Document 8LEV7BYGEnxomzddpOn1Yz85

Indexed W. Theobald, Vila. F&F !> Lawson, WilJU* P&F P. B0 Cochran, Wllm. F&F Dc McBtarney, Wii P&P a. B0 Davis, Wilta* P&F i} a M. Mestor, 11o F&F Jo So Allen, Mil,, F&F Ra Ee Thomas, Mewburgh L0 to Wise, Sxp,, Station Jo Bo Pickens, Flint Files 1865 Report Sto-. R-58-44 p,T^r:,? :JA!j E, lo du Pont de lemoars Ss Company, 2ne 0 F0 3 F0, Research Division Marshall Laboratory Research Report THE EFFECT OF VAHXATXOHS IK PISME mKim OK THE PROPERTIES OF EMULSION PAINTS Date Issued? Period Covered? Project MOo s Previous Reports notebook Kg0s June 24, 1958 January 1956 June 1958 (Part Time) P2155 (Formerly P-20702 and P20S0l) r m-56-23, R-57"17, R-57-62 6166, 6248, 624-9, 638.8, 6389, 6553. 6554, 6767 PREPAH BY ^TTT^OTEnisr: APPROVED BY J N 425 THE EFFECT OF VARIATIONS II. PI6MBNT PACKIMB -.-0W THE FR0PSET1ES Qg"BHPLSIP8 mOSTS TABLE 0P COHTBlfS Jt03ft <>. eoaooaeaeeooooeaeaoesoBefiroeoooae Objective. 3cEl^d C*0I^OXUL0ll0iHiiS o<Hed(i0Qt}#9oitaoe Action rfakeno **** eeaoeooe**ooo**o**<> ACiCn0WX^^a^ntll 9QOOfl'e<*eoo*aei30aa$fae?e*e*cooo ^aQ.o-&Ofio<saftCiti'<3oooo&<aoo-o< Packing Index and Void oltimed for TiOg/^agneaiuiH Silicate Pigmentation^ ecoe-oeee^aeo oaa&eaoofro^ooo Packing Index of TIOg/Ga 00^ P 11OmS ...... .....oooo.oo..ooo.oa Effect of Particle Size Distribution on Various Paint Properties............... A. Base of Brushing...... o o o e a B, Shrinkage Cracking.....e........ . S, Scrub Resistance................ D. Sheen Reduction................. R Elongation. oooooc-ooocoo P Permeability to Water... 00000900 y 0. Erosion.Do............ oooaooocoo H. Dirt Collection............ 3 6 O O I. Screen Staining.........lOOOflCOO^fr Bibliography. . ...;.aO0ooodoeo9ocdoooovotfi<&a'O Page go. 1 1 2 2 3 4 5 6 7 7 8 9 10 11 15 16 17 17 18 LIST Qg TABLES (SEE ATTACHED PAGE) DUP030008885 MSI? OF MBL1S Packing Index Constants, Packing Index, Void Volusses, Critical Pigment Volume ConeenfemtiosMi for M-90 s^fss^a^^fteoefj^o-sfjs^ees-sae* Shrinkage racking Eatings Showing that Cracking Is Reduced fey Increasing the Packing *. s . . oo*,&&<!> Scrub Resistasiee vs, Packing Index B5& Sheen vs, Ratio of W50A~l42/W-90... 77 F Elongation vis, ftetio o-i %l-50/M^ife/M-90, & Packing Index.\ ........ Smaface Area @s Calculated Polymer thickness vs Ratio 50/M-142/M-90 30@F Elongation t o . Ratio ~50A~l42Ah*90. 30F Elongation with Various Extenders*. *,, ,, 3$F Elongation of Various Polymer with TiOg/Calciu Oarfeosate Increased 30F Elongation fro W-93/M6/i-3Vw-XO04 low Permeability of Lytron 680 with -50/W-142/v0 0 o 4* c tp a <3 o o o o a o % Erosion vs. Ratio of ~S0/I4a/W~9 at Various PSVX, ?po<sc-Rtr*o#o^c'<9oew<s>0' ?&fg Mo. 6 7 8 9 1 11 12 13 14 14 15 15 16 DUP030008886 Tm k f f s c t o f v a r ia t iq k s xi f ig me n t t a c e x io m TEE PROPERTIES QF SBTOIOH PA1MFS XllfROBIJCflOMs In order to predict paint properties fro variations in pigmentation it is probably more Important to know the particle sisse distribution than to know the chemical composition of the pigmentation,, The effect of particle sise distribution on paint properties is readily demonstrated by use of the pigment packing concept which Str* Ba Bosse has described in w4j Process** Standard Formulating Practice f p -01A and in "48 Process" Standard Formulating Practice FP-01-B* The advantage of this pigment peeking concept over Asbeck and Van Loos5 critical pigment volume concentration is that packing indexes can be readily calculated for most combinations of pigments from data which is already available in to? formulating practices. This report will illustrate -the effect of systematic changes in the particle sise distribution on the packing character!sties of extenders and on various paint properties. The paint properties we investigated were those which we predicted would affect the performance of emulsion house paints e.g. elongation, erosion resistance, sheen, water (scrub} resistance, dirt collection, and shrinkage cracking. Reference has already been made to some of this work in the following reports s RM-3S-23, R~S7*= 17, and r -57-62. OBJECTIVES The taain objective of the project under which this work was done was to formulate a durable emulsion house paint. Xt was hoped that a better understanding of the role of pigment packing would aid in eliminating some of the deficiencies of these emulsion paints, e.g. insufficient retained elongation? poor coalescence, excessive permeability and excessive dirt collection at low pigment volume concentrations. DUP030008887 2" Bxmmm.&h p o o b c x mb s o h b s The pigment packing ia' greatly improved by mixing medium mid coarse particle sine extenders with fine particle size titanium dioxide. By calculating the packing index for various pigment combinations# the system with the best packing and lowest interstitial volume can be determined,, When higher* packing index pigmentations are used in emulsion paints, the following advantages are observed (i) Increased elongation, (21 increased water (scrub) reals T>i M (3) Bec2?@sused sheen. (4) Improved brushing especially at high solids, (5) decreased shrinkage cracking* (6) Lower raw material cost due to the possibility of increasing the pigment volume concentration and of including sore extender. However* a higher packing index pigmentation usually results la some aerifies in dirt collection unless the pigment volume concentration is increased. C&leiuis carbonate which Is a good extender for packing with titanium dioxld causes screen staining and some grades f salciuiB carbonate Increase the erosion It is believed that the Increase in elongation ~ and some of the other advantages of higher packing index combinations* are due to the higher critical pigment volume' concentration and to the lower specific surface i.. areas of such pigmentations* kGTmm mKM% The emulsion house paint which was selected for trial marketing (lelease Letter R-l6) was based on the vehicle (Hhoplex MK33) and the extenders (W4 and W88) ';on which we ted the longest durability background In 195^. Since then other theoretically better pigmentations have been exposed but no significant durability'advantages have shown up as yet. DUP030008888 S> ^ Use Is being asade of the better pigment packing combinations in experimental latiees such as pols^JLsobutylene fco raise: the pigment volume concentration^ to decrease dirt collection without sacrificing elongation* r up The advantages of the improved pigment packing A*demonstrated la this work were development of cheaper ^higher piimgmpeonrttavnotluimnefceheoneentraitOio#l^^^.y Interior paints, 0g.0 triples,, "Flow Kofce" and a faeap^/^f% polyvinyl acetate Interior paint,, The low cost f these ** paint suggested similar work in styrene butadiene paints. vT * As A ~ result "Flow Kote" was made more scrub resistant, flatter and cheaper (Release letter #1705) by Increasing the packing and the pigment volume concentration with calcium carbonate. i' h test method (TM-250) has been issued by W* B0 Callahan for the measurement of paciciag indexb 0 The Physical Testing @roup will soon be equipped to sake measurements using this new test method. ftgKMOWLBPCI gfBBHTg: The packing Index calculations used in this report are based on 3m Base9 & formula and nomograph The experimental, work was don expeditiously and carefully by J* J Gallagher0 The writer wishes to acknowledge fche helpful suggestions and stimulating discussions provided by D0 Bos.se, D. L. Herndon, M. Orel?, wa $0 Horaitorook, w,, J0 McOoneghey and J,, J0 Hikollch, MJHshfta 6/18/58 6/20/58 DUP030008889 4 gCgCqSSXQKs Polyvinyl acetate house paints based on Kiv&eefc 8l900 emulsion cracked less in Series 13757 when pigmented with extender and TiCWihaa when pigmented with unextended TIOg. It was hoped to completely eliminate emklng*. i. b f still further improving pigmentation (toy finding the optimum pigment volume concentration and the optimism extender/TiQg ratio* and 2* By improving the vehicle (modifying the polymer to obtain better coalescence* water resistance, low temperature elongation retention) <> The latter approach has been emphasised in several research report (RH57-17* B7gg)e This report will describe attempts to detsnniae the effect of systematic variations in pigmentation <tn various paint; properties* The particle size distribution* the shape and the amount of extender can be used to control the number and the size of the Interstices or voids which must be filled, by polymer in properly formulated paints* If the total void vblufae is small* the critical pigment velum concentration will be higher* (The critical pigment volume concentration * ` 100 X _ ___ the volume of pigment ^S^voISSe pfgiiSF'^f'^li'^TOl^S^orfEe when tightly packed*j Packing index also is inversely proportional to the void volume* h defined by B* Bdsse the packing index the volume of ent iqu: when the pigment or mixture of pigments is dynamically packed* dynamically packed Is defined as 53the minimum solid particle packing at which appreciable mechanical interference between pigment particles can be obtained throughout the mixture when subjected to high shear rates (> 1000 se7i)w DUP030008890 f Sup.3o, o 8, -5 It was reasoned that If the voids* calculated fro the packing index* were minimized by the proper choice of extender* a given volume of polymer should be able t fill the voids, more completely after the water evaporated,, In emulsion paints the discrete polymer particles have to coalesce Into these voids and on to the pigment particles,, In the Meal case the polymer should be evenly distributed over the pigment surfaces* It should not be wasted for filling up voids which can be more cheaply filled with pigment particles of -the optimum sis distribution. Packing Index and Void Volumes for Ti0/SlKgneIu Since the packing index fr. *TlPur" R~6l0 (-50) is 0*78 OlOOl 100 volumes of W-50 when <n 1 ,,|$i dynamically packed have 128 volumes of Interstice ^ voids* Similarly since the packing index of iiagnesiuil^/*' 1*0^ silicate (W~4) is 0*54* C^XOO) 100 gallon of this extender require 185 gallons of liquid for dynamic.packing* All mixtures of these two pigments can be packed more densely because the fine W50 can fill the voids between the -4 particles* and thus s?aet as a liquid*" This packing effect has been calculated. F3.gu.re I shows that the mixed system j5Q/4ypaeks tightest In the range where -50/w-4 * 50/50 fcp 40/60* A hundred volumes of a 50/50 ratio of W-50/W-4 requires only 75 volumes of liquid to fill the voids* whereas separately W-50 requires 128* and -4 require 185 gallons. The composition range from 50/*4 * 50/50 to 40/60 is described, as the balanced range. When W~50/w~4 I greater than 50/50 the system is described as an excess finer pigment system? when ~5G/w 4 Is less than 40/60 it is an excess coarser pigment system. The formulas used for calculating whether a system 1 excess finer or excess coarser are' given on pages 39 and 40 of Standard Formulating Practice FF01B Most white emulsion house paints are formulated as excess finer systems because most of the pigment has to be TiOg to obtain sufficient hiding. Here extender DUP030008892 &Uc. '30, S,893 "S" can fee added, however, in colored house paints and these generally showed Improved resistance to crackingc More extender can he used in white paints if the pigment volume concentration is increased, Better pigment packing makes higher pigment volume concentration practical, because it Increases elongation (see Figure IX and paragraphs^** Elongation) More extender can also be used in whit paints without sacrificing hiding if the solids are increased0 Usually higher solids decreases, stability, and ease of brushing* However, better*5pigment packed system have improved stability and brushing at higher solids* 5 The best lead for increasing the extender content was to improve the pigment packing so that higher solids and higher pigment volume concentrations would to possible* Higher pigment volume concentration was also desirable- to reduce dirt collection and to reduce cost* &n increase in pigment volume concentration fro 25 to 3598 In & Rhoplex A0-33 (S&AllA/tlM) emulsion house paint reduces cost by..about 12$ per gallon (when the TiO and the solids ar kept constant),, With these advantages in fflind it was decided to study the effect of pigment packing in Rhoplex Ad-33 and Celanese CL-202 (Ae/DBM) evulsion paints*' At the time these latexes were the best candidates for emulsion house paints* Packing Index for TIOg/Ca CO3 Pigmentations, Calculations based on the packing indexes and the effective diameters listed in PP-01-B indicated that the packing index could be varied over quite a wide range if various mixtures were taken of a good packing coarse extender, e.g,,, -90, a good packing medium extender, e.go, -142, and a fine titanium dioxide, ,g,,, W-50, The "constants" for these pigments have changed somewhat probably due to batch-to-.batoh variations, etc. The following table lists the constants recorded In the 2/18/55 and the 10/18/57 editions of Standard Formulating Practice FP-Ol-S!." Code Description ;v , jra.VJfU.IlK AHaex To/fmf 2/18/55 directive maseter W7WWT mms~ -50 -142 -90 "TIPure R-610 Atomlte PaSO^ Whiting Q&QO3 0,78 1.33 1.24 0.71 1.57 1,42 0,5 '4,5 10 0,4 microns 3 microns 10 microns DUP030008894 7-- ifhe constants as offy2/l6/g^were used to calculate fehe following p&eklhg-^iafSSxes void volumes and critical pigment volume concentrations for various mixtures of W*jO, WX42, W~SO. Volumes of Pigments, Plne/I^dium/Coarse -^50/" jA2,/^gQ 1 00 1 10 1 20 1 1' 1 1 82 Packing Index . 0,71 i.a 1*8 2.0 2,4 Calculated "&ri;ti@al oid . Pigment Volume' , Volume --- ..,, 'Con*-centration" V; 141# 41# 83#. 55# 56# 67# 43* 73# Itiese calculated "critical pigment volume concentration" which are based on packing indesses of the Individual pigments^ give only a rough approximation f the true critical pigment volume concentration-which as defined originally by tofesek and Van loo (Industrial Engineering Chemistry 4g, 1470, (1949) wag that level of pigmentation at which there are 4st enough.vehicle solids present in the dry film to fill the voids between the pigment particles. The above system of W-5Q/&~142A*"9G was selected for this study because it gave a wide range of packing index. Effect of Particle Sis Distribution on various Paint Properties*. As predicted, various paint properties improved as the packing index ms increased. . &. Base .of Brushinss* The pigmentations with the highest packing indexes gave paints with the best application properties. She differences were most noticeable at high solids and at the highest pigment volume concentration. with a straight Ti.0g pigmentation, the brushing mss very poor. With increasing amounts 'of. "good packing" extender' the slip under the brush improved considerably. DUP030008895 B o Shrinkage Cracking* Emulsion paints often show mud cracking on drying or on exposure if formulated with too hard a polymer, with too little plasticiser, with too little coalescing agent, of8 if allowed to dry at too low temperatures, A convenient laboratory test is ft allow the emulsion paint to dry ever a soft, tacky oil paint, k good formulation will not crack during drying. The W-50/Ml4g/fe9O paints baaed Bhoplex AC**33 and eelane.se 1>202 at 30 40 and 5^ pigment volume concentration showed progressively less cracking with Increase in the calculated packing Index, The following table shows that this cracking is worse at high, pigment volume concentmfe ions but can be eliminated even at 40 o? 50^ pigment volume concentration by improving--the packing with medium and coarse grades- of calcium' carbonate ,, ... onafijsi 01 USUAL o-io gelus? mmm t h a t m INOEB&SIH0 JEflL 'ACKXMCt fflL w~5o/Wri4$/to-go Pine^edlmia/' \ - - j; ,. . . Coarse . ' .Pigment Volume 'Concentration Pacfel'sm Index Q,,71 {measured) i 1,2 (calculated) 1.8 2,0 2A " DUP030008896 Q ... Photograph 1 shows that in the Bhoples AO-33 paints the- cracking was reduced tout not eliminated by Increasing the packing index. After these photographs were taken the writer showed that the cracking could be completely eliminated from low ?,,$ Miopias: &0-33 paints if easein by weight on the paint) was added. reason for this decreased shrinkage cracking in the presence of casein Is not fully understood. It may to due to the improved pigment wetting or to the improved flow imparted by the casein* ?.. Scrub Resistancet Hhepleas &C-33 and Celanes GL"202 paints had saeh good scrub resistance at PC*s of 30-4(^ that it was necessary t go 5G~6C$ PC before sufficient failures were obtained to show differences due to pigmentation. The following table shows that the Celanese CL-202 paints at pigment volume concentration showed less failure (when scrubbed with 1$ Ivory Flakes for 8a000 strokes after drying overnight) in the pigmentations with the highest packing index. e f f e c t m in g r b as in o momms o f tesozm AM) USBS FASTIOLE SIZE CALCIUM CARBONATES OS scum .RESISTANCE OF PO&YVIHYL AGITATE C0F0Z.YHRR ___ _ SmLSIOS PAINES (500- PFO) __ %l"50/M=l4S/fI-90 firie/lfediu/ hoarse Appearance After QOOO Scrubs 1/0/0 Considerable erosion 1/1/0 Slight ?s 1/2/0 Considerable. 1/1/1 1/2/2 Ho erosion n ----- ' -... ... Packing Index O.T 1*2 1.8 2.0 2.4 DUP030008897 The excellent scrub resistance and. low sheen of these high pigment volume concentration paints, pigmented with good packing extenders* hat- been of practical importance in the development of Dripless *'Flow Kobe" (see E-57",19a The development of a Gelled 'Thixotropic Interior- Flat Wall Emulsion Paint by Fw 1. Kirkpatrick), cheaper modifications of "Flow lstew (Release Letter HL-1705 High Pigment Volume "Tufcote), and cheap polyvlixyl acetate, interior paint (Harshali Laboratory Sales Development Memo Report SK-57-11)* Competitive Products Report R4l 5/17/57 by H, R, Heikel shows the good balance of properties possessed by these cheaper higher F.V'.O, paints* D * Sheen Reduction? Low sheen Is desirable in both interior and exterior emulsion paints* Although the sheen did decrease with increasing 'packing index, this was probably coincidental*. The low sheen is probably due to the rougher texture of the higher packing index paints which contain ore coarser extenders,, The following table shows that X Rhoplex AO-33 paints have lower sheen than # Celanese 0J>22. fx\ \#t 2s Increasing the pigment volume concentration 1 \P* & decreases the sheen* k 4^' 3*' Increasing the coarseness of the pigmentation with more extender* :.S6ereases the sheen. EFFECT OF HEDZUH AND COARSE p a k e e c x e s iz e , o mn iu m c a r b o n a t e AT VARIOUS FTCS OM THE 85 SHEEN '* N-50A-1^2/W-90 30. 40 30 10 11 12 11 12 0 i 13 37 31 0 13; 9, 8 0 9 10 ' 1% 1 2 3 '4 2 124 Celanese g x ^s o s Paints 10 11 12 11 12 50 40 30 0 50 4? [51 0 11 23 ; 4? 0 7 18 14i 1 3.. 16" '27 2 2 7 0 DUP030008898 11 s., igjonggations In emulsion house paints the main deficiency was and probably still is.insufficient elongation to withstand the swelling sal contraction of wood or old paint substrates* The following table shows that as the packing indess of the pigmentation was' Increased the elongation increased,,... mPB&si 6f ; mi &m domb e mmx&LB 1' ms oAuum c a r b o n a t e s m t e e ?t f s l q mmt x o m*** o f mnmm f &iw f s m %m y.v.c. f~5/f^W^90 SSopiex Fine/^ediuas/Goarse ....AC-33 . 1 0 0 $# 1. 1 0 350 12 0 1380 11 1 14a I2 2 2450 SeXanese 03>2Q2 270 620 14S0 170 2030 tacking Index .7 1.2 1.8 2.0 2.4 *95^ confidence limit $ <}*Rata of elongation on Xnafcron * 200/minute. An analysis of variance of .the above data showed that the TiOg/oalcluas carbonate ratio was significant,with a 95^ probability in controlling the elongation (page 131s notebook 6249),, 'Although the triplicate measurements of.elongation were sufficient to show the significance at 990 .probability level of the TlOg/exten&e# ration they &3?a not show a significant difference between the elongation of the HhopXex MH33 and. the Celanese Gb*202 paint The graph on Figure.IS illustrates the striking effect of these specially elected pigmentations and insignificant effect of the polymer on the. 0 elongation of these paint films. The same elongation data which were plotted in Figure 11 to show the effect of packing index havebeen plotted la Figure III to show, the effect of the surface area f the pigment. It is apparent that the increase in elongation is roughly proportional to the decrease in the pigment area. DUP030008899 - 22 The following table Illustrates how replacing `piG.'j with medium and coarse extender., decreases the surface area of the pigrants>ancl increase the average fchietaiees of the polymer around the pigments ' 1FF20T OF MEDXOH MIB GGA833 BaEEBHDBRS 01 mi s u r p a s s mm o f t e e Fwmm&Txm MB OH TEE THICKNESS OF THE POLYMER OH THE FIQMBHT Pigmentation .: Fine/Jfedium/Ooarse Calculated ^hlekness of Polymer When S CC-IS , Calculated Are Spread ver ' Surface Area of 40 6CS of figment ''40 SOS Pigment (Of. 40$ P.T.C.i .... 1" 0 0 Sv2 x 10T om 27 i 1. 1 0 1.1 55 n 5? 530 12 1 2' i *79" S3 n af7fS 7$0 780 1 a 2 50n 55 1200 Phe surface areas of the pigmentations were calculated fro the specific surface diameters obtained from the pigment supplier or from the Haw Material Index* National Paint9 famish & Lacquer Mmc* larch 1996e & less accurate .estimate could fee made from the effective diameters listed in Formulating Practice FP~01*B or from data on the particle sise distribution of extender pigments given in a letter fro 8a 0. Fox to J,, Ho&ndrews 2/3/98. A possible explanation for the increased elongation which accompanies a decrease in the surface .area of the pigment is as follows* In a 40fl' pigment volume concentration paint* we have 40 volumes of pigment bound with 60 -volumes 'of polymer. If these 40 volumes of pigment are all fine particle else W-50* the surface area will foe four times' greater than 40 volumes of W-50/W*l42/&90 (** 1/2/2). DUP030008900 - 13 ~ The greater the are$ of pigment the thinner the polymer must he spread. The thinner polymer lay&rs will he difficult to attain because' of polymer cohesion and limited coalescence. The thinner layers will also foe less easily distorted by stress because of adsorptive forces* &lmi the greater the area of the pigment the greater will foe the number of flaws between pigment and polymer. These flaws hMoMtedly^cohtrifoute' to' low elongation and cracking on exposure. It seems reasonable to assume that polymer adsorbed on the surface of a pigment would not readily foe distorted by applied stress. Such a pigment system would show low elongation. If the thickness of the polymer on the pigment were Increased the elongation should foe higher. This is one of the reasons for the increase In elongation which accompanies the decrease in FfO for all emulsion paints in the range of 20*S^ PVC,, It also may foe one of the reasons for the Increased elongation which occurs when TiOg is replaced by larger particle sise extenders. When extenders replace TiOg the specific surface area of the mixed pigment is decreased. A given volume of polymer can therefore form a thicker film round each pigment particle and the resulting paint film can then be distorted further. For improved durafolbility we need high elongation not at 77F> but at low temperatures. At 30*F, Shop lex AC "*33 and Celanes CL-202 paints lose so much of the elongation, that the effect of increasing the amount of extender is not As striking as at 77aF. EFFECT OF MEDIUM AMD COARSE PARTICLE SIZE CALCIUM CARBONATES GW THE 30F .BIflNOATION** OF BMPL3I0U PAIHT3 AT 405$ PC Pigmentation i/-50/W~lf7tT90 % Elongation- Rhoplex AC-33 Celanise CL^StOS 10 0 0.9 11 0 2.2 12 0 3=5 111 2.4 12 2j 3,0 *99* Gonfidence~Lia&tT^ ' + O.^v 0.5 1.0 1.0 0.9 1.0 | | #"Ftat@ of Elongation on Xnsfcron. ** ^/minute. DUP030008901 -- Most thermoplastic polymers which are sufficiently non-fcacky for house paints, have such low elongations at 30aW that the differences between paints with different pigmentations are often obscured by experimental errors* The data in the following' table illustrate the effect of extender on the 30"& elongation of Rhoplex 40-33 paints,, The data do not correlate particularly well with the packing indexes of the pigments. #40 (301-918) #42 (301-888) T & 8 White (87-894) 1.8 2.5 4.9 Confidence limit for 95$ probability ** 4- 0.7 Least significant difference * T.0 The *good packing calcium carbonate (M>90} gives a higher elongation^, ass shown in the _ Sable* when it replaces the poorer packing 4/W-88 (magnesium sllleate/ssiea) combination which is sed in #44'Acrylic Emulsion House''Faint.. ^ wr 4/W-88 -90 gpostare Rhoplex 40-33 ^ 1.9 I 'Polyvinylpropionate iFolyVinylprcpionate/j di^inyladipate '! 1.7 Firestone5s Ctr&ffe Acrylic 1.4 finylidene Chloride/j Lata octyl acrylate not available 2.1 1,2 10.7 6.3 12n month iS3n s-15783 S-15764 mW 55 6 12 W n n "155791 S-158241 1 1 95$ Confidence Limit for 30F Elongation + 0.7$. DUP030008902 15 - Since the paints in the above tables were exposed. & higher packing index ptgenfcatin"W~93/W~X6/ W-34/W-5.004 (titanium dioxide ZL-59*r/?Ti-Pqi?e" FP/b&rytes/ R8aiaaeo!' calcium carbonate ** 13/3/7/7) has been tested in Rhoplex AC-33 and found to give much higher 30F elongations than the pigmentation at present being used in #44 Acrylic Emulsion House Paint* X80REASED EXOWATIQ1 MS 3Q*F RBSOTfflMg fff Pigmentation f=537iSwf^l^OT H>0/tf-l6/W-Vto-88 Initial Elongation 2*1 Elongation After 7 Months D. 45 J----------Or-4* 1*5 This pigmentation is also being tested in polyiso butylene emulsion house paints* This vehicle la especially suitable for this approach because it requires very high pigment volume, concentrations to decrease the tack* The higher the PTC the-'more important does the pigment packing become* and the easier it is to formulate balanced instead of excess finer paints* F* Permeability to Waters Another requirement in emulsion house paints for improved resistance to cracking Is decreased permeability t water* The lowest permeability of any emulsion paint measured by the writer was shown by a Lytron ^80 emulsion paint pigmented with fine TiOjg/raedium OaCOg/coarse CaCQg # The Impermeability my be due to the dense packing of the -50/!,)*l42/w`90 and the -excellent coalescence of lyfcron 680,, The following table show that this paint (lytron 680 with W-$0A-l6/W-l42/W-90 at 350 P0) has such low permeability to water that it approaches that of #42 Outside White* the control solution paint* LOW PEfBffiABXLXTy OF LYTR0N 680 FAXIT mMBMTBP WITH W-50A<-l43/W-90 Pigmentation Water Evaporated from Payne Cu p W-50/Wl4g/W90 0ol4 gretss/tey/isil W-50/W-4/W-88 0*5 " " ia Control Solution l Paint - #42 OutsideV White J 0.11 " 8S 55 DUP030008903  16 * Cl* . Erosions Replacing fell halte resistant ^fi^Pure R-Sl Cl-30) with medium (|f~l42) and coarse (W-9GJ calcium carbonates increased the erosion rate of both del&nese CL202 and Rhoplex AC33 paints at 30, 40 and 50$ pigment TOlume concentrations* *Phe percentage & of the usual 2*5 ail films which eroded in 18 month Delaware South Vertical are shown in the following tables. was* warn. PAifficiarKS %mtm c TrarosicaF w WSOSDSST&mm Hhoplex AC"33 Faints ,,>ir-- Oelane.se CL-202 faint "Fwr-~ wgo/W" 14s/W90 50/Ml42/W-90 100 Z-.7* 0.6 0.8 X 0 0 1.2* l.l 1.7 1 1 0 5*6 4.0 3*4 1 1 3*2 2.7 2.2 1 2 0 5.6 5*0 4.4 1 2 3*9 3.0 2.5 1 1 1 1\ 2 4*3 3*9 1 1 4.1 3*3 2.9 tu1 2 2 9*7 4.4' 1 2 3*1 7.8 4.2 Controls #40 Outside White #42 " " 13.1* 9.9 ^ erosion of a 2.5 ail film in 18 months Delaware South Vertical* DUP030008904  - IT H c Birfc_...goilecfctong At constant PVO Btooplei: &C*-33 and Oels.ne.se 0J>20g paints became progressively dirtlei? on exposure as the mtio of TiOg to calcium carbonate was decreased,, This my "be due to the lower critical P?6 or to the coarser texture of these paints, X Screen Staining; s Calcium carbonate increased the copper and iron screen staining of these aiauisios paints but the staining n&s not as bad as calcium carbonate In linseed oil paints. hfm DUP030008905 FF-01-& "47 Process ' Standard Formulating Practice, B. Boss (13/9/54) FP-OI-B *48 Process" Standard Formulating Practice, D. Bosae (2/18/55 - tables revised 10/18/57} SH6-23 Accelerated racking of Bsmisioa faint* M, F. NeDowell (11/6/56) Bur&biXIty of Vinyl Acetate 0nolytaer Emulsion Faints (3/T/57). R-*57-62 durability % Physical Properties of .ileiyi.i aiulslon House Faints (9/24/5?)* Release Letter Rl6 Acrylic BsuXsiott House faint 389*095 Release Letter #1705 High Figment Volume Ooneeatratlon "Tufeote" Rubber Base Wall Faint (5/20/57). W250 Test Method, for Packlag Msx, IK57-19 The development of a Helled. Thixotropic Interior Flat Mali Smulsloa Faints K, X, Kirkpatrick C 3/11/57 ) SH57-H Polyvinyl Acetate 'Interior Paint* J, Kilkeary (4/30/57). #41 Competitive Products Report,, H ,R. Helkel 5A4/57. Raw. fSaterlal index,, national Faint Varnish ft Lacquer Association SS&reh 1956* Rgtender Figments. Particle Sis distribution Data, latter of C, e. Fox to 3+ F* McAMrews 2/3/58* FIGURE I CALCULATED GAU^NS OF LIQUID REQUIRED t o Io t I^g Sy Pii^SK GALLONS OF VARIOUS MIXTURES 'Qjr A FINE T102 (W50) AKD A imy 4~ j. 4 " '_ t o ..... y - \` !\ L\ - * 'p - i' , -- ' Z" tu 5 - .+ -' - ., . .y -- ft ' < ** ^ . ,,.i. r - *V p -i{4 - - * ; k- ' ` * 8 ...i.. .y T O yy ,!* 1 * >?' ; 4 ' U :< , * *. <y H >4 TiyV; r f > * OCm .* i ii.: j '' r ;. y . . ... :.tl, ; y:.:i O . *i .. .,..4..: ... ;, ... y ..... :v . y_ ' --" ... V, .. :: rrr. ....: ` . v;: TMr~ ; ; P-rr~ r._j ............. ; 100 90 80 70 60 W 50 " 1'.. ':- j ~ j ' ' ^ 'j';' .~ -- ............ .... j1.; .. .. ` ; ..... . . j; . ...PT-- t .... . 1. . 'j IP --i~~-- :... j:'. : J Jr.'A ."' ; ;; ; ; ; .'s'. ' ':! .... :. y ;p ...pj ..p TTi-j.-T } j;; ;i|ir :- JMQM yp--- 'J\.}:.:.:'.'.L ; ; ... ,'.;.. -' f p r.pttt ' :::/ . - r ' i- i ! 1' r~"h ' - i. i. .. . j1 --.... __L : I - i' : ..j v~;f. -:r: ---- - :J ,* 1 t... Lqn; ' : j -- -. 'il ' --Liy . i'.y h1 ' -'; `~j7~ 1} . . | . -- - f. - "* ..Pj-;. *..'.*r,1}f|1.';.*..; t - .... .. * k ` |' * ? ~ - ~y qq * -I "'"ZZ _.._. L*, -.. 1 ! --r :r _J__h:: j;;'! ..... "1 . - ~L J..y.L. - .V . ...J, , . ; .T..P. V -- i i - 'j! ' :*- . . . i*j.*--. ,-,:r . i.. i H:: >. '' " --i .... :: ... i. y ' t' - .j. .. ,- .... x. ... i. .. - s1 '- .....~ f- ... ' j: l ...'f --.v. ..... --{ ..-''-4 ' L\ TM' ;. j;:: >,' | ; -1 mt . i ' Lii-ii 1 izAh. :' \ - : p 70 a 0 90 100 PARIS 0F W50 DUP030008907 r*o.  0c rl *<ou u* 23 a> as U o<o# 50% P.V.C. 40% P.V.C. 30% P.V.C. r_ Packing Index 71 (2/18/55) EFFECT OF PACKING INDEX AND PARTICLE SIZE DISTRIBUTION ON SHRINKAGE CRACKING OF 30. 40 & 50% P.V.C. RHOPLEX AC-33 PAINTS PHOTOGRAPH I DUP030008909