Dow Cellulosics

ETHOCELEthylcellulose PolymersTechnical Handbook

Tech

nica

lH

andbook

Table of Contents

1 Introduction ............................................................41.1 General Properties ..........................................4

2 ETHOCEL Polymers ................................................62.1 Structures ........................................................62.2 Products ..........................................................62.3 Nomenclature ..................................................7

3 Applications ............................................................84 Formulating with ETHOCEL................................10

4.1 Choice of Solvents ........................................104.1 Aromatic Hydrocarbon-Alcohol Mixtures ....114.2 Viscosity vs Concentration............................124.3 Blending for Intermediate Viscosities ..........134.4 Polymers ........................................................174.5 Pigments and Dyes........................................174.6 Heat and Light Stabilizers ............................174.7 Film Properties ..............................................184.8 Plasticizers ....................................................194.9 Solvent-Free Emulsions ................................19

5 Pharmaceutical Applications ..........................205.1 Granulation ....................................................205.2 Coating ..........................................................205.3 Tablet Binding................................................21

6 Specialty Applications ......................................226.1 Personal Care ................................................226.2 Food Applications..........................................236.3 Animal Feed ..................................................236.4 Conductive Pastes ........................................236.5 Ceramics ........................................................236.6 Printing Inks ..................................................23

Gravure Ink ....................................................24Heat-Transfer Printing ..................................24Solvent-Free Hot Melt Inks ..........................24

6.7 Hot Melt Strippable Coatings ......................256.8 Room-Temperature Lacquers ........................256.9 Gel Lacquers ..................................................25

7 Safe Handling of ETHOCEL Products ..............267.1 Health Considerations ..................................267.2 Combustibility................................................267.3 Dust Explosion ..............................................267.4 Spills ..............................................................267.5 Disposal ........................................................267.6 Storage/Handling ..........................................26

2

Table of Tables

Table 1. Physical properties of ETHOCEL Standard polymers ..........4

Table 2. ETHOCEL polymers................................................................7

Table 3. Typical use map for ETHOCEL polymers..............................9

Table 4. Viscosity and film properties of ETHOCEL Std. 10 polymer in single solvents (15 g polymer in 100 mL solvent) ..............................................................10

Table 5. Solvent compositions for minimum solution viscosity for ETHOCEL polymers in common binary solvents..........10

Table 6. Solvents for ETHOCEL polymers ................................14–16

Table 7. Film coverage with ETHOCEL polymers and other cellulose products......................................................18

Table 8. Plasticizers with varying softening effects on ETHOCEL polymers ........................................................19

Table 9. Selection of ETHOCEL polymers for pharmaceutical applications ..............................................20

Table 10. Viscosity of ETHOCEL Std. 10 Premium solutions in ethanol ............................................................20

Table 11. Diphenhydramine HCl release rates in deionized water ..................................................................21

Table 12. Selection of ETHOCEL polymers for specialty applications ........................................................22

Table of Figures

Figure 1. Softening point and melting point temperatures as afunction of ethoxyl content of ETHOCEL polymers ............5

Figure 2. Chemical structure of cellulose............................................6

Figure 3. Chemical structure of ethylcellulose....................................6

Figure 4. Example of nomenclature for an ETHOCEL Standard polymer ................................................7

Figure 5. Viscosity of 5% solutions of ETHOCEL Std. 100polymer in toluene with various alcohols ........................11

Figure 6. Viscosity-concentration chart for ETHOCEL Standard polymers ............................................12

Figure 7. Blending chart for intermediate viscosities of ETHOCEL polymers..............................................................13

Figure 8. Load-elongation curves for ETHOCEL polymers................19

Figure 9. Drug dissolution of ETHOCEL Std. 10 Premiumgranular vs. fine particle....................................................21

3

ETHOCEL* is a trademark of TheDow Chemical Company for its family ofthermoplastic cellulose ethers. Thesepolymers have provided excellent serviceto industry since their commercialintroduction by Dow in the mid-1930s.

These multifunctional, water-insoluble,organosoluble polymers are used inmany pharmaceutical and specialtyapplications. They function as binders;tough, flexible film formers; masking andtime-release agents; water barriers; andrheology modifiers, to name a few.

For additional information, seewww.ETHOCEL.com.

1.1 General PropertiesETHOCEL ethylcellulose polymers arecolorless, odorless, tasteless, andnoncaloric. They have outstandingchemical and physical properties (Table 1).These properties make them useful inmany applications—from pharmaceutical,food, and personal care applications tospecialty applications, including some ofthe most sophisticated electronic devices.1

Flammability Once ignited, ETHOCELwill support combustion. However,ETHOCEL offers no greater fire hazard onstorage and handling than does paper orcellulose in the same physical form.

Thermal Stability ETHOCEL is stable upto its melting point (~160°C, 320°F). Theviscosity of ETHOCEL polymers is stableto high temperatures. It has good outdoordurability and toughness at both high andlow temperatures.

Low Ash Content ETHOCEL has a verylow ash content, making it useful inapplications such as conductive inks and pastes, dielectrics, ceramics, andfluorescent lighting.

Stability to Light ETHOCEL does notdiscolor on exposure to strong sunlightnor does it promote the discoloration ofplasticizers or polymers.

Chemical Stability/ResistanceETHOCEL is a stable, slightly hygroscopicmaterial. It is inert to attack by aqueousalkalies, even when hot and highlyconcentrated. It is resistant to saltsolutions and resists oxidation below itssoftening temperature.1 All applications may not be suitable for all regions.

Table 1. Physical properties of ETHOCEL Standard polymers

Appearance white powderOdor noneTaste noneDensity (bulk), g/cm3, ETHOCEL Std. 4, 7, 10, 20, 45, 100 0.4Density (bulk), g/cm3, ETHOCEL Std. 200 & 300 0.3Specific gravity, g/cm3 1.12–1.15Glass transition temperature, °C (°F) 129–133 (264–271)Softening point, °C (°F), see Figure 1 133–138 (271–280) Melting point, °C (°F), see Figure 1 165–173 (329–343)Film properties

Refractive index 1.47Tensile strength See Figure 8, pg. 19

Electrical propertiesDielectric constant at 25°C, 1 MHz 2.8–3.9Dielectric constant at 25°C, 1 kHz 3.0–4.1Dielectric constant at 25°C, 60 Hz 2.5–4.0Power factor at 25°C, 1 kHz 0.002–0.02Power factor at 25°C, 60 Hz 0.005–0.02Volume resistivity, ohm·cm 1012–1014

Dielectric strength, V/0.0254 mm 1500

Ref: Majewicz, T.G., et al., eds., “Cellulose Ethers,” Encyclopedia of Polymer Science and Technology, JohnWiley & Sons, Inc., New York, 2002.

Introduction

* Trademark of The Dow Chemical Company4

Figure 1. Softening point and melting point temperaturesas a function of ethoxyl content of ETHOCEL polymers

Note: ETHOCEL ethylcellulose polymers are produced in two ethoxyl types (Medium andStandard). See Section 2.2, pg. 6.

44 45 46 47 48 49 50

Ethoxyl Content, Percent

220

210

200

190

180

170

160

150

140

130

120

428

410

392

374

356

338

320

302

284

266

248

Ethoxyl Type Designation

Tem

pera

ture

,°C

Tem

pera

ture

,°F

Medium Standard

Melting Point Range

Softening Point Range

Thermoplasticity ETHOCEL possessesexcellent thermoplasticity. UnplasticizedETHOCEL softens and becomes plastic at135°C to 160°C (Figure 1). It can becompounded with plasticizers, waxes,and polymers while in a plastic condition.Plasticized ETHOCEL softens at muchlower temperatures than unplasticizedETHOCEL and forms the basis ofcompositions for molding, extruding,and laminating uses.

Flexibility Films made from ETHOCELpolymers are highly flexible and retaintheir flexibility at temperatures wellbelow freezing.

Film Formation ETHOCEL is an excellentfilm former. Films made from ETHOCELare tough, with high tensile strength andan unusual degree of flexibility even atlow temperatures. ETHOCEL polymersyield a greater volume of film-formingsolids than any other cellulose derivative.

Compatibility ETHOCEL is compatiblewith most common plasticizers andpolymers. It yields clear films with awider variety of plasticizers and polymersthan any other cellulose derivative.

Water Resistance ETHOCEL is anexcellent water barrier. Films of ETHOCELabsorb little moisture either on exposureto the atmosphere or after long immersionin water.

Binding The good binding qualities ofETHOCEL are useful in applications suchas tableting and microencapsulation.

Controlled Release ETHOCEL allowscontrol of the release of activeingredients from solid dosage forms.

Solubility ETHOCEL dissolves in a widerange of solvents such as aliphaticalcohols, chlorinated solvents, andnatural oils. It is practically insoluble inglycerin, propylene glycol, and water.

5

2.1 StructuresETHOCEL ethylcellulose polymers arederived from and have the polymeric“backbone” of cellulose, which is anaturally occurring polymer. Themolecule has a structure of repeatinganhydroglucose units (Figure 2). Notethat each anhydroglucose unit (ring) hasthree reactive -OH (hydroxyl) sites.

Cellulose is treated with an alkalinesolution to produce alkali cellulose,which is subsequently reacted with ethylchloride, yielding crude ethylcellulose.(Figure 3).

2.2 ProductsThe Dow Chemical Companymanufactures and markets manydifferent ETHOCEL products toaccommodate the needs of customersfor different physical properties, uses,viscosities, and solubilities.

ETHOCEL polymers are white granularpowders with a bulk density ofapproximately 0.4 g/cm3. The differencesin physical properties of ETHOCELpolymers result largely from variation inethoxyl content.

ETHOCEL polymers are produced in twoethoxyl types (Standard and Medium) thatcover the range of the most useful ethoxylcontent. “Standard” polymers have anethoxyl content of 48.0 to 49.5%; and“Medium” polymers have an ethoxylcontent of 45.0 to 47.0%. Mediumpolymers are supplied on a veryrestricted, made-to-order basis only.

ETHOCEL polymers are also producedand marketed in a number of differentviscosities. Viscosity increases as thelength of the polymer moleculeincreases.

Standard and Medium ethoxyl types areavailable in Premium grades, useful inregulated applications, and Industrialgrades (Table 2). Premium grades aredesigned to meet the requirements ofpharmaceutical applications. However,the physical and chemical propertiesof ETHOCEL polymers apply to bothPremium and Industrial grades.

ETHOCEL Std. 7, 10, and 100 Premiumpolymers are also available in a fineparticle size. These products aredesignated ETHOCEL Std. 7 Premium FP,Std. 10 Premium FP, and Std. 100Premium FP. They were designed forpharmaceutical formulations but areuseful in other applications such aspersonal care or applications that requirehigh surface area polymers.

Figure 2. Chemical structure of cellulose

ETHOCEL Polymers

6

HO

HO

HO

HO

HHO

OH

H

n-2OHO HCH2 CH2

O

O CH2O

O

OH

H H

H H HHH

H

C2H5

HHO

HC2H5

O

CH2

H H

H H

O O

OHO H

H

CH2

O

C2H5

O

O

C2H5

C2H5

C2H5

O

O

O

O

H

H

HH

OH

CH2

n-2

H

H

H

H H

H H

OH

OH

OH

OH

OH

Figure 3. Chemical structure of ethylcellulose

2.3 NomenclatureETHOCEL is a trademark of The DowChemical Company for a line of celluloseether products. The letters following(Std., Med.) identify the ethoxyl type andethoxyl content (the chemistry designation).

The number that follows the chemistrydesignation identifies the viscosity of thatproduct in millipascal-seconds (mPa·s).Viscosity of a 5% solution is measured at25°C in an Ubbelohde viscometer. ForMedium products, solvent is 60% tolueneand 40% ethanol. For all other ETHOCELproducts, solvent is 80% toluene and 20%ethanol. Note: millipascal-seconds(mPa·s) is equivalent to centipoise (cP).

ETHOCEL products are correctly specifiedby listing the ethoxyl content (as Standardor Medium), the nominal viscosity, and thegrade (Premium or Industrial). For example,ETHOCEL Std. 20 Premium polymercorrectly describes a Dow ethylcelluloseproduct with:

• “Standard” ethoxyl content(48.0–49.5%).

• Nominal Ubbelohde viscosity of 20mPa·s for a 5% solution (in 80%toluene and 20% ethanol) measured at25°C. (See Table 2 for ranges.)

• Intended use in pharmaceuticals orother regulated applications.

Product Viscosity Ethoxyl Content, %Viscosity Range, Standard MediumC

Designation mPa·s (cP) 48.0–49.5 45.0–46.54 3–5.5 ETHOCEL Std. 4a —7 6–8 ETHOCEL Std. 7a,b —

10 9–11 ETHOCEL Std. 10a,b —14 12.6–15.4 ETHOCEL Std. 14a,c —20 18–22 ETHOCEL Std. 20a —45 41–49 ETHOCEL Std. 45a —50 45–55 — ETHOCEL Med. 50a,c

70 63–77 — ETHOCEL Med. 70a,c

100 90–110 ETHOCEL Std. 100a,b ETHOCEL Med. 100c

200 180–220 ETHOCEL Std. 200 — 300 270–330 ETHOCEL Std. 300 — 350 250–385 — —

a Premium in addition to Industrial grades are available.b Fine particle forms are available.c Supplied on a restricted, made-to-order basis only.Note: Viscosities are for a 5% solution measured at 25°C in an Ubbelohde viscometer. For Medium

products, solvent is 60% toluene and 40% ethanol. For all other ETHOCEL products, solventis 80% toluene and 20% ethanol.

Table 2. ETHOCEL polymers

Figure 4. Example of nomenclature for an ETHOCEL Standard polymer

7

Indicates viscosity (in mPa·s or cP) of 5% solution in a mixture of toluene and ethanol

(see Table 2)Identifies product grade (Premium or Industrial)

Trademark of The Dow Chemical Company Identifies physical form

(fine particle)

ETHOCEL Std. 10 Premium FP

Identifies ethoxyl type, content (Std., Med.)

Personal Care ETHOCEL polymersare approved for use in cosmetics.Ethylcellulose is listed in the InternationalCosmetic Ingredient Dictionary andHandbook. It is also listed in the JapaneseStandards of Cosmetic Ingredients.

ETHOCEL is soluble in many organicsolvents, including ethanol and naturaloils. It yields strong, flexible films at lowconcentration. It provides excellentwater resistance and can be used toprotect water-sensitive ingredients. Itcan be used to mask or control therelease of active ingredients.

ETHOCEL has been used in lipsticks andnail polishes (gives long-lasting brilliance),as a fragrance stabilizer, and as athickener for perfumes and body creams(waterproof sunscreens).

ETHOCEL ethylcellulose polymershave provided excellent functionality inmany pharmaceutical and specialtyapplications for more than 60 years.ETHOCEL polymers are essentiallytasteless, odorless, noncaloric, andphysiologically inert. They offer anattractive range of physical propertiesand can be blended with other materialsto achieve intermediate characteristics.

Pharmaceuticals ETHOCEL Premiumproducts are among a very small numberof water-insoluble excipient polymersthat are approved and accepted globallyfor pharmaceutical applications. They areproven organosoluble polymers for tabletcoatings, controlled-release coatings,microencapsulation, granulation, andtaste masking.

Food/Feed ETHOCEL is used as a flavorfixative in encapsulation and as a vitamincoating. It is approved for and used ininks for marking fruits and vegetables, asa component of paper and paperboard incontact with aqueous and fatty foods,and for certain uses in animal feed.ETHOCEL polymers are approved for usein animal feed in Europe per Directive70/524/EEC for all species or categoriesof animals. International Feed Name and International Feed Number (IFN): ethyl cellulose 4-08-045. The IFN willassist feed producers in having their feedproducts approved by regulators such asthe U.S. Department of Agriculture, theCanadian Food Inspection Agency, andthe UN Food and AgricultureOrganization (FAO).

Ceramics ETHOCEL is used in ceramicapplications as a rheology modifier andbinder. It provides green strength to theunfired ceramic and burns out cleanly,leaving no residue after firing.

Conductive Pastes ETHOCEL is usedin conductive pastes and inks. It functionsas a rheology modifier and as a binderand stabilizer for metal pigments. It burnsout cleanly, leaving no residue after firing.

Printing Inks ETHOCEL is used ingravure, flexographic, and screen printinginks. It is soluble in common solventsystems and is compatible withplasticizers, waxes, and other polymerscommonly used. It functions as a rheologymodifier, dispersant, and binder forpigments and as a polymeric binder forpigment chips. It contributes to theformation of tough, abrasion-resistantfilms. It reduces tack of ink films andimproves printability on difficult substrates.Ink films dry quickly because of thepermeability of films of ETHOCEL polymers.

Applications

8

Adhesives • • • • • •Ceramics • • • • •Conductive pastes • • • • • •Electronics • • • • • • •Fluorescent lighting • • • • •Food/Feed • • • • • • • •Food packaging • • • • • • •Hot melts • • • • •Personal care • • • • • • • • •Pharmaceutical • • • • • • • • •Printing inks • • • • • • •Varnishes/lacquers • • • • •

Bin

der

Cont

rolle

dre

leas

e

Film

form

er

Low

ash

Mic

roen

caps

ulat

ion

Prot

ectiv

eco

atin

g

Rheo

logy

mod

ifier

Tack

Tast

em

aski

ng

Wat

erba

rrie

r

Prem

ium

grad

es

Indu

stria

lgra

des

Table 3. Typical use map for ETHOCEL polymers

9

Specialty Coatings ETHOCEL bringsan unusual combination of properties tospecialty coatings applications.

Hot Melts ETHOCEL dissolves readily inmany hot polymers, plasticizers, and oiland wax mixtures. It has excellentthermoplasticity.

Adhesives Hot melts using ETHOCEL canbe easily heat-sealed. ETHOCELcontributes added strength especiallywhere stresses may be applied to afreshly sealed joint.

Paper Coatings ETHOCEL providesremarkable toughness (resistance toscuffing) and flexibility at roomtemperature and low temperatures. Thecoating has good gloss and blockresistance and retains a low rate ofwater vapor transmission.

Fluorescent Lighting ETHOCEL acts as arheology modifier and binder for coatingfluorescent lighting tubes. ETHOCEL isremoved by heating. It burns cleanly,leaving no residues, which allows thetriphosphor coating to adhere to theglass tube.

Other Applications ETHOCEL is alsoused in waterproofing coatings, high-temperature/maintenance coatings,enameling, lacquers, varnishes, andmarine coatings.

ETHOCELFunctionality Products

4.1 Choice of SolventsAny given application usually employs several different solvent combinations.Solutions of ETHOCEL ethylcellulose polymers in aromatic hydrocarbons are highlyviscous; consequently, only low-solids solutions are possible when these solvents areused singly. Ethanol and methanol yield solutions of ETHOCEL polymers having lowerviscosity than do aromatic hydrocarbons, but the properties of the films are affected.There are mixtures of aromatic hydrocarbons with methanol or ethanol that yieldsolutions of ETHOCEL polymers having a lower viscosity than is obtainable witheither solvent type used singly. These mixtures also deposit films having goodstrength. This is shown by the data on the 80-20 toluene-ethanol solvent included inTable 4 for comparison.

The lower molecular weight aliphaticesters and ketones produce solutions ofETHOCEL polymers that have comparativelylow viscosities and that yield films of goodstrength and extensibility. However, it ispreferable in most cases to use thesesolvents with a small proportion of oneof the lower molecular weight alcoholsbecause of the lower viscositiesobtainable for such mixtures (Table 5).

Solutions of ETHOCEL polymers willtolerate dilution with petroleum thinnersto an unusually high degree for cellulosederivatives. However, the resultantpolymer solution will have a higherviscosity than if it had been preparedwith an aromatic solvent.

The most practical solvents for ETHOCELpolymers are mixtures that have beenformulated to yield solutions having thelowest viscosity consistent with goodfilm properties and that have a suitableevaporation rate.

Table 4. Viscosity and film properties of ETHOCEL Std. 10polymer in single solvents (15 g polymer in 100 mL solvent)

Solution Properties @ 25˚C Film Properties

SolventYield Point,

kg/cm2

SpecificGravity

Elongation%

Viscosity, mPa·s (cP)

1900

590

560

360

470

320

1930

260

n-Butanol

Butyl acetate, 90%

Ethanol, Formula 30

Ethyl acetate, 99%

Ethylene dichloride

Methyl ethyl ketone

Toluene

80-20 Toluene-ethanol

6

7

—a

9

5

7b

12

7

0.848

0.901

0.850

0.924

1.238

0.845

0.890

0.887

425

430

—a

440

420

428b

440

440

a Too brittle to test properly.b Films showed “orange peel.”

Table 5. Solvent compositions forminimum solution viscosity for ETHOCELpolymers in common binary solvents

Solvent Mixture Solvent CompositionAromatic/ethanol 20% ethanolAromatic/ester No change by varying esterEsters/ethanol 20% ethanol

Ketones/ethanol 20% ethanolAromatic naphthas/ethanol 30% ethanolAliphatic naphthas/ethanol 30% ethanol

FormulatingWith ETHOCEL

10

Figure 5. Viscosity of 5% solutions of ETHOCEL Std. 100 polymerin toluene with various alcohols

4.1. Aromatic Hydrocarbon-AlcoholMixturesSolvent mixtures may be formulated fromaromatic hydrocarbons and the lowermolecular weight aliphatic alcohols toyield solutions of ETHOCEL polymershaving low viscosity. Figure 5 shows theeffect of alcohol content on the viscosityof a solution of an ETHOCEL polymer in amixture with an aromatic hydrocarbon.The curves show the viscosities of a 5%solution of ETHOCEL Std. 100 polymer inmixtures of toluene with four lowmolecular weight aliphatic alcohols. Theviscosity is extremely high in toluenealone; it decreases rapidly with theaddition of small percentages of alcohol.As the alcohol content increasessignificantly the viscosity rises with allalcohols except methanol. This increase

is greater with higher molecular weightalcohols. Figure 5 also shows that alower minimum viscosity can be obtainedwith ethanol or methanol than withbutanol.

The shape and relative position of theviscosity curves of Figure 5 change onlyslightly when the concentration ofETHOCEL polymer is increased.Substitution of xylene or ethylbenzenefor the toluene has little effect on thealcohol content at which the minimumviscosity is obtained, the actual viscosityat the minimum with any one alcohol, orthe shape of the curves. Therefore, theviscosity of a solution of ETHOCELpolymers will be dependent primarily onthe kind of alcohol used, and on itspercentage in the solvent.

11

0 10 20 30 40 50 60 70 80 90 100Alcohol in Solvent, Percent by Volume

400

350

300

250

200

150

100

50

Visc

osity

,mPa

. s,2

5°C

5

4

321

1. Methanol

2. Ethanol, Formula #30

3. Ethanol, absolute

4. Isopropanol, 98%

5. Normal butanol

4.2 Viscosity vs ConcentrationThe relationship between solutionviscosity and concentration for a seriesof product viscosities is shown in Figure6. Viscosity determinations were madeat 25°C in 80-20 toluene-ethanol. FromFigure 6, it is possible to select theviscosity of the ETHOCEL polymer requiredto obtain a solution of desired viscosityand concentration; it also permits thesolids content at a given solution viscosityto be determined. The amount of dilutionrequired to obtain a given solutionviscosity can also be estimated fromFigure 6. The data suggest the possibilityof using high-viscosity ETHOCEL polymersas efficient thickeners for organicsolvent-based formulations.

Figure 6. Viscosity-concentration chart for ETHOCEL Standard polymers

12

5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

Concentration in Weight Percent

Visc

osity

,mPa

. s,2

5°C

(Solutions in 80-20 Toluene-Ethanol by Weight)

NOTE: Viscosity grade is indicated on vertical axis (5% solutions)

40000

35000 32500 30000 28000 26000 24000 22000

20000

18000 16000

14000

12000

10000900080007000

6000

5000

45004000

3500

3000

2500

2000180016001400

1200

1000900800

700600

500450400350300

260

200

160140120

100

80

6050

40

3025

20

14

10

7

5

Figure 7. Blending chart for intermediate viscosities of ETHOCEL polymers

4.3 Blending for IntermediateViscositiesIf viscosities intermediate to those listedare required, refer to the blend chart(Figure 7). On the vertical axes are theviscosities for two different ETHOCELproducts measured in any given set ofunits at the same conditions. On thehorizontal axis is shown the percentageof one of the viscosity types of ETHOCELin the blend.

For example, to produce a 5% solution ofETHOCEL polymers having a viscosity of75 mPa·s by blending 100 mPa·s materialwith 50 mPa·s material: A line is drawnconnecting these two viscosities asindicated by the dashed line on the chart.The point of intersection of this line withthe 75 mPa·s line shows that 45% of the50 mPa·s material is required in the blend.

Figure 7 can be used for blendingviscosity types of ETHOCEL polymerswith each other, and with nitrocelluloseas well. For accurate results, theviscosities of ETHOCEL polymers andnitrocellulose should be measured in thesame solvent under the same conditionsof temperature and concentration.

0 10 20 30 40 50 60 70 80 90 100

Percent in Blend of Resin of Viscosity on Right Hand Scale

Vis

cosi

ty,m

Pa. s

1000950900850

1

800750700650

600

550

500480460440420400380360340320300280260240

220200190180170160150140130120

11010095908580757065605550464238

34

28262422201816

14

12

1098

7

6

5

4

3

2

30

Vis

cosi

ty,m

Pa. s

1000950900850

1

800750700650

600

550

500480460440420400380360340320300280260240

220200190180170160150140130120

11010095908580757065605550464238

34

28262422201816

14

12

1098

7

6

5

4

3

2

30

13

Table 6 shows the solubility of ETHOCEL polymers in a number of common singlesolvents. The table does not list concentrations or viscosities, or all solvents forETHOCEL polymers-it is only intended as a general guide. Again, ETHOCEL polymersare most soluble in blends of aromatic hydrocarbons and aliphatic alcohol.

Table 6. Solvents for ETHOCEL polymers

A. HYDROCARBONSSolvent Solubilitya of ETHOCEL Polymers

Type Name Standard ethoxyl Medium ethoxylAromatic hydrocarbons Toluene Sol clear Gels

Xylene Sol clear GelsEthylbenzene Sol clear Sol gelsIsopropyl benzene Sol clear SwellsDiethylbenzene Sol gels SwellsDiphenylethane Sol gels Swells

Cycloaliphatic Cyclohexane Swells Insolhydrocarbons Cyclohexene Sol clear Sol clear

Methyl cyclohexane Swells InsolAromatic naphthas – Swells SwellsAliphatic naphthas Petrobenzol Swells Swells

Troluoil Swells SwellsAliphatic petroleum thinner Swells SwellsBenzosol Swells SwellsTolusol Swells SwellsV.M. & P.b Swells Swells

Naval stores Dipentene Sol clear SwellsTurpentine, gum spirits Sol hazy Swells

Chlorinated aliphatic Chloroform Sol clear Sol clearhydrocarbons Carbon tetrachloride Sol clear Gels

Ethylene dichloride Sol clear Sol clearTrichloroethylene Sol clear Sol clearPropylene dichloride Sol clear Sol clearTrichloroethane Sol clear Sol clearPerchloroethylene Sol hazy SwellsTetrachloroethane Sol clear Sol clearMethylene chloride Sol clear Sol clear

Chlorinated aromatic Monochlorobenzene Sol clear Sol hazyhydrocarbons o-Dichlorobenzene Sol clear Sol hazy

Trichlorobenzene Sol clear Swells

a Solubility rated on a mixture of 2 g ETHOCEL in 18 mL of solvent. The followingabbreviations were used to indicate the six degrees of solubility observed:

Sol clear—Soluble, solution clear of haze and free from gelsSol hazy—Soluble, solution hazy and free from gelsSol gels—Soluble, solution of granular nature due to presence of gelsGels—Completely gelatinizedSwells—Swollen or incompletely gelatinizedInsol—Insoluble

b Varnish Makers and Painters

14

B. ALCOHOLS AND ETHERSSolvent Solubility of ETHOCEL Polymers

Type Name Standard Ethoxyl Medium EthoxylMonohydric aliphatic alcohols Methanol, anhydrous Sol clear; Swells Sol gels

Ethanol, anhydrous Sol clear; Swells GelsEthanol, Formula 2B Sol clear; Swells GelsIsopropanol, 91% Sol clear; Swells SwellsIsopropanol, 99% Sol clear; Swells Swellssec-Butanol Sol clear; Swells GelsIsobutanol Sol clear; Swells Sol gelsn-Butanol Sol clear; Swells Sol gelsOctyl (2-ethylhexyl) alcohol Sol clear; Swells Gels

Monohydric cyclic alcohols Cyclohexanol Gels Sol clearFurfuryl alcohol Sol clear GelsMethyl cyclohexanol Sol clear GelsTetrahydrofurfuryl alcohol Sol clear GelsBenzyl alcohol Sol clear Sol clearPhenyl ethyl alcohol Sol clear Sol clearPine oil Sol clear Sol gels

Polyhydric alcohols Ethylene glycol Insol InsolDiethylene glycol Insol InsolGlycerin Insol InsolTriethanolamine Swells Insol

Ether alcohols DOWANOL* PM glycol ether Sol clear GelsDOWANOL DPM glycol ether Sol clear GelsDOWANOL EP glycol ether Sol clear GelsDOWANOL DB glycol ether Sol clear Gels

Ethers Ethyl ether Sol hazy SwellsIsopropyl ether Sol hazy SwellsDioxane Sol clear Sol clearMorpholine Sol clear Sol clearn-Butyl ether Swells SwellsPhenyl ether Swells Sol hazyBenzyl ether Sol hazy Swells

aSolubility rated on a mixture of 2 g ETHOCEL in 18 mL of solvent. The followingabbreviations were used to indicate the six degrees of solubility observed:

Sol clear—Soluble, solution clear of haze and free from gelsSol hazy—Soluble, solution hazy and free from gelsSol gels—Soluble, solution of granular nature due to presence of gelsGels—Completely gelatinizedSwells—Swollen or incompletely gelatinizedInsol—Insoluble

*Trademark of The Dow Chemical Company

Table 6. Solvents for ETHOCEL polymers

15

C. ESTERSSolvent Solubilitya of ETHOCEL Polymers

Type Name Standard Ethoxyl Medium EthoxylAcetates Methyl acetate, 99% Sol clear Sol clear

Ethyl acetate, 85-88% Sol clear Sol clearIsopropyl acetate Sol gels Sol clearsec-Butyl acetate Gels Sol clearIsobutyl acetate Gels Sol clearn-Butyl acetate Sol gels Sol clearsec-Amyl acetate Swells Sol clearCyclohexyl acetate Sol gels Sol clearGlycol diacetate Gels Sol clear

Esters of hydroxy acids Ethyl lactate Sol gels Sol clearIsopropyl lactate Sol gels Sol clearn-Butyl lactate Sol clear Sol clearMethyl salicylate Sol gels Sol clear

D. KETONESSolvent Solubilitya of ETHOCEL Polymers

Type Name Standard Ethoxyl Medium EthoxylKetones Acetone Sol clear; Swells Sol gels

Methyl ethyl ketone Sol clear; Swells Sol gelsMethyl isobutyl ketone Sol clear; Swells SwellsMesityl oxide Sol clear Sol gelDiacetone alcohol Sol clear GelsCyclohexanone Sol clear GelsMethyl cyclohexanone Sol clear GelsAcetophenone Sol clear Sol gels

aSolubility rated on a mixture of 2 g ETHOCEL in 18 mL of solvent. The followingabbreviations were used to indicate the six degrees of solubility observed:

Sol clear—Soluble, solution clear of haze and free from gelsSol hazy—Soluble, solution hazy and free from gelsSol gels—Soluble, solution of granular nature due to presence of gelsGels—Completely gelatinizedSwells—Swollen or incompletely gelatinizedInsol—Insoluble

Table 6. Solvents for ETHOCEL polymers

16

4.4 PolymersIn formulating with ETHOCEL polymers,other polymers are used to improvegloss, rubbing properties, adhesion, andresistance to certain solvents. Generally,the percentage of modifying polymer isapproximately equal to that of theETHOCEL polymer, and the amount ofplasticizer will be about one-half that ofthe polymer total. However, dependingon the application, the ratio of ETHOCELpolymer, plasticizer, and modifyingpolymer can be varied greatly. ETHOCELproducts are compatible in allproportions with the following modifyingpolymers:

• Most pure phenolics• Modified phenolics• Coumarone indenes• Natural polymers• Processed natural polymers• Rosin• Rosin derivatives• Long oil alkyds

There is limited compatibility with ureaformaldehydes, alkyds of medium oillength, vinyl butyral polymers, and vinylacetate polymers. Small percentages ofETHOCEL polymers can be added tothese polymers, or small percentages ofthese polymers can be added toETHOCEL products, usually withoutcausing incompatibility or haze.Approximately equal ratios of suchpolymers and ETHOCEL polymer will,however, invariably produce hazy orincompatible films.

ETHOCEL polymers are incompatiblewith most of the short oil alkyds andvinyl chloride-type polymers.

On curing, certain urea formaldehydeand melamine formaldehyde polymersreact with ETHOCEL polymers to greatlyimprove the solvent resistance andsoftening point of the finished films.Such compositions have been used, forexample, as top coats to protect a gel-lacquered surface that might come incontact with solvents that would attackthe ETHOCEL polymer alone.

4.5 Pigments and DyesETHOCEL polymers do not react withpigments and dyes. ETHOCEL productscan be pigmented by any of the usualmethods and can be dyed with any dyessoluble in the solvents being used.

ETHOCEL polymers are excellentpigment-dispersing media. Dispersionsof this type have been made on a two-roll or three-roll mill, and the resultantchips may be used to pigment bothlacquers and inks.

17

4.6 Heat and Light StabilizersExtended exposure to heat and/orultraviolet light can lead to degradation.Therefore, heat and light stabilizers areoften added, particularly in unpigmentedformulations. Octylphenol and butylatedhydroxyphenol have performedeffectively as antioxidants in this use,and 2,4-dihydroxybenzophenone hasbeen used effectively as an ultraviolet-light absorber.

Generally, combinations of 1% to 2%antioxidant plus 0.5% to 1% ultravioletlight absorber (based on total solids) giveadequate protection against both heatand light degradation. Pigmentedformulations seldom require lightstabilization.

4.7 Film PropertiesETHOCEL products yield a greatervolume of film-forming solids per unitweight than do most other commercialcellulose derivatives, as shown in Table7. Films of ETHOCEL polymers arecompletely transparent, colorless,flexible, and tough.

The tensile strength and elongationproperties of films of ETHOCEL polymersbear a relationship to the intrinsicviscosity of the ETHOCEL product used inmaking the films. Films made with thehigher viscosity types of Medium andStandard ETHOCEL products are strongerand tougher than those of low viscosity.This is shown in Figure 8.

Figure 8 also shows that Mediumethoxyl ETHOCEL products possessgreater hardness and toughnessthan do Standard ethoxyl ETHOCELproducts of similar viscosity.Hardness is measured by resistanceto deformation; the yield points offilms shown in Figure 8 may be

Table 7. Film coverage with ETHOCEL polymers and other cellulose products

Specific Area Covered, Quantity to CoverMaterial Gravity of Filma m2/kg (in2/lb) Equal Area kg (lb)

ETHOCEL Standard polymer 1.13 35 (24,500) 0.45 (1.00)ETHOCEL Medium polymer 1.17 34 (23,700) 0.46 (1.03)Cellulose acetate butyrate 1.22 32 (22,700) 0.49 (1.08)Cellulose acetate 1.37 29 (20,200) 0.50 (1.10)Cellulose nitrate 1.65 24 (16,800) 0.66 (1.48)aThickness = 0.25 mm (0.001 inch)

used to determine their relativehardness. An understanding of thedifferences between Medium andStandard ETHOCEL products is helpful informulating coatings for maximumflexibility and toughness. At acomparable molecular weight (viscosity),the Medium ethoxyl ETHOCEL product is“tougher” than the Standard ethoxylETHOCEL product.

When mixtures of alcohols with aromatichydrocarbons are used as solvents forETHOCEL polymers without largeproportions of plasticizers or otherpolymers, the mechanical properties ofthe deposited film are affected by thelast solvent to evaporate. This isindicated by the data in Table 4, pg. 10,which show that brittle films weredeposited from certain alcohol-typesolvents, but that strong, flexible filmsresulted from aromatic hydrocarbonsolvents. In general, when ethanol ormethanol is used to reduce solutionviscosity in mixtures with aromatichydrocarbons, the solvent mixturesshould be formulated so that thearomatic hydrocarbon is the last solventto leave the film. For example, theproportion of ethanol in mixtures withtoluene, which has a somewhat slowerevaporation rate than ethanol, should notexceed 30%. With a slower evaporatinghydrocarbon, such as xylene, the ethanolcontent can be increased to about 40%.

18

4.8 PlasticizersETHOCEL products are compatible withmost common plasticizers. Plasticizersexert greater softening action onETHOCEL polymers than on most othercellulose derivatives. The Mediumethoxyl type requires greaterconcentrations of plasticizers to producea given degree of softness than does theStandard ethoxyl type. Table 8 listsplasticizers with high and low softeningeffect.

In many formulations using ETHOCELpolymers, 5 to 30% of plasticizer (basedon the total solids) is sufficient toproduce satisfactory flexibility. Thechoice of plasticizer depends on the

other components and the temperaturerange or other application or useconditions, rather than on the particularETHOCEL polymer. The most widely usedplasticizers include phthalates,phosphates, glycerides, and esters ofhigher fatty acids and amides. For use incompositions that are resistant to lowtemperatures, long-chain, ester-typeplasticizers are recommended. Examplesinclude dibutyl sebacate, butyl stearate,glycol esters of coconut oil fatty acids,and butyl ricinoleate.

Plasticizers used with ETHOCEL polymersin pharmaceutical applications includedibutyl sebacate, triethyl citrate,triacetin, and acetylated monoglycerides.

Figure 8. Load-elongation curves for ETHOCEL polymers

4.9 Solvent-Free EmulsionsSolvent-free emulsions of ETHOCELpolymers may be customer-prepared byheating and melting a blend of anETHOCEL polymer with a plasticizer. Theresulting homogeneous, hot mixture isthen emulsified with hot water toproduce an emulsion of very finelydivided particles of thermoplasticmaterial in water. Clear, colorless filmsresult when these emulsions are castinto films and dried. Film properties maybe varied by altering:

• Plasticizer

• ETHOCEL product used

• Ratio of plasticizer to ETHOCELpolymers

• Drying time and temperature

Table 8. Plasticizers with varying softening effects on ETHOCEL polymers

Higher Softening Effect Lower Softening EffectDibutyl phthalate Diphenyl phthalate

Castor oil Dicyclohexyl phthalateButyl phthalyl butyl glycolate Cresyldiphenyl phosphate

Butyl stearate Benzyl phthalate 19

0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40Elongation, Percent

800

700

600

500

400

300

200

100

0

Load

,kg

/cm

2

1. Standard-ethoxy ETHOCEL resin

Solvent: 80 Toluene — 20 Ethanol

2. Medium-Ethoxy ETHOCEL resin

Solvent: 60 Toluene — 40 Ethanol

ALL FILMS: 0.040 mm 0.002 mm

Up to 10 mPa.s

11360

9940

8520

7100

5680

4260

2840

1420

0

Load

,psi

Up to 20 mPa.s

Up to 50 mPa.s

50-150 mPa.s

100-250 mPa.s

Up to 100mPa.s

2

1

Table 9. Selection of ETHOCEL polymers for pharmaceutical applicationsApplication ETHOCEL PolymerControlled-release coatings ETHOCEL Std. 7, 10, or 20 Premium

ETHOCEL blended with METHOCEL E5 or E15 Premium LV polymer

Microencapsulation ETHOCEL Std. 45 or 100 Premium

Tablet coating ETHOCEL Std. 7, 10, or 20 Premium

Granulation ETHOCEL Std. 10, 20, or 45 Premium

Binder/direct compression ETHOCEL Std. 7 Premium FP, 10 Premium FP, or 100 Premium FP

Table 10. Viscosity of ETHOCEL Std.10 Premium solutions in ethanol

ETHOCEL (%) HPMC (%) Viscosity (mPa·s)15.0 0 454

15.0 0.4 480

15.0 1.5 577

ETHOCEL Premium ethylcellulose polymers are recognized and used globally

for many different functional purposes in pharmaceutical products. They are

frequently used in controlled-release, solid-dosage formulations as well as for

protective coatings for water-sensitive or reactive ingredients. They are also useful

as granulation binders, as film formers, to improve tablet integrity and appearance,

and to mask the taste of bitter active ingredients.

ETHOCEL Premium polymers meet the requirements of the Food Chemical Codex,

the U.S. National Formulatory (NF), the Japanese Pharmaceutical Excipients (JPE)

Monograph, and the European Pharmacopeia (EP). Refer to the product’s Certificate

of Analysis for a statement of compliance to the current version of each of these

regulatory documents.

ETHOCEL FP polymers were developed specifically for use as excipients in

controlled-release matrix formulations. As water-insoluble excipients, ETHOCEL

polymers can effectively control the release of an active ingredient by modifying the

size and length of the diffusion path. In this role, ETHOCEL polymer is typically used

in combination with water-soluble excipients such as METHOCEL* cellulose ethers

(hypromellose (HPMC) and methylcellulose). By varying the type and amount of the

insoluble excipient ratio and the particle size, a wide variety of release rate profiles

can be achieved.

Table 9 provides guidelines for selecting the right ETHOCEL polymer for

pharmaceutical applications.

5.1 GranulationPremium ETHOCEL polymers are often used

for solvent granulation of water-sensitive

materials. Tablets made with ethylcellulose-

granulated materials are strong and have

good dissolution properties. ETHOCEL

polymers may also be used for extrusion

granulation because of the thermoplastic

nature of ethylcellulose. Dissolution times

may be extended or modified by varying

the amount of ETHOCEL polymer in a

granulation or by adding water-soluble

binders to the granulating fluid containing

the ETHOCEL polymer.

5.2 CoatingETHOCEL polymers have long been used

as solvent-based tablet and bead coatings.

They form strong films with good adhesion.

Because ethylcellulose is water-insoluble,

it is often used in conjunction with other

water and organic-solvent soluble polymers

such as METHOCEL cellulose ethers.

Sustained or delayed release coatings can

be achieved by varying the ratios of

ETHOCEL and METHOCEL polymers. The

viscosity of solutions of ethylcellulose

prepared in ethanol with hypromellose

(HPMC, METHOCEL E5 Premium LV), is

listed in Table 10.

Pharmaceutical Applications

20

* Trademark of The Dow Chemical Company

INS92001.qxd 9/22/05 9:39 AM Page 20

Table 11. Diphenhydramine HCl release rates in deionized water

ETHOCEL 30% Drug Released 50% Drug Released 80% Drug Released5% coating 10 min 20 min 150 min10% coating 25 min 50 min 270 min15% coating 45 min 75 min 360 min

Figure 9. Drug dissolution of ETHOCEL Std. 10 Premium granular vs. fine particle

21

The technology of making and sprayingsolvent-free emulsions of ETHOCELpolymers (as discussed on pg. 19) has beenused in the pharmaceutical industry to coattablets with ethylcellulose in the absenceof volatile, flammable, organic solvents.

5.3 Tablet BindingETHOCEL products are used as tabletbinders in dry granulation or direct com-pression formulations. Figure 9 illustratesthe comparative dissolution of diphenhy-dramine hydrochloride from tabletsprepared with granular and fine powderforms of ETHOCEL Standard Premiumproducts at two different ethylcelluloseto drug ratios at a constant compressionforce of 3600 kg (8000 lb). The drugrelease rates are significantly affected bythe level of polymer in the tablet and theparticle size. The higher the polymerconcentration and the smaller theparticle size, the slower the release rate.

The ETHOCEL and METHOCEL polymersshould be dissolved in a solvent (orsolvent blend) at approximately 10 to15% solids. A plasticizer (e.g. glycerine)may be added to the mixture. Thefollowing solvents are recommended:

• Ethanol• Methanol• Acetone• Chloroform and ethanol blend• Ethyl lactate and ethanol blend• Methyl salicylate and ethanol blend• Methyl salicylate• Toluene and ethanol blend• Methylene chloride and ethanol blend

Spray coating can be used to apply a thinfilm coating of ETHOCEL to the surfaceof tablets or non-pareils. A solution ofETHOCEL is typically made with a solventand a plasticizer. The solution is appliedto the tablets or non-pareils using equip-ment such as a Wurster fluidized bed. Thesolvent evaporates, leaving a film coatingof ETHOCEL polymer. Typical processtemperatures include an inlet temperatureof 55 to 60°C, product temperature of 35to 45°C, and exhaust temperature of 30 to40°C. These temperatures were used in a9-inch Wurster fluidized bed with a 4 kg(8.8 lb) batch size. Different solvents andplasticizers have been used to makesolutions of ETHOCEL for spray coating,for example:

Component Weight PercentETHOCEL Std. 10 Premium 10Triacetin USP 1Acetone 89

The coating thickness, and thus releaseprofile, can be varied by changing thenumber of passes through the fluidizedbed. The above formulation was used toapply a controlled-release coating of

ETHOCEL to diphenhydramine, HCl-coated, non-pareils using a Wursterfluidized bed. Coating levels of 5%, 10%,and 15% were tested for dissolution rates.Table 11 shows the time for 30%, 50%,and 80% drug release in deionized water.

Although it is not a true encapsulationprocess, time-release capsules are oftenmanufactured by spraying solutions ofMETHOCEL and ETHOCEL polymers ontosmall beads of active ingredients. Widevariations of release rates or releasepatterns can be achieved by varyingpolymer ratios and coating weights.

ETHOCEL polymers also are used in acoacervation process to microencapsulateparticles. The microencapsulation ofparticles in a boiling cyclohexane-ETHOCELpolymer mixture is described in the NCRprocess (U.S. Patent No. 3,567,650) and isused in some pharmaceutical applications.

0 500 1000

100

80

60

40

20

0

Time, Minutes

%D

rug

Rele

ased

Ratios shown in legend indicate ratio of ETHOCEL Std. 10Premium to diphenhydramine hydrochloride.

Std-10, 1:3Std-10 FP, 1:3Std-10, 3:1Std-10 FP, 3:1

ETHOCEL ethylcellulose polymershave provided excellent functionality inmany specialty applications for morethan 60 years. They have been used asviscosifiers, binders, and film formers inapplications such as conductive pastes,printing inks, ceramics, and specialtycoatings. Table 12 provides guidelines forselecting the right ETHOCEL polymer forspecialty applications.

6.1 Personal CareETHOCEL polymers are approved for usein cosmetics. Ethylcellulose is listed inthe International Cosmetic IngredientDictionary and Handbook (INCI). The INCIname for ETHOCEL is ethylcellulose. It isalso listed in the Japanese Standards ofCosmetic Ingredients.

ETHOCEL ethylcellulose polymers arenaturally derived polymeric materials.ETHOCEL is not a skin sensitizer, it is notirritating to the skin, it is not mutagenic.

ETHOCEL is soluble in many organicsolvents, including ethanol and naturaloils. It yields strong, flexible films at lowconcentration. It provides excellent waterresistance and can be used to protectwater-sensitive ingredients.

ETHOCEL has been used in lipsticks andnail polishes (it gives long-lastingbrilliance), as a fragrance stabilizer, andas a thickener for perfumes and bodycreams (waterproof sunscreens). It canbe used to mask or control the release ofactive ingredients. Refer to Section 5 formore information on controlled release,granulation, coating, and tablet binding.

ETHOCEL FP polymers may broadenformulation options available in the areaof personal care. ETHOCEL polymershave been used for decades in thehydrated state as water-resistant filmformers in sunscreens, lipsticks, andointments. The enhanced lipophilic andhydrophobic properties of ETHOCEL FP inthe unhydrated state can be used toimprove controlled release of oilyactives, improve stability of an active,and in viscosity modification. Refer towww.ETHOCEL.com for the mostrecent information.

Specialty Applications

22

Table 12. Selection of ETHOCEL polymers for specialty applications

Application ETHOCEL PolymerConductive pastes ETHOCEL Std. 4, 7, 10, 45, 100, 200, 300 Premium and IndustrialCeramics ETHOCEL Std. 10, 45, 100 Premium and IndustrialPersonal care ETHOCEL Std. 7, 10, 20, 45, 100 Premium and IndustrialRotogravure andflexo packaging inks ETHOCEL Std. 4, 7, 10, 20 Industrial Screen printing paste ink ETHOCEL Std. 45, 100, 200, 300 IndustrialLow-solids coatings ETHOCEL Std. 100, 200, 300 IndustrialSpecialty coatings ETHOCEL Std. 4, 7, 10, 20, 45, 100, 200 Industrial

6.2 Food ApplicationsETHOCEL polymers are odorless,tasteless, and film-forming and aretherefore used in food applications suchas flavor encapsulation, inks for markingfruits and vegetables, and as a componentof paper and paperboard packaging incontact with aqueous and fatty foods.The specifications applicable to fooduses are defined in the Food ChemicalsCodex. ETHOCEL Premium polymers meetspecifications of the Food ChemicalsCodex. Refer to www.ETHOCEL.comfor the most recent information.

6.3 Animal FeedETHOCEL polymers are organo-solublefilm formers. These polymers can beused to control the release of nutrients in animal feed pellets or granules. Theyalso protect nutrients or any otheringredient against external ingredientattacks—water in particular. In addition,moisture retention can also be achievedby coating the ingredient with ETHOCELpolymers.

6.4 Conductive Pastes

ETHOCEL polymers are used inconductive pastes. They function as arheology modifier and as a binder andstabilizer for metal pigments. They burnout cleanly, leaving no residue afterfiring. An example of a solution for aconductive paste is given below.

Component Weight PercentETHOCEL Std. 45Industrial polymer 5–10Butyl CELLOSOLVE™acetate/terpineol blend 90–95Dispersing agent 0.1

A final conductive paste might combine20 to 40% of the solution describedabove with 60 to 80% metal powders.

23

6.5 CeramicsETHOCEL polymers are used in solvent-based ceramics as rheology modifiersand binders. They provide green strengthto the unfired ceramic and burn outeasily, leaving no residue after firing.

6.6 Printing InksGenerally, ETHOCEL polymers are usedto enhance the quality of flexographicand gravure inks. However, they also canbe used as a binder in theseformulations. They favorably impacttoughness and flexibility of the ink film,resulting in better folding resistance.They also improve printability on difficultsubstrates and contribute to theformation of tough, pinhole-free filmseven at low coating thickness. Theyshow good compatibility with most ofthe resins and pigments used in theseinks and show excellent solubility incommon solvents such as toluene, ethylacetate, and ethanol.

6.6 Gravure InkGravure printing is used for relativelylarge-volume, high-quality, high-speedruns for printing high-qualitypublications, magazines, catalogues,and advertisements. It is also used inpackaging for quality color printing ontransparent and flexible films. ETHOCELis soluble in solvents commonly usedin gravure printing. It functions as arheology modifier, improves printabilityon difficult substrates, and acts as adispersant and binder for pigments.An example of a packaging gravure inkis given below:

Component PartsMagenta concentrated ink 100Ink varnish 30Toluene 40ETHOCEL Std. 10 Industrial polymer 1

6.6 Heat-Transfer PrintingIn heat-transfer printing, the ink isprinted or deposited onto paper and thentransferred with heat to fabrics (e.g.polyesters, triacetate, and acrylics).As an example, a heat-transfer inkformulation could contain:

Component PartsDye 1–5ETHOCEL Std. 10 Industrial polymer 12–20Solvent 75–85Thermoplastic binder (for tack) 0–10

6.6 Solvent-Free Hot Melt InksETHOCEL products may also be used asthe base polymer in formulating solvent-free hot-melt inks, which are used toprint textile fabrics, novelty designs andinformation on T-shirts, manufacturers’labels, and patterns for embroidery. Ageneral composition is:

Component PartsCastor oil 6Paraffin wax 40ETHOCEL Std. 10 Industrial polymer 16Pigments 20Heat stabilizer 0–10

All ingredients except the ETHOCELpolymer are heated to 150°C (302°F). TheETHOCEL polymer is added slowly, withagitation. A homogeneous liquid inkresults when the ETHOCEL polymermelts.

24

6.8 Room-Temperature LacquersRoom-temperature lacquers areconventional lacquers in which thecoating is applied at room temperatureand the film is formed by evaporation ofthe solvent. ETHOCEL Standardpolymers are recommended for this typeof application because of greatersolubility in typical organic solvents andgreater compatibility with a wide rangeof modifying polymers.

ETHOCEL Std. 4, 7, and 10 products aretypically used in lacquers where:

• Minimum viscosity development isdesired at maximum lacquernonvolatile (solids) content, or

• Somewhat reduced toughness can beaccepted, or

• Compatibility with other lacqueringredients is needed

ETHOCEL Std. 45 and 100 products areused in lacquers where greatertoughness is desired combined with thegreater solubility of Standard vs.Medium grades. These two ETHOCELproducts are also used where maximumviscosity at minimum concentration isdesirable. ETHOCEL Std. 20ethylcellulose is a natural compromise.

ETHOCEL Medium products are used inlacquers where maximum toughness isdesired and the somewhat lowersolubility in particular solvents is not aproblem.

6.9 Gel LacquersA gel lacquer of ETHOCEL polymer is hotlacquer composed primarily of ETHOCELpolymer, plasticizer, and solvents. The gellacquer is a homogeneous liquid at ornear the temperature of boiling water.When allowed to cool, the lacquerbecomes a gelled mass resembling toughgelatin.

Dipping a cool (room temperature) objectinto a hot gel lacquer congeals a thicklayer of lacquer onto the object’s surface.While drying, the applied lacquer shrinks,resulting in a tight-fitting, uniform plasticcoating. In a single dipping, a dry coatingthickness ranging from 0.004 to 0.08 cm(0.0015 to 0.03 inch) is possible. Thethickness of the coating is controlled bythe temperature of the object beingdipped and by the composition of thelacquer. The ability to obtain unusuallyheavy coatings with very few dips is aresult of the phenomenon of gelation andis a primary advantage of these gellacquers.

6.7 Hot Melt Strippable CoatingsHot melt strippable coatings are 100%nonvolatile systems. These hot melts areused by industry primarily to protectmetal parts against corrosion anddamage during handling, shipment, andstorage.

Room-temperature parts (or objects) arecleaned and then dipped into the hotmelt. Within 5 seconds, a tight envelope0.2 to 0.25 cm (0.07 to 0.10 inch) thickwill gel around the part. The part is thenlifted from the melt and cooled.

The materials used with ETHOCELpolymers in a transparent hot meltstrippable coating must be carefullyselected because of the hightemperatures encountered in the diptanks (177 to 191°C, 350–375°F) andbecause of the long heating periodsinvolved. Heat-stable, nonvolatilemineral oils, polymers, and plasticizersmust be chosen; antioxidants and heatstabilizers are recommended. If thecoating is to be transparent, theingredients must be compatible.

The materials in a typical strippablecoating formulation could include:

Component Weight PercentETHOCEL polymer 25Mineral oils 50Polymers and plasticizers 15Heat stabilizers 7Antioxidants 1Color stabilizers 1Waxes 1Total 100

25

Material Safety Data sheets on ETHOCELethylcellulose polymers are available tohelp customers further satisfy their ownhandling needs and those that may beimposed by regulatory agencies. Thisinformation should be requested and readPRIOR to handling or use of the product.Refer to www.ETHOCEL.com for themost recent information. The materialsused in formulating with ETHOCELpolymers (solvents in particular) mayconstitute separate hazards from toxicityor flammability. Be certain to gethandling and safety recommendationsfor each such product from its supplier.

7.1 Health ConsiderationsETHOCEL polymers are thermoplasticpolymers having a polymer “backbone”obtained from cellulose, a naturallyoccurring carbohydrate polymer.

Dusts from ETHOCEL polymers couldconceivably cause temporary mechanicalirritation to the eye under extremeconditions. They are considered as nuisancedusts when assessing workplace exposureand control. However, the products areconsidered to present no significant orunusual health hazard to personnel innormal industrial handling. As a result,no special precautions need be observedto handle the products safely other thanthe possible need for a local exhaustsystem to control dust during openingand dumping of bags.

7.2 CombustibilityDusts or fine powders of ETHOCELproducts in air can reach explosive levels,and care must be taken to prevent this.

ETHOCEL products are organic materialsand will burn under the right conditions ofheat and oxygen supply. ETHOCEL polymers

will melt upon exposure to an open flame.Once melted and ignited, these polymerswill support combustion. Fires can beextinguished by any availableextinguishing agent.

7.3 Dust ExplosionMechanical handling can cause formationof dusts. To reduce the potential for dustexplosion, do not permit dust toaccumulate. Material can be ignited bystatic discharge. Electrically ground allequipment. Do not permit dust toaccumulate. Dust layers can be ignitedby spontaneous combustion or otherignition sources. When suspended in air,dust can pose an explosion hazard.

7.4 SpillsTo prevent accidents, good housekeepingrequires that spills of ETHOCEL productsshould be thoroughly vacuumed or sweptup. For small spills of liquid formulationsof ETHOCEL polymers, a solid absorbentshould be used to absorb the liquid. Anysolvents should then be allowed toevaporate, and the absorbent containingthe ETHOCEL polymer should be disposedof via approved landfill or incineration.

For large liquid spills, appropriate dikingprecautions should be taken until the solu-tion can be collected for proper disposal.In liquid solution spills, solvents maypresent significant health and fire hazards.

7.5 DisposalETHOCEL polymers are not water-solubleand do not biodegrade in aquatic environ-ments. The polymer should, therefore,present no ecological hazard to aquatic life.

ETHOCEL products present no significantecological problems, and therefore can bedisposed of by recycling, reclaiming, orburning in an adequate incinerator or byburial in an approved landfill. Incineration

should be done under carefully controlledconditions to avoid the possibility of adust explosion.

If it is necessary to dispose of a formu-lation that includes ETHOCEL products, itis recommended that the suppliers of allformulation ingredients be consulted beforedeciding on a suitable disposal method.

In disposal of any wastes, be certain allapplicable federal, state, and localregulations are met.

7.6 Storage/HandlingThe shelf life for ETHOCEL Standard gradesis a nominal three years from date ofmanufacture. For ETHOCEL Mediumgrades, the shelf life is two years fromdate of manufacture. ETHOCEL productsshould be stored at temperatures notexceeding 32°C (90°F) in a dry areaaway from all sources of heat.

In storage or use, good housekeeping isrequired to prevent dusts or fine powdersof ETHOCEL polymer from reachingexplosive levels in air. When handlingETHOCEL polymers in large quantitiesor in bulk, refer to general precautionsoutlined in NFPA Code Nos. 68, 69and 654.

As with any organic chemical material,ETHOCEL polymers should not be storednext to peroxides or other oxidizing agents.

Premium ETHOCEL products are subjectto the “Good Manufacturing Practices”of the Food and Drug Administration.Materials in these applications shouldnot be stored near hazardous or non-food chemicals.

To prevent odor transference, ETHOCELPremium polymers should not be storedadjacent to any foul-smelling material.1 National Fire Protection Association, Battery March

Park, Quincy, MA 02269

Safe Handling of ETHOCEL Products

26

Regulatory StatusFood and PharmaceuticalsETHOCEL Premium polymers meet the requirements of the following FDA regulations:

21CFR 73.1—Color additive for foods. Diluent in inks for marking food supplements in tablet form, gum andconfectionery; inks for marking fruits and vegetables; and as diluent in color additive mixtures for coloring shell eggs.

21CFR 73.1001—Color additive for drugs. Diluent used in ink to mark ingested drugs and externally applied drugs.

21CFR 172.868—Certain direct food uses. As a binder and filler in dry vitamin preparations; as a component ofprotective coatings for vitamin preparations and mineral tablets; and as a flavor fixative in flavoring compounds.

21CFR 175.105—Adhesives. Generally recognized as safe. (Cross reference to 182.90).

21CFR 175.300—Resinous and polymeric coatings.

21CFR 176.170—Components of paper and paperboard in contact with aqueous and fatty food. Generallyrecognized as safe. (Cross reference to 182.90).

21CFR 176.180—Components of paper and paperboard in contact with dry food. Generally recognized as safe.(Cross reference to 182.90).

21CFR 177.1210—Closures with sealing gaskets for food containers. (Cross reference to 175.300).

21CFR 182.90—Substances generally recognized as safe-substances migrating to food from paper and paperboardproducts. Ethylcellulose.

ETHOCEL Premium ethylcellulose polymers meet the requirements of the Food Chemicals Codex, the InternationalCodex Alimentarius, and the National Formulary (NF). They meet the requirements of the Japanese PharmaceuticalExcipients (JPE) Monograph as well as the requirements of the European Pharmacopoeia (EP).

ETHOCEL ethylcellulose polymers meet the requirements of Directive 2002/72/EC relating to plastic materials and articlesintended to come into contact with foodstuffs.

Cosmetics and Personal Care ProductsETHOCEL ethylcellulose polymers are allowed for use in cosmetics. Ethylcellulose is listed in the International CosmeticIngredient (INCI) Dictionary. The INCI name for ETHOCEL is ethylcellulose. Ethylcellulose is also listed in the JapaneseStandards of Cosmetic Ingredients (JSCI).

ETHOCEL ethylcellulose polymers meet the requirements of Directive 96/335/EC establishing an inventory and a commonnomenclature of ingredients employed in cosmetic products (INCI).

Animal FeedInternational Feed Name and International Feed Number (IFN): ethyl cellulose 4-08-045. The IFN will assist feed producersin having their feed products approved by regulators such as the U.S. Department of Agriculture, the Canadian FoodInspection Agency, and the UN Food and Agriculture Organization (FAO).

United States FDA Regulation 21CFR 573.420—Certain uses in animal feed. As a binder or filler in dry vitamin preparationto be incorporated into animal food.

ETHOCEL industrial and Premium grade ethylcellulose polymers are approved in Europe for animal feed under Directive70/524/EEC for all species or categories of animals.

27

*

For more information, complete literature, and product samples, you can reach a Dow representative at the following numbers:

From the United States and Canada:call 1-800-447-4369fax 1-989-832-1465

In Europe:toll-free +800 3 694 6367+

Phone: 32-3-450-2240Fax: 32-3-450-2815

In Latin America:Phone: 55-11-5188-9222

Fax: 55-11-5188-9749

In the Pacific:Call 60 3 7958 3392Fax 60 3 7958 5598

All Pacific countries except Indonesia & Vietnam:Toll-free call 800 7776 7776Toll-free fax 800 7779 7779

+Toll free from Austria (00), Belgium (00), Denmark (00), Finland (990), France (00), Germany (00), Hungary (00), Ireland (00), Italy (800 783825), The Netherlands (00), Norway (00), Portugal (00), Spain (00), Sweden (00), Switzerland (00) and the United Kingdom (00).

Or you can contact us on the Internet at:

www.ethocel.com

NOTICE: No freedom from any patent owned by Seller or others is to be inferred. Because use conditions and applicable laws may differ from one location to anotherand may change with time, Customer is responsible for determining whether products and the information in this document are appropriate for Customer’s use and forensuring that Customer’s workplace and disposal practices are in compliance with applicable laws and other governmental enactments. Seller assumes no obligation orliability for the information in this document. NO WARRANTIES ARE GIVEN; ALL IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSEARE EXPRESSLY EXCLUDED.

Published September 2005Printed in the USA *Trademark of The Dow Chemical Company Form No. 192-00818-0905 X AMS