Document QxYqB0qR6pGOkbeZXnKOM1gk

11th AMlfAL PflOGRESS REPORT v > y/j| ' 'i N Elev^y6^^S^mTw^^ia'psed'sincM& r, sion'vchiclej'Rlibplex-AC-33, was introaii<^a'fa',th&T>Mp%lU' \j\ emuIsion^polyinervprovided>;ajtoi3gn|la^L]3lg^^^^^^* j: was; designed;; pnmarijyj4fpr|_iaasonry^5U^^^^^^pw? ; - followed in i96i by' Rhoplex' AC-34r sp be usedon.wbpd.siirfac.es^JTsepfjthe^lgQmm^^^1*^ ' "'I . exposure. series - included in ''6arlier:dssueMbM^E I,. nut gt vcu.ijiua; j uuijjjuuauau^ ' \-A ;. and noliae: exposures jn tnejrnuaaelpmis ft ''ii, < ' * ' *i / ^ i /S > ! i A*::'. - GL0005699 V>4f > V' - S^SGs^r ^ . -^D0O^J00 Characteristics and Treatment of Surfaces Commonly Painted Acrylic emulsion house paints are being success fully applied to an ever-increasing variety of substrates. These surfaces differ greatly in their condition and have different performance re quirements. Therefore, the number of suggested formulae has been increased to cover the wide range of surfaces involved. Earlier systems were designed for good general overall service and were too limited in number to give an optimum cost-performance balance for all substrates. In this section the more common of these painting surfaces will be discussed with recommendations for surface preparation and suggested starting formulations. Repaint Substrates Previously Painted Wood Sound Non-Chalking and Glossy Surfaces The main problem in repainting gloss paints and aged but unweathered surfaces found under eaves and in other protected areas has been that of obtaining satisfactory adhesion. This is particularly true under wet conditions. Rhoplex AC-34 is renowned for its excellent adhesion to oil paints and primers under either wet or dry conditions and has eliminated such surfaces as a serious problem, as may be seen in Figure 1. However, proper surface preparation is essentia] to attain maximum adhesion and durability. Surfaces should be cleaned of all dirt and mildew, and surface gloss or oily de posits should be removed by either chemical or physical means, using sandpaper or solvent-type cleaners. Iron nailheads should be countersunk and puttied or primed with an oil paint before the Rhoplex AC-34 paint system is applied; otherwise, rust will bleed through the topcoats. Any of the suggested topcoat formulations can be used successfully, and will give satisfactory performance over a properly prepared surface. Selection of the particular formula will depend on the desired cost-performance relationship. Fig u r e 1. Test fence (facing north} consisting of white pine clapboards topped by eave with an 18-inch over hang. Clapboards were first painted with an oil primer, then given two coats of dark green oil-type gloss (non chalking) trim paint. The finish was weathered one year and then given two costs of an emulsion paint (35 PVC tint base) without surface preparation. Emulsion paint on left has polyvinyl acetate copolymervehicle; in center, Rhoplex AC-34; on right, vinyl acetate copolymer. Photo shows condition after three years' exposure. 3 GLt>005 ?0l Sound Chalky Surfaces How well a paint performs over chalk is a func tion of the type of chalk, degree of chalk, weather conditions at time of application and the formulation involved. Experience with Rhoplex AC-34 paints over standard self-clean ing oil and emulsion house paints on test panels, test houses and in actual commercial applications has been very satisfactory. Although many of these tests have been conducted on undisturbed chalky surfaces, for optimum performance under all application conditions preliminary surface preparation is recommended. Surface prepara tion not only insures maximum performance, but also guards against failures due to unusual or problem substrates or weather conditions, and permits successful application of a wider variety of lower cost, high pigment volume content formulations. As a further safeguard against loss of adhesion on chalky surfaces, some paint manufacturers modify the first coat of an emulsion paint with oil or alkyd. This is done either through modifi cation of the prepared paint, or through an oil or alkyd addition at time of application. Formulation 204, given in the formulation sec tion of this report, is an example of a product that can be used for this purpose. Such materials give some improvement in adhesion over chalky surfaces, but with some reduction in the wetadhesion characteristics of Rhoplex AC-34. They should not be used in topcoats, where they may cause early color fading and increase dirt col lection and mildew. There are various types of chalks, not nor mally found on wood, which are difficult for emulsion paints to penetrate and bind properly, and these are discussed in a later section. The degree or rate of chalking is important because it is an indication of the sponginess or porosity of the old paint film. Chalk has a definite water demand. This results in a strong wicking force which rapidly extracts the water from new paint, causing the film to form on the surface rather than penetrating to the substrate. This is true of all porous surfaces, and they should be prewetted with water and the Rhoplex paints applied to the damp surface. Weather conditions can also have a pro nounced effect on the drying speed of the paint. If the paint dries too fast, penetration is reduced. The influence of low humidity, dry breezes and direct sunlight in causing premature film forma tion will be minimized by proper surface preparation. Formulation is a major factor in the exterior performance of a paint. Thickener level, solids content and pigment volume content can all affect the wicking and drying rates of a system, as well as its water sensitivity. Paints with low pigment volume content, high solids and low thickener content insure maximum performance. With proper surface preparation, however, all of the appropriate suggested starting formulations will provide a high degree of satisfactory performance. The best procedure for preparing the surface consists of a thorough washing with plain water, rinsing and applying the emulsion paint while the surface is still damp. Any exposed nailheads should be treated before painting as described earlier. Unsound Surfaces In this category are those previously painted surfaces which show signs of inadequate adhe sion such as cracking, flaking, peeling, lifting or blistering. The only method of preventing a con tinuation of these failures is the removal of the poorly adhering coating to obtain a sound surface. Photo A in Figure 2 shows a weathered oilpainted surface with some cracking and peeling. However, considerably more of the paint is already loose and, when scraped, can readily be removed from the surface. The condition after dry scraping is shown in photo B. These photo graphs illustrate the need for careful surface preparation to avoid subsequent adhesion fail ures after the surfaces have been repainted. Reoccurrence of failure due to a poorly adher ing paint film can be minimized through applica tion of the more highly pigmented emulsion paint systems. These coatings relieve localized stresses because of their reduced film continuity and flexibility, since less binder is present. Oilbased paint films which are readily oxidized and become brittle are subject to fine cracking and checking. With oil paints the poorly adhering layer will continue to loosen, crack and flake, and re-establishment of a good sound surface will be a difficult and tedious job. 4 GLDO057O2  Wb Although scraping is recommended, it is real ized that complete removal by this method is not always easily accomplished. Quite possibly the old paint not removed may continue to show a loss of adhesion, regardless of the paint used for recoating. The time involved for the appearance of this additional failure is usually several years, and spot patching of these areas, should they appear, is commonly employed. As sound a surface as possible should be re established, including the puttying or priming of exposed nailheads as described previously. If the surface is bare wood, one of the suggested Rhoplex AC-34 bare-wood primers should be used, followed by a suitable topcoat system. Mildew Surfaces with mildew growth should first be washed thoroughly with Clorox or an equivalent product at a concentration of one pint per gallon of water, then rinsed by hosing with clear water. The substrate is then considered a sound repaint surface and is treated as described earlier. Knots Knots in a substrate are a problem for two rea sons: U) they may become loose and cause paint film rupture, and (2) they contain high concen trations of tannins which stain the paint. Nothing short of removal of the knot can guar antee no loosening. Shellacking tends to contain the tannins and prevent staining if the knot does not move and break the shellac film. Previously Painted Masonry and Cement Asbestos Shingles Sound Repaint Masonry Surjaces These substrates should be treated in the same manner as sound surfaces on previously painted wood. In addition, the lower cost, 55-percent pigment volume content Formulation 309 may be used over these dimensionally stable surfaces. The excellent results; possible when sound masonry surfaces are repainted with Rhoplexbased paints are illustrated by the house front pictured in Figure 3. Fig u r e 3. Excellent adhesion and color retention are shown on sound repaint masonry surface in this six-year exposure. Fig u r e 4. Rhoplex paint over cement paint which had been surface-conditioned by coat of clear Rboplex emulsion. This photo was made eight years after painting. However, sandblasting would have been a safer method of preparation. Cementitious Coatings This group includes the lime, whitewash and socalled artificial or synthetic chalks. In general, these surfaces are dangerous to repaint since they continue to disintegrate or deteriorate under the new paint. This results in poor adhesion with the passing of time even if apparently good adhesion is obtained initially. Satisfactory serv ice with Rhoplex AC-34 systems is often obtained over these surfaces, as may be seen in Figure 4. However, the incidence of problems and paint failures associated with these chalks is high. 7 GLD005705 These chalks sometimes contain materials which are not efficiently wetted by water, leading to loosely bound aggregates which crumble or lose adhesion readily. The water demands of such porous surfaces are very high and lead to exces sive wicking and premature drying of the paint film on the surface. Predarapening the surface and/or diluting the first coat of paint often helps penetration and performance. There is no foolproof method of repainting heavily chalking cement surfaces, and they must be removed by sandblasting to obtain a nondisintegrating substrate. Aged Cement Asbestos Surfaces If the original coating is intact, the cement asbestos surface may be treated as a sound repaint surface. If the shingle or board itself has begun to dis integrate, exposing fibrous material, but is still in fair condition, a problem similar to that de scribed under Cementitious Coatings may exist. Predampening the surface or diluting the first paint coat with water often yields satisfactory performance. For a high degree of degradation, those prob lems associated with cement coatings are present, and there is no foolproof method of preventing continuing failure. Best performance under these circumstances is achieved through the penetra tion and binding of the substrate with a surface conditioner prior to application of the topcoat paint. When the above substrates have been properly prepared, all of the suggested formulations will provide a high degree of good performance. Because of the relative dimensional stability of cement asbestos surfaces, the lower cost, 50- and 55-percent pigment volume content Formulations 308 and 309 may be of special interest. Unpainted Substrates Wood Wood has a number of characteristics which are potentially detrimental to the performance of a paint applied to it. For example, the dimensions of wood vary with its moisture content. The degree of this fluctuation is not uniform across a board; consequently, for long-term satisfactory performance, any coating applied to wood must be sufficiently flexible to withstand dimensional fluctuation without rupturing or losing adhesion. In addition to picking up moisture, the struc ture of most woods is such that moisture is readily transmitted through the panel. This property is of special significance in cold weather, when the temperature gradient from the interior of a house to the outside surfaces provides a driving force for moisture trans mission. The result of this phenomenon is a tendency for blister formation, which has been a serious problem with oil paints. A desirable property in a paint, therefore, is adhesion to the substrate under wet conditions. Many types of wood contain extractable color bodies, saps, tannins, rosin, etc., which can adversely affect their cos.tability and the appear ance of the paint system. Of all the vehicles used in exterior coatings, regardless of type, Rhoplex AC-34 contains the best balance of properties necessary for maxi mum performance in the presence of these prob lem conditions. Its all-acrylic backbone insures long-term durability and retention of flexibility. Its outstanding wet adhesion and blister resist ance have made it the standard for the paint industry. Exposures of up to 11 years' duration of paints based on the Rhoplex emulsions dramatically illustrate the outstanding general durability and retention of elasticity of acrylic polymers. Seven years of exposure experience with Rhoplex AC-34 have confirmed its superior durability, resistance to grain cracking, flaking and blistering and wet adhesion over oleoresinous and wood substrates. A stain-resistant primer, Formulation 305, has been developed for cedar and redwood. These woods are relatively dimensionally stable and do not require coatings with the degree of graincrack resistance necessary for white or yellow pine. Although until recently acrylic primer formu lations have not been purposely developed for nonstaining types of bare wood, all published Rhoplex AC-34 exterior systems have been rou tinely tested on such surfaces. The results have been so outstanding we do not hesitate to recom mend application of Rhoplex AC-34 primers to 8 61.0005706 new or bare wood. Formulation 304, with which we have considerable experience including over four years' south 45 exposure on southern yel low pine, has been adopted as a suggested start ing primer for nonstaining woods. Typical test panels from this exposure series are pictured in Figures 5 and 6. Note that none of the Rhoplcx AC-34 self-primed panels shows any grain cracking or flaking. Formulation 303 has been designed specifically for bare wood surfaces. However, exterior expo sure experience with this new formulation is limited. Although primers of this type have been tested with only one topcoat, for ultimate performance two should be applied. The topcoat formulation should be selected on the basis of the nature of the wood and the desired performance. The greater the cracking forces in the wood and the longer the desired durability, the higher should be the level of free binder in the formulation. In general, two coats of any of the published suggested starting formulations (except Formula tion 309, recommended for masonry only) will give excellent service. Using Rhoplex AC-34 paints from priming the bare wood to applying topcoats takes fullest advantage of the blister resistance, grain-crack resistance and durability of this acrylic vehicle. In addition, such a system provides a sound repaint surface which will retain good adhesion and avoid the failures described under Unsound Surfaces. The use of basic silicate of white lead, as in Formulation 305, minimizes stain-through when cedar and redwood arc painted. The primer will discolor, but this is not normally transmitted to the topcoat. Occasionally, boards may be en countered which are very oily. These may re quire two coats of primer to completely seal off all the stain bodies. If water flows down the unpainted back of a staining-type wood panel and then over a leadcontaining coat, a relatively long-lasting dis coloration may occur. Therefore, a topcoat with out lead content is recommended. It is extremely important to use the proper dispersant and to test carefully the stability of lead-containing paints. Masonry This category includes previously unpainted con crete, stucco, cement asbestos siding and cinderblock. The main problems encountered with these substrates are related to their alkalinity, porosity or water demand and their surface texture. Acrylic emulsions are not subject to the hydrolysis or saponification which occurs with most other vehicles. It is essential, for the rea sons previously discussed, to satisfy the water demand of these substrates. Highly porous cinderblock may often require a fill coat to seal and smooth the surface. Generally, two coats of any of the suggested topcoat formulations are sufficient for highly durable performance. Galvanized Surfaces Galvanized steel is one of the increasing variety of substrates which have been coated success fully with Rhoplex AC-34 house paints. Most newr galvanized metal is given a surface treatment to prevent "white rust". Although ex perience indicates it is not always necessary, in order to insure maximum paint adhesion this coating should be removed before painting. Sometimes wiping with mineral spirits is helpful. An alternative is exterior aging of the galvanized metal for at least 6 months. Acrylic emulsion paints retain a very high percentage of their original flexibility for ex tended periods of time. Therefore, they will expand and contract with the metal as tempera ture changes. Oleoresinous coatings dry by oxi dation and become brittle with time; therefore, they cannot flex with the metal and experience early cracking and flaking. Application of Rhoplex AC-34 paints to the bare metal is essen tial for best results. No special formulations have been developed for this surface, but 30- to 40-percent pigment volume content house paints have been utilized with very satisfactory results. Present experience on galvanized metal with paints having a pigment volume content higher than 40 percent is limited. Although the flexibil ity of a paint film will be somewhat reduced as pigment volume content is increased, these sys tems show enough promise to encourage manu facturers to test them. 9 CLDo o 5?07 Fig u r e 5. Four-year south 45` exposure of Rhoplex AC-34 T pamt, seif-primed, on yellow pine. Note the 'usistance to gram cracktng of Rhoplex AC-34 on right compared to paints made with Rhoplex AC-33 on left. Fig u r e 6. Rhoplex AC-34 paint on left versus solubilized linseed oil emulsion paint on right after two years' self 's^ primed south 45 ` exposure on yellow pine. Note the excel lent whiteness and resistance to grain cracking of the Rhoplex AC-34 paint. Rhoplex AC-34 Paint Fornmlation Dispersion, Pigmentation and Colorants Hiding, stability, chalk resistance, tint retention, in fact all phases of performance of a paint, are dependent upon the quality of the pigment dis persion. Although pigment dispersion may be good initially, uniformity of the dispersion may decrease with age if it is not properly prepared. A high percentage of the complaints concerning poor performance of a paint can be attributed to lack of good pigment dispersion stability. For this reason, accelerated stability tests such as freeze-thaw, heat stability, color rub-ups and lap tests are of extreme importance in assessing the long-term quality of a paint. Any ingredient used m the preparation of a paint can affect its stability and performance characteristics. It is for this reason that the effect of every ingredient substitution or addition should be assessed separately. Concentration-Aggregation Test Each prime pigment and extende" requires a certain amount of material to disperse it prop erly. The amount of dispersant required for each pigment or extender varies widely depending on the grade, type and manufacturer. In addition, the presence of too much or too little dispersant will be detrimental to tiie stability of pigment dispersions. Our laboratory has devised a titration method for determining the maximum dispersant require ment of any pigment or extender, or of combina tions of pigments and extenders. In this method, 50 grams of pigments or ex tenders is mixed with sufficient water so that a stiff, slightly moist mass forms. The dispersing agent, in water solution, is then added in small increments with thorough mixing. When the pig ment mass becomes fluid enough sc that surface ripples disappear on gentle shaking of the con tainer, the pigment is deflocculated. A small portion of the pigment system (about 1 cc.) is then removed and placed in a watch glass. To this small portion an ionic thickener is added. A suitable thickener is Acrysol GS. The quantity added is not critical, but in our work from 2 to 3 drops of Acrysol GS reduced with water to 6-percent solids was used. This quantity of ionic additive is sufficient to cause severe flocculation or even gelation of the pig mented system if the amount of dispersant used was insufficient. Additional dispersant should then be added to the main dispersion and another small portion tested in the same fashion. Test results using a variety of pigments in this method are shown in Table I. The dispersant demand percentages in Table I constitute a change from values listed in previ ous Progress Reports. This is due to the adop tion of an improved method of translating the results of the concentration-aggregation test to use in practice. The titrating solution was at 10-percent solids and contains Tamol 731 and Triton CF-10 at a solids weight ratio of 1:1. In the past, the pub lished percent dispersant solids value reflected the total 6olids used (i.e., Tamol 731 and Triton CF-10). Now, in order to simplify the use of the method, the assumption is made that Triton CF-10 has no activity as a pigment dis persant. The values in Table I reflect only the percent of Tamol 731 solids required by each pigment. As previously noted, the values in Table I constitute maximum dispersant requirements. In practice, it has been found that good dispersion may be achieved with lower quantities. In white paints, about 62 to 70 percent of the theoretical total dispersant requirement is needed. In tint bases, the percentage is often higher (up to about 80 percent) to promote better acceptance and development of colorants. GL0005709 11 TABLE ! Dispersant Demands of a Number of Pigments and Extenders for Tamol 731 (25%) Pigment (50 gm.) Amount of Water Added (ce.) Barytes #1 Calcium Carbonate Atomite Duramite Purecal 0 Snowflake Suspenso Whiting Clay (ASP-400) 325 Mica Silica Silver Bond B 1160 Talc Asbestine 3X Nytal 300 Rutile Titanium Dioxide Ti-Pure R-610 Titanox RANC Ti-Pure R-901 Ti-Pure R-902 Anatase Titanium Dioxide Ti-Pure FF Titanox A-168LO Zinc Oxide Kadox 515 AZO-ZZZ-ll Iron Oxide Kroma Red (RO-8097) Red (R-2899) Brown (Hoover #7565) Yellow (YL0-4088) Germantown Lamp Black Nickel Titanate (Sun Yellow C) 8 18 18 38 14 17 26 32 15 17.5 27 30 24 23 21 20 32 35 45 40 17 30 36 35 112 24 Dispersant Solution1 Required for Dispersion in the Presence of Acrysof GS (cc.) 2.4 Percent of Tamol 731 Solids Based on Dry Pigment 0.24 3.0 0.2 3.0 2.0 1.8 10.0 9.0 7 0.30 0.02 0.30 0.20 0.18 1.00 0.90 4.5 0.45 2.8 0.28 5.5 6.5 0.55 0.65 12.0 15.0 24.2 25.7 1.20 1.50 2.42 2.57 24.0 18.5 2.40 1.85 12.5 1.25 15.8 1.58 3.8 4.1 9.6 10.2 21.3 0.38 0.41 0.96 1.02 2.13 2.2 ' 0.22 ' A 1:1 solids mixture of Tamol 731 (25%) and Triton CF-10 at 10% total solids in water.; 12 GLD005710 For example, the pigmentation of Formulation 306 is as follows: Material Unit Tamol 731 Dispersant Solids Demand, Required, Pounds % Pounds Ti-Pure R-610 240 1.2 Ti-Pure FF 10 2.4 Asbestine 3X 100 0.6 Snowflake calcium carbonate 110 0.2 Total Concentration-Aggregation level (Tamol 731 solids) Tamol 731 (25%) required at Concentration-Aggregation level Tamol 731 (25%) used in F-306 (68.6%) 2.88 0.24 0.60 0.22 3.94 lb. 15.761b. 10.7 lb. A wetting agent is required to realize maxi mum dispersant efficiency. The level of Triton CF-10 used in a paint formula will be determined by consideration of the specific pig mentation, as well as the brushing and drying characteristics of the paint. In order to minimize the water sensitivity of the paint film, excessive quantities of wetting agent should be avoided. In practice, between L and 3 pounds of Triton CF-10 per 100 gallons of paint is sufficient, with 1.5 to 2.5 pounds per 100 gallons being the amount normally used. Tamol 731 (25 percent) is normally the dis persant chosen because of its excellent perform ance and high efficiency with a wide range of pigments and extenders. Triton CF-10 exhibits efficient wetting characteristics coupled with low foaming characteristics. Reactive Pigments For those instances when a reactive pigment such as basic lead silicate or zinc oxide is in corporated, Tamol 850 (30 percent) has demon strated superior performance as the dispersant, imparting improved stability to such a system. The dispersant demands of a number of pig ments for Tamol 850 are listed in Table II. Because of its limited use in Rhoplex paints, no specific percentage limits of the theoretical levels have been determined. Tamol 850 (30 percent) is relatively poor for dispersion of organic pigments. Incorporation of Colorants Water-Dispersed Colorants These are designed for use in emulsion paint systems and generally give no problems in color acceptance and color development. Universal Colorants Colorants of this type are designed to be in corporated into both water-thinned and oleoresinous coating systems. Because of this, they generally leave something to be desired in per formance with either system and special formu lation techniques are needed. California Ink 8800 and the Rockcote 7600 line of colorants, how ever, have given particularly good results with paints based on Rhoplex AC-34 and should be considered if color problems are encountered. A combination of morpholine and soya fatty acids (MSFA) has been useful in improving the performance of most universal colorants with Rhoplex paint formulations. The levels and techniques involved in using morpholine and soya fatty acids are somewhat different from those for Tamol 731 (25 percent). Determination of dispersant demand values with morpholine and soya fatty acids has been complicated by the inability of the ionic thick ener to wet and thus flocculate the dispersion. Empirical methods for arriving at a proper dis persant content have, therefore, been employed. Early work with Formulation 247 at 35-percent pigment volume content indicated that between 12 and 22 pounds of morpholine and soya fatty acids per 100 gallons yields a universal tint base having excellent shelf, heat and freeze-thaw stabilities. The precise level of morpholine and soya fatty acids used in a specific case is nor mally dictated by the behavior of a given uni versal colorant line in color acceptance and development. GU>00571T 13 TABLE II Dispersant Demands of a Number of Pigments and Extenders for Tamol 850 (80%) Method: The basic method described on page 11 was employed. Best results were obtained by adding 4 drops of 5% aqueous Triton X-102 (wetting agent} just after the initial water, and titrating with 5% aqueous Tamol 850. Pigment (50 gm.) Amount of Water Added (cc.) Dispersant Solution1 Required for Dispersion In the Presence of Acrysol GS (cc.)* Percent of Tamol 850 Solids Based on Dry Pigment Basic Lead Silicate EP-202 Oncor 45X 26 20 4.1 0.41 0.3 0.03 Calcium Carbonate Atomite Pureca! 0 Snowflake Suspenso Whiting 17 36 15 17 2.6 ; 2.9 1.0 1.5 0.26 0.29 0.10 0.15 325 Mica 64 4.4 ? 0.44 Silica Silver Bond B 1160 20 25 0.4 0.04 03 0.03 Talc Nytal 300 42 2.7 0.27 Rutile Titanium Dioxide ' Ti-Pure R-610 Titanox RANC Ti-Pure R-901 Ti-Pure R-902 24 23 23 22 6.1 5.1' 10.2 11.7 0.61 0.51 1.02 1.17 Anatase Titanium Dioxide Ti-Pure FF Titanox A-168L0 36 35 5.3 0.53 33 0.33 Zinc Oxide Kadox 515 45 5.9 0.59 AZO-ZZZ-11 45 1.5 0.15 1 Tamol 850 at 5% total solids m water. 5 This is a maximum. Lower quantities are used in practice. 14 GLD005712 During the course of cur work with universal colorants, several other pertinent observations were made: 1. For complete neutralization of soya fatty acids with morpholine, a fatty acids-morpholine ratio of 70 parts to 80 parts by weight is sufficient. For best results, the temperature of this exothermic reaction should be maintained below 105F. 2. For additional improvement of the ac ceptance and development of some universal colorants, the use of extra morpholine (up to 50 percent by weight of the MSFA em ployed) has proved helpful. This morpho line may be incorporated into the MSFA during its preparation. 3. As an aid in minimizing the viscosity drop often encountered when using high levels of certain colorants, incorporation of up to a maximum of 6 pounds of Acrysol G-I10 (22 percent) per 100 gallons of paint is suggested. 4. As the pigment volume content of a uni versal tint base is increased, the minimum MSFA level must also be increased slightly (by about 1 to 2 pounds per 100 gallons for each 5-pereent pigment volume content increase). 5. As the titanium dioxide level of the tint base is reduced, the range of MSFA used should be decreased proportionally, holding the formulation constant in all other respects. 6. Another method of obtaining a pre liminary starting weight of MSFA is to determine the proper Tamol 731 solids level according to the procedures described above, then use approximately 4.25 to 5.25 times this value. The precise level should be adjusted to obtain satisfactory tint base stability and color development. It is still desirable to add the excess morpholine men tioned above. 7. Although much higher levels of predis persed colorants are often used in practice, a maximum of 4 fluid ounces per gallon is recommended for optimum performance and durability. A more desirable method of producing deeper colors is to reduce the titanium dioxide level; this both improves durability and reduces costs. Pigment-Binder Relationships Every pigment or combination of pigments re quires a specific amount of vehicle to cement all the particles and to form a continuum of binder. This fixed value is known as the system's binder demand. The performance of a paint film (i.e., its tint retention, chalk resistance, dirt pickup and grain-crack resistance) depends on the actual level of binder used relative to the sys tem's binder demand. This can be most accu rately determined by actual service tests. Pig ment volume content is not a measure of this binder to pigment relationship because it consid ers only total volume of pigment and does not take into account the number of pigment parti cles, their shape, surface characteristics or sur face area. The difference in performance between large and small particle size extenders, at constant pigment volume content, has been recognized for years. Yet, even average size can be mis leading since it does not take into account the number of particles, their shape or the magni tude of the particle size distribution curve. For example, at constant pigment volume content the level of titanium dioxide, solids level, and type and size of the extenders can all signifi cantly affect the performance characteristics of a paint. Titanium Dioxide Titanium dioxide has the greatest binder demand of the more eommonly employed pigments. The higher the level of titanium dioxide, the more binder (via lower pigment volume content and/or higher solids) is required to maintain resistance to chalking, erosion and fading and promote gen eral durability. The types and levels of titanium dioxide used in the published formulations are based on exposure experience with the chalkresistant sulfate grades such as Ti-Pure R-610, Titanox RANC and Unitane OR-640, and freechalking anatases such as Ti-Pure FF and Titanox A-MO. Substitution with other grades should be made in accordance with the recom mendations of their manufacturers. 15 GLOOO*113 Extenders Every extender has some characteristics, physi cal or chemical, which make it unique. There are chemical differences between calcium carbonates, clays, taics and zinc oxides. Each one of these classes will impart different performance proper ties to a given paint. Also, the physical charac teristics of the various types as well as the physical variations within a class can produce significant performance differences in a given paint. As mentioned previously, the binder demand of an extender is related to its shape and the number of particles per unit of volume. Average particle size does not take these factors or par ticle size distribution into account. For this reason, extenders should be thoroughly evaluated and not substituted arbitrarily in a paint for mula. This is true despite the fact that their published physical constants may be similar. In general, extenders with broad particle size dis tributions will have higher binder demands than those with narrow distributions, especially when their average sizes are similar. This is why narrow particle size distribution calcium carbon ate is recommended for tint bases. Its low binder demand promotes maximum chalk resistance and tint retention. Talcs, with their wider size dis tributions, are often used in whites to obtain brighter whiteness, cleanliness and ease of chalking. Solids Content At constant titanium dioxide content, reducing solids involves reducing extender and binder. This significantly lowers the binder level relative to the binder demand of the pigmentation and results in less chalk resistance or ultimate dura bility. The thickness of the dry paint film depends on the solids content. Film thickness is impor tant for maximum durability, especially over dimensionally unstable substrates. Additives Antifoamers These materials are necessary to minimize the formation of foam during manufacture and to prevent foaming during application. Any good commercial material can be used, but levels should be checked to determine the quantity necessary for good protection with freedom from "fish eyes". To achieve this it has been found most efficient to split the antifoamer, half in the grind, and half in the letdown. When incor porating the final aliquot, moderate agitation should be used. The formation of a vortex should be avoided. In the absence of good stir ring, or sometimes even with it, "fish eyes" may be temporarily present at the necessary level of antifoamer. If present after ample time for the finished paint to have equilibrated (approxi mately 24 hours), "fish eyes" are indicative of excess antifoamer concentration. Preservatives A preservative is required in a paint to give protection from microbiological growth both in the can and on the final paint film. The level of preservative is determined by the particular vehicle, substrate, geographical location and exposure location. Phenyl mercury compounds are the most commonly used preservatives. Acrylic emulsion house paints have been found to be inherently resistant to microbiological growth, but a film preservative is invariably used. Higher levels than those required for can stability are needed for painting over substrates which are either already innoculated with mil dew or constitute a nutritional surface because of the presence of oleoresinous materials. In partially protected areas where excessive surface dirt can accumulate, the presence of a preserva tive in the acrylic emulsion paint film serves to retard or eliminate the growth of mildew. The type, level and method of incorporation of the preservative are important, since these factors can influence the stability and ultimate performance of the finished product. Preserva tives which are relatively water soluble are detri mental. Such materials tend to wash out of the paint film with time. Solubilized grades of mercurial preservatives also exhibit a tendency to react with other ingredients in the paint, such as the dispersant. Reaction between these two ingredients effec tively reduces both the dispersant and fungicide concentrations, causing pigment flocculation and reduced microbiological resistance. When these solubilized types are incorporated in the let- 16 etD05 7U Fig u r e 7. Rhoplex AC-34 paints exhibit excellent resistance to saponification by alkali in masonry surfaces and cement asbestos shingles. Rhoplex AC-34 paints on left show no change, whereas polyvinyl acetate copolymer paints saponify. down, this reaction may be minimized; however, this method introduces the danger of local shock. The solid grades of mercurials are preferred because they are relatively water insoluble, are easily incorporated in the grind and have little effect on paint stability. Occasionally, the rheo logical properties of the grinding paste will be altered by the presence of the solid preservative. If found to be undesirable this may be overcome by either cooling or diluting the paste. This does not affect the final paint constants or perform ance. Levels of solid grades used vary from 0.1 to 1.5 pounds of mercury metal per 100 gallons of paint, but the amount most commonly em ployed is 1.1 to 1.2 pounds. Both 100-percent phenyl mercuric propionate and 100-percent phenyl mercuric acetate have given good results. Most mercury compounds are very sensitive to hydrogen sulfide originating in such sources as salt-water marshes, papermill operations and coke furnaces. Reaction of the mercury with hydrogen sulfide may produce black or brown discoloration of the paint film. The solid grades of the material seem to be significantly more resistant to discoloration than solubilized types. In locations where hydrogen sulfide concentra tions are high, the only practical solution is to omit mercury from the formulation. A number of other materials have been proposed to replace mercury as a film preservative, but none of those tested to date has been effective in controlling mildew. Thickeners In order to achieve a desirable paint consistency which will prevent pigment settling, avoid drip ping and assist in applying proper film thick nesses, it is necessary to pigment at relatively high solids, use high-water-demand extenders or incorporate thickening agents. <SLD005?15 !' GLD005716 The most common thickeners are the cellulosics. The presence of these materials will increase the paint's water sensitivity, detract from its flow properties and will sometimes adversely affect dispersion and application prop erties. For this reason, the preferred method of attaining the desired consistency is through increased solids. Increasing the solids improves film build and overall durability and perform ance. The published topcoat formulations are of the order of 40-percent solids by volume. The maximum level of dry eellulosic thickener which should be employed in Rhoplex AC-34 paints will vary depending on the formulation constants, but generally should not exceed about 3.5 founds per 100 gallons of paint. For ultimate performance and wet adhesion, minimum quanti ties should be used. Those interested in maximum durability and those investigating one-coat systems can and should test higher solids levels. However, very satisfactory performance, especially over dimen sionally stable substrates, can be achieved at much lower volume solids content. The mini mum will vary depending on such factors as pig ment volume content and type of pigmentation. Formulations below 38-percent volume solids should be tested carefully for durability before manufacturing. The thickener grades suggested for use in the published formulations are the easily wettable types such as QP grades of hydroxyetbyl cellu lose. Other grades or types usually give satis factory durability if reasonable levels are used and if such factors as dispersion are not affected. It is important that these materials be used or incorporated in accordance with their manufac turer's recommendations. Coalescents Coalcscents are helpful in obtaining good film formation under borderline application condi tions. In addition to low temperatures this includes high winds or other conditions leading to premature drying. Coalescents are particularly useful at higher pigment volume contents. To avoid local shock leading to flocculation or coagulation, the coalcscent should be prediluted and added slowly with good agitation. This is particularly important when the coalescent is incorporated during the letdown operation. Formulations 303 and 313 contain 3 pounds of pine oil per 100 gallons of paint. Test work has shown that considerable improvement in film formation without a noticeable reduction of paint stability properties is achieved by the presence of this material. Somewhat higher levels may be desirable for best results under poorer conditions of paint application. In many cases, these higher levels may reduce freeze-thaw resistance. The optimum concentration wiU depend on the desired, minimum film-forming temperature and stability requirements. Other materials such as tributyl phosphate and glycol ethers are often used as coalescents in Rhoplex AC-34 house paints. Hydrolyzable esters or highly soluble materials will adversely affect shelf stability, and should be avoided. The quantity of coalescent which may be incorporated into paint without loss of stability properties can vary with the specific formula tion being considered. Thus, determination of a satisfactory coalescent level becomes a matter of trial and error. To determine this level, a range of concentrations of the coalescent are postadded to samples of the paint. These paints are tested for freeze-thaw and heat stabilities until the range yielding the desired degree of performance is found. More thorough evaluation of paint containing this level of coalescent should then be conducted. Oleoresinous Modification Numerous house and panel exposures clearly indicate that good performance can often be attained with unmodified Rhoplex AC-34 paints over natural-chalking oil house paints. This is definitely true if a reasonable degree of surface preparation is undertaken. However, emulsions do not penetrate chalk as well as solution bind ers. This fact can readily be demonstrated in laboratory tests, but is not as apparent in actual practice. Many manufacturers using Rhoplex AC-34 are successfully producing complaint-free unmodified paints. Others feel it is necessary to modify with an oleoresinous material to obtain a sufficient degree of safety over chalk. The advantages of modification include better penetration of chalk and the ability to formulate higher solids paints. The disadvantages or properties which require special attention are: increased chalking and loss of tint retention, GL0005717 19 increased susceptibility to dirt pickup and mil dew, decreased stability (especially with extreme heat and cold) which results in loss of penetra tion and decreased blister resistance. If modification is considered, to retain the inherently good durability and blister resistance of the Rhoplex AC-34 system no more than 25 percent of the Rhoplex AC-34 binder should be replaced. The weight per gallon of the dry poly mer in Rhoplex AC-34 is 9.5 pounds. This value will be useful in calculations involving the sub stitution of oleoresinous binder for part of the Rhoplex AC-34 in a formulation. Formulation 204 was originally designed as an additive for Rhoplex AC-33. This system is typical of the wide variety of materials available for use in oleoresinous modification, and con stitutes a satisfactory starting point for initiat ing such tests. To use this formulation as a modifier, an equivalent volume of emulsion solids should be removed. The solids of Formulation 204 are 57 percent by weight to achieve optimum penetration. Using modifiers with higher solids will tend to increase film build, but will also decrease the degree of penetration. In many cases the oleoresinous material can readily be added in the binder letdown step without any special treatment. If pre-emulsifi cation is desired, materials such as Triton N-10I or a mixture of equal parts of Triton X-114 and Triton X-100 can be used. It is also important to add extra preservative when using oleoresinous materials. Other Additives Ethylene Glycol The primary function of ethylene glycol is to improve the freeze-thaw resistance and wet-edge characteristics of a paint. The importance of the latter is not always fully appreciated. The sig nificance of excessive wicking and premature drying has been discussed earlier. Ethylene glycol has a moderating effect on these actions and tends to improve penetration, adhesion and film coalescence. Some caution should be exer cised in using excessive levels (over 30 pounds per 100 gallons of paint) as this will introduce some early water sensitivity. Ammonium Hydroxide In order to obtain maximum stability with the published topcoat formulations it is usually nec essary to adjust the pH to 9.4 to 9.7. Although use of a pH meter is preferred, approximate determinations may be made with pH indicator paper. These values will usually drop to about 9.2 to 9.5 with time or accelerated testing but should not, under normal circumstances, fall below these levels. Standard Control and Laboratory Testing Procedures In the development of new formulations it is necessary to be able to assess those properties which are essential in a satisfactory exterior emulsion paint. Many of these evaluating pro cedures may also be useful as production control tests. Details of the following methods used in our laboratories are available upon request: Paint Constants Viscosity: modified Stormer at200r.p.m. pH Weight per gallon Luminous reflectance and contrast ratio Performance Properties Color acceptance and development: rub-up and lap tests before and after artificial aging. Wet adhesion: adhesion to gloss enam els utilizing a Gardner scrub machine. Blister resistance: blister box with vapor temperature at 140 F. Minimum paint film formation tem perature Accelerated Stability Heat: Vfc- or 1-pint samples held at 140 F. for 100 hours to 1 week. Freeze-thaw: Vfc- or 1-pint samples held at --5 to 15 C. for 16 hours and room temperature for 6 to 8 hours per cycle. Three to five cycles are normally required. 20 GLD005718 Suggested Formulations ior Exterior Testing The following suggested formulations for Rhoplex AC-34 are not tailormade for the individual paint manufacturer. They do, how ever, constitute examples of Rhoplex AC-34 paints which will yield highly satisfactory per formance. These formulations embody the latest formulation principles for Rhoplex AC-34 and are designed to exhibit a good general balance of cost and performance. A summary list of the formulations is provided in Table HI. The formulations and raw materials used should be checked closely during initial testing and exposure in order to furnish a sound basis for any desired modification. Comparable raw materials from other suppliers should give equally satisfactory performance in these sys tems; however, slightly different dispersant levels may be required when pigment grades which ex hibit different dispersant requirements are used. A list of raw materials appears at the end of this section in Table IV. Where several grades of a particular ingredient are listed, the grade listed first is the one employed in our work on the suggested formulations. GLD005719 21 TABLE III Summary Table of Formulations See pages 23 to 28 for formulation details. Formulation Pigment Volume Content, % Solids Volume, % 303 Highest Quality Primer for Bare Wood 29.8 44.7 Solids Weight, 58.2 Approximate Raw Material Cost per Gallon^ $1.72 304 High-Quality Primer for Bare Wood 34.7 42.2 57.4 $1.68 305 High-Quality Primer for Staining Wood 306 High-Quality White Topcoat 34.7 38.1 . . 56.6 $1,84 '/Y . 39,7 40.9 58.2 $1.79 307 Lower Titanium Dioxide Content White Topcoat 308 White Topcoat for Sound Repaint Surfaces 44.7 49.8 38.5 38.5 56.3 .-Hv . Y*V* 56.9 . $1.54 $1.41 309 White Topcoat for Repaint of Masonry 54.8 40.0 59.3 $1.37 310 Light Tint Base 39.8 41.8 58.0 ___ $1.58______ 311 Light Universal Tint Base 40.0 40.0 V 56.3 $1.60 312 Medium Tint Base 45.0 40.0 56.4 $1.28 313 Medium Universal Tint Base 45.0 40.0 56* $1.33 204 Additive and Surface -- 51.8 , 56.7, Conditioner December 1964 3 22 Y ' ' :Y 3 GLD005720 -'V. Formulation 303 Highest Quality Primer for Bare Wood based on Rhoplex AC-34 Material Pounds Gallons Tamo! 731 (25%) ............................................... Triton X-102....................................................... Antifoamer........................................................... Ethylene glycol................................................... Pine oil................................................................ Hvdroxyothy! cellulose (2.5% solution) ...... Preservative............................................. .......... Rutile titanium dioxide....................................... .... Calcium carbonate ............................................. .... Crystalline silica................................................. 7.0 1.0 25.0 77.2 1.8 150.0 153.2 50.0 0.76 0.22 0.13 2.69 0.33 9.41 0.11 4.29 6.79 2.27 Grind the above in a high-speed mill (Cowles, S800-4500 feet per minute for 10-15 minutes) Letdown: Rhoplex AC-34 (46%)....................................... .... Antifoamcr.......................................................... Ammonium hydroxide (28%) ......................... Pigment volume content.................... .... 649.8 1.0 2.0 1123.0 29.8% 73.01 0.13 0.27 100.41 Volume ....................... ........... pH ....................................................... Viscosity range ......................... ......... Approximate raw material cost--$1.72/gallon 9.4-9.7 Formulation 304 High-Quality Primer for Bare Wood based on Rhoplex AC-34 Material Pounds Gallons Water .......................................................................... 30.0 3.60 Tamol 731 (25%) ....................................................... 8.6 0.93 Triton CP-10............................................................. 2.6 0.28 Antifoamcr....................................... .......................... 1.0 0.13 Ethylene glycol.................................................. 20.0 2.15 Pine oil ...................................................................... 3.0 0.33 Preservative.......................................................... .. 1.8 0.11 Hydroxyethvl cellulose (2.5% solution).................. 100.0 12.19 i. Rutile titanium dioxide............................................... 171.0 4.89 Calcium carbonate ..................................................... 186.5 8.26 Water-ground mica................................. .................. 30.0 1.28 Grind the above in a high-speed mill (Cowles, 3800-4500 feet per minute for 4 10-15 minutes) t \ Letdown: Rhoplex AC-34 (46%)............................................... 561.6 63.10 \ Water.............................................................. .. 7.2 0.87 \ Antifoamcr.................................................................. 1.0 0.13 t Ammonium hydroxide (28%) ................................. 1.0 0.14 j 1125.2 98.39 l Pigment volume content............................ 34.7% v Solids: Weight ...................... ............ ... 57.4% l Volume.......................................... 42.2% j> oH ........................................................ . 9.4-9.7 .. }. Viscosity range ......................!Y....;. 75-81 Krebs units . Approximate raw material cost--$1.68/gallon >. .. i v ' > GLD005721 .23  rV'kC Formulation 3071 Lower Ti^niurri.DioxiM&^iemtWHi^b^dl:.base&jon Pounds Gallons Ethylene glycol-'r.t.;;-.. ..,,,' 20.0: ' 1 -V: 2.15 . Pine oil i-i';'-/-v:-i-s i'.V,':;** 0^3 - Preservative .. .-. .V^'.'v;;'.-.7.'.'V^A^'t.^v.av.V. ,, ' .- -r 1.8 vK//>:..-\ 0.11 Hydroxyethyl cellulose (2.57o'solution):,:' 140.0 : ' ..'*.. y.17.07 [ Rutile titanium dioxide....... . -,._ 190.0 vV. V-; 5.43 \ Anatase titanium dioxide.'..7.v^S'A'^iVH- 10.0 '-7->: .0.31 i TTnallnc ''.* '-'' X m10n0.n0 "v- 'V 44..9211: Calcium carbonate 164.1 7.27 > Grind the above in a high-speed null (Cowles, 8800-4600 feet per minute for [ 10~16 minutes) j Letdown: -;7 y c *v' Rhoplcx AC-34 (46%)'... ..'.:;........................... .. Antifoamer....................................... . 440.2 , 1.0 . 49.46 0.13 \ 38.5%? pH :..94-9.7 -V'-'y ' ' ' - Viscosity range: ;':\ V:`.\'^rV.'?|'./;'.,i .80-86 Krebs unite: I Approximate j^ */aces based 071 Water . Material, y;iy.;..vy,,:', . .yy: V. ;7 | Antifoamer .......V'. lyy. [ Ethylene glycol.; i. .:;.. ..... i Pine oil .......... . :v;V..:r.. Preservative.............. ;.......... ; Hydrox> ethyl cellulose: (2.5% solution).-7:. .v-i.. i Rutile titanium dioxide ....7..y.7........ 1 Talc :.......... - Pounds..'; Gallons 135.6' V 16.28 - 8.4 - ;-uc 0.91 = 2.o 0.23 l-Or;:? v :- 0.13 :. 25.0fci:,,'F*.-'r.:T }." 2.69 3.0':W- * * 0.33 1.8. . 0.11 120.0 y 14.63 175.0;;..' . '-.5.00 Viscositytfrafg , App^oxiraaterav^^^ ;Formulation 309 Material Pounds Gallons Water .......... .......................................... . Tamol 73: (25%) .................................. Triton CF-10............................................................ Antifoamcr............................................................. Ethylene glycol...................................................... Pine oil...................................................................... Preservative............... ....:................................... Hvdroxvcthv) cellulose (2.5% solution).............. . Rutile titanium dioxide........................................... . Talc .......................................................... i.............. Calcium carbonate ........................ ...................... . 138.98.3 2.0 1.0 25.0 3.0 1.8 120.0 175.0 25.0 360.0 16.68 0.90 0.23 0.13 2.69 a 0.33 0.11 14.63 5.00 1.05 15.95 . Grind the above in a high-speed mill (Cowles, 8800-4500 feet per minute for 10-15 minutes) Letcown: Rhoplex AC-34 (46%)........................................... Antifonincr.............................................................. Ammonium hydroxide (28%) .............................. . Pigment volume content ;................. ... ; Solids: Weight ...................................... .. Volume.................................. .. pH ................................................ .. Yiscositv range ..................................... .. . 375.4 1.0 2.0 42.18 0.13 0.27 1238.4 - 100.28 54.8% : 59.3% 40.0% 9.4-9.7 74-80 Krebs units Approximate raw material cost--$1.37/gallon Formulation 310 it I- Material Pounds Gallons Water ......................... ............................ Tamol 731 (25%)................................... Triton Ci'-10................................................ Antifoamcr............................................... Ethylene glycol................... .................. Pine oil............................... ................... ;... Preservative................................................... HydroxycUiyl cellulose (2.5% solution) 49.6 8.2 2.0 1.0 20.0 3.0 1.8 118.2 170.0 262.0 . 5.95 0.89 0.23 0.13 2.15 0.33 0.11 14.41 4.86 11.61 Grind the above in a high-speed mill (Cowles, 3800-4500 jeet per minute for 10-15 minutes) . ' .. - r' ' ; ............. v" Letdown: . v\'r. . Rhoplcx AC-34 (46%) V. i . I .'.;-i, ;V.*.YC;Y. 516.0 r 57.98 Antifoamcr...................... ........... ........... .1.0;.; ./.-' 0.13 Ammonium hydroxide (28%) 2.0 . '/V ' 0.27 1154.8.5;Y,&. 99.05 Pigment volume content :. A i y. :. 1. .1. J 39.8%^ - ;... ,- Solids: Weight:'.;v... Volume :'.Y':i: ' .......... 58.o%fe-\ 4i.8%v^:-'<'v.^:r,; pH . 9.4-9.7>*^;,, . Viscosity .'.YYVY , 80-86 Krebs unite Approximate raw 2(5 itf Formulation 311 Light Tint Base for Universal Colorants based on Rhoplex AC-34 Material Pounds Gallons Water .................... 55.0 Soya fatty acids) Prcmfe 9.1 Morpholine ) 3.9 Morpholine 6.0 Antifoamor 1.0 Ethyleneglycol ......................................... 25.0 Preservative........................................... 1.8 Hydroxvothyl cellulose (2.5% solution) 100.0 Rutile titanium dioxide.................................................. 17107.0.0 Calcium carbonate 251.4 Pine oil................ 3.0 6.60 1.18 0.48 0.72 0.13 25.0 2.69 0.11 12.19 4.86 11.14 0.33 Grind the above i 10-15 tni'iiites) 00-4500 feet per minute fi Letdown: Rhoplex AC-34 (46%) ................................................. 49479.70.0 55.84 Antifoancr.................................................................. 1.0 0.13 wr&olG',10(22;/c)ipremic....................... 6.0 18.0 0.68 2.16 Water.................................................................... 4.1 0.49 Ammonium hydroxide (28%) ................................. 2.0 0.27 1154.3 100.00 Pigment volume content....................40.0% 40.0% Solids: Weight 56.3% Volume 40.0% pll ................................................................ 9.4-9.7 Viscosity range ....................,..................... 85-92 Krebs units Approximate raw material cost--$1.60/gallon Formulation 312 Medium Tint Base based on Rhoplex AC-84 Material Water ..................... Tamol 731 (25%) .. Triton CP-30........... Antifoancr___ .... pine oil Preservative Pounds 76.6 6.0 1.5 1.0 25.0 3.0 1.8 140.0 100.0 342.0 Gallons 9.20 0.65 0.17 0.13 2.69 0.33 0.11 17.07 2.86 15.15 Grind the above in a high-speed mill (Cowles, 8800-1(500 feet per minute for 10-15 minutes) Letdown: Rhoplex AC-34 (46%) .................. ................. .. ! 455.4 ^ y 51.17 Antifoamer.............................................................. . 1.0 0.13 Ammonium hydroxide (28%) ................ 2.5 0.33 3155.8 99.99 Pigment volume content .............. Solids: Weight ............V.i 45.0%. > ' 56.4%r" Volume ............' 40.0%-`;y - yyy' pH .............. ii#? 9.4-9 Viscosity range ..'. ...... .: ;>.!&.. y-- 78-85 Krebs units> . y.V. r ; Jl Approximate raw material cost--$1.28/galIoriw ' * ,, . y.y yyy ^yvy. ; v Vo*-:*. Formulation 313 Material Pounds Gallons Water .............. Soya fall) acids Premix Morpholii c Morpholine----Antifoamer___ Kthylene glycol Preservative .. Hydroxyc-.hyl cellulose (2.5% solution) Rutile titanium dioxide......................... Calcium carbonate ....................... ...... Pine oil 40.0 I 5.8 2.5 4.2 1.0 25.0 1.8 100.0 100.0 342.0 3.0 4.80 0.75 0.30 0.51 0.14 2.69 0.11 12.19 2.86 15.15 0.33 Grind the above iti a high-speed mill (Cowles, 3800-^00 feet per minute for 10-15 minutes) Letdown: Rhoplex AC-34 (46%)............ Antifoamer............................... Acrysot G-l 10 (22%) ? pTemjx Water i Ammonium hydroxide (28%) Water........................................ Pigment volume content................... Solids: Weight ................................... Volume ................................... ................................................ 'Viscosity range ................................... Approximate raw material cost--$1.33/gallon 455.4 51.17 1.0 0.14 6.0 0.68 18.0 2.16 2.5 0.34 42.8 5.13 1151.0 45.0% 56.6% 99.45 40.0% 9.4-9.7 84-92 Krebs units Formulation 204 Material Pounds Gallons Duraplcx DX-656 (50%)........................................... Alkali-refined soya oil................................................. Cobalt drier (6%)....................................................... Manganese drier (6%)............................................... Mineral tl inner.......................................................... Anti-skinning agent.............................................. Preservative (Super Ad-It).................................. 208.0 312.0 3.3 2.1 200.0 0.8 12.0 . 738.2 27.0 40.3 0.4 0.3 30.9 0.1 1.5 100.5 Solids: Weight ................. 56.7 % Volume ............................... 51.8 % Ratio of alkyd to oil solids ................... .25:75 P'ricr calculated as metal on solids: ; Cobalt ..... .r 0.05%...: Manganese . . !:; 0.03% :: v . .. % . ! If desired, alkali-refined linseed oil may be substituted for soya oil. Lead drier (1%) should be used instead of manganese in this case. X V '1,.' .; / -- Gl 0005 726 .V.'-oV  Raw Materials Used for Preparation of Formulations ^303 to 313 Material Soya fatty acids Designation Wecoline S Supplier Drew Chemical Corporation Morpholine Morpholine, water-white Chemicals Division of Union Carbide Corporation Antifoamer Nopco NXZ Balab 748 Pine oil Hydroxyethyl cellulose Preservative Yarmor 317 Cellosize QP-15000 Cellosize WP-4400 Metasol 57--100% grade Rutile titanium dioxide Ti-Pure R-610 Titanox RANC Unilane 0R-640 Anatase titanium dioxide Ti-Pure FF Titanox A-168LO Unitane 0-220 Talc Asbestine 3X Nytal 300 Calcium carbonate Snowflake Crystalline silica Silver Bond B Basic silicate of white lead EP-202 Oncor 45X Nopco Chemical Company Balab, Incorporated Hercules Powder Company Chemicals Division of Union Carbide Corporation Metalsatts Corporation E. 1. du Pont de Nemours & Co., inc. Titanium Pigment Corporation American Cyanamid Company E.!. du Pont de Nemours & Co., Inc. Titanium Pigment Corporation American Cyanamid Company International Talc Company R. T. Vanderbilt Company Thompson-Weinman & Company Tamms, Incorporated Eagle-Pichei Company National Lead Company Gt-0005727 29 Paint Nannfactnre with Rhoplex Emulsions Several types of conventional paint manufactur ing equipment can be used very satisfactorily for the production of Rhoplex AC-34 exterior paints. The usual procedure is to make an aqueous pig ment dispersion. Part of the Rhoplex AC-34 may have to be added to furnish sufficient liquid to wet the pigment, but minimum quantities should be used. Although the exact procedure depends on the equipment available, the following general in structions should be helpful in the preparation of paints: 1. Charge a high-speed disperser with the dis persing and wetting system, coaleseent, antifoamer, water and thickener solution. 2. Add the solid preservative; then add the required pigments and the extenders together in several small portions, mixing all dry materials thoroughly before adding each portion. For deep-toned paints, the colored pigments are also added at this time. 3. Mix at high speed. In our laboratory equip ment 4000 feet per minute peripheral speed was used for 12 minutes. 4. The resulting dispersion is then reduced in a mixer at low mixer speed by adding the balance of the Rhoplex AC-34. The pH should be ad justed, if necessary, to 9.4 to 9.7 with ammonium hydroxide, and additional antifoamer added. 5. The paint is then tinted and packaged. Pebble mills can also be used for the produc tion of these paints. Generally, it is necessary to charge more emulsion to the pebble mill then is required for other methods. The charge is ground for the required time; then the final addition of vehicle, ammonium hydroxide and antifoamer is made. Application o! Rhoplex Emulsion Paints Paints made with Rhoplex emulsions may be applied by brush, roller or spray gun. Since the paints brush easily, brushes 4 to 6 inches wide may be used. Brushes with tapered nylon bristles are among the most satisfactory. They retain their fiber stiffness because they do not absorb water, yet permit uniform coverage and freedom from lap marks. Nylon brushes are cleaned easily since the paints do not penetrate the filaments appreciably. Brushes or rollers should be wet with water before painting. It is good practice to keep a pail of water handy and change brushes every hour or so, putting the used brushes in the pail. This will prevent drying in the brush. Rollers can be used very satisfactorily. Dip rollers are preferable since they are lighter, easier to clean and create less foam during application than the fountain type. Long-nap rollers are used on rough cement, brick or stucco. For spray applications, paints may be used at approximately the same viscosity as for brush ing. External-mix spray guns should be used at 20 to 40 pounds line pressure. Bleeder-type guns usually clog. In all exterior applications one should be sure enough paint is applied. Since emulsion paints spread very easily, thin coats can be applied which will give reduced hiding and durability. Spreading rate should be from 250 to 450 square feet per gallon depending upon the surface roughness, water demand, previous treatment and type of surface. Paints based on the Rhoplex emulsions dry very quickly, so that window sash should be moved shortly after painting to avoid sticking. If a torch is used to remove old emulsion paints, it should be moved rapidly over the surface, applying just enough heat to soften the paint and permit its removal by a scraper. 30 GLD005??8 TABLE V Principal Newtown Test Farm Exposure Series used in .Preparation of Progress Report No II1 Series Number Exposure Date Surface Painted Principal Vehicles Pigment Volume Colors Content Object of Exposure Vehfcle StudieS 60N September 1960 White Pine Yellow Pine Cedar Rhoplex AC-34 Rhoplex AC-33 Rhoplex B-6Q-A m 40% 63Y 63 BJ Eave Exposures March 1963 July 1963 Between September 1961 and June 1963 White Pine Chalky Oil Gloss Trim Spruce White Pine Yellow Pine Chalky Oil Chalky Acrylic Gloss Trim Chalking Oil House Paints of Various Ages Rhoplex AC-33 35% Formulation 204 Rhoplex AC-34 35% Rhoplex AC-34 Usually Commercial Paints 35% White To illustrate performance Red differences with emphasis Blue on Rhoplex AC-34 on bare wood. White To determine value of oil addition. White To determine value of alkyd and oil additions in increasing adhesion. White Pink To determine adhesion and performance over gloss trim and chalking oil paints, both south vertical and under eaves. Formulation V ariabtes 53B&C August 1963 60P July 1960 60Y October 1960 610 August 1961 Cedar Rhoplex AC-33 Asbestos Shingles White Pine Rhoplex AC-33 Primed Cedar Asbestos Shingles White Pine Primed Cedar Rhoplex AC-33 White Fine Rhoplex AC-34 Primed Cedar Asbestos Shingles 30%-5Q% 30%-40% 30%-35% 30%-45% White To determine formulation variables which control performance. White To determine extender, Ti02 ratio and thickener variables which control performance. Red To determine variations in Blue chalking rate with two commercial grades of TiOs and two extenders. Riue To illustrate effect of vary ing levels of T1O2 on performance. 63BF July 1963 White Pine Cedar Rhoplex AC-34 35%-60.8% White To correlate pigment bind ing capacity with per formance. 63BA June 1963 White Pine Gloss T*im Chalking Oil Yellow Pine Chalking Acrylic Rhoplex AC-34 40%-45% White T0 check published formu lations. Film Preservatives 54F January 1955 58PP October 1958 White Fine Rhoplex AC-33 Asbestcs Shingles White Fine Rhoplex AC-33 Asbestcs Shingles 28% 40% 62H February 1962 White Pine Rhoplex AC-34 .30% White Todetermine effectiveness of various preservatives. White To provide additional ex posure of zinc oxide and barium metaborate pre servatives. White To provide additional pre servative studies. , 1 Many other test series were also reviewed for this Report and are available for inspection by visitors. - GLD0057?9 Structure Ackerman House Adams House Baiderston House TABLE VI Some Laboratory-Controlled House Paint Tests with the Rhople-, Major Test Substrates1 Composition siding Stucco Cinderblock Wood panels Clapboard Previous Costing1 Oil paint, moderate chalk None Cement-type paint Dark red stain Heavily chalking oil paint Major Formulation 40 PVC gray-green; Rhoplex AC-34 40 PVC white; Rhoplex AC-34, CaCOs and ta extenders 32 PVC dark red; Rhoplex AC-33 35 PVC white; Rhoplex AC-34, CaC03 extendi Balmer House Clapboard Heavily chalking oil paint 35 PVC white; Rhoplex AC-34, talc extender Berger House Bogenrief House Caulfield House Connor House Plywood and batten Cedar clapboard Clapboard Stone and brick Clapboard Light to moderately chalking oil paint Moderately heavy chalking oil paint Moderately heavy chalking oil paint Cement-type paint Burned off for repainting 35 PVC medium-tone green; Rhoplex AC-34 40 PVC white; Rhoplex AC-34, CaC03 and ta extenders 35 PVC white; Rhoplex AC-34, CaC03 extend 35 PVC white; Rhoplex AC-33, talc extender 35 PVC white; Rhoplex AC-34, CaC03 extend Faust House Gusman House Haag House Harmon House Hurwitz House McBurney House Redwood clapboard Philippine mahogany clap board Composition "clapboard," wood trim and galvanized iron Wood and composition siding Philippine mahogany clap board Smooth stucco Light to moderately chalking oil paint Light to moderately chalking oil paint New--none, except for factory primer on composition board Heavily chalking Rhoplex AC-33 paint Very dark stain, some "chalk ing" Moderately chalking cement paint 40 PVC white; Rhoplex AC-34, CaC03 and ta extenders 35 PVC white; Rhoplex AC-34, CaC03 extend Formulation 244-A (wood primer) Topcoat--40 PVC white; Rhoplex AC-34, CaG and talc extenders 40 PVC white; Rhoplex AC-34, CaCOa and 1; extenders 42 PVC reddish-brown; Rhoplex AC-55 50 PVC white; Rhoplex AC-33, extender mos CaC03 Moody House Cedar clapboard Heavily chalking oil paint 40 PVC white; Rhoplex AC-34, talc extender Newtown Conference Room Building Newtown Service Building Van Hook House Cinderblock Cinderblock Clapboard and stucco New, with cement-type fillercoat 40 PVC light green; Rhoplex AC-34 Moderately chalking cement paint Heavily chalking Rhoplex AC-33 paint 35 PVC light green; Rhoplex AC-33 (first o modified with oil/alkyd) 40 PVC white; Rhoplex AC-34 1 In addition, the wood trim was usually painted white at the same time. Frequently, colored Rhoplex formulations were used on some trim items, such as shutters. ^0005730 32 Emulsions (Eastern Pennsylvania) Method of Application Brush Number of Coats Two Painting Date June 1963 % Comments Excellent appearance with little chalk or dirt retention. Brush Two September 1958 Appearance is still very attractive. Little chalking; film failure limited to scattered grain cracking on wood. Brush Two July 1961 The carbonate-extended formulation has resulted in light chalking and moderate dirt retention. Brush Two June 1962 Good cleanliness and moderate chalking have resulted from the use of talc in this white formulation. Brush Two August 1961 Good condition. No intercoat failure and a minimum of fine cracking of the plywood. Brush Two July 1963 Very good cleanliness with light chalking. Brush Two July 1961 Brush Two August 1956 Brush Two June 1961 Brush Two July 1963 Brush Two August 1960 Brush plus probably some roller Brush Two (primer plus topcoat on bare wood) Two Summer 1963 August 1963 Moderate chalking is providing improved cleanliness. There is a modest amount of lifting due to failure at the oil paint/wood interface. The 1956 paint on the masonry is chalking heavily; appearance is very good although there is some lifting and peeling from the old cement paint layer. The 1961 paint is practically perfect, and is exhibiting light to moderate chalk and dirt retention. Verygood appearance, but some scattered failure at the old oil paint/wood interface required repairing. Chalking is moderate and cleanliness is good. Adhesion has been excellent Excellent adhesion and freedom from cracking. Slight chalking with very good cleanliness. Excellent performance. Slight chalking; very good cleanliness. Brush Two July 1960 Excellent adhesion and freedom from cracking. No obvious color fading. Brush Two April 1956 Brush Two June 19S2 Roller 'i *>J Roller 1 One April 1963 One modified, one May 1959 unmodified Brush on wood, Two roller on stucco June 1963 Two walls still in excellent condition. One required repainting (Rhoplex AC-34 paint) in 1962 because of failure in the cement paint layer near the ground. Very good cleanliness. Moderate to moderately heavy chalk. Scattered blisters due to failure at old oil paint/wood interface. Very slight chalking; very good cleanliness and adhesion. Moderate chalk. Good appearance with scattered lifting or peeling, partly due to substrate failure. Excellent performance; slight chalk and very good cleanliness. In general, the surfaces were prepared for painting by light sanding, spot scraping and priming problem areas. Then loose dirt and chalk were reduced with plain water. 33 GLD005731 Properties o! Individual Rhoplex Emulsions lor Exterior Use Rhoplex AC-33 It has now been more than eleven years since the first 100-percent acrylic emulsion paint vehicle, Rhoplex AC-33, was introduced to the paint in dustry. The tough, adherent, flexible, and colorretentive acrylic polymer in Rhoplex AC-33 has provided exceptional performance in exterior emulsion paints. These paints have shown un usually good resistance over the years to climatic extremes and to the effects of sunshine, rainfall, frost, and to alkali from masonry surfaces. Acrylic emulsion paints based on Rhoplex AC-33 have been firmly established since 1953 as the standard of durability and appearance for ex terior emulsion coatings on stucco, cinderblock, concrete, cement asbestos shingles and other masonry surfaces. Such paints give unusually good alkali resistance, adhesion and color retention. Rhoplex AC-34 Rhoplex AC-34 was introduced in 1961 as the first new 100-percent acrylic emulsion polymer spe cifically designed for use on exterior wood sur faces. Exposure tests show that the long, favorable exposure history of Rhoplex AC-33 also applies to paints made with Rhoplex AC-34. However, several advantages are obtained when paints made with Rhoplex AC-34 are ap plied to wood surfaces: 1. Greatly improved resistance to grain crack ing and flaking when applied to bare wood. 2. Much better adhesion over old oil paints and oil-based primers. 3. Excellent adhesion to glossy oil paints and oil-based primers under wet conditions. 4. Outstanding blister resistance. 5. Higher pigment binding capacity permitting use of higher pigment volume content paints. Rhoplex AC-55 In 1957 Rhoplex AC-55 was introduced as a higher solids acrylic emulsion closely related to Rhoplex AC-33. Rhoplex AC-55 utilizes an anionic dis persing system rather than the nonionic system utilized in Rhoplex AC-33. As a result, Rhoplex AC-55 provides a wider range of compatibilities with tinting colors and difficuit-to-disperse tube colorants. Emulsion paints made with Rhoplex AC-55 exhibit the film properties characteristic of acrylic polymers, particularly excellent adhe sion, flexibility and color retention, and resistance to water, sunlight and alkali. Rhoplex B-60A Rhoplex B-60A has the same polymer composi tion as Rhoplex AC-33, but is lower in viscosity. In some formulations it shows better color ac ceptance than Rhoplex AC-33. Physical Properties of Rhoplex Emulsions The physical properties of these emulsions are tabulated below: Rhoplex Rhoplex Rhoplex Rhoplex Property AC-33 AC-34 AC-55 B-60A Solids Content 46-47% pH (approxi- mate) 9.0-9.5 Appearance Weight per Gallon White Milky Liquid 8.9 lb. Specific Solids 1.15 4847% 9.2-9.8 White Milky Liquid 8.9 lb. 1.15 49.550.5% 9.0-9.5 White Milky Liquid 9.0 lb. 1.16 46-47% 9.0-9.5 White . Milky Liquid 8.9 lb. 1.15 All of the Rhoplex emulsions listed above show excellent storage stability. However, if Rhoplex AC-33 is to be stored in bulk, occasional mild agitation should be used to prevent creaming on standing with increase in solids at the bottom of the tank. The other three emulsions show little tendency to cream. All four emulsions have excellent heat resist ance and freeze-thaw stability. Rhoplex AC-33 is particularly outstanding in freeze-thaw stabil ity so that containers in which it is shipped do not cany a "protect from freezing" marking. All of the emulsions have excellent pH stability. 34 GLD05 73? Acrysol, Durable*. Rhoplex. Tamol and Triton are trademark* Rea. U.S. Pat. Off. and in principal forties countries. In certain foreign countries Aeryso and Rhoplex product* ate sold under the trademark Primal; Tamol under the trademark Orotan. NOTICE These suggestions and data are based on information we believe to be reliable. They are offered in good faith, but without guarantee -aseemditrons-aod- methods of useef our product* and "the Quality of'ttatemlsparehoed from others are beyond our control. We recommend that the prospective user determine the suitability cl o u t material* and suggestions before adopting them on a commercial scale. Suggestions for uaea of our products or of product* pur chased from others should not be understood aa recommendations that they be used in violation of any patesta. December ISM GL DOO5733 ROHIVf .. ^ PHILADELPHIA, PA. 19106 GLOO 0573 4