low viscosity - Enhances adhesion to plastics - Flexible and thermoformable - Good cure rate

CN9006, CN991, and CN929 - Aliphatic urethane acrylates - Used to formulate weatherable flexo inks

CN9006 - Is very hard and fast curing

CN991 and CN929 - Flexibility

Oligomer Letdowns for UV FlexoLetdowns provide additional physical properties suchas weatherability, cure speed, and adhesion.

SR9003 - Has some pigment grinding capability - All are good diluents of other UV components - Improved transfer - Weatherability (in some instances)

The physical properties of these monomers arepresented in the table.

Amine Acry late2125CN386



AL Urethane Acrylate23(400)CN929




Epoxy Acrylate21250CN131B


2

2

Health Rating

2

3


AL Urethane Acrylate(660)CN991


StructureViscosity

25˚ C (60˚ C)










2

2

Health Rating

2

3


AL Urethane Acrylate(660)CN991


StructureViscosity

25˚ C (60˚ C)

US

11

CN2281 - Low viscosity - Excellent cure rate

CN2282 - Higher viscosity - Good flexibility - Excellent cure - Enhances film toughness

1300157022001450Plastic Viscosity

24102Yield Stress

0.20.30.30.4Particle Size

35.035.040.040.0% Pigment

7.04.610.07.0% Solsperse 39000 1

38.0% SR492

20.060.453.053.0% CN2282/monomer blend

ClariantCibaCibaDegussaSupplier

Rubine L6B05Irgalite AXLIrgalite GLVOSpecial Black 250Supplier Code

PR 57:1PY 14PB 15:4PBk 7Pigment

MagentaYellowCyanBlack

1300157022001450Plastic Viscosity

24102Yield Stress

0.20.30.30.4Particle Size

35.035.040.040.0% Pigment

7.04.610.07.0% Solsperse 39000 1

38.0% SR492

20.060.453.053.0% CN2282/monomer blend

ClariantCibaCibaDegussaSupplier

Rubine L6B05Irgalite AXLIrgalite GLVOSpecial Black 250Supplier Code

PR 57:1PY 14PB 15:4PBk 7Pigment

MagentaYellowCyanBlack

CMYK MillbasesThe millbase is the first step, and most crucial, inmaking a UV flexo ink. The millbase containspigment, oligomer, monomer, and a dispersant.The dispersant is needed to provide long termflocculation stability.

CN2270 - Low viscosity - Excellent flow properties - Some pigment wetting

CN2262 - Good toughness - Low cost

CN371 - Higher viscosity - Fastest surface cure speed - Very low extractables

CN386US - Lower viscosity - Fast surface cure - Higher extractables - Higher yellowing

12

Magenta Flexo Ink

PropertiesCure SpeedCure Speed was run with a Fusion 400 W/in H bulbat 650 fpm. Prints were made with a 600 line/in aniloxCavanaugh hand proofer. 11 mJ/cm2 was the energy.

Yield Stress and plastic viscosityYield Stress and Plastic Viscosity were run on aBrookfield DVIII+ Rheometer with a CP42 spindle.Yield stress was 2.0 D/cm2 and plastic viscosity was 605cps.

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Surface Energy

CMYK Flexo InksThe millbases are let down with monomer, oligomer,photoinitiator, and additives into the final ink. by varying

the letdowns, many different inks can be made fromthe same millbase.

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 Chemicals2 supplied by Lamberti USA, Inc.3 supplied by Shamrock Technologies4 supplied by Byk Chemie

13

Screen Ink Formulation Goals

Excellent adhesion to many substratesFlow under shear stressGood printability through screenGood resolutionExcellent color fastnessBalance of cure speed and flexibilityPossible weatherability

MonomersLower the viscosity of the formulationProvide adhesion through substrate swellingAllow for adjustment of hardness or softnessof the cured inkIncrease cure speedIncrease solvent resistance with crosslinkdensity

THEICTA33SolidSR368

THFA316SR285

IBOA119SR506

CTFA2115SR531


3 EO TMPTA2360SR454

HDDA2210SR238

2

2

Health Rating

4

1


DiPETA7000SR399LV

2-PEA12SR339

StructureViscosity (25˚ C)

THEICTA33SolidSR368

THFA316SR285

IBOA119SR506

CTFA2115SR531


3 EO TMPTA2360SR454

HDDA2210SR238

2

2

Health Rating

4

1


DiPETA7000SR399LV

2-PEA12SR339

StructureViscosity (25˚ C)

Health Ratings were pulled from the product MSDSAcrylates / molecule is an average

Suggested MonomersSR531

Increases flexibility of system withoutdecreasing toughnessAllows for thermoformability

SR399LV and SR454Increase cure speedPigment grinding capabilities

SR601Very fast cure speedToughness and scratch resistance ofan oligomer

SR238 and SR285Adhesion to difficult substratesHigh Draize value limits use

SR506Common diluent used in screen inksHigh TgOdor issue

SR339Adhesion to polar plastics

SR368Increase scratch and abrasion resistance

Screen printing inks are moderately viscous inks whichexhibit different properties when compared to otherprinting inks such as offset, gravure and flexographicinks though they have similar basic compositions. Thereare five different types of screen inks but the focus inthis bulletin is on UV curable screen inks.

The screen printing process uses a porous meshstretched tightly with proper tension for to accuratecolor registration over a frame made of wood or metal.The mesh is made of porous fabric or stainless steelmesh. A stencil is produced on the screen photochemi-cally and defines the image to be printed.

Screen printing ink is applied to the substrate by plac-ing the screen onto which ink with a paint-like consis-tency has been placed. Ink is then forced through thefine mesh openings using a squeegee that is drawnacross the screen, applying pressure thereby forcingthe ink through the open areas of the screen. Ink willpass through only in areas where no stencil is applied,thus forming an image on the printing substrate. Thediameter of the threads and the thread count of themesh will determine how much ink is deposited ontothe substrates.

OligomersGive the cured ink the main attributesToughnessWeatherabilityScratch resistanceSome provide adhesion

Monomer Properties for UV Screen

Screen Inks

14

AL Urethane Acrylate22(1100)CN963B80











2

Health Rating

2


Epoxy Acrylate150000CNUVE151

StructureViscosity

25˚ C (60˚ C)












2

Health Rating

2


Epoxy Acrylate150000CNUVE151

StructureViscosity

25˚ C (60˚ C)

Suggested Oligomers

CN131BIncreases flexibility of systemAllows for thermoformability

CN133Increase cure speedIncreases hardness

CN371Aids in surface cure

CN2262Low cost oligomerGood toughness and abrasion resistance

CNUVE151Flexible epoxy acrylate

Oligomer Properties for UV Screen CN710New oligomer for adhesion to plasticsDesigned for choroplastWorks well on many plastics

CN991WeatherableFlexibleLow viscosity

CN963B80WeatherableVery hard

CN981Good combination of flexibility andtoughnessGood adhesion to plastics such aspolyesters

CN966B85Very flexible oligomerAlso available in IBOA and EOEOEA cutsto change propertiesExcellent adhesionPoor scratch resistance

CN9001ThermoformableExcellent toughness with good elongationweatherable

CN9893Very flexible oligomer

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

Screen Ink Formulation

1 supplied by Ciba Specialty Chemicals2 supplied by Lamberti USA, Inc.

15

Adhesion Properties

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16

SMA® Resins in High P/B Dispersions and Stable Inks

SMA® resins are low molecular weight styrene/maleicanhydride copolymers. They are available both as baseresins and as partial mono esters. Commercial productsare supplied in solid form, either as flake or powder,and as aqueous ammonia solutions. SMA® resinstypically are harder, have higher glass transitiontemperatures, and offer higher acid numbers thanconventional styrene acrylic copolymers.

SMA® resins deserve recognition as effective agentsfor pigment wetting, grinding, and dispersing inwaterborne inks and coatings. Their outstandingperformance in these applications facilitates thepreparation of stable aqueous pigment dispersionswhich have higher pigment/binder (P/B) ratios andhigher pigment loadings than are recommended forcompetitive styrene/acrylic systems. Despite theirhigher total solids, these dispersions exhibit lowerviscosities and equal or better color strength (whendiluted to equal pigment loading) than do the styrene/acrylic dispersions.

This bulletin will describe the preparation of sometypical SMA® dispersions with various pigments andwill show how these dispersions can be used to preparestable inks with a variety of commercial emulsions. TheSMA®s were used as aqueous ammoniacal solutions,indicated by the “H” which follows their identifyingnumber.

Typical Properties of SMA® 17352H% Solids 24.0 - 26.0Acid Number (of Solid Resin) 270pH 8.0 - 9.5Tg (glass transition temperatureof the solid resin) 124 °CSurface Tension (1% solution) 36.9 dynes/cm

SMA® Demonstrates Excellent Color andViscosity StabilityColor and viscosity stability are important parametersof any dispersion formulation. Color stability refers tothe retention of color strength as the dispersion ages,either at ambient or elevated temperature conditions.Viscosity stability refers to the minimization of viscosity

rise over time or with heat aging. The loss of stabilitycan be due to inadequate adsorption of the polymeronto the pigment surface, or orientational phenomenarelated to the pigment:polymer association that limitthe adsorption layer thickness.

With phthalo blue pigments, SMA® 17352Hdemonstrated better color stability in the dispersionover time than did some competitive acrylic resins.

With various metallized azo red pigments, dispersionsmade from these pigments follows: SMA® 17352Hwill produce more viscosity stable dispersions athigher pigment to binder ratios than typical styreneacrylic resins. Examples of dispersions made fromthese pigments are as follows:

Dispersion of Lithol Rubine with SMA® 17352

Dispersion Preparation:The RD 5721(1) pigment was dispersed at 6:1 p/b ratioand 38% loading for the SMA® formulas, and 4:1 p/bat 38% pigment loading for the Competitive Acrylicformulas. A 50:50 blend of a Competitive Acrylic andSMA® 17352H was also used to make one of thedispersions.

Premixes were made using a blender. All liquidingredients (with the exception of 28 g of water, whichis retained by the mill media from a prior rinse andbecomes part of the batch) were weighed into theblender and mixed for 30 seconds to homogenize. Thepigment was weighed into the blender and allowed tomix at slow speed for two minutes to begin the processof wetting it out. The sides of the blender were scrapeddown, and the pigment subsequently premixed at highspeed for fifteen minutes.

After the premix step, the dispersions were milled forvarious grind times based on their viscosity/amperagedraw (see below) on an Eiger Mini-100 mill using 0.8-1.0 mm zirconium silicate beads and 5000 rpm.

The first 30 ml of liquid was removed from the mill onrecirculation and discarded.

17

Lithol Rubine Dispersions with SMA® 17352H

FORMULA 1 FORMULA 2 FORMULA 3

Uhlich RD 5721(1) 171.00 171.00 171.00Competitive Acrylic 142.50 —— 52.78SMA 17352H(11) —— 118.75 52.78

Dehydran® 4100(2) 3.15 3.15 3.15Water 133.35 157.10 170.29

TOTAL 450.00 450.00 450.00

Pigment Loading 38% 38% 38%P/B 4 6 6Resin % 9.5 6.33 6.33

FORMULA 1 Competitive Acrylic, 10 minutes slight speckle 4 ampsFORMULA 2 SMA® 17352H, 20 minutes moderate speckle between 4-10 NPIRI 2.5 ampsFORMULA 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 toequalize, as much as possible, the amount of workbeing done on the pigment. Lower viscosity bases areadvantageous but may produce erroneous results whencompared to higher viscosity bases milled for the sameamount of time. This is because the higher viscositybases may develop more color than the lower viscositybases due to higher shear forces generated in the mill,rather than due to any specific interactions betweenthe pigment and the resin.

The SMA®-containing dispersions were much lowerin viscosity, which explains why it took longer toachieve acceptable grind. The conclusion here is thatthey could ultimately be loaded higher in pigment (toabout 40% pigment loading by weight).

After milling, the dispersions were reduced to 35%pigment loading and their viscosities measured on a

Brookfield LVF viscometer. Tint strengths of theoriginal dispersions as well as their 35% counterpartswere measured.

Results and Discussion:The reductions of these dispersions to 35% producedthe following viscosities (60 rpm, Brookfield LVF):

Formula 1 Competitive Acrylic 1062 cpsFormula 2 17352H 125 cpsFormula 3 17352/Competitive Acrylic 756 cps

Inks were made from these dispersions per theformulas below and proofed on Leneta 3NT-3. Theseinks were prepared by making the vehicle first (allcomponents except pigment dispersion) and thenadding this vehicle to the pigment dispersion withmixing. Brookfield viscosities of the inks weresubsequently measured.

The SMA®-containing dispersion was much lower inviscosity and therefore exhibited only about half theamperage draw on the mill as the did the CompetitiveAcrylic dispersion. The grind times were adjusted to

account for this.

No scratches were seen on the gauge; “pepper” orspeckle frequency noted as follows:

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INK FORMULATIONS FROM SMA®-BASED DISPERSIONS

INK A INK B INK C

17352H dispersion —— 34.29 ——Competitive Acrylic dispersion 34.29 —— ——

Comp. Acryl./17352H dispersion —— —— 34.29Competitive Acrylic 13.33 —— 7.40SMA® 17352H —— 12.50 7.41

XHD 47J(4) 0.50 0.50 0.50ECO 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 12.00Solution resin % 7.00 5.00 6.00Emulsion resin % 23.00 25.00 24.00TOTAL 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 cpsINK B 17352/SMA 172.5 cps 199 cpsINK C 50/50 [Competitive Acrylic/17352]/ 2177 250 cps 165 cps

The inks which contained 17352 were the most shockstable. Inks made from the competitive solution resinexhibited some shocking. All the inks printed at highercolor density than the Competitive Acrylic control, yetwere at comparable (or lower) viscosity at one month.The combination of SMA® 17352H and CompetitiveAcrylic produced dispersions and inks that were thelowest in viscosity upon aging.

Color strength (tint) measurements of the dispersionsshowed all SMA® containing formulas to have slightlyhigher strength (4 – 5%) than the Competitive Acryliccontrols. The 17352 containing dispersions showedthe highest color strength and stability overall.

In general, many reds showed better color and viscositystability when dispersed with SMA® 17352H vs.typical styrene acrylics. Another example is that of

rhodamine (Pigment Red 81), which, due to its inherentchemistry, tends to be unstable in alkaline waterbasedmedia. SMA® 17352H makes a thin and stabledispersion at 6/1 pigment:binder ratio that is compatiblewith acrylic letdown resins:

Example formulation at 38% pigment loading:

RD 8181(5) 171.00SMA 17352H 118.75DeeFo XHD 47J 5.00Water 155.25

TOTAL 450.00

This can be media milled in accordance with the aboveprocedures, taking care that the millbase temperaturedoes not exceed 120°F, as the pigment is sensitive tocolor changes upon prolonged heating.

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An equivalent formula made with the CompetitiveAcrylic at its recommended use level of 4:1 P/Bproduced a dispersion which became solid in 2–3 days.Rhodamine dispersions at 4:1 and 6:1 P/B with SMA®

17352 remained fluid and low in viscosity (< 200 cpsfor 6/1) even after two months aging.

Calcium Lithol Dispersions with SMA® 17352H

Formula A Formula B Formula C

Competitive acrylic @ 36.6% solids 33.30 17.30 ——SMA® 17352H @ 24.3% solids —— —— 26.10Permanent Red 2B(12) 33.00 38.00 38.00Surfynol® DF-70(13) 1.00 1.00 1.00Dee Fo® 1144A/75(10) —— —— 0.50Water 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

RPM0.5 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% pigmentFormula B - Competitive acrylic dispersion, 38% pigmentFormula C - SMA® 17352H dispersion, 38% pigment

Dispersion of Calcium Lithol withSMA® 17352HAnother metallized azo red that has the tendency tobe unstable in aqueous systems is Pigment Red 48:2.The dispersions below were prepared in accordancewith the same procedure described above:

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Calcium Lithol Dispersion Viscosities, 38% pigment loading

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

0 10 20 30 40 50 60

Brookfield RPM

Vis

cosi

ty, c

ps

Formula B, 24 hr. ambient Formula B, 7 days ambientFormula B, 7 days heat aged Formula C, 24 hr. ambientFormula C, 7 days ambient Formula C, 7 days heat aged

It is apparent from the dispersion viscosity data thatthe SMA® 17352 dispersion is much lower in viscosity.This holds true at equal pigment solids or lower pigmentsolids to the acrylic-containing dispersion, whetherambient or heat-aged.

Inks made from SMA® 17352 dispersion showedsimilar low shear viscosity but higher high shearviscosity, which is conducive to better ink transfer(lower pseudoplasticity):

INK FORMULAS:CALCIUM LITHOL INKS

Comp. Acrylic SMA® 17352H

Competitive acrylic @ 36.6% solids 6.40 ——SMA® 17352H —— 19.20Pigment Dispersion* 42.40 36.80Surfynol DF-70 0.20 0.20Lucidene® 605(15) 42.80 42.80Water 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.

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Ink Viscosities, 7 day ambient aging

0

200

400

600

800

1000

1200

0 10 20 30 40 50 60

B r o o k f i e l d R P M

Comp. Acrylic SMA 17352

Red 48:2 Inks - Lucidene 605 emulsion letdown after 7 days ambient aging

Comp. Acrylic SMA® 17352RPM

0.5 992 9602.5 422 7365 298 63010 221 53450 122 354

Comparative tint strengths of these inks showed theSMA®-containing ink to be 22% stronger than the all-acrylic ink. This is indicative of lower amounts ofpigment flocculation, either on preparation or on agingof the SMA® ink.

Dispersion of Phthalo Blue With SMA® 17352These dispersions were prepared at 6/1 pigment:binder ratio and 41% pigment loading, using theprocedures outlined above. The exception here is thatall the dispersions were milled for 15 minutes.

BLUE Dispersion A BLUE Dispersion B

Competitive acrylic @ 34% solids 20.4 ——SMA® 17352 @ 24% solids —— 28.5PB 15:3 (Aarbor International) 41.0 41.0Dee Fo XHD 47J(4) 0.5 ——Dee Fo PI-35(6) —— 0.5Water 38.1 30.0

TOTAL 100.0 100.0

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The viscosity of the SMA®-based dispersion washigher than that of the Competitive acrylic standard(2150 cps @ 60 rpm vs. 652 cps @ 60 rpm).

Color development for both dispersions was equalinitially, but it was noted that the Competitive acrylic

dispersion lost more color strength ( ~ 10+%) overtime than did the SMA® dispersion (~ 3%).

Similarly, with Daicolor Pope DC 3127, but at optimalpigment:binder ratios for the resins:

BLUE Dispersion C BLUE Dispersion D

Competitive acrylic @ 34% solids —— 27.9SMA® 17352H @ 24% solids 28.5 ——DC 3127(9) 41.0 38.0Dee Fo XHD 47J —— 0.5Dee Fo PI-35 0.5 ——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%pigment loading, whereas the competitive acrylicdispersion could only be prepared at 38% pigmentloading. This was still too viscous for an adequateviscosity measurement to be taken. The SMA®-containing dispersion was 3700 cps at 60 rpm on aBrookfield LVF, however.

Again, in measuring color strength, both dispersionswhen adjusted to equal pigment loading exhibitedsimilar color development, but over time, theCompetitive acrylic dispersion lost 10% color strength.

A Note Regarding Ink Preparation:A difficulty which is often encountered when preparinginks from pigment dispersions (especially those whichhave high pigment loading) is “shocking”. Thisdestabilization of the dispersion, caused by flocculationof the pigment, can occur during the introduction ofthe letdown vehicle to the pigment dispersion. It isespecially a problem with mechanical ink blending/metering systems in which the ingredients of the inkare introduced together without continuous mixing.

The best way to avoid pigment flocculation when usingany pigment dispersion is to prepare the let downvehicle separately and add it to the pigmentdispersionwith mixing. If this is not practical, the

dispersion can be added to the vehicle, but a smalldegree of pigment flocculation can occur. Adding thedispersion with agitation can mitigate this, though nottotally prevent it.

Though all pigment dispersions demonstrate slightflocculation when added in this manner, SMA® 17352has demonstrated more resistance to this effect in manypigment systems at high pigment: binder than do typicalstyrene-acrylics at lower pigment: binder levels.Susceptibility to this behavior is dependent not onlyon the dispersant system and p:b ratio, but also on thecomponents of the letdown vehicle and the nature ofthe pigment in question.

In summary, SMA® 17352 provides:

· Stable dispersions with high pigment:binderratiosthis allows for a higher solids content andconsequent increase in throughput. Also, thisreduces binder level, giving more formulationflexibility.

· Lower viscosity dispersions with reducedpseudoplastic behavior vs. dispersions made withconventional acrylic dispersing resins.

· Stable inks with improved long-term shear andcolor stability.

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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 Cray Valley 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 KGAADee Fo® is a registered trademark of Ultra Additives, Inc.SMA® is a registered trademark of Cray Valley Company.Surfynol® is a registered trademark of Air Products and Chemicals, IncLucidene® is a registered trademark of Rohm and Haas Company

1540 01/10

Corporate Headquarters

Cray Valley USA, LLC468 Thomas Jones Way, Suite 100

Exton, PA 19341

Tel: 877-US1-CRAY (877-871-2729)

E-mail: [email protected]

For contact information worldwide, please refer to Cray Valley's web site at:http://www.crayvalley.com

The information in this bulletin is believed to be accurate, but all recommendations are made without warranty since the conditions of use are beyond Cray Valley Company'scontrol. The listed properties are illustrative only, and not product specifications. Cray Valley 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 process.

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