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UNION COATINGS CARBIDE MATERIALS BAKELITE VINYL BUTYRAL RESINS PRODUCT INFORMATION BAKELITE* VINYL BUTYRAL RESINS BAKELITE Vinyl Butynil Resins arc partial butyrals of poly(vinyl alcohol) resins, supplied in both dry resin and solution forms and covering a range of molecular weights. They are widely useful in the coatings and adhesives areas and are the base for the wellknown wash primers. BAKELITE Vinyl Butyral Resins are characterized by excellent adhesion to nonporous surfaces such as glass, metal, and plastic (particularly to epoxy- and phenolic- based materials). Although these resins readily absorb up to eight per cent of their own weight in water, they retain good film integrity during cycles of sorption and desorption. BAKELITE Vinyl Butyral Resins are tough, flexible, and shock-resistant and they retain these characteristics over a wide tem perature range. They are thermoplastic, softening at about 135F., but they may be crosslinked by reaction with many resins and reagents. Although the light stability of vinyl butyral resins is excellent, they are seldom suitable (unmodified) for exterior exposure. They tend to fail by chalking from water absorption. BAKELITE Vinyl Butyral Resins do not discolor on prolonged heating at temperatures up to 200 F. At higher temperatures, they become amber in color and, on prolonged heating, may lose their alcohol solubility and become more hydrocarbon soluble. BAKELITE Vinyl Butyral Resins are typically dissolved by strong mineral acids and alcohols. They are swelled by weak acids, ketones, esters, and aromatic hydrocarbons. Strong alkalies have a slight effect. Aliphatic hydrocarbons, natural oils and mineral oils have little or no effect. The presence of plasticizers and other modifiers will influence this performance. BAKELITE Vinyl Butyral Resins retain their properties under unusually high pigment loading and with unusually large amounts of rosin, ester gum, and other low molecular weight resins. See Figure I for the impact resistance of different pigment loadings. UCC 039282 September, 1971 F-43030 1971 by Union Carbide Corporation BAKELITE. CELLOSOLVE, FLEXOL, and UNION CARBIDE are registered trade marks of Union Carbide Corporation, USA Ihis information is not to be taken as a warranty or representation for which we assume legal responsibility nor as permission or recom mendation to practice any patented invention without a license. It is offered solely for your consideration, investigation and verification UNION CARBIDE CORPORATION * COATINGS MATERIALS 270 PARK AVENUE, NEW YORK, N. Y. 10017 BAKELITE VINYL BUTYRAL RESINS TABLE 1 TYPICAL PHYSICAL PROPERTIES BAKELITE Vinyl Butyral Resin Form Resin Solids, % Viscosity Solutions Chemical Composition, of Resin % by wt. Vinyl Acetate Vinyl Alcohol*51 Viscosity at 10% Solids, Cps. Specific Gravity XYHL XYSG XYLS-1 XYLS-2 XYLS-4 Dry Resin Dry Resin Solution! i) Solution*2> Solution*3) -- 20.0 20.0 25.0 0.90*4> 1.23<4> 12.000 to 18.000 cps. 6,000 cps. 2,300 cps. 0.5 0.5 0.5 0.5 0.5 19.5 19.5 19.5 19.5 19.5 162<2> 680*2) 320*6) 218*6) 100*6) 1.12 1.12 0.840 0.887 0.914 * FOOTNOTES: ^ * XYHL in isopropanol ^Inherent viscosity, ASTM D-1243-58T Procedure A (2) XYHL in ethanol Is* Hydroxyl content of dry resin calculated as vinyl alcohol (3) XYHL in ethanol......................................... ethyl acetate............................... water............................ .. 4 . . . . mixed solvents......................... 41.0 19.0 6.0 9.0 Solution diluted to ten per cent total solids with ethanol Total............................................ 75.0% by wt. SOLUBILITY Alcohols are the best solvents for BAKELITE Vinyl Butyral Resins. Ketones, esters, and aromatic hydrocarbons do not dis solve them. When used as diluents, however, they can reduce solution viscosity below that obtained with alcohol alone. This apparent anomaly is explained by the presence of both hydrophilic hydroxyl groups and organophilic butyral groups. Table 2 lists the solvents typi cally considered for use with BAKELITE Vinyl Butyral Resins. Figure II shows the influence of diluent on viscosity of a ten per cent solution of XYHL in ethanol. BAKELITE Vinyl Butyral Resins are more soluble in alcohol solutions containing water than in anhydrous alcohols. Figure III shows this latent solvent effect in a water/ isopropanol system for XYHL at 20 per cent solids content. Figure IV shows the three-way inter-relationships of isopropanol, water and resin. Compositions that fall within the en circled area are soluble. Systems bordering this area may be gelatinous or turbid. uec 039284 BAKELITE VINYL BUTYRAL RESINS TABLE 2 TYPICAL SOLVENTS FOR VINYL BUTYRAL RESINS Acids Formic Acid Acetic Acid Alcohols Methanol Ethanol Isopropanol Butanol Esters Methyl Acetate Ethyl Acetate COMPATIBILITY Plasticizers may be added to increase flex ibility for some applications and to reduce viscosity for hot melts. BAKELITE Vinyl Butyral Resins are compatible with FLEXOL Plasticizers DOP, 3GH, and TOF, with many other chemical-type plasticizers, and with certain natural oils. Raw castor oil is com patible but tends to soften the film without developing elasticity. It may be used ad vantageously, however, with chemical-type plasticizers. BAKELITE Vinyl Butyral Resins are compatible with a variety of natural gums and INSOLUBILIZATION OF VINYL BUTYRAL RESINS The hydroxyl groups of BAKELITE Vinyl Butyral Resins are reactive and can be used as crosslinking sites to improve water and solvent resistance. BAKELITE Phenolic Resins BKS2710 and BKS-2600, urea-formaldehyde, and melamine-formaldehyde are useful as crosslinking agents. Urethane prepolymers are useful, too, if urethane grade solvents are used. Alcohols, for example, react with Glycol Ethers Methyl CELLOSOLVE CELLOSOLVE Solvent Ketones Diacetone Alcohol Cyclohexanone Isophorone Special Solvents Propylene Oxide 1,4-Dioxane Cresol Morpholine Pyridine resins. Compatibility with synthetic resins, however, is limited to types that can tolerate the alcohol needed to dissolve the vinyl butyral. Generally, the compatibility of vinyl butyral resins is the same regardless of mo lecular weight. One important exception is that XYLS-4 is compatible from 1-9 to 9-1 (by weight) with RS-type nitrocellulose and with SS-type nitrocellulose, while XYHL and XYSG and the other solutions are not com patible with RS-type nitrocellulose. Compati bility data for vinyl butyral resins appears in Table 3. isocyanates. Systems crosslinked with phenolic, urea, and melamine resins must be baked at 275 F. for 30 to 45 minutes (or at higher temperatures for shorter schedules). Phosphoric acid esters or para-toluene sul fonic, phosphoric or sulfuric acids (at 0.5 to 1.0 per cent on the crosslinker) can be used to speed the cure. ucc 039285 INCH -- pounds BAKELITE VINYL BUTYRAL RESINS FIGURE I 1/1 1/2 1/3 1/4 1/5 1/6 RESIN/PIGMENT, by weight 4 ucc 039286 BAKELITE VINYL BUTYRAL RESINS FIGURE II VISCOSITY OF XYHL AT TEN PER CENT TOTAL SOLIDS IN ETHANOL/DILUENT MIXTURES VISCOSITY at 25C., centipoises ETHANOL, per cent by weight (Balance: toluene, butyl acetate or acetone) 5 UCC 039287 VISCOSITY at 25C., centipoises BAKELITE VINYL BUTYRAL RESINS FIGURE III VISCOSITY OF XYHL AT 20 PER CENT TOTAL SOLIDS e UCC 039288 BAKELITE VINYL BUTYRAL RESINS FIGURE IV Isopropanol, 100% XYHL, 100% 7 uec 039289 BAKELITE VINYL BUTYRAL RESINS TABLE 3 COMPATIBILITY*1' OF BAKELITE VINYL BUTYRAL RESIN Resin or Oil/Vinyl Butyral Resin 9/1 4/1 1/1 1/4 1/9 "Acryloid"'2' B-66 "Acryloid"'2' B-82 "Acryloid"'2' A-101 "Amberol"'2' No. 226 BAKELITE Phenolic Resin CKR-2432 BAKELITE Phenolic Resin BKS-2710 BAKELITE Phenolic Resin BKS-2600 "Beckacite"'3' 1110 "Beckacite"'3' 1111 "Beetle"'4' 212-8 "Beetle"'4' 216-8 "Beetle"'4' 227-8 Ccc Ccc Ccc Ccc Ccc c 1C IC IC SIC SIC SIC 1C IC SIC 1C IC IC 1C IC IC 1C IC IC c c c c c c IC c c c c c c c c IC c c Cellulose Acetate Cellulose Acetopropionate Cellulose Acetobutyrate Chlorinated Rubber Cumar Resin P-25 1C IC IC IC IC 1C IC IC IC SIC 1C IC IC IC IC ic IC IC IC IC 1C IC IC IC IC "Duraplex"'2' C-45LV "Durez"'5' No. 550 IC IC IC IC IC ccCCC Copal Ester Gum, Synthetic R-103'6' "Melmac"'4' 245-8 Sll IC IC IC IC ccccc IC IC IC "Nevillac"'7' Resin Hard "Neville"'7'Resin R-17 "Nevidene"'7' R-1 Ccccc IC IC IC IC IC IC IC IC IC IC Nitrocellulose SS ccccc Nitrocellulose RS (XYHL, XYSG, and solutions) SIC SIC IC IC IC "Uformite"'2' F-240 "Cymel"'4' 300 "Cymel"'4' 301 "Varcum"'3' #250 ccccc c c c cc ccccc ccccc Castor Oil, Raw Castor Oil, Blown Linseed Oil, Bodied Tung Oil Mineral Oil ccccc ccccc IC IC IC IC IC IC IC IC IC IC IC IC IC IC IC Shellac Damar, Dewaxed Congo Hard Manila Loba Ccccc ccccc ccccc ccccc ^ Code C = Compatible 1C = SIC = SI I = Incompatible Slightly Incompatible Slightly Insoluble (2>Rohm and Haas (3)Reichhold Chemicals, Inc. ^American Cyanamid Co. ^Hooker Chemical Corp. ^General Electric Co. ^^Neville Chemical Co. 8 ucc 039290 BAKELITE VINYL BUTYRAL RESINS _____________ STRUCTURAL ADHESIVES Crosslinked with one-step and two-step phenolic resins, structural adhesives based on BAKELITE Vinyl Butyral Resins XYHL and XYSG are characterized by the following properties: Excellent film integrity and adhesion to nonporous surfaces even after prolonged and intermittent water immersion. Toughness and flexibility. Shock resistance. Light and heat stability. Vinyl butyral/phenolic structural adhe sives are used for aircraft construction, brake linings, printed circuits, and wall and honey comb construction. Vinyl butyral/phenolic ratios depend on the end-use requirements. A 100/40 ratio will yield optimum roomtemperature shear and peel strengths. Higher phenolic concentrations will allow more crosslinking and yield higher elevated-temperature shear strengths. Since most structural appli cations require good strength properties at reasonably high temperatures, most commer cial vinyl butyral/phenolic adhesives are for mulated at 100/50 to 150 ratios. Phenolic resins act as tackifiers and crosslinking agents. Both one-step and two-step resins are used. Two-step resins are preferred for applications requiring short cure cycles (about 15 minutes) or lower temperature cures (about 300F.). BAKELITE Phenolic Resins BKS-2710, BKPA-5904, and BKPA5864 are specifically recommended. BKS2710 is a one-step resin. BKPA-5904 and BKPA-5864 are two-step resins. To prepare the adhesive, blend the sol vents and the phenolic resin solution until a uniform solution is obtained. Add BAKELITE Vinyl Butyral Resin XYSG or XYHL slowly. Continue mixing until a homogeneous solu tion is prepared. WOOD SEALERS AND FINISHES, TRANSFER COATINGS FOR RIGID URETHANES An ethanol solution of BAKELITE Vinyl Butyral XYHL and BAKELITE Phenolic Resin BKS-2710 is widely used in the wood finishing area as a knot sealer. Applied over knots, it seals in the prevents them from paint film FORMULA SUGGESTION VP-2756 . KNOT SEALER MIL S -12935 (CE) Ingred ients BAKELITE Phenolic Resin BKS-2710 (60% N.V.) BAKELITE Vinyl Butyral Resin XYHL Ethanol, 95 per cent Total...................................................................... Parts by Weight 5.0 0.5 9.5 15.0 Per Cent by Weight 33.3 3.3 63.4 100.0 9 ucc 039291 BAKELITE VINYL BUTYRAL RESINS Combinations of BAKELITE Vinyl Butyral Resins and nitrocellulose are widely used as sealers for furniture finishes. They are characterized by toughness, adhesion, and sandability without modification with stearate sanding aids. Combinations of BAKELITE Vinyl Butyral Resins and nitrocellulose are also useful as transfer coatings for the rigid urethane foam used in molded furniture components. In this process, the transfer coating is applied on silicone RTV or urethane elastomer molds and allowed to dry. The liquid foam chemicals are charged and allowed to blow. In forming the part, the urethane foam bonds to the transfer coating. When it is cured, the part is removed from the mold for further finishing. BAKELITE Vinyl Butyral Resin XYLS-4 is recommended over other vinyl butyrals be cause it has better compatibility. It permits flic use of the more economical RS-type nitrocellulose. Additionally, sealers based on XYLS-4/RS nitrocellulose can be sprayed at 30 to 50 per cent higher solids than com parable systems based on XYHL/SS nitro cellulose. FORMULA SUGGESTION WOOD SEALER AND URETHANE TRANSFER COATING BAKELITE Vinyl Butyral Resin XYLS 4 Nitrocellulose, 1/2 sec. RS dry base "Paraplex" Plasticizer 5B Parts by Weight Sealer Transfer Coating 40.0 10.0 10.0 40.0 10.0 10.0 Solvents Methyl Isobutyl Ketone (MIBK) Toluene Ethanol Methyl Isobutyl Ketone (MIBK) Butyl Acetate Ethanol Equal parts by weight to spray viscosity - - - -- 25 25 50 to spray viscosity Pigments Red Iron Oxide Yellow Iron Oxide Titanium Dioxide (Ti02) Lampblack - 4.2 - 8.3 - 1.1 - 0.3 or as desired for basic color 10 ucc 039292 BAKELITE VINYL BUTYRAL RESINS STRIPPABLE COATINGS Strippable coatings for metals and plastics, such as high-pressure melamine laminates or styrene, high-impact styrene or acrylic, are easily formulated from BAKELITE Vinyl Butyral Resins. The low-viscosity resin solution XYLS-4 is particularly well suited for this ap plication because it is sprayable at higher weight per cent solids (than a similar formula made with XYLS-1). FORMULA SUGGESTION . STRIPPABLE COATING Ingredients Parts by Weight BAKELITE Vinyl Butyral Resin XYLS-4 Raw Castor Oil 100.0 5.0 Total ............................................................. 105.0 Procedure Thin to spray viscosity with a suitable thinner, such as butanol/toluene (20/80 by weight) for metals or butanol/isopropanol or ethanol mixtures for plastic surfaces attached by aromatic hydrocarbons. Emulsified vinyl butyral resin also func tions well as a strippable coating. Formula Suggestion VC-3140, available from Union Carbide Sales Offices, can be used as a starting point for preparing vinyl butyral emulsions. METAL FINISHES One-half to two per cent of BAKELITE Vinyl Butyral Resins XYHL or XYSG are used to control the "eyeing" of phenolic resin baking solutions applied over imperfectly cleaned surfaces. In larger proportions, XYHL can be used to improve the flexibility of phenolic resin baking finishes, such as BKS-2600 and BKR2620. XYHL will range from 10 to 100 per cent of the weight of the phenolic resin. In creasing the butyral resin content increases the haze and decreases the chemical resistance of the films. A coating based on one part of BAKELITE Vinyl Resin XYHL and two parts of BAKELITE Phenolic Resin-Baking Solu tion BKS-2600 will, however, withstand com mercial can-forming operations at thicknesses up to 0.3 mil and has extremely good re sistance to steam processing. BAKELITE Vinyl Resin XYHL can be 11 ucc 039293 BAKELITE VINYL BUTYRAL RESINS used in clear finishes for exterior exposure when modified with a urea-formaldehyde resin. For example, a 3/1/1 ratio of XYHL, FLFXOL Plasticizer 3GH, and "Uformite" resin F-240 has given outstanding service as a clear coating on chromium plate. Ethanol/ toluene or methyl ethyl ketone/xylene/ butanol mixtures have proved satisfactory for thinning. Both air-dry coatings and those baked for ten minutes at 350F. were satis factory after 1300 hours in an accelerated weathering unit and after 103 days of roof exposure. At a slight sacrifice in performance, a higher solids coating can be obtained using equal proportions of the two resins. METAL CONDITIONERS Wash primers, metal conditioners or pre treatments are applied as thin coatings of between 0.1 and 0.5 mils and air-dried to establish a firm bond to metal surfaces. This inhibitive film serves to prevent corrosion and undercutting of the film by rust as well as providing a firm anchor for subsequent paint coats. Wash primers provide a temporary pro tection against atmospheric rusting, and must be protected by topcoats before exposure to the weather. These topcoats can be applied within 15 minutes of the application of the wash primer, since the vinyl butyral resin solution dries entirely by solvent evaporation. If desired, this drying can be speeded by heat. The fact that wash primers can be applied with conventional spray equipment eliminates the need for expensive tanks, ovens, and tech nical control required for conventional metal pretreatments. Moreover, the simplicity of operation permits one to prepare metal sur faces and apply a coating in the field that is at least equivalent to a shop-applied system. Phenolic, oleoresinous, alkyd, epoxy, and alkyd-melamine paints adhere to the washprimed metal. Coatings based on BAKELITE Vinyl Resin VAGH or VAGD develop excel lent adhesion. Nitrocellulose, itself, has rela tively little adhesion to the wash primer film but alkyd-modified nitrocellulose will adhere well. In general, coatings based on vinyl chlo ride copolymers (except VAGH or VAGD), vinylidene chloride, and acrylic and methacrylic resins do not adhere to the wash primers. Just as alkyd resins improve the ad hesion of nitrocellulose lacquers to wash primers, suitable blends of VAGH or VAGD with other vinyl resins will develop the re quired adhesion. USE OF METAL CONDITIONERS The wash primer holds the paint system firmly to the steel and prevents the spread of underfilm corrosion despite occasional me chanical breaks in the film. These areas can be easily cleaned and touched up without damage to the surrounding finish. 12 039294 BAKEUTE VINYL BUTYRAL RESINS Multiple coats of this all-vinyl system can be applied quickly, with resultant economies in dry-dock service. In addition, the protective life of the system leads to greater savings since less frequent painting is necessary. The outstanding results in the marine field have been duplicated in other fields. Pipe lines, oil storage tanks, and offshore drilling rigs are protected with the wash primer-vinyl paint system. The speed of application and abrasion resistance of this system have led to many applications on bridges, dam gates and barges. Air conditioning equipment, particu larly fans where the corrosion on the edge of blades is severe, is often protected by the wash primer system. Wash primers are used widely to coat galvanized iron, a surface that is usually dif ficult to paint. Exterior signs and outdoor movie screens that are wash-primed retain their paint despite cold weather shock instead of having to be repainted each spring as has been customary. APPLICATION OF METAL CONDITIONERS To establish adhesion to a metal surface and to prevent rusting, grease, oils, rust, scale, and other contaminants should be removed from the surface before applying the wash primer. Grit or sandblasting are more effective than wire brushing or flame descaling. Acid washes should not be used, since salts left on the surface may be a source of osmotic blisters. The performance of wash primers over rusty steel is always poorer than over clean steel. Moreover, on a rusty surface, the results are often erratic. When a wash primer is ap plied to a surface covered with mill scale, galvanic action between the steel and the mill scale can be accelerated and lead to more rapid failure. This latter effect is more often observed in underwater exposures. The econ omies possible by less frequent painting can only be realized by avoiding the erratic and inferior performance resulting from improp erly prepared surfaces. Wash primers may be applied by conven tional methods, such as spraying, dipping, brushing, or roller coating. They should be applied as a wet coat to cover the surface and penetrate cavities and corrosion pits. They should be applied thin in an alcohol dilution, since a heavy coating of wash primer may detract from the performance. The dry film should not exceed about 0.5 mils. Precautions should be taken to avoid conventional paint thinners for this dilution, since even small amounts of high boiling aliphatic hydro carbons may precipitate the butyrai resin during drying. Although not good practice, the wash primers may be applied over wet metal. In this case, the thinner should contain adequate butanol to prevent resin precipitation. Usual ly, 30 per cent butanol in the thinner will give good performance. On wet or rough surfaces, brush application will help the wash primer penetrate any pits in the surface. 13 UCC 039295 BAKELITE VINYL BUTYRAL RESINS PREPARATION AND STORAGE OF METAL CONDITIONERS Pigmented wash primers are made in con ventional paint equipment, precautions being taken to prevent contamination by incom patible ingredients. The vinyl butyral resin is dissolved in the solvents, care being taken to add the resin slowly to prevent the formation of large resin clumps. The pigment base should be prepared from the base solution by dispersing the pigment in a pebble mill, grind ing to a Hegman gauge reading of 7. Steel mills and equipment should be avoided since the alcohol solvents used often lead to rapid rusting, and the iron contamination which is introduced into the wash primer detracts from the adhesion. For the same reason, the con tainers used for storage should be lined with a phenolic resin-baking or vinyl resin coating or should be of a non-reactive metal such as terneplate. The acid diluent should be packaged in glass or polyethylene containers or in con tainers having a suitable baked phenolic or vinyl resin coating. The same precautions are required if the diluent and base are combined in a one-package wash primer. Table 4 lists suggested pigment grinding bases and diluent compositions for several representative wash primers. CHARACTERISTICS AND SELECTION OF METAL CONDITIONERS The original wash primer, WP-1, was de veloped by Union Carbide to improve shipbottom paints. Several government specifications have been written around the original WP-1 wash primer formula. All formulations contain the same essential ingredients but differ in the choice of solvent or the color of the tinting pigment; some specifications do not allow the use of any tinting pigment. Formula sugges tions for the two most widely used two- package wash primers, as well as formulations for other one-and two-package wash primers, are shown in Table 4. Of course, the formulator must carefully follow the composition of the wash primer listed in each particular specification. Two-package wash primers must be used within eight hours after the acid diluent has been mixed into the base grind. Beyond the eight-hour period, the wash primer loses its adhesion to metals, even though the appearance seems unchanged. BASIC ZINC CHROMATE METAL CONDITIONERS, WP-1 PRIMERS WP-1 primers (both MIL-C-15328B and M1L-C-15328C) give outstanding adhesion to a wide variety of surfaces, including the following: steel stainless steel zinc cadmium tin aluminum galvanized iron magnesium glass WP-1 formulations are the preferred primers for use where exposure to salt water or salt spray is involved. These metal conditioners give maximum protection where the topcoat is a relatively permeable type such as alkyd, oleoresinous, or emulsion paint. For outstanding performance, the WP-1 14 UCC 039296 BAKELITE VINYL BUTYRAL RESINS type wash primers should be topcoated with a coating based on BAKELITE Vinyl Resin VAGH or VAGD. This approach is an espe cially effective system in sea water and corro sive atmospheres. On fresh-water immersion or under conditions of high humidity, however, this system may develop osmotic blisters when the temperature is above 100F. The reason is the lack of ionic permeability with coatings based on vinyl and phenolic resins. Pigmentation of the topcoats with leafing alu minum pigments may minimize the osmotic blisters. In general, however, where higher temperatures and humidity are encountered, the wash primer should contain fewer soluble ions. The rust inhibitive action of WP-1 primers is enhanced as the quality of the pigment dis persion is improved. This improved dispersion is best obtained by extended grinding rather than by the use of grinding aids, since most surface-active agents detract from the protec tion afforded by the wash primer. In the mixing of WP-1 primers, add the diluent to the base slowly, with agitation. In that way, the thinner concentration is bal anced and local gelation prevented. The mix ing should be done in clean containers. Con tamination by oils or high boiling naphthas, such as mineral spirits, is detrimental to performance. The proportion of acid diluent is an im portant factor in the performance of wash primers. While a variation of 10 to 20 per cent in the volume of acid diluent does not bring about noticeable changes in the performance of the wash primer, larger variations should be avoided. Do not reduce viscosity with extra acid diluent. If further reduction in viscosity is required, use isopropanol or butanol. On certain surfaces, such as clean magnesium, the proportion of acid diluent may be reduced by 75 per cent, but the necessity to do so should be established by experiment. PHENOLIC MODIFIED WASH PRIMER The phenolic-modified wash primer VP2849 was developed to improve the durability of the wash primer itself. It is suggested as a replacement for WP-1 where the wash primer system will not be topcoated within three months. Exposure tests show that the phenolic wash primer itself will protect steel from cor rosion in atmospheric conditions in excess of two years. Three year atmospheric exposures of the phenolic wash primer topcoated with a vinyl chloride-based system show comparable performance to that of the conventional WP-1 type wash primer previously discussed. LEAD CHROMATE METAL CONDITIONER The lead chromate wash primer VP-2894 was developed specifically for use on steel and may not develop as good adhesion as WP-1 on other metal surfaces. VP-2894 is suggested as a replacement for WP-1 primers where the coating system is subjected to fresh water im mersion or condensing moisture, or where the acid diluent is mixed with the base and uec 039297 BAKELITE VINYL BUTYRAL RESINS TABLE 4 COMPOSITION OF WASH PRIMER VP-2980 WP-1 (MIL-P 15328B) Using XYHL Parts by Weight VP-3446 WP-1 (MIL-P-15328B) Using XYLS-1 Parts by Weight Basegrind: BAKELITE Vinyl Butyral Resin XYHL BAKELITE Vinyl Butyral Solution XYLS-1 BAKELITE Phenolic Resin BKS-2710 Basic zinc chromate pigment1 (insoluble) Lead chromate pigment (low in soluble salts) Chromic phosphate pigment Strontium chromate pigment Precipitated red iron oxide Magnesium silicate (talc) Lampblack Titanium dioxide, rutile Phthalo blue piqment2 Isopropanol, anhydrous Ethanol, 95 per cent Xylene Butanol Water Toluene Methyl isobutyl ketone Sub-Total Acid diluent Phosphoric acid, 85 per cent Water Isopropanol, anhydrous Ethanol, 95 per cent Sub-Total TOTAL 7.33 - 7.07 1.05 0.08 46.24 16.37 1.96 - -- 80.10 3.67 3.27 12.96 19.90 100.00 36.75 7.08 1,04 0.08 16.85 17.56 0.82 -- 80.18 3.66 3.28 12.88 19.82 100.00 VP-3374 WP-1 (MIL-P-15328C) Using XYHL Parts by Weight 7.01 - 6.76 4.88 2.13 42.68 15.64 1.88 -- 80.98 3.50 3.13 12.39 19.02 100.00 VP-3447 WP-1 (MIL-P 153280 Using XYLS-1 Parts by Weight 35.05 6.76 4.88 2.13 14.64 17.18 0.34 80.98 3.50 3.13 12.39 19.02 100.00 ^Denotes one package wash primer. The acid diluent can be added to the grind without affecting the shelf life of the primer, The other wash primers mentioned in Table 4 are two package primers The base grind and the acid diluent have to be stored separately After mixing, they should be used within a short time, since there is a gradual decline in the adhesion of films applied after the mixed primer has aged several hours. Suppliers: ^*2813 Zinc Chromate {Harshaw Chem.l, X-22S9 {Hercules Inc.) or equivalent. ^^X-3367 (Imperial Color), BT425D (E. I. du Pont de Nemours & Co., Inc.) or equivalent. 16 uce 039298 BAKELITE VINYL BUTYRAL RESINS VP-2849 Phenolic Modified Parts by Weight VP-2894* Lead Chromate Modified Parts by Weight VP-3448* (MIL-C-14504A) Parts by Weight VP-2979* Chromic Phosphate Modified Parts by Weight 10.39 15.58 3.46 -- -- 0.86 2.16 9.00 _ -- 8.60 -- -- - 1.40 9.41 -- 4.31 _ -- 4.31 - 1.96 9.0 -- 9.0 - 1.4 - 34.20 7.80 7.80 10.39 _ 92.64 53.00 - -- _ 13.00 85.00 58.96 -- -- 16.48 95.43 - 54.5 -- -- 16.1 90.0 1.84 -- -- 5.52 7.36 100.00 2.90 2.90 9.20 - 15.00 100.00 2.74 1.83 -- - 4.57 100.00 1.8 1.8 -- 6.4 10.0 100.00 17 UCC 039299 BAKELITE VINYL BUTYRAL RESINS stored for a long period. Storage tests of eighteen months have not revealed any dete rioration in the primer. This means that a one-package primer can be supplied and the material can be used in dip tanks. Since the composition is designed for storage, VP-2894 is prepared at a somewhat higher solids con tent and, as formulated, may be too viscous for spraying. Thinning 20 to 30 per cent with butanol will reduce the composition to spray viscosity. The easier dispersibility of lead chromate usually results in a smoother primer than can be obtained with basic zinc chromate, an ad vantage where gloss coatings are applied over the primer. Where the thickness is determined visually, however, the coating may be applied too thick. Coatings applied over the VP-2894 primer should not be pigmented with lead pigments. Topcoats based on red lead, chrome yellow, and chrome orange have shown poor adhe sion, especially if the wash primer is aged some time before coating. Moreover, the VP2894 primers have given some indication of poorer adhesion over wet surfaces than WP-1 primers, especially when heavy films are ap plied. Additional thinning with butanol before application, or warming during drying, usually eliminates these difficulties. Finally, the VP2894 primers are somewhat slower in develop ing adhesion; although on steel the final ad hesion is equal to that of WP-1 primers. To sum up, VP-2894 is formulated for use on steel. VP-2894 is definitely poorer than WP-1 primers on aluminum and magnesium and the performance of this wash primer should be checked on other metal surfaces before use. CHROMIC PHOSPHATE METAL CONDITIONER VP-2979 or XE-5298 Salt-free chromic phosphate serves as an excellent rust inhibitor in vinyl butyral solu tions. Wash primers based on chromic phos phate may be combined with the acid diluent as a one-package system. These chromic phos phate wash primers show less tendency to develop osmotic blisters than the WP-1 primers, basic zinc chromate formulations. For this reason, they are to be preferred in locations involving high humidity or fresh water immersion. Formula VP-2979 is shown in Table 4 and is suggested for use on steel. While this formula has not been tested as extensively as the WP-1 formulations, it gives excellent per formance in all types of accelerated tests, and is offered as a starting point for the develop ment of improved single-package primers. Like the VP-2894 formula, this chromic phosphate wash primer is formulated with higher resin and lower phosphoric acid con tent. Thus the formulation as written is more viscous and may require additional thinning with alcohol for spray applications. Since chromic phosphate pigments are prone to settle in the container, the composition should not be stored at too low a viscosity. 18 UCC 039300 BAKELITE VINYL BUTYRAL RESINS SELECTED REFERENCES Suggested Mechanisms of Changes with Time in WP-1 Wash Primer Metal Condition ing Composition, E. R. Allen. Corrosion v 17 n 6 June 1961 p 114-18. History of wash primers with emphasis on laboratory research; mechanism is postulated to explain loss of ad hesion with time of reactive type WF-1; phase rule studies of zinc tetraoxychromate, in trinsic viscosities of recovered polymers, re actions involving formation of phosphoruschromium-resin complex, deposition of ter tiary zinc phosphate on metal, and modifica tions made in WP-1; several organic structural formulas are included. Wash Primer Development and Character istics, L. R. -Whiting. Corrosion v 15 n 6 June 1959 p 45-7 (discussion) 47-8. Reacted wash primers discussed mainly; formulation of WP-1 reactive type and its advantages; wash primer reaction; reacted and non-reactive wash primers; application recommendations. Mechanism of Wash Primer Action, J. Kruger. M. C. Bloom. Indus. & Eng. Chem. v 48 n 8 Aug 1956 p 1354-60. During World War II, L. R. Whiting and P, F. Wangner empirically developed compositions known as wash primers considered one of the most important steps in corrosion prevention in recent years; initial attempt to investigate structure of this wash primer film on iron sur face, its mechanism of formation, and its mode of action in retarding corrosion and increasing paint adhesion. Introduction to Wash Primers, E. S. Beck. Metal Finishing v 56 n 1, 2 Jan 1958 p 58-60, Feb p 614. Value of wash primer for cor rosion resistance, adhesion, or durability; com position and properties of WP-1 wash primer; application within certain ranges of film thick ness; primer was developed which used lead chromate as pigmentation in place of basic zinc chromate; other wash type primers. Wash Primer Has Good Adhesion To Metal, M. Barlet. Ind Finishing 43:93-4 Feb 1967. Wash Primers For Metal; Not For Fiber glass, Ind Finishing 37:106-7 Apr 1961. STORAGE AND HANDLING OF RESINS AND RESIN SOLUTIONS Store dry resins in a cool dry place, away from direct sunlight or other sources of heat. To avoid contamination, keep all containers sealed when not in use. In the storage and handling of resin solu tions, observe the same safety practices that apply for flammable solvents. Keep containers sealed when not in use. Maintain adequate ventilation when being used. Eliminate poten tial sources of ignition. The two main dif ferences between resin solutions and solvents are (1) the possible reactivity of the resin and (2) the higher viscosity of the resin solution. Avoid unwanted exposure to reactants and catalysts. In the transfer of resin solutions, size the pipelines, pumps, and motors for the higher viscosity. For details on the storage and handling of particular resins and resin solutions, phone or write the Union Carbide office nearest you. See the back page for phone numbers and addresses. 19 IJOO 039301 BAKELITE VINYL BUTYRAL RESINS SHIPPING DATA FOR RESIN SOLUTIONS Subject to change without notice Weight per Gallon, lb. at 20 C. at 15.56C. A Pounds per Gallon, C. Coefficient of Expansion at 20 C. at 55C. Flash Point<a> F. Type Container and Net Contents 55-Gallon DOT Warning Label Required Freight Description Rail Truck Dangerous Article Description on Container XYLS-1 XYLS-2 XYLS-4 7.12 7.15 0.00718 7.18 7.21 0.00716 7.61 7.65 0.00810 0.00101 0.00105 70 0.00100 0.00103 62 0.00106 0.00110 60 390*b) Red 394<b) Red 419(c) Red Plastics, Synthetic, Liquid, Noibn Plastic Materials, 0/T Expanded, Liquid Noibn Resin Solution (Flammable Liquid) FOOTNOTES: la' Tag open cup, ASTM method 0 1310 Ih) DOT 17H Steel Drum, UCC No. 2 baked phenolic lined. (c) DOT 17E Steel Drum, UCC No. 2 baked phenolic lined. PRECAUTIONARY LABELING XYLS-1 and XYLS-2 WARNING: FLAMMABLE Keep away from heat, sparks and fire. Do not leave container open. Use with adequate ventilation. FOR INDUSTRY USE ONLY XYLS-4 WARNING: FLAMMABLE Breathing of vapors harmful. May cause eye irritation. Do not breathe vapors. Avoid contact with eyes. FOR INDUSTRY USE ONLY F 43030 3/71 1QM UNION CARBIDE CORPORATION COATING MATERIALS 270 PARK AVENUE, NEW YORK, N. Y. 10017 Lithographed tn U S A