ENGINEERING RESEARCH INSTITUTE UNIVERSITY OF MICHIGAN ANN ARBOR FINAL REPORT DEVELOPMENT OF A LIQUID POLYVINYL ACETATE PAINT January 1, 1954, to September 15, 1954 L. L. CARRICK F. L. KECK Project 2195 THE REARDON COMPANY ST. LOUIS, MISSOURI October, 1954

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ENGINEERING RESEARCH INSTITUTE ~ UNIVERSITY OF MICHIGAN FOREWORD On January 1, 1954, Mr. Fred L. Keck under the supervision of Dr. L. L. Carrick began an investigation of moisture control paint. The initial work was directed toward the development of a dry polyvinyl acetate base paint that once dispersed in water and applied could not be reemulsified. Work continued along these lines until March 3, 1954, at which time Mr. C. Clark of the Reardon Company's Product Development Department advised during his visit to our laboratories that development of a liquid polyvinyl acetate masonry paint (similar to Gelvatex) should take precedence over a-dry powder paint. This statement, that our work should be on the development of a liquid polyvinyl acetate masonry paint, was reaffirmed by Mr. Ben Zmuda, Reardon's research director, during his visit on April 15, 1954. Messrs. H. Davis, B. Zmuda, and C. Clark of the Reardon Company visited our laboratories on August 23, 1954, and advised that the Reardon Company had decided against marketing a liquid polyvinyl acetate paint. As a result, that phase of the project (i.e., development of a liquid polyvinyl acetate paint) was closed. On the ensuing pages may be found a summary of the work done on the development of a liquid polyvinyl acetate paint..____________.....___ ii ___________________

ENGINEERING RESEARCH. INSTITUTE ~ UNIVERSITY OF MICHIGAN TABLE OF CONTENTS Page FOREWORD ii DEVELOPMENT OF A LIQUID POLYVINYL ACETATE PAINT 1 Evaluation of Water Resistance of Polyvinyl Acetate Latices 1 Investigation of Dispersion Methods 2 Pigment Water Demand 5 Adhesive and Cohesive Force Phenomenon 6 Aging of Vehicle Systems 6 More Important Formulations 7 EXPERIMENTAL RESULTS 8 CONCLUSIONS 11 APPENDIX 12 Modified National Starch Formula 4C 13 Modified Dupont Formula 14 Modified Colton Chemical Formula 16 Modified Rohm and Haas Formula 17 Bakelite Formula 19 Pigment Water Demand 21 Surface Tension 23 GLOSSARY 25... __1_11_._..iii ____

ENGINEERING RESEARCH INSTITUTE ~ UNIVERSITY OF MICHIGAN DEVELOPMENT OF A LIQUID POLYVINYL ACETATE PAINT Preliminary investigation of the Gelvatex polyvinyl acetate paint samples submitted by the Reardon Company revealed the following information. pH: Range from 6.2 for white to 6.5 for bisque. (White after 7 months storage had a pH of 6.5; however it had developed an acetic odor and a lumpy consistency. Long term stability is questionable.) Total solids: Range from 40.3% for cactus green to 14.3% for white. Water content: White sample only, 55.7%. Pigment analysis: White sample only. Free silica (no silicates); approximately 63% (TiO2). PVA content: No successful method for extracting (isolating) the polyvinyl acetate was found. Evaluation of Water Resistance of Polyvinyl Acetate Latices Aa initial examination of the water resistance of various polyvinyl acetate latex films (without any film conditioning agent such as plasticizer and/or solvent) was made. Of the commercial polyvinyl acetate latices investigated, Coltoni's Vinac WR-20 gave the best water resistance by itself. However, this material also displayed a tendency to skin in the container. The next best latices as far as water resistance was concerned were Bakelite's WC-130 and Dewey and Almy's Everflex G. The water resistance of all latices except those containing polyvinyl alcohol, a protective colloid, improved on addition of a film conditioning agent such as dibutyl phthalate.._____________________________________ _____.

ENGINEERING RESEARCH INSTITUTE ~ UNIVERSITY OF MICHIGAN Investigation of Dispersion Methods Examination of the mixing procedures and basic polyvinyl acetate formulations suggested by the various latex manufacturers was conducted. These formulations with slight modifications are found on pages 13 through 20 of the appendix. Included with the formulations are the mixing procedures, observations, approximate costs as of June 1, 1954, and other pertinent data. In formulating the polyvinyl acetate paints, three methods were used for pigment dispersion: colloid mill, ball mill, and 3-roll mill. In general, entrapped air was a major difficulty especially where no antifoam agent was used. The degree of air entrapment was very bad in the colloid mill and ball mill and required weeks to work its way out of the paint. Depending on the formulation, dispersion by the 3-roll mill produced pigment dispersion containing negligible to objectionable quantities of entrapped air. In the Bakelite formulation where the dispersing agent was of the sulfonate type, it was found that entrapped air could be eliminated by adding the protective colloid (thickening agent) after the pigment had been dispersed. Probably a small portion of protective colloid could be present during pigment dispersion without causing entrapped air, but no study was made of the critical amount. Entrapped air also resulted when a nonionic dispersing agent such as Tergitol NP-35 was used as a pigment dispersing agent. In some cases the presence of a defoamer before dispersion prevented excessive entrapped air. An acrylic paint using Rohm and Haas' polymer Rhoplex AC-33 is very susceptible to foaming. Essentially an air free dispersion containing an antifoam agent can be made on a 3-roll mill, but other means of dispersion create excessive entrapped air. A series of paints employing varying procedures were made up according to the following basic formula. Ingredient Percent Lbs/gal Cost/lb Gallons RMC/00 lbs Water 20.1 8.33 --- 2.416 Daxad 11 0.2 ---.25 ---.05 TiPure R-510 20.0 34.99.245 0.572 4.90 ASP 400 7.5 21.66.02 0.347.15 Metronite BXXXX 8.0 23.74.0175 0.337.14 Ethylene glycol 2.9 9.3.1875 0.312.54 *WC-5510 27.6 9.10 see below 3.035 6.14 Cellosize WPHS 5% 13.0 8.33.48 1.560.31 Glyoxal 30% 0.6.10 48.185 0o057.11 Tergitol NPX 0.1 8.8.315 00.11.03 100.0 8.647 12.37 *Composition of WC-5510:

ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN I Lbs Lbs/gal Cost/lb 1 Gallons \R MC WC-130 latex solids 14.4 9.94.39 1.46 5.62 Dibutyl phthalate 1.44 8.75.3575 0.165.52 Water 11.76 8.35 --- 1.41 27.6 3.035 6.14 Pigment = 35.5% Vehicle = 64.5% Vehicle nonvolatile = 26.35 PV = approximately 43.6% Lbs/gal = 11.55 Viscosity = 76-82 KU Ratio of pigment to nonvolatile vehicle solids: By volume 1: 1.3 By weight: 0.45 2.31 lbs TiO2/gal 1.66 lbs WC-130 solids/gal 5.12 lbs water/gal Cost = approximately $L.43/gal The order of dispersion found to be most satisfactory is as follows. 1. Dissolve the dispersing agent in the water. 2. Add pigments and fillers to No. 1 with stirring to insure wetting. 3. Disperse these materials by any suitable means. In the case of 3-roll mill dispersion some water should be withheld to insure a satisfactory pigment paste. 4. The remaining components, ethylene glycol, plasticized latex WC-5510, Cellosize WPHS, Glyoxal, Tergitol NPX, and any previously withheld water, should be added in sequence making sure that each is thoroughly dispersed before the next addition. Dispersion on a 3-roll mill caused no entrapped air even when Cellosize WPHS was present in the pigment dispersion. The same is true when plasticized latex WC-5510 was also included. However, the inclusion of the latex in the pigment dispersion resulted in a completed paint having a -______5 3

ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN viscosity of 72 KU compared to 76 KU for a paint having the plasticized latex WC-5510 added after pigment dispersion. The paint regardless of preparation shows a slight tendency to thixotropy. In the colloid mill and ball mill, foaming resulted when Cellosize WPHS and/or plasticized latex WC-5510 were present. Addition of these items after dispersion eliminated entrapped air. Hence, the pigment dispersion should contain water, dispersing agent, and pigments only. Following this rule the viscosity of a paint whose pigment was dispersed in a ball mill was 82 KU. Using the colloid or 3-roll mill, the viscosity was usually 76 KU. This viscosity difference is probably the result of the fineness of grind. Fineness (Hegman Scale) Colloid or 3-roll mill 4.5 Ball mill 65 It is interesting to note that after four months aging, the two paints (KU of 76 and 82) did not alter viscosity and were easily redispersed into a very smooth flowing paint. When the plasticized latex WC-5510 was substituted with 10% dibutyl phthalate plasticized Shawinigan Latex TS-22, the paint showed greater settling. Difference in latex viscosity and the extent of compatibility with the paint formulation probably attributed to the greater settling. The formulation on pages 2.and 3 was modified by adding three parts of zinc oxide (KIdox 15) and decreasing the TiO2 the same amount by weight. The finished paint was very thixotropic, but fluid on stirring with an initial viscosity of 83 KUo After four months storage the paint is still stable and shows no increase in viscosity. Difficulty encountered in dispersing the zinc oxide was overcome by adding ethylene glycol to the pigment prior to milling. A series of paints substituting various quantities of Cellosize WP-300 for Cellosize WPHS and corresponding quantities of water were made. Included in the series was a direct substitution of a 3% solution of Cellosize WP-300 for the 5% solution of Cellosize WPHS. This substitution seemed logical, since both solutions have the same viscosity as measured on a modified Krebs Stormer Viscosimeter. However, in all instances, standing for ten days or so produced a thickened paint that could not be satisfactorily redispersed. It was decided at this time that some fundamental data would have to be determined since the trial-and-error method of formulating leaves much to be desired. Literature references were of no assistance in supplying necessary data..____________ _. _

ENGINEERING RESEARCH INSTITUTE ~ UNIVERSITY OF MICHIGAN Pigment Water Demand The water demand, arbitrarily taken as the amount of water containing a given percentage of dispersing agent necessary to make a fluid paste which will fall from the end of a spatula, of various pigments and fillers with various wetting agents was determined At the same time the nature of the pigment paste such as consistency, ability to flow, dilatancy, foaming tendency, etc., were noted. In addition, surface tension data of various dispersing and wetting agents at different concentrations and in combination with antifoam agents were determined. Data on water demand and surface tension may be found in the appendix beginning on page 21. Preliminary investigation on water demand of the titanium dioxides disclosed that TiPure R-510 and Unitane OR-540 required the least amount of water for dispersion. Knowledge of the water demand of the various pigments provides for an estimate of the free available water present in any polyvinylacetate system. The viscosity of the system is dependent on this free available water. Preliminary investigation of surface tension indicated that these data can be useful in predicting water demand. It was found that the lower the surface tension the greater the pigment water demand. Two zinc oxides, New Jersey Zinc's Kadox 15 and XX505, did not show dilatancy regardless of the dispersing agent used and hence are promising pigments. From the preliminary data it appears that dispersing agents having high; surface tensions produce dilatant dispersions with some zinc oxide pigments. All dilatant zinc oxide dispersions impart dilatancy when added to plasticized latex WC5510 Further addition of a thickening agent such as Cellosize WPHS resulted in rapid viscosity increase. The resultant paste which resembles "silly putty" is of questionable value in polyvinyl acetate paints. A small quantity of nondilatant zinc oxide dispersion added to titanium dioxide produces a satisfactory pigment paste. Because zinc oxides are reactive pigments, large quantities and dilatent types may promote unstable systems. Of the fillers, Metronite BXXOX, magnesium calcium carbonates, and silicates had the lowest water demand and showed excellent flow, ASP 400 appears to be the most promising of the clays examined. Lorite, calcium carbonate plus diatomaceous silica, might be considered, although Metronite BXXXX and ASP 400 appear to be by far the best fillers. As dispersing agents, Daxad 11, Blancol, and similar condensed naphthalene sulfonates appear very satisfactory. Nonionics, alkyl aryl polyethylene glycol ethers, are not as efficient and have a tendency to produce a foamy dispersion. For dispersion of some organic pigments, nonionics may be necessary to obtain the best color. 5

ENGINEERING RESEARCH INSTITUTE ~ UNIVERSITY OF MICHIGAN Adhesive and Cohesive Force Phenomenon Early investigation of the Gelvatex samples revealed that there was a powerful attractive force exerted between the pigment and the polyvinyl acetate latex. As a result, no solvent tried (including Carbitol) would extract all the polyvinyl acetate from the pigment. Paints having the basic formulation listed on pages 2 and 3 behaved the same way. In each case sufficient polyvinyl acetate remained to impart strength and toughness to the pigment mass. It was thought that there was a critical amount of polyvinyl acetate, as a monomolecular layer, absorbed on any given surface area of pigment and an attempt was made to determine whether there was a critical amount and, if so, the quantity. In attempting to duplicate the adhesive force phenomenon it was found that addition of the extracting medium, Carbitol, to the paint caused heat generation in most cases. An addition to the pigment polyvinyl acetate slurry (water,pigment and polyvinyl acetate) of dispersing agent, such as a protective colloid, vinyl acetate monomer, extender pigments, diphenylamine (vinyl acetate monomer inhibitor), ammonium polyacrylate, alcohol, and various combinations of these materials, did not produce strength and toughness in the extraction treated pigments. The polyvinyl acetate latex was for all practical purposes completely extracted from the pigment mass leaving no strength. It was noted, however, that the addition of vinyl acetate monomer followed by the polyvinyl acetate latex did impart more strength to the pigment mass than any other combination. Also of interest is the fact that the addition of ammonium polyacrylate allowed the pigment mass to be easily crumbled and this fact may be helpful in developing a dry polyvinyl acetate paint. Another interesting fact was that Carbitol added to a pigment slurry containing water did not extract the polyvinyl acetate latex. Evidentally a water-Carbitol mixture is not as good for extraction purposes as a straight Carbitol, Aging of Vehicle Systems Since Bakelite suggests the addition of ammonium polyacrylate to a paint, aging studies on different vehicle combinations were initiated. It was found that the viscosity and surface tension of the vehicle (all materials in a finished paint except pigments and fillers) did not change on aging for 100 hours at 1200F. However, a vehicle similar to the one appearing on pages 2 and 5 separated into two layers, while' a similar formulation containing ammonium polyacrylate did not result in settling or layering. Consequently the function of the ammonium polyacrylate is one of suspension stability and not necessarily as a thickening agent. __________________________.6 __________________________

ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN More Important Formulations The following formulation was made up Just prior to discontinuing the development of the liquid polyvinyl acetate phase of the project, T iPure R-510 19.5 ASP 400 9.8 Tergitol NP-35 0o3 Water 31.1 Ethylene glycol 2.36 WC-5510 28.3 K-707 (15% T.S.) 2.64 Carbitol 1.7 Cellosize WP-300 (5%) 4.3 Daxad.11 Trace 100.0 Mixing Procedure..1o To the piggment add Tergitol NP-55, Daxad.1 and sufficient water for ball milling (about 75%). Grind overnight and discharge into mixing tank. 2. With adequate agitation add the remaining constituents in the following order: ethylene glycol, plasticized latex WC-5510, K-707 (ammon'ium polyacrylate), Carbitol, Cellosize WP-300, and the remaining water. A paint processed according to the above formulation (similar to Bakelite's suggestion) exhibited excessive foaming because Tergitol NP-35, a nonionic, was present during the pigment dispersiaon. It took three weeks for the foam to work its way out of the paint at which time the paint looked very good. Initial viscosity and the viscosity after aging for one month were essentially the same, 75 KU. Because of the foaming tendency the paint was reformulated using an increased amount of Daxad 11, eliminating Tergitol NP-35, and decreasing the water content to give an initial viscosity of 75 KIU. The pain.t exhibited no foam and looked very promising. However, on aging for a month the viscosity increased to 107 KU which means that more water must be present initially to maintain viscosity stability. A formulation similar to the formula on pages 2 and 3, except Cellosize WPHS is replaced by Cellosize WP-3Q00, appeared very satisfactory after storing for one month. The viscosity had not changed, being about 67 KU, Because this pigmentation is very promising and because of the fact that - 7 -7

ENGINEERING RESEARCH INSTITUTE ~ UNIVERSITY OF MICHIGAN ammonium polyacrylate appears beneficial, a paint using the following formulation and procedure was made. TiPure R-510 20,0 ASP 400 7.5 Metronite BXXXX 8,0 Water 20.1 Daxad 11 0.2 Ethylene glycol 2.5 wc-551 28. K-707 (15% T.S.) 2.6 Carbitol 1.7 Cellosize WP-300 (5%) 4.0 Tergitol NPX 0.1 Water 5.0 100.0 Mixing Procedure* 1. Items through Daxad 11 were ball milled overnight. 2. Discharge into a mixing tank and add the remaining items in the order listed with constant agitation, The addition of the plasticized latex WC-55.10 causes the pigment slurry to become very viscous. The K-707 increases the viscosity still more, but continued stirring results in a fluid slurry. It is imperative to have adequate stirring; otherwise lumps will remain and these will persist ina the finished paint. This paint has a pigment volume of 42 6 which is probably too near the outer range to be satisfactory. No long range storage data are available other than that the initial viscosity of 70 KU( has not changed in three weeks. EXPERIMENTAL RESULTS Polyvinyl acetate paint films are noted for their permeability, that is, ability to transmit water vapor. For comparison purposes the '"specific permeability", defined as the number of milligrams of water which have permeated through one square centimeter of film of one millimeter thickness in 24 hours, was determined on the following polyvinyl acetate systems. 8

ENGINEERING RESEARCH INSTITUTE ~ UNIVERSITY OF MICHIGAN TABLE I POLYVIIYL ACETATE FILM PERMEABILITY Specific Conditions of _____ Samrple ______Permeability Test Film National Starch 207 1 (submitted by Reardon) Gelvatex ash 156 1 Gelvatex cactus green 128.1 Gelvatex bisque 159 1 Gelvatex white 140.1 Gelvatex white.ll 2 Shawinigan 201 137 2 WC-551 145 2 TS-22 plus 109 dibutyl phthalate 92 2 Formula pages 2 and 3 with WC-130 195 2 Formula pages 2 and 3 with TS-22 197 2 1, Films were cast on a tin panel, removed by stripping in a mercury bath, aged two days at room temperature (around 70OF), and then placed in a Payne permeability cup. Test was run at room temperature (average 70.F') 2, Films were cast on a tin parnel, aged 90 hours at 1200F, removed by stripping in a mercury bath, and then placed in a Payne permeability cupE Test was run at room temperature (average 78~F)o It is interesting to note from the above data that aging of the white Gelvatex sample resulted in lower vapor transmission:, This was probably the result of part of the plasticizer being lost from the film. Polyvi',yl. acetate paints having high pigment volumes (formulat.ion on pages 2 and 3) have higher permeabilities. Plasticized latex WC-5510 and similarly plasticized Shawinigan latex TS-22 should have approximately the same specific permeability. These latices are supposedly very similar in nature, Several polyvinyl acetate paints were applied in one and two c-at systems on asbestos shingles and exposed on the roof of the East Engi neeriing Building, University of Michigan. The asbestos shingles which had been weathered for five years were prewet before the polyvinyl acetate paints were applied in order to eliminate pinholing. The panels were held in the test rack at an angle of 45~ facing towards the south To date there is no difference in exposure results between the one and two coat systems' Data representative of both systems are found in Table II. _ 9

ENGINEERING RESEARCH INSTITUTE ~ UNIVERSITY OF MICHIGAN TABLE 1I EXTERNAL EXPOSURE RESDLTS Months Hidings Formulation Exposed. Cheakin:g!... CChalk:iL.g.... Power 1. Dupont, pages 14 and 15 3 None Yes 8 2o Gelvatex white 3 No:e No&e 7 3. Shawinigan 201 3 Honoe No:xe 7 14 Rohm and Haas, pages 17 and.18 3 None Yes 8+ 5 Bakelite, pages 19 and 20 3 None Non.e 7 6. Basic formula, pages 2 and 3 a, With WC-5510 3 None None 8 b. With TS-22 3 None No.e 8 c. With zinc oxide substitution 3 No-ie None 9 d. With Cellosize WP-300 1 None None 8 7. Basic formula, page 7 with Daxad 11 1 None lone 8 8. Basic formula, page 8 1 None None 9 *10 = best; 0 complete failure The paint rack itself mad-e of white pine and hemlock was pair:ted. with the followirng systems. Primer Topcoat 1. White.lead White lead 2. White Tead Polyvinyl acetate (f'rinrmla, pages 2 ad.d 3) 3. Polyvinyl acetate White lead 4. Polyvinyl acetate Polyvinyl acetate -(formula, pages 2 a:d. 3) 5, Polyvinyl acetate Acrylic (Rohm and B.bLaas forml.aa, page' IT:) It is interesting to note that checking occurred. in system Nc, 4 polyvinyl acetate primer-polyvinyl acetate topcoat. These checks were grain checks, No checks were visible after 3-1/2 months in the other systems. The two systems having a polyvinyl acetate topcoat were cleaner than the others, Films of po.lyviny acetate paiLts applied. on white pirie pa'els and. exposed in an Atlas Weatherometer also showed grain checks. This occrred when the panels were not backed. atd. also when estirely coated with polyvin.yl acetate paint. _________________________.1 _________________________

ENGINEERING RESEARCH INSTITUTE ~ UNIVERSITY OF MICHIGAN CONCLUSIONS Long term exposure data are not available but rather data oi limited exposure; the results of which are not significant. It appears that the addition of ammonium polyacrylate to the paint is beneficial in that it helps prevent settling and at the same time improves the hiding power. The last formulation developed which is found on page 8 offers the most promise, however the exposure was for only 30 days~ It in.orporates the best materials tested so far* ammonium-polyacrylate, ASP 400, Metronite BXXXX, Daxad 11, and Cellosize WP-300 The application qualities of this paint were very satisfactory. A variation of the formulation on pages 2 and 3, that is, the substitution of three parts zinc oxide for titanium dioxide oI a weight basis, is also very promising, especially if increased resistance to altra-violet light is desired, Since there was no breakdown of film integrity during the first 3 months of external exposure, the exposure of the polyvinyl acetate panels on the roof of the East Engineering Building should be continued. -__________________.I1.1.

ENGINEERING RESEARCH INSTITUTE ~ UNIVERSITY OF MICHIGAN APPENDIX

ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN MODIFIED NATIONAL STARCH FORMULA 4C Ingredient Percent Lbs/gal Cost/lb Gallons RMC/1YO0 lbs TiPure R-510 23.9 34.99.245 0.683 5585 Asbestine 3X 6.9 23.74 0.0175 0.291.12 Mica 325 w.g. 1.0 23.49 0.0775 0.040.08 Monoammonium phosphate 0.6 15 0 1o 01,O 0 o06,l Tergitol NPX 0.1 8.8 315 0.011,03 Resyn 12K51 32-7 9.1.22* 34595 7.19 Diethylene glycol 1.0 931.2025 0.107.20 Cellosolve 2,0 7.74 o20 0 259 4, Glyoxal 30% 0 5 10 48 185 0o.048 09 Water 27o3 8.33 --- 3.280 Acrysol GS 4,o 8.9 o125 o450.50 100.0 8o804 15007 *Estimated cost of Resyn 12K51. Pigment = 31.8% Vehicle = 68.2% Vehicle nonvolatile = 29.1% PV = approximately 35.7% Lbs/gal = 11.36 Viscosity 93 KU Ratio of pigment to nonvolatile vehicle solids: By volume i: 1.8 By weight I 0.567 2.72 lbs TiOa/gal 2.05.lbs Resyn 12K51 solids/gal 5,21 lbs water/gal Cost = approximately $1.71/gal Mixing Procedure 1. Dissolve monoammonium phosphate in a portion of the water. 2. Add pigments and fillers to (1) with constant agitationo 3. Add remaining water with constant agitation, 4. Add diethylene glycol, Cellosolve and Acrysol GS with constant agitation. 5. Add Tergitol NPX with constant agitation. Complete the dispersion by passing thrpugh a 5-roll mill. 13 5

ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN 6. Add Resyn 12K51 with constant agitation. 7- Add glyoxal with constant agitation. Observations Initial viscosity was 93 KU. Lowering the Acrysol GS content did not appreciably lower the viscosity. Initially all viscosity variations produced by the addition of Acrysol GS resulted in smooth paints that were thixotropic. On aging a week they develop soft agglomerates. Shortly thereafter the paints approached a consistency of custard, making them useless The exact cause was not established, but it may have been the Resyn 12.K51 itself. Acrysol GS, a sodium polyacrylate, will coagulate when in contact with small quantities of a weak acid such as acetic. The sample of Resyna 12K5l on aging did develop an acetic odor and became very viscous indicating an unstable system. The most comon cause of unstability was a poor emulsion stabilizer, Replacement of Acrysol GS with carboxymethyl cellulose or another thickening agent would probably result in a more satisfactory paint, but no further work was done with Resyn 12K51 since other latices appeared better. Also a sample of a paint known as formula 3A submitted by National Starch was not satisfactory. Pigment dispersion made in a colloid mill instead of a 3-roll mill resulted in entrapped air, MODIFIED DUPONT FORVBULA Ingredient Percent Lbs/gal Cost/lb Gallons RWI (TiPure FF 4.8 32,32.225 o0.149 1.8 (TiPure R-610 19.0 3-4.99.245 0543 4,65 (Mica 325 mesh w.g. 2.7 23.49 0.0775 o0115.21 (Methocel 400 (51o) 11 8.34.66 1.330.37 (Balab 259 0.2 850**.40* 0o.24 8 (Water 14.3 8.33 17.16 Emulphor EL-719 O..2 8.85** 36 o 0)23.07 Water 7 1 8.33 -- 0.852 (Aerosol OT (100b) 0.2 9.0** 1.00 0.022,.20 (Carbitol 3.2 8.55.2075 0.375 66 (Water 0.8 8.33 -- 0096 Elvacet 81-900 32.9 9.2 Q0.215** 30580 7-07 Dibutyl Phthalate 2.7 8.75.3575 0.039.97 99.2* 9.134 15 36 *"Dowicide't A preservative was not included. Paint made with 1"Dowicide.B preservative caused agglomeration. **Figures estimated. 14

ENGINEERING RESEARCH INSTITUTE ~ UNiVERSITY OF MICHIGAN Pigment = 265% Vehicle = 73.3% Vehicle nonvolatiles = 30% PV = approximately 27o7% Lbs/gal = approximately 10.85 Viscosity = 82 KU Ratio of pigment to nonvolatile vehicle solidso By volume 1: 2.62 By weight 1 - 0,-786 2.61 lbs TiO0/gal 1,99 lbs Elvacet 81-900 solids/gal 5.20 lbs water/gal Cost = approximately $1,68/gal Mixing Procedure 1. Add with constant agitation the pigments and fillers to the Methocel followed by water and then Balab 259. 2. Disperse on 3-roll mill, 3. Dissolve Emulphor EL-719 in water -ad add to pignment dispersion with constant agitation. 4. Aerosol OT dissolved in Carbitol and water and added to pigment dispersion with constant agitation o 5. Dibutyl phthalate plasticized Elvacet 81-900 added with constant agitation. Observations Foaming occurred when the pigment was dispersed in a colloid mill in the presence of Emulphor EL-7119. No foaming occurred in the above mixi'g procedure. Paint is thixotropie and has an initial viscosity of 82 Kio, After four months storage the paint was easily redispersed. However, its visco-sity had increased to 100 KU which is too high for satisfactory application. 15

ENGINEERING RESEARCH INSTITUTE ~ UNIVERSITY OF MICHIGAN MODIFIED COLTON CHEMICAL FORMULA Ingredient Percent Lbs/gal Cost/lb Gallons PMC Vinac WR-20 32.9 9.2 0.215** 3.580 7.07 Dibutyl Phthalate 2.7 8.75 0.3575 0.309.97 TiPure R-610 23.8 34.99 0.245 0,680 5.83 Mica 325 mesh w.g. 2.7 23.49 0.0775 0.115.21 Methocel 400 (5%) 11.1 8.34.66 1.330.37 Water 14.3 8.33 -1.716 - Erulphor EL-719 0.2 8.85**.36 0.023.07 Water 7.1 8.33 -- 0.852 Aerosol OT (100%) 0.2 9..0** 1.00 0.022.20 Cellosolve 3.2 7.74.20 0 414.64 Water 0.8 8.33 --- 0.096 -' 99.0* 9.137 15.36 *"Dowicide" A preservative was not included. Paint made with "Dowicide" B preservative caused agglomeration as it did with the Dupont formula. No antifoam agent was added. **Figures estimated. Pigment = 26.8% Vehicle 73.2% Vehicle nonvolatiles = 29.7% PV = approximately 27.3% Lbs/gal = approximately 10.85 Viscosity = 78 KU Ratio of pigment to nonvolatile vehicle solids: By volume 1: 2.66 By weight 1: 0.786 2.61 lbs TiOa/gal 1.99 lbs Vinac WR-20 solids/gal 5.20 lbs water/gal Cost = approximately $1.68/gal Mixing Procedure 1. Add with constant agitation the pigments and fillers to the Methocel. 2. Disperse on 3-roll mill. 16

ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN 5. Dissolve Emulphor EL-719 in water and add to pigment dispersion with constant agitation. 4. Dissolve Aerosol OT in cellosolve and water and add to the pigment dispersion with constant agitation. 5. Vinac WR-20 preplasticized with dibutyl phthalate added with constant agitation. Observations Initial viscosity of the paint was 78 KU. After four months storage, the paint is readily redispersed and the viscosity has risen to 90 KU. The suggested method of preparation resulted in no foaming, but the same method (no antifoam present) using Dupont's Elvacet 81-900 resulted in some foam. Colton's suggested formula is identical to Dupont's except that no anatase TiO2 is used and cellosolve is substituted for Carbitol. Paints made from Vinac WR-20 tend to skin, an inherent characteristic of the resin. MODIFIED ROHM AND HAAS FORMULA Ingredient Percent Lbs/gal Cost/lb Gallons RMCG/l0 lbs TiPure FF 12.5 32.32 0.225 0.387 2.81 TiPure R-610 5.3 34.99 0.245 0.152 1.30 Asbestine XXX 16.5 2.74 00175 0.695.29 Rhoplex AC-33 56.5 8.67 0.265 6.520 14.95 Water 5.1 8.33 -- 0.613 - Acrysol A-3 (1% NH3salt) 0.5 8.5*.15* 0.059.07 Tamol 731 (10% solution) 0.5 8.33*.15 0.060.08 Boric acid 0.6 12.0 0.07 0.050.04 Diethylene glycol 1.1 9.31.2025 0.118.22 Balab 259 0.2 8.50*.40* 0.235.08 Ammonium hydroxide 28% 1.2 7.5.04 0.160.05 (to pH of 9.0) ~*Figiures eStimteid. 100.0 8.949 19.89 *F^igures eltimted.. 17 17

ENGINEERING RESEARCH INSTITUTE U NIVERSITY OF MICHIGAN Pigment = 34.3% Vehicle = 65.7f Vehicle nonvolatiles = 42.5 PV = approximately 30% Lbs/gal = approximately 11.2 Viscosity = 71 KU Ratio of pigment to nonvolatile vehicle solids By volume 1: 2.53 By weight 1: 0.76 1.99 lbs TiOz/gal 3.2 lbs AC-33 solids/gal 4.12 lbs water/gal Cost = $2.22/gal Mixing Procedure 1. Add Balab 259 to a portion of AC-33 with agitation. 2. Add Tamol 731 and Acrysol A-3 to water with agitation, 3. To a mixtare of pigments, extenders and boric acid, add (2) with agitation. 4. To a mixture of (2) and (3), add (1) with agitation. 5. Stir in additional AC-33 to make moist paste. (About 1/2 of total AC-33 used.) 6. Disperse paste by passing through a 3-roll mill. Very little entrapped air. 7. Add remaining AC-33 with agitation. Small agglomerates still remain. 8. Add diethylene glycol and sufficient ammonium hydroxide to a pH of 9.0. Observations The AC-33 is very susceptible to foaming. For the most part foaming could be eliminated if the antifoam agent were present in the material being dispersed on a 3-roll mill, Other methods for dispersion were unsatisfactory, Agglomerates were present in the paint prior to the addition of ammonium hydroxide, which changes the pH from 6.0 to 9.0. ___________________________________ 18.....

ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN Initial viscosity of the paint was 71 KUo After four months the paint settled a little but was readily redispersed. The viscosity increased slightly to 76 KU. BAKELITE FORMULA Ingredient Percent Lts/gal Cost/lb Gallons RMC/100 lbs TiPure R-510 25.2 34.99 0.245 0.720 6.17 Mica 325 mesh w.g. 2.8 23.49 0.0775 0.119.22 WC-10* 23.3 see below see below 2.538 5.54 Ce.losize WPHS (5%) 9.3 8.33 0.48 1.117.22 Ethylene glycol 2.3 9.3 0.1875 0.247 Glyoxal (30%) 0.5 10.48 0.185 0.048.09 Daxad.11 0.2.- 0,25 --.05 Tergitol NPX 0.1 8.8 0.315 0.011.03 Water 36 8.33 -- 4.360 100.0 9.160 12,75 *Composition of WC-10: Lbs Lbs/gal Cost/lb Gallons R-MC WC-130 latex solids 13.0 9.94.39 1.31 5.07 Dibutyl Phthalate 1.3 8.75.3575 0,148 47 Water 9.0 8.33. — 1.08 - 235. 2558 554 Pigment 28% Vehicle = 72% Vehicle nonvolatiles = 21.1% PV. approximately 36.5% Lbs/gal =.10 9 Viscosity = 55 KU Ratit of pigment to nonvolatile vehicle solids: By volume 1 1.74 By weight 1: 0.51 2.75 lbs TiOa/gal 1.42 lbs WC-130 solids/gal 4,97 lbs water/gal Cost = $1.39/ga l......19 ~

ENGINEERING RESEARCH INSTITUTE * NIVERSITY OF MICHIGAN Mixing Procedure 1. Dissolve Daxad 11 in water. 2. Add pigments and fillers with agitation. 3. Stir in Cellosize WPHS. Disperse on 3-roll mill or colloid mill. 4. Add WC-IO, ethylene glycol, Glyoxal and Tergitol NPX in order with agitation. Observations The viscosity of the paint was 55 KU. The finished paint contained large quantities of entrapped air because the Cellosize WPHS was added prior to the pigment dispersion which was then 3-roll milled or run through the colloid mill. Paint settled very badly, although it could be redispersed with sufficient stirring. The paint contfains too much water and/or not enough Cellosize WPHS. Four months aging increased the viscosity to 64 KU. 20

ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN PIGMENT WATER DEMAND 1% Daxad* 11i- solution Pigment Fluid paste/100 g** Comments OR 540 (TiO0) 37.2 Paste does not flow TiPure R-610 46.4 Paste does not flow TiPure R-510 37.6 Paste does not flow TiPure R-110 47.8 Paste does not flow TiPure FF 95.6 (Anatase TiO2 requires more TiPure LO 94.4 solution than rutile TiO2; has slightly better flow N.J.Z. Kadox 15 95-100 Extremely fluid paste required for removal from spatula, fair flow N.J.Z. XX505 55.5 Very promising ZnO pigment Fair flow N.J.Z. XX503 30 Dilatant E.P. 730 20 Dilatant E.P. 417 32.5 Dilatant E.P. 427 ' 42.5 Dilatant E.P. 415 28 Dilatant 1/2 505; 1/2 503 4. 0 Mixture of di.latant and plastic ZnO was not dilatant but showed fair flow 1/2 505; 1/2 R-510 53 Fluid requirements are not additive Lorite 66.5 Initial d.ilatancy good flow; smooth paste Nytal 300 85 Difficult to disperse; grainy type paste; fair flow ASP 400 52.5 Excellent flow ASP 100 7.15 Good flow; no dilatancy ASP 1100 60.0 Good flow; no dilatancy Asbestine 3X 62.5 Smooth paste; no flow Metronite BXXXX 26.4 Slight initial d.ilatancy Excellent flow Mica 325 104 Very dilatant Wollastonite P-l 53.6 Dilatant; poor flow Wollastonite P-4 47.6 Add additional 5cc promotes good flow but grainy texture Hydrite 72.0 Smooth paste; fair flow Hydrite Flat 47.6 Smooth paste; fair flow Hydrite PDO10 104 Smooth paste that is very fluid but tends to resist flow *Sodium salts of polymerized alkyl naphthalene sulfonic acids **Milliliters of solution required to impart sufficient fluidity to the paste so that it will fall from the end of a spatula. 21

ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN PIGMENT WATER DEMAND (CONT.).1 solution Igepal* C0-630 Pigment Fluid paste/lOO g Comments Metronite BXXXX 36.5 Foams; paste like whipped cream TiPure R-510 89.0 Foamy paste Hydrite Flat 86.0 Slightly dilatant ASP 100 210.0 Very fluid ASP 400 84.0 Smooth paste Wollastonite P-4 65.0 Very foamy; appears grainy E'.P. 415 116.0 Very foamy; not dilatant XX 505 148.5 Foamy; fair flow Asbestine XXX 90o0 Smooth paste; no flow Lorite 72.5 Initial dilatancy; foamy paste, fair 'flow Nytal 300 100.0 Some entrapped air; fluid paste.1 solution Blancol** Metronite BXXXX 25.5 Slightly dilatant; smooth paste TiPure R-510 4355 Poor flow; lumpy paste Hydrite Flat 49.0 Very dilatant; good flow; smooth paste ASP 100 68.0 Dilatant; good flow; smooth paste ASP 400 54.5 Same Wollastonite P-4 52.5 Very dilatant; not foamy; smoo0th E.P. 415 30.0 Very dilatant; excellent flow; smooth XX 505 66.0 Asbestine XXX 69.0 Smooth paste; poor flow not dilatant Lorite 66.5 Initial di.latancy; good flow smooth paste Nytal 300 84.0 Difficult to disperse; paste appears grainy but it flows *alkyl aryl polyethylene glycol ether **sodium salt of condensed naphthalene sulfonic acid 22 ~

ENGINEERING RESEARCH INSTITUTE ~ UNIVERSITY OF MICHIGAN PIGMENT WATER DEMAND (CONT.) 1% solution Nekal* BX-76 Pigment Fluid paste/lO g Comments Metronite BXXXX 34.5 Foamy; like CO-630 TiPure R-510 1.14.0 Very foamy paste Hydrite Flat 81.0 Slightly dilatant Like co-630 ASP 100 145.0 ASP 400 74.0 Wollastonite P-4 50.0 Foamy paste; very dilatant -E.P. 415 67.0 Not dilatant; drops clean XX 505 116.0 Very foamy Asbestine XXX 96.5 Very foamy Lorite 68.5 Initial dilatancy; foamy "-'.~~~~~~ ~~~paste; fair flow Nytal 300 104 Foam; fluid paste *sodium salt of alkyl naphthalene sulfonic acid plus 20% anhydrous sodiuun sulfate SURFACE TENSION*, Wetting Agents Temperature, 0C Dynes/cm Distilled water 26 73-3** 1% Nekal BX-76 27 32.6 1% Blancol 27 6209 1% Igepal C0-630 27 34. 0.5% Daxad 11 26 72.4-73.2.1% Daxad 11 26 69.5-71.9 2% Daxad 1.1 26.5 71.3 3-71.9 1% Darvan 1 26.5 67.8-68.4.1 Darvan 2 26 57. 1-53.7 1% Tamol 731 26 51.3-48.7 1% Tamol N 22.5 71.6-72.8 1% Petro AA 29.5 33-5 1% Tergitol NP-35 26 39.9 *Measured on tensiometer C7-6. **In some instances the values increased or decreased indicating a surface phenomenon. Results appearhigh since distilled water value should be 71.9. 23..

ENGINEERING RESEARCH INSTITUTE ~ UNIVERSITY OF MICHIGAN SURFACE TENSION (CONT.) Defoaming Agents Temperature, ~C Dynes/cm 1% Nopco JMY 26 31.6 1% Nopco JMU 26 31.8 DeAirex 506 28 33 9 DeAirex 510 28 34.4 S/V Foamrex S 28 45.4-43.5 AF Paste S-1 28 33.0 Balab 189 28 30.4 Balab 259 28 31.1 Note: The last 3 defoamers and to some extent S/V Foamrex S exhibit poor homogeneity in solution, i.e., a layer rises to the surface. The first 4 defoamers in solution form a homogenous emulsion. S/V Foamrex S solution is like pearl essence. Mixtures of WettingAgents and Defoamers Temperature, ~C Dynes/cm 0.% JMU - 0.25% Daxad 11 25 44.3-41.0. 5% JMY - 0.25% Daxad 11 22 31.8 0.5% JMY - 1% Daxad 11 22 40..5-38.2 0.5% JMY - 0.5% Darvan 1 22 42.0-40.6 0.5% JMU - 0.5% Darvan 1 22 44.3 0.5% JMY - 0.5% Nekal BX-76 23 39.2-38.5 0.5% JMU - 0.5% Nekal BX-76 23 39.6 0.5% JMY - 0.5% Tamo.l 731 23 43.3 0.5% JMU - O.5% Tamol 731 23 43.3-38.8 0.5% DeAirex 506 - 0.5% Daxad 11 28 41.2-40.5 0.5 DeAirex 510 - 0.5% Daxad 11 28 41.2-40.2 0,5 Petro AA - 0.5% Daxad 11 30 36~5 0.5% Blancol - 0.5% JMY 30 30.8 0.5% Igepal c0-630 - 0.5% JMY 30 35.0 0.5% Tamol N - 0.5 JMY 30 30.8 0.5% Darvan 2 - 0.5% JMY 30 30o4 0.5% Tergitol NP-35 - 0.5% Daxad 11 26 43.4 0.5% Petro AA - 0.5% Darvan 1 30 36.0 0.5% DeAirex 506 - 0.5% Darvan 1 30 37.6 0.5% Balab 259 - 0.5% Darvan 1 30 34.8 0.5% Balab 259 - 0.5% Daxad 11 30 35.6 Note: Blancol and JMY solution has a very active surface. 24

ENGINEERING RESEARCH INSTITUTE UNIVERSITY OF MICHIGAN GLOSSARY Trade Name Description Supplier Resin Latex WC 130 Polyvinyl acetate latex emulsion Bakelite Company Elvacet 81-900 Polyvinyl acetate latex emulsion Dupont Company Vinac WR-20 Polyvinyl acetate latex emulsion Colton Chemical Co. Shawinigan TS-22 Polyvinyl acetate latex emulsion Shawinigan Products Resyn 12K6l Polyvinyl acetate latex emulsion National Starch Co. Everflex G Polyvinyl acetate latex emulsion Dewey and Almy Co. Rhoplex AC-33 Acrylic resin emulsion Rohm and Haas Co. Thickeners Acrysol GS Sodium polyacrylate Rohm and Haas Co. Acrysol A-3 Polyacrylic acid Rohm and Haas Co. K-707 Ammonium polyacrylate B. F, Goodrich Chem.Co Cellosize WPHS Hydroxyethyl cellulose Carbide and Carbon Cellosize WP-300 HydroXyethyl cellulose Carbide and Carbon CMC Caiboxymethyl cellulose Hercules Powder Co. Methocel Methyl cellulose Dow Chemical Co. Pigments TiPure R-110 Titanium dioxide (rutile) Dupont Company TiPure R-51O Titanium dioxide (rutile) Dupont Company TiPure R-610 Titanium dioxide (rutile) Dupont Company TiPure FF, LO Titanium dioxide (anatase) Dupont Company Unitane OR 540 Titanium dioxide (rutile) American Cyanamid Co. Kadox 15 Zinc oxide New Jersey Zinc, Inc. XX505, XX503 Zinc oxide New Jersey Zinc, Inc. E.P. 415, 417, 427, 730 Zinc oxide Eagle Picher Co. Fillers ASP 100, 400, 1100 Aluminum silicate Edgar Bros., Inc. Metronite BXXXX Calcium magnesium silicates and carbonates MetroNite Company Mica 325 w.g. Mica English Mica Co. Asbestine 3X Magnesium silicate International Talc Nytal 300 Magnesium silicate R. T. Vanderbilt Co. Wollastonite P-1 Calcium silicate Godfrey L. Cabot, Inc. Wollastonite P-4 Calcium silicate Godfrey L. Cabot, Inc. H. Hydrite and Hydrite PD-10 Hydrated aluminum silicate Georgia Kaolin Co. Hydrite Flat Hydrated aluminum silicate Georgia Kaolin Co. Lorite Calcium carbonate; diatomeacous silica National Lead Co............ ~25..

ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN Trade Name Description _Supplier Dispersing and Wetting Agents Emulphor EL-719 Polyoxyethylated vegetable oil General Dyestuff Corp. Aerosol OT American Cyanamid Co. Tergitol NPX Alkyl phenyl ether of polyethylene glycol Carbide and Carbon Tergitol NP-35 Alkyl phenyl ether of polyethylene glycol Carbide and Carbon Daxad 11 Sodium salts of polymerized alkyl naphthalene sulfonic acids Dewey and Almy Co. Blancol Sodium salt condensed naphthalene sulfonic acid General Dyestuff Corp. Nekal BX-76 Sodium alkylnaphthalene sulfonate General Dyestuff Corp. Igepal CO- 630 Alkyl phenoxy polyoxyethylene ethanol General Dyestuff Corp. Tamol 731 Rohm and Haas Co. Tamol N Rohm and Haas Co. Darvan 1 Polymerized sodium salts of alkylnaphthalene sulfonic acids R. T. Vanderbilt Co. Darvan 2 Polymerized sodium salts of subsituted benzoid alkylsulfonic acids R. T. Vanderbilt Co. Petro AA Alkyl aryl sodium sulfonate Petrochemicals Co. Defoamers JMY Nopco Chemical Co. JMU Nopco Chemical Co. DeAirex 506 E. F. Houghton and Co. DeAirex 510 E. F. Houghton and Co. S/V Foamrex S Socony Vacuum Co. AF Paste S-1 Polymer Southern Inc. Balab 189 Balab Co. Balab 259 Balab Co. Miscellaneous Carbitol Diethylene glycol monoethyl ether Carbide and Carbon Cellosolve Ethylene glycol monoethyl ether Carbide and Carbon Glyoxal Glyoxal Carbide and Carbon 26

UNIVERSITY OF MICHIGAN 3 9015 02654 4893