Butvar Properties and Uses Brochure

Butvar® polyvinyl butyral resin

Properties and uses Contents

Contents

1 Introduction 21 Wood finishes 1 Uses 21 Protective wash coats and sealers 1 Technical support for specific applications 21 Knot sealers 22 Adhesives 2 Properties 22 Structural adhesives 2 Chemistry 22 Phenolic resins 6 Product types 22 Expoxies and other thermosetting resins 6 Butvar: the right resin solution 23 High-strength bonding procedure 13 Compatibility 23 Performance characteristics 15 Insolubilizing reactions 23 Adhesive strengths 17 Applications 24 Hot melt adhesives 17 Wire enamels 24 Textile coatings 17 Surface coatings 24 Advantages as textile coating 17 Wash primers 25 Ceramic binder applications 17 Military specification wash primers 26 Tape casting 18 Nonspecification wash primers: 26 Thick films B-1030 with Butvar 27 Toners and printing inks 18 Single-package wash primer: 28 Storage and handling B-1011 with Butvar 28 Storage 19 Chromate-free wash primers with Butvar 28 Toxicity and FDA status 20 Metal coatings 28 Quality control

29 Material sources Introduction

Polyvinyl butyral resins are employed in Uses a wide array of industrial and commercial Some of the applications in which Butvar is a vital applications. These unique resins offer ingredient include: impressive performance, as well as • Ceramic binders outstanding versatility. • Inks/dry toners • Wood coatings Butvar® polyvinyl butyral resins have a combination of properties that make them a key ingredient in a variety of • Wash primers successful formulations. Some of these properties for which • Composite fiber binders Butvar is widely used are outstanding binding efficiency, • Structural adhesives optical clarity, adhesion to a large number of surfaces, and • Other diverse uses toughness combined with flexibility. Butvar resin was pioneered by Monsanto in the 1930s as Solutia offers six grades of Butvar resins that cover a broad the key ingredient for automotive safety glass interlayers. range of chemical and physical properties. These resins It still enjoys widespread use in automotive and are generally well suited either as a major ingredient of architectural applications for laminated safety glass. a formulation or in smaller quantities to enhance the properties of other resins. Technical support for specific applications Solutia’s technical support and research staff for Butvar resins can assist in your specific application needs. The Customer Service Center at 1-800-964-5224 stands ready to receive your orders for samples and technical literature, as well as purchase orders for shipment of Butvar resin.

1 Properties

Chemistry The conditions of the acetal reaction and the concentration of the particular aldehyde and polyvinyl alcohol used are Acetals, such as polyvinyl butyral, are formed by the closely controlled to form polymers containing predetermined well-known reaction between aldehydes and alcohols. The proportions of hydroxyl, acetate, and acetal groups. The final addition of one molecule of an alcohol to one molecule of product may be represented by the following stylized structure. an aldehyde produces a hemiacetal. Hemiacetals are rarely isolated because of their inherent instability but, rather, are The proportions of A, B, and C are controlled, and they are further reacted with another molecule of alcohol to form a randomly distributed along the molecule. stable acetal.

Polyvinyl acetals are prepared from aldehydes and polyvinyl alcohols. Polyvinyl alcohols are high molecular weight resins containing various percentages of hydroxyl and acetate groups produced by hydrolysis of polyvinyl acetate.

H H H

1 1 1 R — C + R — OH R — C — OR + R — OH R — C (— OR )2 + H2O

O Alcohol OH Alcohol

Aldehyde Hemiacetal Acetal

H H H CH2 H CH — C CH — C CH2 — C C 2 2 OO OH O

C C O H C3H7 CH3

A B C PV Butyral PV Alcohol PV Acetate

2 Table 1. Physical properties of Butvar® resins (white, free-flowing powder)

Property Units ASTM method B-72 B-74 B-76 B-79 B-90 B-98 Volatiles,a max % — 3.5 3.0 5.0 5.0 5.0 5.0 Molecular wt (weight — (1) 170–250 120–150 90–120 50–80 70–100 40–70 average in thousands) Solution viscosity cp (2) 7,000–14,000 3,000–7,000 500–1,000 100–400 600–1,200 200–400 15% by weight Solution viscosity cp (2) 1,600–2,500 800–1,300 200–450 75–200 200–400 75–200 10% by weight Ostwalda solution cp (3) 170–260 37.0–47.0 18.0–28.0 9.0–16.0 13.0–17.0 6.0–9.0 viscosity Specific gravity — D792–50 1.100 1.100 1.083 1.083 1.100 1.100 23˚/23˚ (±0.002) Burning rate ipm D635–56T 1.0 1.0 1.0 1.0 0.9 0.9 Refractive index — D542–50 1,490 1.490 1.485 1.485 1.490 1.490 (±0.0005) Water absorption % D570–59aT 0.5 0.5 0.3 0.3 0.5 0.5 (24 hours) Hydroxyla content expressed as % — — 17.5–20.0 17.5–20.0 11.5–13.5 11.0–13.5 18.5–20.5 18.0–20.0 polyvinyl alcohol Acetate content expressed as % — — 0–2.5 0–2.5 0–2.5 0–2.5 0–2.5 0–2.5 polyvinyl acetate Butyral content expressed as % polyvinyl — — 80 80 88 88 80 80 butyral, approx. aSpecification properties

All properties were determined by ASTM methods except the following: • Molecular weight was determined via size exclusion chromatography with low-angle laser light scattering (SEC/LALLS) method of Cotts and Ouano in tetra-hydrofuran.b • Solution viscosity was determined in 15% by weight solutions in 60:40 toluene: ethanol at 25˚C, using a Brookfield Viscometer. Also in 10% solution in 95% ethanol @ 25˚C using an Ostwald-Cannon- Fenske Viscometer. • Ostwald solution viscosity for each product type measured with an Ostwald.Cannon-Fenske Viscometer. The solvents and solids levels used are as follows:

Percent Temperature Product solids Solvent (C˚) Anhydrous B-72 7.5 20 methanol SD 29 ethyl B-76, B-79 5.0 25 alcohol Anhydrous B-74, B-90, B-98 6.0 20 methanol bP. Dublin, ed., MicrodomainsMicrodomains In In Polymer Polymer Solutions Solutions (New (New York: York: Plenum Plenum Press, Press, 1985), 1985),pp. 101-119. pp. 101-119.

3 Table 2. Chemical properties of Butvar® resins

Property Units ASTM method B-72 B-74 B-76 B-79 B-90 B-98 Resistance to: Weak acids — D543-56T E E E E E E Strong acids — D543-56T E E E E E E Weak bases — D543-56T E E E E E E Strong bases — D543-56T E E E E E E Organic solvents: Alcohols — D543-56T P P P P P P Chlorinated — D543-56T G G F F G G Aliphatic — D543-56T E E F F E E Aromatic — D543-56T F F P P F F Esters — D543-56T F F P P F F Ketones — D543-56T F F P P F F

Key: E – excellent G – good F – fair P – poor

Table 3. Mechanical properties of Butvar resins

Property Units ASTM method B-72 B-74 B-76 B-79 B-90 B-98 Tensile strength: Yield 103 psi D638-58T 6.8–7.8 6.8–7.8 5.8–6.8 5.8–6.8 6.3–7.3 6.3–7.3 Break 103 psi D638-58T 7.0–8.0 7.0–8.0 4.6–5.6 4.6–5.6 5.7–6.7 5.6–6.6 Elongation: Yield % D638-58T 8 8 8 8 8 8 Break % D638-58T 70 75 110 110 100 110 Modulus of elasticity 105 psi D638-58T 3.3–3.4 3.3–3.4 2.8–2.9 2.8–2.9 3.0–3.1 3.1–3.2 (apparent) Flexural strength, yield 103 psi D790-59T 12–13 12–13 10.5–11.5 10.5–11.5 11–12 11–12 Hardness, Rockwell: M — D785-51 115 115 100 100 115 110 E — D785-51 20 20 5 5 20 20 Impact strength Izod, ft.lb./in. D256-56 1.1 1.1 0.8 0.8 0.9 80 notched ½" x ½" *Specification properties

4 Table 4. Thermal properties of Butvar® resins

Property Units ASTM method B-72 B-74 B-76 B-79 B-90 B-98 Flow temperature, ºC D569-59 145–155 135–145 110–115 110–115 125–130 105–110 1,000 psi Glass transition ºC (4) 72–78 72–78 62–72 62–72 72–78 72–78 temperature (Tg) Ash content at 550ºC: In nitrogen % (5) <3.0 <3.0 <2.0 <2.0 <3.0 <3.0 In air % (5) <1.0 <1.0 <0.75 <0.75 <0.75 <0.75 Heat distortion ºC D648-56 56–60 56–60 50–54 50–54 52–56 45–55 temperature Heat sealing temperature ºF (6) 220 220 200 200 205 200

• Glass transition temperature (Tg) was determined by Differential • Heat-sealing temperature was determined on a 1-mil dried film Scanning Calorimeter (DSC) over a range of 30˚C to 100˚C on dried on paper cast from a 10% solution in 60:40 toluene:ethanol. granular resin. A dwell time of 1.5 seconds at a 60 psi line pressure was used • Ash content of the Thermal Gravimetric Analysis (TGA) was on the heat sealer. determined as a weight loss versus temperature profile conducted at a heating rate of 10˚C/min.

Table 5. Electrical properties of Butvar® resins

Property Units ASTM method B-72 B-74 B-76 B-79 B-90 B-98 Dielectric constant: 50 cps — D150-59T 3.2 3.2 2.7 2.7 3.2 3.3 103 cps — D150-59T 3.0 3.0 2.6 2.6 3.0 3.0 106 cps — D150-59T 2.8 2.8 2.6 2.6 2.8 2.8 107 cps — D150-59T 2.7 2.7 2.5 2.5 2.7 2.8 Dissipation factor: 50 cps — D150-59T 0.0064 0.0064 0.0050 0.0050 0.0066 0.0064 103 cps — D150-59T 0.0062 0.0062 0.0039 0.0039 0.0059 0.0061 106 cps — D150-59T 0.027 0.027 0.013 0.013 0.022 0.023 107 cps — D150-59T 0.031 0.031 0.015 0.015 0.023 <0.24 Dielectric strength (l" thickness): Short time v/mil D149-59 420 420 480 480 450 400 Step-by-step v/mil D149-59 400 400 390 390 370 380 *Specification properties

5 Product types Butvar: the right resin solutions The properties of the various types of Butvar® resins are Butvar brand resins generally are soluble in alcohols, glycol described in Tables 1 through 5. The resins are offered in a ethers, and certain mixtures of polar and nonpolar solvents. variety of molecular weight ranges and viscosities. B-76 and A representative list of Butvar solvents can be found in B-79 have a lower hydroxyl content than the other Butvar Table 6. In general, Butvar B-98 resin will show the same resins. This permits broader solubility characteristics. general compatibility characteristics as B-90 and, therefore, should prove advantageous where physical and chemical As a general rule, the substitution of butyral groups for properties of B-90 are desired but lower solution viscosities acetate groups results in a more hydrophobic polymer with are necessary. The same is true for Butvar B-79 in relation a higher heat distortion temperature. At the same time, the to B-76. polymer’s toughness and adhesion to various substrates is considerably increased. The outstanding adhesion of the When an alcohol is the only solvent, the viscosity of a polyvinyl butyral resins is a result of their terpolymer Butvar solution increases as the molecular weight of the constitution. Because each molecule presents the choice of alcohol increases. Blends of alcohols with aromatic solvents three different functional groups to a surface, the probability provide the best starting point for the development of of adhesion to a wide variety of substrates is increased solvent systems. Where alcohols, such as ethyl or isopropyl, substantially. are employed either alone or in a mixture with other solvents, use the 95% grades. The presence of water gives lower solution Although polyvinyl butyral resins normally are thermoplastic viscosities than solutions utilizing anhydrous alcohols. and soluble in a range of solvents, they may be crosslinked through heating and with a trace of mineral acid. Crosslinking Butvar solutions show very marked viscosity increases as resin is generally caused by transacetalization but also may solids increase. This effect is shown in Graphs 3 through 10. involve more complex mechanisms, such as a reaction between acetate or hydroxyl groups on adjacent chains. The lower hydroxyl content of Butvar B-76 and B-79 permits solubility in a wider variety of organic solvents as compared As a practical matter, crosslinking of the polyvinyl butyrals to the other grades of Butvar. One notable exception, is carried out by reaction with various thermosetting resins, however, is the insolubility of Butvar B-76 and B-79 in such as phenolics, epoxies, ureas, diisocyanates and methanol. All other types of Butvar contain sufficient melamines. The availability of the functional hydroxyl groups hydroxyl groups to allow for solubility in alcohol and in in Butvar resins for condensations of this kind is an hydroxyl-containing solvents. The presence of both butyral important consideration in many applications. Incorporation and hydroxyl groups permits solution in mixtures of alcohol of even a small amount of Butvar resin into thermosetting and aromatics. compositions will markedly improve toughness, flexibility, and adhesion of the cured coating. Viscosities of Butvar resin solutions containing mixed solvents depend on the ratio of alcohol to aromatic. Viscosity curves Polyvinyl butyral films are characterized by high resistance for Butvar B-76, B-90, and B-98 in Graph 2 show minimum to aliphatic hydrocarbons, mineral, animal, and vegetable points in the general vicinity of 50% alcohol:50% aromatic. oils (with the exception of castor and blown oils). They withstand strong alkalis but are subject to some attack by strong acids. However, when employed as components of cured coatings, their stability to acids, as well as solvents and other chemicals, is improved greatly. Butvar will withstand heating up to 200˚F for prolonged periods with little discoloration.

6 Table 6. Solubility of Butvar® resins Butvara Butvarb Butvarb Solvent B-72, B-74 B-76, B-79 B-90, B-98 Acetic acid (glacial) S S S Acetone I S SW 2-Butoxyethanol S S S n-butyl acetate I S PS n-butyl alcohol S S S n-butyl propionate I S I Cyclohexanone S S S Diacetone alcohol PS S S Diisobutyl ketone I SW I Dimethyl esters PSc S PSc N,N-dimethylacetamide S S S N,N-dimethylformamide S S S Dimethylsulfoxide S S S Ethyl acetate, 85% S S S Ethyl acetate, 99% I S PS Ethyl alcohol, 95% or anhydrous S S S Ethylene dichloride SW S SW Isophorone PS S S Isopropyl acetate I S I Isopropyl alcohol, 95% or anhydrous S S S Methyl acetate I S PS Methyl alcohol S SW S Methyl amyl ketone SW S PS Methyl ethyl ketone PS S PSc Methyl isoamyl ketone I S SW Methyl isobutyl ketone I S I Methyl propyl ketone SWc S SWc Methylene chloride PS S S N-methyl-2-pyrrolidone S S S Naphtha (light solvent) I SW I Propyl propionate I S I Propylene dichloride S S S Tetrachloroethylene SW SW SW Tetrahydrofuran S S S Toluene SW SW SW Toluene: ethyl alcohol, 95% (60:40 by weight) S S S 1,1,1-trichloroethane SW S SW Xylene I PS SW a5% solids solution agitated for 24 hours at room temperature b10% solids solution agitated for 24 hours at room temperature cClear solution at 50º–80ºC

Key: S – soluble PS – partially soluble I – insoluble SW – swells

7 A common solvent for all of the Butvar® resins is a Aliphatic hydrocarbons can be tolerated in only very small combination of 60 parts toluene and 40 parts ethanol proportions. Aromatic hydrocarbons, alcohols, esters, ketones, (95%) by weight. The viscosities of all the Butvar resins and halocarbons, when not active solvents, are generally in this solvent blend are shown in Graphs 2 and 3. The satisfactory as diluents or latent solvents. Solvent blends viscosities of Butvar resins in alcohols are shown in Graphs are more likely to be successful when their mean solubility 4 through 8. Graphs 9 and 10 present the viscosities of parameter and hydrogen bonding fall within the ranges Butvar resins in 2-Butoxyethanol. shown in Graph 1 and Table 8.

For compositions of Butvar, methyl alcohol will tend to give The Butvar resins can be dissolved quite rapidly using the lowest viscosity and, therefore, will permit the use of conventional techniques. To ensure thorough and uniform higher solids when used as a component of a solvent blend. wetting of all particles, it is important to add the resin When much more than 10% to 15% alcohol is used in a slowly to the solvent system with adequate stirring. With formulation for spray application, blushing may result. some mixed solvents, it may be desirable to slurry the resin in the hydrocarbon or other nonsolvent component and add The solvent blends in Table 7 are suggested for all Butvar the more active solvent components to the slurry under grades. They are useful as starting points in the development adequate agitation. of solvent blends for the other types.

Selection of a suitable solvent system involves a number of factors. End-use and application technique used will necessitate consideration of solution viscosity, cobweb formation, blushing, evaporation, solvent release, and toxicity characteristics. In most cases, the choice of components of solvent blend will involve compromises in at least some of these factors so that a desired combination of properties may be obtained.

Table 7. Suggested solvent blends for Butvar® resins

A B C D Diacetone alcohol 22.5% 20.0% 15.0% — n-butyl alcohol 22.5 20.0 15.0 — Ethyl alcohol, 95% 10.0 20.0 20.0 55.0% Xylene 45.0 40.0 30.0 — Toluene — — 20.0 45.0 Total 100.0 100.0 100.0 100.0 Relative viscosity High Medium Low Low Relative evaporation rate Slow Medium Medium Very fast Application technique Spray Dip, roll Dip, roll Brush Drying technique Bake Bake Bake Air dry

8 D H Graph 1. Hansen solubility parameters of Butvar® resinsa 30 30 Polyvinyl butyral Hansen solubility Dispersive Polar H-bonding Sphere radius 24 24 parameters δD (MPaa) δP (MPaa) δH (MPaa) (MPaa) ● B-90 and B-98 21.72 7.85 14.55 15.0 18 18 P ● B-72 and B-74 21.19 8.70 14.02 13.7 12 12 ● B-76 and B-79 17.72 7.18 12.62 9.7 6 6 a HSPiP Software, Version 4.0.08, 2013. 15 6 In general, solvents or solvent mixtures having δD, δP, and δH coordinates within a polymer 18 12 21 sphere, RED ≤1, are solvents; those outside a sphere are nonsolvents. 18 24 2 2 2 ½ Relative Energy Difference (RED) = [4(δD2-δD1) +(δP2-δP1) +(δH2-δH1) ] /Sphere Radius 24 27 30

Table 8. Hansen solubility parameters for common solvents and solvent mixturesa Dispersive Polar H-bonding Solvent Solvent ratio (wt%) δD (MPaa) δP (MPaa) δH (MPaa) Acetone 100 15.5 10.4 7.0 2-butoxy ethanol 100 16.0 5.1 12.3 n-butyl acetate 100 15.8 3.7 6.3 Diisobutyl ketone 100 16.0 3.7 4.1 N,N-dimethylacetamide 100 16.8 11.5 9.4 N,N-dimethylacetamide/xylene 60/40 17.2 7.2 7.3 Dimethyl sulfoxide 100 18.4 16.4 10.2 Dioxane 100 17.5 1.8 9.0 Dioxane/tetrahydrofuran 50/50 17.1 3.9 8.5 Ethanol 100 15.8 8.8 19.4 Ethanol/water 95/5 15.8 8.2 20.5 Ethyl acetate/ethyl alcohol 99/1 15.8 5.3 7.3 Ethylene dichloride 100 18.0 7.4 4.1 Ethylene glycol 100 17.0 11.0 26.0 Isopropanol 100 15.8 6.1 16.4 Isopropanol/water 98/2 15.8 6.3 16.8 Methanol 100 14.7 12.3 22.3 Methyl amyl ketone 100 16.2 5.7 4.1 Methylene dichloride 100 17.0 7.3 7.1 Methyl isobutyl ketone 100 15.3 6.1 4.1 Propylene glycol monomethyl ether 100 15.6 6.3 11.6 Propylene glycol monomethyl ether acetate 100 15.6 5.6 9.8 Tetrahydrofuran 100 16.8 5.7 8.0 Toluene 100 18.0 1.4 2.0 Toluene/ethanol 50/50 16.9 5.2 11.0 Trichloroethane 100 16.8 4.3 2.0 Xylene 100 17.8 1.0 3.1 Xylene/N,N-dimethylacetamide 50/50 17.2 6.1 6.6 aCharles M. Hansen, Hansen Solubility Parameters: A User’s Handbook, 2nd Edition, CRC Press (2007).

9 Graph 2. Viscosities of Butvar in Graph 3. Viscosities of Butvar in 60/40 toluene-ethanol (95%) (15% solids) toluene-ethanol (95%) (by weight)

1,800 — B-76 100,000 — B-72 — B-90 — B-76 1,600 — B-98 — B-79

10,000 — B-90 — B-98 1,400

1,200 1,000

1,000

100

800

600 10

400

Brookfield Viscosity at 25ºC-cp 1 0510 15 20 25 30 200 Percent total solids

Brookfield Viscosity at 25ºC-cp 0 0 20 40 60 80 Toluene 100 80 60 40 20 Ethanol

Solvent composition by weight

10 Graph 4. Viscosities of Butvar in methanol Graph 5. Butvar in ethanol (95%)

100,000 — B-72 100,000 — B-72 — B-90 — B-74 — B-98 10,000 10,000

1,000 1,000

100

Brookfield Viscosity at 25ºC-cp 10 0510 15

10 Percent total solids

Brookfield Viscosity at 25ºC-cp 1 0510 15 20 25 30

Percent total solids Graph 6. Butvar in ethanol (95%)

100,000 — B-76 — B-79 — B-90 — B-98 1,000

100

Brookfield Viscosity at 25ºC-cp 10 0510 15

Percent total solids

11 Graph 7. Butvar in n-Butanol Graph 9. Butvar in 2-Butoxyethanol

100,000 — B-72 10,000 — B-76 — B-74 — B-79 — B-98 10,000

1,000

100 100 Brookfield Viscosity at 25ºC-cp Brookfield Viscosity at 25ºC-cp 10 10 0510 15 0510 15

Percent total solids Percent total solids

Graph 8. Butvar in n-Butanol Graph 10. Butvar in 2-Butoxyethanol

10,000 — B-76 100,000 — B-72 — B-79 — B-74 — B-90 — B-90 — B-98 10,000 1,000

1,000

100 100 Brookfield Viscosity at 25ºC-cp 10 Brookfield Viscosity at 25ºC-cp 10 0510 15 0510 15

Percent total solids Percent total solids

12 Compatibility The compatibility of Butvar® polyvinyl butyral resins with plasticizers, modifiers, and other various resins is well established. Butvar readily lends itself to compounding with other additives to enhance its physical and chemical properties. Plasticizers are often used to impart improved flexibility over a broader temperature range. See Table 9.

Table 9. Plasticizers for Butvar® resin Known Butvar:plasticizer Type Name or trademark compatibility level Hexanoate Eastman TEG-EH (triethylene glycol di-2-ethylhexanoate) 1:1 Adipate Santicizer® 97 (dialkyl adipate) 4:1 Santicizer 367 (dihexyl adipate) 3:1 Dioctyl adipate (DOA) 4:1 Blown linseed oil Linseed oil — Citrate Tributyl citrate — Phosphate Santicizer 141 (2-ethylhexyl diphenyl phosphate) 1:1 Santicizer 148 (isodecyl diphenyl phosphate) 1:1 Santicizer 154 (Tert-butylphenyl diphenyl phosphate) 1:1 Santicizer 143 (triaryl phosphate ester blend) 1:1 Tricresyl phosphate (TCP) 1:1 Triphenyl phosphate (TPP) 2:1 Phthalate Santicizer 261 (alkyl benzyl phthalate) 2:1 Santicizer 278 (alkyl benzyl phthalate) 4:3 Santicizer 160 (butyl benzyl phthalate) 1:1 Dibutyl phthalate (DBP) 1:1 Dialkyl phthalate 4:1 Dioctyl phthalate (DOP) 4:1 PE glycol ether Pycal™ 94 — Polyester Paraplex™ RGA-8 — Process castor oil #15, #30, #40 2:1 Raw castor oil #1 Castor 1:1 Ricinoleate Flexricin™ P3 (butyl ricinoleate) 2:1 Rosin derivatives Hercolyn™ — Sebacate Dibutyl sebacate — Sulfonamide Ketjenflex™ 8 (n-ethyl toluenesulfonamide) 1:1 Ketjenflex™ 9S (toluenesulfonamide) 2:1 The values given in this table are a guide to the compatibility limits of the plasticizers in the various resins shown. (If no value is given, the limit is unknown.) The highest concentration tested was 100 phr. Where the value is given as 1:1, some plasticizer/ resin combinations may have even greater compatibility. However, since the values given apply to a resin type, the compatibility with a particular commercial grade should be checked when evaluating a specific compound, particularly if the plasticizer content of the formulation is to be near the ceiling value indicated.

13 Crosslinkers such as Santolink® phenolic and Resimene® amino resins are used to impart greater toughness and thermal resistance. Table 10 depicts the compatibility of Butvar® polyvinyl butyral resins with other modifiers and resins.

Table 10. Compatibility of Butvar with various resinsa Butvar Butvar B-72, B-74, Solvent B-76, B-79 B-90, B-98 Acrylate — I I Alkyd Beckosol™ 11-035 P P Duraplex™ 11-804 P P Cellulose Cellulose acetate I I Cellulose acetate butyrate P P Ethyl cellulose P P Nitrocellulose, RS™ C C Nitrocellulose, SS™ C C Chlorinated rubber — I I Coumarone-indene — I I Epoxy Epi-Rez™ 540-C C C Epon™ 1001F, 1007F C C Araldite™ 6069 C C Fossil Damar C C Isocyanate Desmodur™ AP Stabil C C Melamine formaldehyde Resimene® 717 and 881 P P Resimene® 730 and 741 P P Phenolic OxyChem™ 02620, 92600, 29107 C C Durite™ P-97 C C Methylon™ 75-108 C C Santolink® EP 560 (butyletherified) C C SP-1044 resin C C Rosin derivatives Pentalyn™ H P P Staybelite™ ester 10 C P Vinsol™ C C Shellac — C C Silicone DC 840 C P DCZ 6018 C P Sulfonamid Ketjenflex™ MH P P Urea formaldehyde Resimene® 918 P P Vinyl chloride copolymer VAGH, VAGD P I aRefers to film compatibility provided mutual solvents are used.

K e y : C – compatible in all proportions P – partially compatible I – incompatible

14 Insolubilizing reactions Reaction with phenolics Many applications for the vinyl acetal resins involve curing with a thermosetting resin to obtain the balance of properties BUTVAR desired. The free hydroxyl groups in vinyl acetal resins present PHENOLIC OH a point of chemical reactivity through which the resins may OH OH be insolubilized. In general, any chemical reagent or resinous HOH2CH(R) C 2OH material which reacts with secondary alcohols will react with the polyvinyl butyral to inhibit solubility. OH + CH3 H CH3 The properties of coatings vary greatly with the type and BUTVAR amount of crosslinking agent used. BUTVAR

O OH OH

H2 CH(R) C 2

CH3 CH3 BUTVAR

Reaction with epoxies (anhydride cure)

CH3 CH3

CH2 CH CH2 O C O CH2 CH CH2 O C O CH2 CH CH 2 O O CH3 OH X CH3 Typical epoxy resin

BUTVAR BUTVAR

OH O

O C O

C C O O C O

O CH CH2 OH O

CH CH2 EPOXY

15 Reaction with dialdehydes Reaction with isocyanates

BUTVAR BUTVAR BUTVAR OH O CH CH2 CH CH CH2 CH C O OH OH NCO O O NH R DIISOCYANATE O R CH NCO HC H+ Tertiary amine HC NH

CH OH

O O C O O BUTVAR O CH CH CH OH OH 2 BUTVAR

CH CH2 CH

BUTVAR

Reaction with melamines

BUTVAR

OH N N

HOH2C NH C C NH (R) HN C C NH CH2OH NN NN MELAMINE C RESIN C HO

NH 2 + NH2 H BUTVAR BUTVAR

O N N

H2C NH C C NH (R) HN C C NH CH2

NN NN O C C BUTVAR NH2 NH2

16 Applications

Wire enamels • Second, these wash primers provide a continuous supply of chromate ions to repair pin holes in the phosphate film, Butvar® resins may be used to overcoat magnet wire so that eliminating the need for a special chromate rinse. coils made from that wire can be cemented with heat or by solvent activation. • Third, the polyvinyl butyral film is chemically bound in the inorganic layers through a chromium complex, providing Coiled or shaped magnet wire with a polyvinyl butyral additional mechanical protection to the metal surface. overcoat is tough and flexible. The presence of hydroxyl groups in the polyvinyl butyral molecule permits the In effect, this type of primer actually phosphatizes the metal polyvinyl butyral not only to crosslink with itself but also at the surface, supplies a corrosion inhibiting pigment in a to crosscure with phenolic or isocyanate resin. tenaciously adhering binder, and dries to take most topcoats.

The overall balance of physical and chemical properties has Wash primers are widely used on a variety of metal made this type of overcoat based on Butvar a leader in the structures, such as storage tanks, ships, airplanes, etc. field for many years. Highway departments also have shown a keen interest in these coatings for bridges, dam locks, and in particular, highway guardrails. In finishing trucks or house trailers Surface coatings fabricated of phosphated or galvanized steel, or aluminum, The Butvar vinyl acetal resin may be used alone or in wash primers provide corrosion resistance and adhesion combination with a wide variety of resins to give functional under single-coat styrenated alkyd and other modified surface coating compositions. Films which may be air dried, alkyd enamels. On metal that is subject to immersion and baked, or cured at room temperature are obtained by proper corrosion conditions, wash primers are specified under compounding. The presence of hydroxyl groups in the urethane and vinyl topcoats. polymer molecule not only enables good wetting of most substrates but also furnishes a reactive site for chemical Military specification wash primers combination with thermosetting resins. The U.S. Navy Bureau of Ships has long recognized the need for the use of the wash primer as a surface pretreatment for Wash primers metals prior to subsequent painting. Military Specification In protective coatings for metal, the best known vinyl DOD-P-15328D entitled Primer, Pretreatment is required to acetal application is in “wash primers,” also referred to be used on all metal surfaces. This primer is a two-package as “metal conditioners.” Compared with other corrosion system containing Butvar B-90 in a solvent system consisting inhibiting materials, wash primers are unique and more of normal butanol and either ethanol or isopropanol. By effective because they offer, in a single treatment, several comparison, the Department of the Air Force and the U.S. means of preventing corrosion.These anticorrosive primers Navy Bureau of Naval Weapons have approved a slightly apply easier, adhere better, and dry faster than the more different pretreatment formulation designated Coating conventional materials. Compound, Metal Pretreatment, Resin-Acid MIL-C-8514C (ASG). This system specifies the use of either Butvar B-76 or The action of wash primers over steel, for example, is Butvar B-90 in a solvent system consisting of butanol and as follows: ethanol. Specific details of both wash primer systems can be • First, an iron oxide and zinc phosphate film, similar to that found in the particular specification involved. formed in the common phosphating processes, is deposited on the metal.

17 Nonspecification wash primers: Single-package wash primer: B-1030 with Butvar B-1011 with Butvar Wash primer B-1030 formulation is a two-package system Wash primer B-1011 is a clear, green single-package primer based on Butvar B-76 resin and a thermosetting phenolic also known as a “reacted” wash primer. Based on Butvar resin. This formulation was designed to give higher early B-90 resin, it has excellent stability in both concentrated water resistance than the well-known military specification and diluted forms and air dries to clear glossy films of very wash primers. Coatings based on formulation B-1030 exhibit low color. Films of the primer possess good adhesion to reduced tendency to blister and to lose adhesion in high steel, phosphated steel, galvanized steel, brass, copper, wood, humidity. The B-1030 formulation also has nonsettling stainless steel, and chrome plate. Although designed to characteristics. In contrast to the older wash primer enhance adhesion, this coating also functions as a corrosion- formulations, B-1030 does not display hard pigment settling inhibiting primer for a variety of topcoats but in many cases, of the base grind. may afford protection as the sole coating.

The thermosetting resin content of the B-1030 formulation not only increases water resistance but also contributes to reduced solvent sensitivity. Thus, good adhesion and corrosion resistance are retained under alkyd, alkyd-nitrocellulose, acrylic, and vinyl topcoats, and also under epoxy, urethane, polyvinyl acetate, and alkyd melamine topcoats.

Table 11. Wash primer B-1030 with Butvar A. Base grind Percent by weight 1. To a solution of: Butvar B-76 1.24 Ethanol, 95% 9.35 Methyl ethyl ketone 9.97 2. Add: Basic zinc chromate pigment 11.52 Celite™ 266 4.82 3. Grind to Hegman fineness of 6, N.S. scale 4. Add solution of: Butvar B-76 7.39 Ethanol, 95% 23.08 Methyl ethyl ketone 24.63 Santolink® EP 560 8.00 Total 100.00 5. Grind for 30 minutes and package B. Reducer Percent by weight Phosphoric acid, 85% 7.50 n-butanol 92.50 Total 100.00 Mix for several minutes and package

Reduced primer properties (Pigment grind to reducer; 1:1 by volume) NVM 19% Weight per gallon 7.5 lb Coverage 533 sq. ft./gal at 0.3 mils dry Pot life 8–12 hours

18 Table 12. Wash primer B-1011 with Butvar Material Percent by weight A. Acetone 44.40 Anhydrous ethanol 36.30 Butvar B-90 11.00 B. 85% phosphoric acid (U.S.P.) 0.72 Water 6.48 C. Chromic acid (99 + %) 0.37 Water 0.73 Total 100.00

Properties NVM 12% Viscosity 21 sec., No. 4 Ford cup Lb/gal 7.0 Coverage 384 sq. ft./gal at 0.3 mils dry

Chromate-free wash primers with Butvar borate, or borophosphate, are suggested. Substitution of these pigments for zinc chromate on an equal weight or Traditional wash primer formulations have generally volume basis are suggested starting points for reformulation. employed zinc chromate as the anticorrosive pigment. A chromate-free wash primer based on U.S. Government Due to toxicity concerns associated with chromates, specification DOD-P-15328D is shown in Table 13. alternative anticorrosive pigments, such as zinc molybdate,

Table 13. Sherwin-Williams chromate-free wash primer Moly-White Butvar** A. Base grind DOD-P-15328D X92 B-90, B-98 Pounds Pounds Gallons Butvar B-90 56.0 56.0 6.10 n-butanol 125.0 125.0 18.48 Isopropanol, 99% 353.0 353.0 53.80 Moly-White X92 — 39.7 1.70 Basic zinc chromate 54.0 1.70 Magnesium silicate, MP40-27 8.0 8.0 0.34 Furnace black 0.6 0.6 0.34 Water, DI 15.0 15.0 1.80 — — 82.26 B. Reducer Phosphoric acid, 85% 28.0 28.0 2.0 Water, DI 25.0 25.0 3.0 Isopropanol, 99% 99.0 99.0 15.0 — — 20.0 Alternative chromate-free pigments are PhosGuard® J-0800 from Mineral Pigments Corporation and Borogard ZB from U.S. Borax.

19 Metal coatings Table 14. Metal coating 2009 Butvar® resins are used in a wide variety of metal coating Material Percent by weight applications in combination with other resin types, such Diacetone alcohol 17.4 as phenolics, epoxies, isocyanates, melamines, ureas, etc. n-butanol 17.4 When used with these various modifying resins, Butvar can Ethanol, 95% 7.7 improve coating uniformity, minimize cratering, improve Xylol 34.7 adhesion, and increase coating toughness and flexibility. Santolink® EP 560 5.1 These resin combinations can be compounded to produce Epon™ 1007F 13.0 baked coatings with good chemical resistance, which also Butvar® B-90 2.0 will withstand postforming. Applications of such coatings 10% phosphoric acid 2.7 can be made by conventional methods including brush, (in above solvents) spray, dip, fluidized bed, etc. End-use applications include Total 100.0 drum and can linings, as well as the wide variety of metallic substrates, which are coated by the fluidized bed technique. Properties Curable coatings containing Butvar resin may be formulated NVM 20% to meet the extractability requirements of the U.S. Food and Application: spray or roller Drug Administration for indirect food additive uses. Cure cycle sequence: Room temperature. Drying 15 minutes, followed by 30 minutes at 190˚F and 20 minutes at 400˚F. Metal coating 2009 is one example of the use of Butvar in combination with other resins—in this case phenolic and epoxy—to produce an excellent coating. This particular combination provides excellent abrasion resistance, toughness, flexibility, adhesion, and chemical resistance. Specific application tests have shown that this system should make outstanding can or drum linings.

20 Wood finishes Knot sealers Protective wash coats and sealers The polyvinyl butyral resins are excellent barriers to bleeding of terpenaceous matter from knots, heart wood, Butvar® resin is widely used as a component of wash and rosin ducts. The Western Pine Association has developed coats and sealers in wood-finishing operations. It provides a superior knot sealer based on Butvar. The system consists good holdout, intercoat adhesion, moisture resistance, of a combination of Butvar and phenolic resins (Table 16). flexibility, toughness, and impact resistance to the coating system. In addition, the wood substrate is protected against discoloration when Butvar is used in the finish. Combinations Table 16. Western Pine Association involving nitrocellulose, shellac, and shellac ester along with knot sealer, WP578 other resin types are used with Butvar under many of the Material Percent by weight common topcoats (Table 15). Butvar is particularly effective Butvar B-90 3.3 for improving the holdout of polyester and polyurethane Durite™ P-97 40.0 coatings, as well as protecting the wood substrate against Ethanol, 95% 56.7 color changes caused by light. Total 100.0 The following starting formulation is representative of the kind of wood sealer or wash coat that can be compounded Properties from Butvar. NVM 23.3% Application: brush

Table 15. Sealer/wash coat with Butvar The preceding formulation is designed for brush application. Material Percent by weight However, it has been adapted to application from an aerosol Butvar B-98 6.1 spray can, giving the same outstanding performance as the Nitrocellulose, RS™, ¼ second 9.2 brush applied system. Butyl acetate 32.9 Ethanol, anhydrous 5.5 Isopropanol, 99% 10.9 Methyl isobutyl ketone 8.8 Xylol 13.3 Toluol 13.3 Total 100.0

Properties NVM 12.5% 20 sec., Viscosity No. 4 Ford cup Cure cycle sequence: Room temperature. Drying 15 minutes, followed by 30 minutes at 190˚F and 20 minutes at 400˚F. Application: Spray or roller

21 Adhesives In a solution adhesive system, the choice of solvents is important both for viscosity control of the solution and Structural adhesives proper drying and filming characteristics. Proper drying of Structural adhesives originally were developed for use in the adhesive film is very important, as only a small amount the aircraft industry to replace rivets and other methods of of residual solvent can affect greatly the various final joining and fastening. Refinements in formulating structural properties. Yet the solvent cannot be so volatile that adhesives led to their use in bonding brake linings, in the blushing occurs. Sprayed films are much more sensitive to electrical and electronic industries on printed circuits, in blushing than brushed or roller-coated films. For brushing, structural composite fiber binders for aerospace or solvents in the boiling range of 75˚ to 100˚C are advised antiballistic applications, and in the architectural field for because they can be removed by air drying and then force the manufacture of interior and exterior curtain walls. drying for 30 to 60 minutes at 105˚C. Solutions for spraying can tolerate small amounts of higher boiling solvents, such Combinations of Butvar® resin with thermosetting resins as xylene and butanol. have long been in use in bonding aircraft components— in fact, the system was the first synthetic resin adhesive Viscosity of the adhesive solution affects the smoothness to be used for bonding metals in structural applications. and the thickness of the final brushed or sprayed film. For brushing, the proper viscosity is obtained at the Phenolic resins following solids content (with a 10:5 PVB:phenolic ratio): Butvar B-90, 21%; Butvar B-72, 16% to 18%. For spraying, In some structural adhesive formulations, Butvar resins are the solids content should be reduced to obtain nonblushing, combined with alkaline catalyzed phenolic laminating resins, noncobwebbing films. such as Durite™ LS-433 or Plyophen™ 22-023. Compared with other general types of structural adhesive systems (epoxy- phenolic and synthetic rubber-phenolic), the PVB-phenolic Epoxies and other thermosetting resins gives the highest shear strength values at temperatures up Butvar resins are compatible with many epoxy resins and to 250˚F. Other outstanding properties of the PVB-phenolic can confer such improvements on epoxy-based systems as system include high peel strength at very low temperatures, increased impact resistance and peel strength. In epoxy excellent dielectric properties, and exceptionally good creep systems, as in phenolic systems, the vinyl acetal resins can resistance as measured by the ability of the bond to carry serve as both coreactant and flexibilizer. sustained loads for extended periods of time. The addition of small amounts of compatible plasticizer to Polyvinyl butyral-phenolic ratios of from 10:1 to 10:20 have an adhesive system combining a vinyl acetal resin with a been used successfully for structural adhesives, although 10:5 thermosetting resin increases the flexibility and impact seems to be the best ratio for a compromise of properties. resistance of the bond with only slight sacrifice in high As the amount of phenolic is reduced, the cured adhesive temperature shear. This increased flexibility is most evident becomes more flexible, and in most cases, peel strength when peeling thick adherends and at high peeling speeds. increases. In addition, because of the increased thermoplastic The tack or heat seal temperature of the uncured adhesive nature of the system, the high temperature shear strength is also is appreciably lowered by the addition of plasticizer. reduced. These effects, i.e., increased peel and reduced high Adhesives with pressure sensitive properties in the uncured temperature shear strength, occur when the cure time is state can be developed which, when cured, will have shortened or the cure temperature is lowered. temperature shear bond strength of more than 1,000 psi. Structural adhesives based on polyvinyl butyral resins can be applied as a solution, an unsupported film, a supported film on paper or cloth, or as a mixture of liquid and solid.1

1See U.S. Patent 2,499,134.

22 High-strength bonding procedure Performance characteristics For high-strength bonds, substrate cleaning is very The quality of a structural bond for a particular application important. Usually the removal of surface contamination, is usually described in terms of its shear strength, peel such as oil film, dust, etc., is sufficient. Such cleaning strength, creep properties, fatigue strength, and normally is achieved by solvent or by detergent wash. environmental resistance. In aircraft applications, high However, for highest strength bonds, chemical surface temperature shear, fatigue resistance, creep, and oil and gas preparation is employed. The following metals require resistance are most important. In printed circuits, peel the preparation noted: strength, blister resistance, and dielectric properties are of primary importance. For architectural use, high peel strength • Aluminum alloys—acid oxidation and long-term resistance to dead load and extremes of • Copper—alkaline oxidation atmospheric environment are the outstanding requirements. • Steel—a pickling bath to remove oxide scale Adhesives based on Butvar® resins excel in all of these characteristics. Care should be taken to avoid touching the cleaned panels or exposing them to any contaminated atmosphere. The The requirements and methods for testing adhesives for adhesive should be applied to the cleaned surface as soon aircraft applications are presented in Military Specifications as possible. MM-A-132 and MIL-A-25463-30. Test methods for architectural and printed circuit applications are contained A dry glue line of 3 to 10 mils has been found quite in various ASTM and NEMA specifications. satisfactory. With solvent systems, this thickness usually can be achieved with 2 to 4 brushed coats of adhesive on Adhesive strengths each adherend. With very thin glue lines, even pressure must be applied to the laminate during cure so that consistent Typical test values for phenolic bonds of Butvar resins bonds be obtained. Thicker glue lines have greater flow and measured by these techniques are in Table 17. absorb unequal curing pressures.

Table 17. Adhesives strengths

Amount of PSI shear strength at Peel at 72ºF Vinyl acetal phenolic, phra Cure 72ºF 180ºF 250ºF 300ºF lb/in. width Butvar B-72 50 30 min, 330ºF 6,000 4,000 1,400 500 25–30 Butvar B-90 50 30 min, 330ºF 5,700 2,800 1,000 — 30–35 Butvar B-72 100 20 min, 300ºF 5,000 3,300 1,100 — 35–40 aphr = parts per hundred resin Test procedures: Shear—aluminum to aluminum as per MIL-A-8431 Peel— 6-mil aluminum to 64-mil aluminum peeled at 5 inches per minute

23 Hot melt adhesives Advantages as textile coating Butvar® makes an excellent base for hot melt adhesives The advantages of Butvar as a textile coating resin stem even where difficult-to-bond surfaces are involved. The many from the following properties: types of Butvar resins allow the best match to individual • Transparency: Butvar can be made into a clear, colorless applications. For example, Butvar B-98 can be formulated to coating with excellent light resistance and aging produce a hot melt with low viscosity characteristics. B-72 characteristics. can be used to produce an adhesive with similar chemical properties but higher viscosity. Other types, such as B-76, • Adhesion: After curing, Butvar adheres readily to practically are available to produce adhesives where less crosslinking is all fabrics, including those normally considered difficult to desirable. coat, such as nylon, viscose rayon, and fiberglass. • Hand and appearance: A coating with Butvar has the soft, Table 18 shows a starting formulation for a hot melt based warm, flexible feel of an uncoated fabric, yet possesses all on Butvar. the functional characteristics of coated fabrics.

Table 18. Typical hot melt formulation • Functional properties: Butvar combines these attributes with functional properties comparable to those of the best Material Parts by weight textile coating materials in the field. During the drying and Butvar B-76 10 curing operations, Butvar is transformed to an elastomer Santicizer® 160 10 which becomes a permanent part of the fabric. Castorwax™ 35 Poly-Pale™ Ester #1 26 Fabrics coated with properly compounded and cured Butvar Staybelite™ Ester #10 19 have outstanding softness and flexibility without tackiness Total 100 of low softening temperatures. They have excellent chemical and water resistance. Films of Butvar resin are tough and will resist abrasion and wear. Coatings can be applied from high solids solutions made with common solvents. Clear coatings Textile coatings with Butvar may be applied from solutions of up to 35% One of the unique uses of Butvar polyvinyl butyral resin is solids; pigmented coatings may be as high as 45% solids. in the textile coating field. It can be compounded to make Solutions of Butvar are ideally suited to coating with either fabrics water resistant and stain resistant without noticeably rubber or pyroxylin spreaders. Solids content can be high affecting the appearance, feel, drape, and color of the fabric. and the solvents fast evaporating. The material will flow well Tablecloths, drapes, slipcovers, shower curtains, aprons, after being spread. For most applications, a light coating smocks, and children’s bibs are some of the more common averaging 1½ oz dry to the square yard is recommended.The items which can be prepared. Outside the home, fabrics solution of Butvar, which can be prepared in a solvent coated with Butvar serve as rainwear, porch furniture mixture of alcohol and naphtha, is applied in generally two upholstering, awnings, and beach accessories. to five passes, depending on the type of fabric and the Butvar, which provides a transparent film, can be applied coating operation. This is followed by a flat topcoat to to practically all common fabrics. Cotton, wool, silk, nylon, remove gloss and tack normally associated with coated viscose rayon, and other synthetics can be successfully fabrics. Usually two topcoats are required for a smooth, coated. As a rule, almost any fairly tight woven fabric with skip-free coating. a flat surface can be made water and stain resistant with The first two coats should be low in viscosity for proper a coating based on Butvar. penetration of the coating into the fiber interstices. The relationship between depth of penetration and coating viscosity will necessarily depend on the fabric construction and must be determined on the basis of trials. If an excessively high coating viscosity is used for the initial coats, peel adhesion, Mullen, and other physical test properties will suffer. Experience has shown that superior coatings are produced by many thin coats rather than

24 by a few heavy applications. Butvar is unique among vinyl resins in its ability to be cured Coated stocks are cured after all coats have been applied. in a manner somewhat analogous to rubber. Curing improves Premature curing of any coat due to overheating will reduce both heat and solvent resistance and adhesion to the fabric. the adhesion of subsequent coats. The time required for Curing Butvar is accomplished by incorporating crosslinking curing will depend on the resins and the catalysts employed resins, such as urea, phenolics, melamines, and isocyanates. and on the temperature of the curing oven. Cure time will Since the reaction involves the hydroxyl groups on the vary from approximately one hour at 250˚F to five minutes chain of Butvar, only a small amount of a modifying resin or less at 350˚F. is needed to increase substantially the heat and solvent resistance of the Butvar resin. Coatings with Butvar have been cured satisfactorily in festoon dryers at 200˚F, in steam heated ovens at 300˚F, in gas ovens, A formulation incorporating such a crosslinking resin is and even dryer cans. In all cases, overheating should be shown in Table 19. avoided to prevent loss of plasticizer and stiffening.

A properly coated and cured fabric will be water resistant; Table 19. Typical textile coating formulation will be resistant to ink stains, coffee, tea, cooking oils, and Material Parts by weight fats; and will have excellent washability. Most soilings can be Butvar B-72 48.0 wiped away with a damp cloth. Should the uncoated side Tricresyl phosphate 48.0 require laundering, neutral soap and warm water should be Ethanol 95% 84.2 used. The coated fabric can be ironed on the uncoated side. Toluene 64.8 Coatings based on Butvar cannot be dry cleaned. Such Water 8.0 treatment will remove the plasticizer and leave a stiff, harsh Resimene® AQ-7550 3.5 coating which will break on flexing. p-toluene sulfonic acid 0.7 p-nonyl phenol 0.2 Ceramic binder applications Compounding Butvar polyvinyl butyral resins are recognized as the 1. Combine solvents and plasticizer. binder of choice in the processing of ceramic tape cast 2. Add Butvar B-72 with stirring; heat if desired to speed solution. materials. The resin imparts excellent green strength and 3. Cool batch, blend in p-nonyl phenol, Resimene AQ-7550, and flexibility to the ceramic tape. It is compatible with many p-toluene sulfonic acid in that order. common solvents and plasticizers and burns out cleanly during sintering. Compound properties Percent solids 39% Butvar resins also are used as a binder medium in thick Viscosity (freshly made) ca 70,000 cps film processing. Butvar is formulated in the solvent vehicle Viscosity (24 hours) ca 75,000 csp used to deposit the circuit pattern on the ceramic surface. Cure cycle sequence: Room temperature. Drying 15 minutes, followed by 30 The primary advantages of using Butvar resins are their minutes at 190˚F and 20 minutes at 400˚F. Application: Spray or roller solubility in a wide range of solvents and uniform adhesion to conductive metals.

25 Tape casting Premix the fish oil in the toluene and MEK and add to ball mill. Add Alumina and ball mill for one hour. Add Santicizer Butvar is regarded as the binder of choice for the ceramic 160 and Butvar B-79. Mill an additional 24 hours. Pour, tape casting process due to the following benefits: de-air for several minutes, and cast. • Butvar resins provide excellent green strength to the • Additional Butvar can be added to most formulations to unified tape. improve interfilm lamination in a multilayer substrate. - Butvar allows multiple tapes to be laminated in the green stage. • A microfiltration system is generally used with - Low Butvar concentrations allow for higher density binder/solvent systems. A five micron or finer filter is substrates after firing. recommended. • Butvar is soluble in many volatile yet inexpensive solvents. - Flexibility in choosing Butvar product types and load Thick films levels for a wide range in binder solution viscosities and, Butvar resins can be used as the binder medium in vehicle therefore, ceramic slip viscosities. formulations for thick film pastes. Our lowest molecular • Butvar is compatible with many of the plasticizers used weight resins, Butvar B-79 and B-98, are recommended for in ceramic systems. either silk screen or steel screen processes. The advantages - Choose from dialkyl phthalates, benzyl phthalates, of using Butvar in thick films include: adipates, or phosphates commonly used. • Butvar is an excellent binder and dispersant for the • Butvar burns out cleanly with a minimum of warpage conductive metals used in thick films. to the fired part. • Thick films with Butvar can be cofired with the green - The product shrinks uniformly. tape in laminated ceramic substrates. - Low gel content minimizes surface defects. • Binder compatibility problems are minimized for cofiring • Butvar has natural dispersing properties and is compatible systems when Butvar is used in both thick film processing with common dispersing agents, such as fish oils or and as the binder in the ceramic tape casting process. phosphate esters.

The medium-to-low molecular weight resins, Butvar Table 21. Thermal properties B-76, B-79, B-90, or B-98, are recommended for use in tape casting processes. Butvar Butvar Test B-76 B-90 A typical tape casting formulation based on 100 gms of Units method B-79 B-98 Glass transition solid ceramic powder is shown in Table 20. C DSC 62–72 72–78 temperature (Tg) Ash content at 550ºC Table 20. Typical tape casting formulation In nitrogen % TGA <2.0 <3.0 Component Parts by weight In air % TGA <0.75 <0.75 Alumnina 100.0 Butvar B-79 5.0 Santicizer® 160 4.3 The apparent glass transition temperature (Tg) was Blown Menhaden Oil Z-3 visc. 2.0 determined by Differential Scanning Calorimeter (DSC). Toluene 14.4 The Thermal Gravimetric Analysis (TGA) was a weight loss MEK 14.4 versus temperature profile conducted at a heating rate of 10˚C/min.

26 Graph 11. Butvar® resin thermolysis profiles: Toners and printing inks Thermal Gravimetric Analysis (TGA) Butvar resins have been used in printing ink formulations for many years. All Butvar resins are alcohol soluble and In nitrogen are often used in solvent-based gravure and flexographic ink formulations to improve flexibility, adhesion, and toughness. The solubility characteristics of Butvar B-79 and 100 100 B-76 in aromatic and other fast-drying solvents allow for 90 compounding90 at low concentrations in high speed, high 80 quality80 printing applications. These properties have also 70 enabled70 Butvar to be used in ink formulations for thick film 60 conductive60 pastes, printer ribbons, and pen inks, as well as in 50 the manufacture50 of offset printing plates and other printing

40 technology40 apparatus. cent) 30 Butvarcent) 30 also serves the toner industry as a secondary binder. 20 Polyvinyl20 butyral is added to the formulations to increase 10 viscosity10 and to improve film integrity over the fuser roll. eight (wt per eight (wt per

W 0 TheW overall0 toughness of Butvar enhances the integrity 50 100 150 200 250 300 350 400 450 500 550 of the toner 50during100 150the milling200 250 process300 350 and400 450extended500 550 machine Temperature (ºC) Heating rate: 10ºC/min operation.Temper This atureminimizes (ºC) the level ofHeating fines without rate: 10ºC/min detracting from the flow properties.

Graph 12. Butvar® resin thermolysis profiles: Thermal Gravimetric Analysis (TGA)

In air

100 100 90 90 80 80

70 70

60 60 50 50

40 40 cent) 30 cent) 30 20 20 10 10 eight (wt per eight (wt per

W 0 W 0 50 100 150 200 250 300 350 400 450 500 550 50 100 150 200 250 300 350 400 450 500 550

Temperature (ºC) Heating rate: 10ºC/min Temperature (ºC) Heating rate: 10ºC/min

27 Storage and handling

Storage Quality control Environments of high heat and humidity should be avoided. To obtain the outstanding quality characteristics of Butvar, Solutia maintains statistical process control over Toxicity and FDA status the manufacturing process. In addition, to ensure that you receive highly uniform material with each shipment, Butvar® resins are regulated by the U. S. Food and Drug the finished product is analyzed in detail to be certain it Administration under parts of 21 Code of Federal Regulations conforms to our rigid specifications. for use as indirect food additives. Butvar resin also has been subjected to acute toxicity and mutagenicity studies. Details on specific coverage of individual studies are available on request.

Table 22. Packaging information

Container type B-72 B-90, B-76 B-98, B-79, B-74 61-gallon fiber drum 145 lb (66 kg) 140 lb (63 kg) 135 lb (61 kg)

28 Material sources

Product designation Owner and/or supplier Product designation Owner and/or supplier Araldite 6069 Ciba Geigy Corporation Arista Chemical Inc. Linseed oil Lansco Colors Reichhold Chemicals, Inc. Basic zinc chromate Rockwood Pigments NA, Inc. Magnesium silicate MP40-27 Specialty Minerals Beckosol 11-035 Reichhold Chemicals, Inc. Methyl acetate Eastman Chemical Company Werner G. Smith Inc. Methyl alcohol Air Products and Chemicals Inc. Blown Menhaden Oil Z-3 visc. R.E. Mistler, Inc. Methyl ethyl ketone Shell Chemical Corporation Borogard ZB U.S. Borax Methyl isobutyl ketone Eastman Chemical Company 2-Butoxyethanol (Eastman™ EB solvent) Eastman Chemical Company Methylon 75-108 OxyChem Butvar® resins Eastman Chemical Company Moly-White X92 Sherwin-Williams Chemical Butyl acetate Eastman Chemical Company Naphtha Shell Chemical Corporation Butyl alcohol Eastman Chemical Company Nitrocellulose RS, SS Dow Wolff Cellulosics Butyl benzyl phthalate Ferro Corporation OxyChem 02620, 92600, 29107 OxyChem Castor Oil #1 (raw), #15, #30, #40 CasChem Inc. p-nonyl phenol Boddin Chemiehandel Castorwax CasChem Inc. Paraplex® RGA-8 HallStar Celite 266 Imerys Filtration Pentalyn H Eastman Chemical Company Cellulose acetate Eastman Chemical Company PhosGuard® J-0800 Rockwood Pigments NA, Inc. Cellulose acetate butyrate Eastman Chemical Company Phosphoric acid, 85% U.S.P. Astaris Chlorinated rubber Hercules Inc. Plyophen 22-023 OxyChem Chromic acid (chromium trioxide) J.T. Baker Inc. Poly-Pale ester #1 Hercules Inc. DC 840 Dow Corning Corporation Pycal 94 ICI Americas Inc. DCZ 6018 Dow Corning Corporation Resimene® 717, 730, 741, 881 Cytec Ind. Desmodur AP stabil Bayer MaterialScience AQ-7550 and 918 Diacetone alcohol Shell Chemical Corporation SP-1044 resin Schenectady Chemicals Inc. Dibutyl phthalate BASF Santicizer® plasticizers Ferro Corporation Dibutyl sebacate HallStar Santolink® EP 560 Cytec Ind. Dihexyl adipate Ferro Corporation Shellac RPM International Inc. Dimethyl esters Invista Staybelite ester #10 Eastman Chemical Company Dioctyl phthalate Eastman Chemical Company Tributyl citrate Morflex Chemical Company FMC Corporation Duraplex 11-804 Reichhold Chemicals, Inc. Tricresyl phosphate Akzo Chemicals Inc. Durite P-97, LS-433 Borden Chemical Company Triethylene glycol di-2-ethylhexanoate Epi-Rez 540-C Solvay Eastman Chemical Company (Eastman™ TEG-EH) Epon 1001F, 1007F Momentive Triphenyl phosphate Triway 2-ethylhexyl diphenyl phosphate Ferro Corporation Vinyl chloride copolymer VAGH,VAGD Dow Chemical Company Flexricin-P3 CasChem Inc. (UCAR solution vinyl resin) Furnace black Columbian Chemicals Vinsol Pinova Solutions Hercolyn Pinova Solutions Xylol (xylene) Exxon Company, USA Isophorone Dow Chemical Company Zinc borate U.S. Borax Isopropanol Eastman Chemical Company Zinc borophosphate Rockwood Pigments NA, Inc. Ketjenflex 8, 9S, MH Axcentive Zinc molybdate Sherwin-Williams Chemical

29 Eastman Chemical Company Corporate Headquarters P.O. Box 431 Kingsport, TN 37662-5280 U.S.A. Telephone: U.S.A. and Canada, 800-EASTMAN (800-327-8626) Other Locations, (1) 423-229-2000 Fax: (1) 423-229-1193

Eastman Chemical Latin America 9155 South Dadeland Blvd. Suite 1116 Miami, FL 33156 U.S.A. Telephone: (1) 305-671-2800 Fax: (1) 305-671-2805

Eastman Chemical B.V. Fascinatio Boulevard 602-614 2909 VA Capelle aan den IJssel The Netherlands Telephone: (31) 10 2402 111 Fax: (31) 10 2402 100 Although the information and recommendations set forth herein are presented in good faith, Eastman Chemical Company and its wholly owned subsidiary Eastman (Shanghai) Chemical Solutia Inc. make no representations or warranties as to the completeness or Commercial Company, Ltd. Jingan Branch accuracy thereof. You must make your own determination of their suitability 1206, CITIC Square and completeness for your own use, for the protection of the environment, No. 1168 Nanjing Road (W) and for the health and safety of your employees and purchasers of your Shanghai 200041, P.R. China products. Nothing contained herein is to be construed as a recommendation Telephone: (86) 21 6120-8700 to use any product, process, equipment, or formulation in conflict with any Fax: (86) 21 5213-5255 patent, and we make no representations or warranties, express or implied, that the use thereof will not infringe any patent. NO REPRESENTATIONS OR Eastman Chemical Japan Ltd. WARRANTIES, EITHER EXPRESS OR IMPLIED, OF MERCHANTABILITY, FITNESS MetLife Aoyama Building 5F FOR A PARTICULAR PURPOSE, OR OF ANY OTHER NATURE ARE MADE 2-11-16 Minami Aoyama HEREUNDER WITH RESPECT TO INFORMATION OR THE PRODUCT TO WHICH Minato-ku, Tokyo 107-0062 Japan INFORMATION REFERS AND NOTHING HEREIN WAIVES ANY OF THE SELLER’S Telephone: (81) 3-3475-9510 CONDITIONS OF SALE. Fax: (81) 3-3475-9515 Safety Data Sheets providing safety precautions that should be observed when handling and storing our products are available online or by request. You Eastman Chemical Asia Pacific Pte. Ltd. should obtain and review available material safety information before handling #05-04 Winsland House our products. If any materials mentioned are not our products, appropriate 3 Killiney Road industrial hygiene and other safety precautions recommended by their Singapore 239519 manufacturers should be observed. Telephone: (65) 6831-3100 © 2013 Eastman Chemical Company. Eastman and The results of insight are Fax: (65) 6732-4930 trademarks of Eastman Chemical Company. Butvar is a trademark of Solutia Inc., a subsidiary of Eastman Chemical Company. As used herein, ® denotes registered trademark status in the U.S. only. All other trademarks are the www.eastman.com property of their respective owners.

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