Document VGN3kwkkYeG2mxB2gj0v35058

Paint Research January, 1953 -12- j|M.62 - Studies in Flat Wall Paint Formulation The Resin Research Department has submitted, the following variations of (4113) for evaluation in Flat-Tone White. RD 5177 P.E.-glycetol-phthalic-rosin-soya varnish. Body - G. A.V. - 1.7. Color - 8. Solids - 30%. Solvent - Shell Sol 72. RD 5156 P.E.-gLycerol-phthalic-Ahitol-dehydrated castor varnish. Body - F. A.V. - 3.7. Color - 8. Solids - 30%. Solvent - Shell Sol 72. HD 5178 P.E.-gJycerol-phthalic-Tosin-adipic-dehydrated castor varnish. Body {A. A.V. - 15.8. Solids - 30%. Solvent - Shell Sol 72 RD 5165 P.E.-phthalic-Abitol-dehydrated castor varnish. Body - F. A.V. - 5.0. Solids-r- 30%. Solvent - Shell Sol 72. RD 5164 P.E.-phthalic-Abitol-dehydrated castor varnish. Body - E A.V. - 3.1. Solids - 30%. Solvent - Shell Sol 72. RD 3674 Glyceryl-ethylene gLyeol-isophthalate-soya varnish. In all cases where'Shell1 s Sol 72 was used in the varnish it was also used as the solvent in the flat wall paint. The experimental batdies of Flat-Tone White were checked for gaieral performance as indicated by the data below. Quart samples were placed in storage to study package condi tion and stability of viscosity over a period of several months. Our initial tests indicated that flats made with RD 5178 are poor in uniformity of tint over various surfaces. The Re3in Research Department has agreed to repeat RD 5156 in order to check our initial tests which appear to be in error. Each paint was reduced with extra thinner to the point where the vehicle broke to check each odorless type of varnish for thinner tolerance. (Chart Follows) 0007-SWP-045573 0007-SWP-000114945 Paint Research January, 1953 -15- gl62 - Cont. Experimental Data on Flat-Tone Paint No. OJ 469 R OJ 470 R 0J 471 R 0J 472 R 0J 473 R 0J 474 R OJ 442 R Vamish Tested (4115) RD 5177 RD 5156 RD 5178 RD 5163 RD 5164 RD 3674 Thinner Used (5027) Shell Shell Sol 72 Sol 72 Shell Sol 72 Shell Shell (5027) Sol 72 Sol 72 Viscosity #5 Fresh 3 Days 6 Days Brushing 12.6* 16.2" 15.2" Good 15.2" 18.4" 17.4" Good 9" 9" 50.0" Good - 6.6" 17.8" 6.0" 25.0" 6.8" 23.6" Too free Good 17.0" 17.8" 20.4" Good 19.0" (24 hrs.) 20.0" (31 days) 22.0" SI. more feel than regular. Flow Good Uniformity of Very Tint on Lap good Uniformity of Very Tint Over good Spackle Good - Good Very good Very good Good - Good SI. short Good Very good Very good Very poor Good Good Very good Good Good Very good Very good Uniformity of Sheen Good - Good - Good - Good - Good Good - Good - Drying Over Night Vashabiliiy Over Glue % Reduced With Sol 72 or (5027) Very good 750 cycles 10056 OK Fair - Very good 770 1500 cycles cycles 10056 OK 25% Broke Good 900 cycles 10056 OK Very good 1000 cycles ioa% OK Very good Very good 1260 1500 cycles cycles 10056 OK 100* OK Reduced Paint Clear Liquid 7/8" (24 hours) 1-1/8" - 1-1/4" 1-1/2" 1-1/2" 1" 0007-SWP-045574 0007-SWP-000114946 Paint Research January, 1953 -16- ^187 - Physical Properties of Pigments Work on the electrokinetic properties of pigment dispersions has indicated that the surface potential and its sign are important criteria of the dispersion characteristics of that pigments Although electro phoretic behavior indicates whether the sign of the charge on a given pig ment is positive or negative, the magnitude of the surface pot^itial is not indicated directly., This is due to the.fact that the electrckinetic migration velocity of pigments suspended in paint vehicles is a function of the dispersive capacity and general nature of the vehicle/thinner combina tion as well as .the actual surface potential or ion capturing capability of the pigment surfaces Titanium dioxide, for instance, may migrate rapidly in an electrical field if suspended in a bodied linseed oil or an alkyd vehicle, whereas the same pigment will show negligible migration when suspended in raw linseed oil, particularly if the pigment is slightly moist. A new approach to this problem, of surface potentials of pigment suspensions is indicated, based on the following gsreral considerations. As is well known, a whole group of colorimetric. pH .indicators is available which change color at a givai hydrogen ion concentration. .These color changes cover substantially the complete pH range from 0 to 14. Each indicator changes color at a very narrow pK region and is consequently characteristic of a very precise conductometric potential equivalent to a precise capacity to either capture or release protons. Under normal'circumstances, i.e., when, pigmarts are suspended in ionic media, the addition of an indicator of the above type to the suspension is ineffective. This is due to the fact that an ionic liquid is in itself capable of acting as a proton donor or acceptor, so that the surface can be "satisfied1' by the mere presence of Such a liquid. However, in an aprotic medium like mineral spirits (neither proton donor nor acceptor,-lop,, non ionic) neither an acid nor base can function alone. If a base .is added'to an acid under these circumstances the proton from the acid can pass to the base so that a neutralization equilibrium is established and the lew of ma3S action is applicable. -Vy .' ` " ; ' . As a consequence, .the' ..equilibrium constant in the neutralization reaction in an aprotic solvent is a measure'of the relative strengths of the neutralized acid and of the conjugate acid. corresponding to the base used. The value of K can thus.be ascertained if the. color.of .the base differs . from that of its conjugate acid. As this'is the. case with the above colori metric pH indicators, it appears that a series of indicators would .be capable of bracketing the surface potential of pigment particles. , ' 0007-SWP-045575 0007-SWP-000114947 #167 - Cont. Paint Research January-, 1953 -17- . The indicators, however, must fill one further prerequisite before they can be employed. They must be adsorbed to the pigment surfaces before proton exchange can take jLace<. This means .that .they must be at 'least partly soluble in the aptotic medium chosen. Screening of a large number of indicators available for this characteristic has yielded only a few so- far which are usable and these lie in-the pK range below .7. It is expected that further work will yield a broader range of indicators;for this work. It is thought that this type of approach will yield valuable information such as the after-bodying tendmcies of some pigment combinations in cer tain vehicles, seeding tendencies and other characteristics associated with the degree of dispersion and agglomeration of pigmait systems sus pended in hydrophylic as well as hydrophobic media. 0007-SWB-045576 0007-SWP-000114948 V 'jfr- Paint Research January, 1955 ^ ; -18S.t . 'v j !.* . r l' . fir v. |f jgflP - Leaded Zinc Pigments Continued carbon arc exposures on this series of yellow leaded zinc pigments have now reached 620 hours. At this stage the panels are showing chalking and are rated as follows: Panel Pigment White Chalk Mask Degree of Chalk A AURL 2298 Light Yellow 7 if; B AURL 2265 " " 7 6 v C AUFL 2267 " -TM 7 5 iff: D AURL 2297 Dark Yellow v*: E 412 Shaded to match D 7 4 9 5 i.r :ri" , v.-Si.1. - Tf - j? 1 ' ' F G R I SUP Tint Base Shaded to match D AURL 2264 Dark Yellow 412 Shaded to match G SUP Tint base shaded to match G 8 9 6 8 7 8 4 7 The above data indicate that the darker yellow leaded zinc pigi - meats are more chalk resistant and produce a chalk that is more nearly self-colored than the other leaded zincs of this series. The poor perform ance of 412 dry shaded would indicate that there probably is a good possi bility of formulating an even more permanent tint base by using colored leaded zinc pigments. Work is under way on this problem and will be fs reported on ah a later date. 0007-SWP-045577 0007-SWP-0001 Paint Research February, 1953 -9- iiC9 - Studies in Flat Wall Paint. Formulation The Resin Research Department has submitted an isophthalic (4113) ' type vehicle coded RD 3694 for evaluation in Flat-Tone White Rex 810. The I,, f. Washburn Company and McWhorter Chemical Company have also submitted . pempires of flat vail paint vehicles for our inspection and test. These vehicles have the following properties. RD 3694 Olyceiyl-Abitol-isophthalate-soya plus Antarox A-400. body - V +. AoVo - 16. Solids - 40%. No. 3540 0., S. Aliyd T. F. Washbum Company S 2415 Odorless Allard Viscosity -- thixotropic. Color - 6 Max. A. Vo - 6 Max, Solids - 39 to 41%. From McWhorter Chemical Company The three alkyds were compared with (4113) in Flat-Tone White Rex 810 for brushing, flow, drying, stain removal, washability, etc. The T. F. Washburn aliyd was very short in flow and poor in uniformity over various surfaces. The S 2415 Odorless Alkyd was similar to (4113) in all tests and slightly better than (4113) in stain removal properties.' The 'S 2415 Aliyd, however, gave slightly high viscosities for Hat-Tone White hich detracted slightly from the brushing properties of the flat wall paint. RD 3694 is too low in body for Flat-Tone White. The experimental flat based on HD 3694 has poor uniformity of tint over various surfaces. Complete test data are presented in the following table. Paint No. 498 R 506 R 499 R 500 R Vehicle Under Test (4113) #3540 S 2415 O.S. Resin Aliyd RD 3694 Aliyd VLscosi-ty #5, Fresh O 'Nite 25 Days ^rushing Plow Drying 11.0" 11.0 13.2 Good Good (-) Good 7.2" 10.0 13.0 Good Poor Good 17.2" 22.2 21.4 Good (-) Good (-) Good 5.0" 7.0 5.0 Too free Good Good (Cont.) 0007-SWP-045578 Paint Research Februaiy, 1955 498 R (4113) Fair + Good (-) Good (-) 830 506 R 499 R #3540 S 2415 u*So Resin Aliyd Good Fair + Vety good Fair + Poor Good (-) 819 688 500 R RD 3694 Alkyd Good Very good Poor 857 26 qrdes 456 44 * 55 cycles 486 70 0007-SWP-000114951 Paint Research February, 1955 -13.r fifl? - Physical Properties of Pigments Further work and literature search has been undertaken to ^ascertain the surface potential of pigment surfaces. A new indicator, Bromophthalein Magenta E (tetrabromophenolphthaleln etlyl ester) is used ty the National Bureau of Standards for assessing the acidity or basicity of organic molecules in aprotic media ty colorimetric changes. It appears that this material might be of particular value for pigment work because of its ability to indicate color change at various values of proton exchange capacity. If the material is not available commer ce dally, an attempt will be made to synthesize it in the laboratory. 0007-SWP-045580 0007-SWP-000114952 Paint Research February, 1953 -14jjfL77 - Pigment Studies A series of rutile titanium pigments are under evaluation for chalk resistance. Included in the series are minimum and maximum chalking standards of Titanium Pigment Company grade Titanox RA NC 1004 dry. Minimum and maximum chalking standards of Calco Unitane OR 640 are also included. Calco has also submitted a sample of their experimental grade HL 177D4 claimed to be a super chalk resistant material. These pigments are being evaluated in the carbon arc Damar vehicle test as well as in exterior gray and Colonial Tellow tints. Results are not sufficiently far advanced to merit report at this time. 0007-SWP-045581 0007-SWP-000114953 Paint Research March, 1953 -10- fifi? - Studies in Flat Vail Paint Formulation The Resin Research Department has submitted three (4113) tyPe vehicles coded RD 5195, RD 5203 and RD 5208 for evaluation as flat wall ''paint vehicles; ED 5195 P.E.-glycerol-phthalate-Rosin Amine D- soya varnish. Body X Acid value - 4.4. Color - 7, Solids - 50. Solvent - (5027). RD 5203 PE,,-glycerol-phthalate--ro sin-soya, varnish. Body -- 0 to P. Add value -- 3.3. Color - 5 +. - RD 5208 P.E.-glyceTOl-phthalate-rosin-soya, varnish (steam blow). Body - U + Add value - 6.0. ... Color -- 5 +. ' The three aDtjfis were compared with (4113) in Flat-Tone Vhite Rex 810 for brushing, flow, drying, washability, etc. The varnishes were |(foimulated to obtain improved stability and compatibility. Tests show jf, that these varnishes are defident in hold-out and in one coat properties f as indicated by the data in. the following table. Test Data - Rex 810 Vith Spedal Vehicles Paint No. 0J 547 R 0J 548 R 0J 549 R 0J 550 R iVehicle tested (4113) RD 5195 RD 5203 RD 5208 'Viscosity - #5 orifice r 3 days :l9 27 10.0* 13.6* 11.8* 16.2* 24.0* 18.0* 11.0* 15.0* 11.0* 10.0* 12.0* 9.0" Brushing Flow Diyiag Bnlformitgr of Sheen Very good Veiy good Good -- Fair - O.K. OoKe Good -- Good - Very good Fair Q.K. Good - Very good Fair 0 oK a Good - * * Tint Uniformity over various sm*f&c6S Good Good - Good Fair Very good Good Fair - Fair - ashabili ty over glue size 480 cydes 560 cydes 482 cycles 460 cycles OO07-SWP-045582 0007-SWP-000114954  fM - Conto Paint Research March, 1953 -11- V During the latter part of January a meeting was held with representatuva'a from Paint Research, Resin Research, Vamish-Resin and Technical ` Service Laboratories presents to discuSs the settling and gelation problems ' encountered with Flat-Tone production. In connection with this problem the Paint Research Department started a series of storage tests to check the . effect of various agents such as Bentone 34 - 62 I 4, high end low amounts of calcium linoleate BI 336, calcium soy ate, Acto 450 (4081), etco The test `paints had been in storage for approximately three months at 80 to 90 F. ^when"the initial inspection was made. The first examination indicated that 16 pounds BI 556 and 4 pounds ; 1826 dry are not sufficient to prevent settling in the Flat-Tone formulations. The Increase in BI 336 from 16 to 24 pounds made a definite improvement in `package condition but further improvessit is needed. We have found that onehalf gallon of lecithin (5094) in addition to the regular suspending agents ^produced a soft paste after three months' storage. This is also true in the case where two pounds Bentone 34 was added to the Bl 336 and 1826 calcium ^stearate as used in the Flat--Tone formulation. From our examination of these storage' samples, ve have recommaided the continuation of 24 pounds of BI 336 .and 4 pounds 1826 dry plus one-half gallon of lecithin (5094) and/or two pounds'Bentone 34. The storage tests on Flat-Tone Dawn Blue Rex 808 indi cated that 312 dry Nytal 500 has better suspension properties than 20 dry Asbestine and should be used in all Flat-Tone rexes. The ratings for package condition as listed in the following table are based on the numerical values assigned to the description of paint conedition as covered by Sherwin-Williams Test Method 414.42 (10 - perfect bu s -- .pension, 0 -- very poor) 0 Package Condition at Approximately 5 Months1 Storage Suspending Agent/100 Gals.______________ Package Batch Rex Bl" 356 1826 ( 5094) (4081) 62 Y~4 InertCondition Rex 810 400 R Card 21 16# 4# -- - 408 R *a 16# 4# - - 409 R Special 16# 4# 1/2 gale - 416 R a 16# 6# - - 417 R 424 R 425 R 429 R 430 R a a a n a 16# 16# 16# 24# 24# * 4# 4# 4# 4# 4# _ _ s# - 451 R a 16# * 4# - - - 200# 20 Dry- - 20Q# 20 Dry - 200# 20 Dry - 200# 20 Dry - 200# 20 Dry 2# 200# 20 Dry 4# 200# 20 Dry- 20Q# 20 Dry - 200# 20 Dry - 200# 20 Dry 4 4 8 6 5 8 5 6 6 4 Varnish partly gelled. 0007-SWF-045583 0007-SWP-000114955 u Paint Research March, 1953 -12- W` ft62 - Cont. Batch Package Condition at Approximately 5 Months1 Storage Suspending Agent /100 Gals0_____ _ Rex BI -336 1826 (5094) -(4081). 62 I 4 Inert Package Condition | 435 R 808 16# 4# - - 20Q# 20 Diy 150# 2247 6 t: 436 R m 16# 4# - - 200# 20 Diy 150# 6300 6 1 437 R KiV % 16# 4# - - 200# 312 Diy 150# 2247 7 p 438 R WBE?1' 439 R P 440 R f| 441 R m m n 16# 4# 16# 4# 16# 4# 16# 4# - - - - - - 200# 2201 Dry 150# 2247 300# 512 Diy 300# 2304 Dry 450# 2247 Diy 4* 7 2 7 *Vamish partly gelled. 0007-SWP-045584 0007-SWP-000114956 Paint Research March, 1953 -16- yjfl7 - Physical Properties of Pigments Work on an alternative method for determining CPVC of a pignent/ ^binder system has continued= The purpose of the study is to eliminate the ^filtration step in the normal CPVC testing method, as this is frequently Stine consuming and sometimes practically impossible for certain specific Epigaeat and vehicle combinations* The systaa, as developed so far, requires gjjomeshat more manipulation and its accuracy is no better than the filtration iethodo It has the advantage, however, of being able to determine CPVC of difficultly filterable pigment/binder systanso Briefly, the method consists of the following steps. The PVC of paint to be tested is brought above the CPVC by the corrvaitional method vehicle substitution. If the PVC is already above the CPVC, this step pity be eliminated. An accurately known volume of the paint (between 0,5 to cc) is flowed out on the surface bf a three inch square of plate glass, the paddle* of paint being regulated so as not to exceed 1,5 to 2,0 inches in ^diameter. The thinner is then allowed to evaporate out of this film, which require from about 10 minutes to an hour. Since there is a deficiency of vehicle in the system due to the Jfact that the PVC has been brought above the CPVC, the pigment particles can pack into the closest system commensurate.with their degree of dispersion, a Similar to that accomplished by the filtration step in the conventional CPVC ^testing method. Consequently, there remains only to determine the volume fof this pigment cake, including all the voids. This volume, divided into the ^true volume of the pigment present (kno>n from the formulation and the accur ate volume of paint originally deposited on the glass plate), will be the ^equivalent of the CPVC of that pigment/hinder system, w. Unfortunately, some difficulties are encountered in determining |rthis snail volume with sufficient accuracy. These stan mostly from the fact since it is necessary to have the PVC of the paint system to he tested ; a Te the CPVC, a substantial volume of the dried pigment cake will consist S'. interstitial air voids. The most accurate method of measuring the small Volume of the cake appears to be the employment of specific gravity measuring techniques. This involves submerging the pigment cake into a liquid such as Y&ter for weighing. Since the water has a tendency to penetrate very slowly *nto the cake, displacing some of the air which is lost as bubbles rising to the top of the water, the results obtained are somewhat inaccurate. This has been circumvented for the most part by sealing the pigsit cake surface with a 3:1 dilution of a latex film such as Rhoplex AC--53, he plate with the film is dipped into the latex and the excess latex is 0007-SWP-045585 0007-SWP-000114957 Paint Research March, 1953 -17- Several other variations in the technique of determining the e of the pigment cake by the same general principles are being conred, A complete report and a recommended method, will be issued as as these sy Stans have been investigated. 0007-SWP-045586 0007-SWP-000114958 MtmrSSXtam 17 - Pigment Studies Paint Research March, 1953 -18- Damar chalking tests covering several grades of titanium oxide ^jjave now been completed in duplicate. To obtain more conclusive data, exterior exposures are under way which relate simple chalking to the more finelusive study of chalking, erosion, and white chalk mask of light tints, Tfbalk ratings at various intervals in the Atlas Twin Arc 9eather-0meter fappear in the following table. Piftaent Chalk Ratings 40 75 175 270 350 410 Hr. Hr. Hr. Hr. Hr. Hr. 2174 dry, Ti Pure R 610 10 10 8 7 7 7 2228 dry, Ti Pure R HO 8 76655 2229 dry K- Ti Pure R 510 9 10 8 7 7 7 2269 dry, Titsnox RA 9 86 6 5 5 Unitane Sample ML 177 D 4 10 10 9 7 7 B Unitane OR 640, Lot HB013 10 10 9 8 7 8 Unitane OR 640, Lot H8072 10 10 9 7 7 8 1004 dry, Titanox RANC" D52 H 21 #7 10 10 7 6 6 6 1004 dry, Titanox RANC D52 H24 #6 10 10 8 7 6 6 1403 dry, Ti Pure FF 44410 0 Ti Pure R HO Z 9 10 6 7 5 5 A review of the above data indicates that the various pigments are ^'forming in much the manner that would be expected. Of particular interest is the performance of Ti Pure 110 Z. . . .. During the early stages of this exposure it performs much like [/ ? ^ure R 510 tut as the exposure progresses the degree of chalking more dosely resembles the Ti Pure R 110 type. 0007-SWP-045587 0007-SWP-000114959 Paint Research March, 1955 -19- In these tests sre could not differentiate between the high and chalking standards of Unitane OR-640. Neither could we illustrate the gjper chalk resistant claims made for the experimental pigment sample 177 D 4. It is possible that as this exposure continues it may be possible to differentiate between them by their final failure. The results on Titanox RANG verify their reported difference, Le D52 HZ1 #7 being less chalk resistant. It is of interest that Uni que OR 640 appears to be more chalk resistant than Ti Pure R 610 or tanox RANC. More extensive experience with multiple samples is required prove or disprove this point. t 0007-SWP-045588 0007-SWP-000114960 Paint Research April, 1953 8- - IPP - fitnidies in Flat Wall Paint Formulation The Resin Research Department has submitted two isophthalate IgjS) type varnishes for evaluation as flat wall paint vehicles; RD 6311: Glycerol-Abitcl-isophthalate-soya with Antarox 400. Body - X. A. V.-ll.l. Solids - 40^. HD 3714; Glycerol-ettylene glycol-isophthalate-soya varnish. Body - T +. A. V. - 10.5. Both vehicles were formulated for Better stability and compatibility Ub mineral spirits and other vehicles on storage,, Various production batches Plat-Tone White and tints made with (4115) have galled on storage due to r compatibility. RD 6311 and RD 3714 are somewhat low in body and gave r poor uniformity of tint over tight and porous surfaces, when used in it-Tone White. Test results appear in the following table. Experimental Vehicles in Plat-Tone i. Paint No. OJ 658 R OJ 659 R 0J 660 R ^Vehicle Tested (4113) I'Viscosity - S-W Cup #5 Orifice ft?; Fresh 7.8* pi . 24 Hr. 8.6* % 7 days 6.8" ED 6311 8.8" 9.0* 4.4* RD 3714 8.4* 8.8" 6.2* ^Brushing IfFlow Good Good Good Good Good Good [*r Drying Good Onifounity of Sheen Good * " Tint Good over various surfaces Good Good Fair Fair Fair - Good Good Fair Fair - Sashability 570 cycles 785 cycles 568 cycles 0007-SWP-045589 0007-SWP-000114961 Paint Research April, 1953 -9- The Resin Research Department has also submitted five odorless (4115) vehicles for evaluation in flat wall paint formulations! RD 5193 Gly cerol-P . E. -phthalate-^Abitol-Dehydrol. Bocfcr - J +. A, V. - 6.0. Solids - 3Q&, Solvent - Sol 72 RD 5196 Gly cerol-Pc E. -phthalate-Ahitol-Dehydrol. Body -- F +. A. V. -- 2.1. Solids - 3056. Solvent - Sol 72 RD 5201 P,,E.-phthalate~Abitol-fehydrol. Boc^y J - K. A. V,, - 14.8. Solids - 3$. Solvent - Sol 72 RD 5205 P.E.-phthalate-rosin-soya. Body E A. V. _ 12.2. Solids - 3($. Solvent - Sol 72 RD 5223 Glycerol-P.E. -phthalate-rosin-maleic anhydride-soya. Laboratory tests have indicated that HD 5223 is much superior to 6193, RD 5196, RD 5201 and I 5205 in uniformity over various surfaces, Evhen used in Flat-Tone Bhite. This varnish will be checked further for fodor characteristics with Syntex 141 Alkyd (Jones-Dabney) and McWhorter flllyd S 2415 (McWhorter Chemical, Inc.) These two competitive alkyds have ^exhibited good uniformity over surfaces that vary in porosity. Test data ^covering the various experimental vehicles appear in the following table: Experimental Data on Elat--Tone White Using Odorless (4113) Type Vehicles "faint No. 0J 601 R 0J 602 R 0J 603 R 0J 604 R 0J 605 R 0J 606 R .Vehicle Under Test (4113) RD 5193 RD 5196 RD 5201 RD 5205 RD 5223 Viscosity - S-Jf Cup #5 Orifice Fresh 9.2" 11.0* 5 days 13,2" 14.0" 12 * 25 " 10.2" 11.4" 12.4" 18.4* 11.0" 13.8" 12.0" 16.2" 11.4" 20.0" 23.0" 20.8" 10.2" 16.8" 17.0" 10.0* 13.0" 10.2" 9.4" 13.8" flushing Flow Good -- Fair Good Fair Fair Fair Fair Fair Good Fair Good SI ,, snort (Cont.) 0007-SWP-045590 0007-SWP-000114962 ; ? , Paint Research Sit' a. April, 1953 -10- 062_ Conto paint No. Drying Experimental Data on Flat--Tone Ifhite Using Odorless (4113) Type Vehicles (Conto) OJ 601 R OJ 602 R OJ 603 R 0J 604 R 0J 605 R OJ 606 R Good Good Good Good - Good - Very good Fair Good -- Good -- Good - Fair + Fair Good Good Fair Very good Very good Very good over various Si surfaces fashability over jfLue size (cycles) Good -- 490 Poor 560 Poor 949 Good - Fair 577 591 Very good 558 The Chicago Technical Service Department reported on December 10 that _'e Chicago Flat-Tone production showed definite settling of the pigment, and Some gelling of the vehicle on storage. This resulted in an investigation of the production records on (4115) for 1952. The Varnish-Resin Laboratory issued ^report on their production of (4115) for this period on January 7. It was decided after a joint meeting with the Chicago Technical rvice, Varnish-Resin, Resin Research and Paint Research Laboratories that rther work should be undertaken to improve the (4113) aliyd vehicle for reproducibility in the factory as well as for compatibility and stability on torage. The Paint Research Department has started various tests to evaluate "spending agents, inerts, pigmentation, etc. In connection with this investigation the Varnish-Resin Laboratory submitted several off-standard production batches of (4115) for evaluation. Off-Standard Batches (4113) Standard Characteristics Tarnish (4115) Batch 90 Batch 91 Batch 92 Batch 97 Batch 106 -Mr (Fresh) U -W 0- V Mr (40 Days) U Z-, - z2 OlTe 10-20 15" 17* Z V+ K - Z3 Z 0 20* 20" 25" (Cont.) 0007-SWP-045591 0007-SWP-000114963 Paint Research April, 1953 -11- fogg - Cent, SL,'if. Off-Standard Batches (4113) (Cont0) Standard Characteristics .tj tVamish fi. V. (4113) Batch 90 Batch 91 Batch 92 Batch 97 Batch 11 3.6 - 5.4 6.3 5.8 5.4 5.8 4.5 'Color IcQids 9 Max. 6 29.5 - 30.5 28.7 6 51.8 6 27.9 5-6 28.9 5 28.8 [Ft,/Gal. 7.12 - 7.29 7.25 7.21 7.15 7.13 7.13 Laboratory batches of Flat-Tone White made with these varnishes were checked for brushing, flow, drying, uniformity of tint and sheen. As idicated above, these vanishes had very poor stability over a period of |40 days. However, the flat wall paints made at the 40 day period have shown good stability over a period of 2D days' storage. It is interesting to note that batches 90, 91 and 97 with viscosities ranging from U to Zy+ gave almost identical viscosities in the Flat-Tone White 'formulation. The (4113) Batch 92 (Z3 body) gave high consistencies, while (4113) JBatch 106 gave low viscosities in Flat--Tone White. In other characteristics such las brushing, flow, drying, uniformity and vashability, we could detect only or variations. The paints will be held in storage for further observations on settling, fpsL formation, consistency changes, etc. Test data are presented in the follow ing tables Experimental Data on Hat-Tone White -Using Various Production Batches (4115) tPaint No. OJ 606 R OJ 609 R OJ 610 R OJ 611 R OJ 612 R ^Vehicle Tested Batch 92 Batch 97 Batch 91 Batch 90 Batch 106 Body (Fresh) * * (40 Days) Z z3 V-W V Z Zy - Z2 0D K 0 (cont.) 0007-SWF-045592 0007-SWP-000114964 BLJZZ&L. Paint Research April, 1953 -12- Experimental Data on Flatr-Tone White Using Various Production Batches (4113) (Cont.) "`Paint No. OJ 608 R OJ 609 R OJ 610 E OJ 611 R OJ 612 R rPaint Characteristics `Viscosity - S-W Cu d #6 Oiifice 55.0* 13.0* 13.2" 13.8* 8.0" 14.6* 13.8* 15.0* 7.0" 13.0* 12.8" 13.0" 7.2" Good Good Good Good Fair - Fair Fair Fair Good Good Good Good Good - Good - Good - Fair Good - Good - Good -- Good - * * over various surfaces Good ^Washability over Glue Size (cycles) Good 457 Good 570 Good 590 Good! 593 0007-SWP-045593 0007-SWP-000114965 Paint Hesearch May, 19S3 -15- "pft? - Physical Properties of Pigments Work on the evaluation of viscosity data obtained on the high shear 'viscometer has continued. An interesting empirical relationship correlating the viscosity of a suspension at infinite shear velocity with the concentra tion of pigment ty volume present in the system has been developed. Thus the plot of the hyperbolic function of the logarithm of the ratio of the viscosity "of the pigmented system to the viscosity of the vehicle, when plotted against 'the volume percentage of pigment present, becomes a straight line. The advant age of this type of presentation over previous methods, based primarily on the Tand derivations, is the ease of determining the two constants of the system. One is the volume percentage of the densest degree of packing to which the jyetem can be subjected. This value seems to correspond closely with the con version of the oil absorption by the spatula method to volumetric terms. The other constant msy be obtained from the knowledge of a single viscosity measure ment of the system. A nomograph has been constructed which correlates these functions in very simple way. With this, the changes in viscosity at infinite shear velocity of a given pigmented lystan with changes in pigment concentration and -Viscosity of the vehicle phase can be obtained readily. Data from the above ^correlates very well with three different pigmented systems studied so far. tore data will be required before the universal application of the method to ill paint systems will be confirmed. Progress is also being made in correlating the viscosity and struc ture of paints at given shear velocities with fundaaental constants of the paint systau. More work is required in this field before definite predictions viscosity behavior of given systems can be made. A talk on viscosity relationships was prepared for a research meeting, end a paper on a similar subject is being written for presentation at the fall eating of the American Chemical Society. I I $ 0007-SWP-045594 Paint Research May, 1953 -16- 177 - Pigment Studies */ Chroma yellow pigments were evaluated in the Veather-Ometer for ^'degree of darkening and were rated visually as follows after Z10 hours' rprposure. Pigment Appearance Rating 12074 V exy dark 2 12150 Considerable darkening 5 12096 Less than considerable 6 12147 Slight darkening 8 D 3060 Slight darkening 8 The good performance of D 5060 affords an additional lemon fyallov that is somewhat less red in mass tone than the 12147 standard. 0007-SWP-045595 0007-SWP-000114967 Paint Research April, 1953 -15- p'a? - Physical Properties of Pigments The preparation of a paper on "Solid-Solid Interactions in Liquid has been started.. This paper will be presented at the American "eaical Society meeting to be held in Chicago during September. A paper on "A Method of Measuring Biushability, Sagging, and Flow"t of Paints" by- R. J. Blackinton, of the Los Angeles Club, appeared in the issue of the Official Digest, pages 205-215. The author indicates t a shear velocity of 3000 reciprocal seconds is sufficient to reproduce e conditions obtained by the average painter in applying a paint on a subjtrate by brush. From the experiences gained with the high shear viscometer eloped and used in this laboratory and described in the paper "A High oar Method of Rating Brushability of Paints" published in the Journal of oid Science in June, 1952, p, 306-515, it appears that these values are t high enough and should be at least 10,000 reciprocal seconds or even gher.m At 3,000 reciprocal seconds some paints, possessing a considerable of structure, mgy be classified as having a greater resistance in thing than others having less structure when actually average painter on would reverse the two ratings. _ The flow rating method proposed in the Blackinton paper has the ^advantage of eliminating one of the important variables encountered in ei actual flow-out mechanisa found in paint application. In the viscometer scribed, no provision is made for the fact that in a paint film thinner is Btantly being lost at a rate which is undeterminable from a rheological dpoint. This has two effects which are not accounted for in the derlvaa as stated in the paper; (1) The viscosity of the film increases with liof thinner, and (2) the film thickness decreases. Furthermore, the rheological flow curve as produced at low and very S;shear velocities is invariably a function of the instrument used for the Buranent. This stems from the fact that at low shear velocities, structure W8 the major role in determining the flow curve of the material being Bted. Unfortunately, this structure can be reduced by two different, and rtly independent physical mechanisms; (l) increased shear, and Increased time at constant shear. No provisions are made in the described Btruaent to include these variables in a reproducible fashion which even toximates the conditions found in actual practice. Therefore, the flow gtings determined by this method may approach the same relative rating found Practice, but the variables not accounted for would make the ratings some- reliable. The closer the instromaat measuring flow comes to the actual i*1 Paint application, the more nearly accurate the ratings >*he flow characteristics would be expected to be. 0007-SWP-045596 Paint Research April,. 1953 -16- A modification of a system for measuring flow suggested by f, Snylie, of Cleveland Technical Service Department, is being evaluated d promises to give consistent ratings with, field tests of the same paints- A special chromic oxide green house paint having poor flow prorties was prepared for the purpose of checking the performance of a les of flow control agents- The test paint formula follows- 350 pounds Magnesium silicate - 312 dry 100 11 Titanium dioxide - 2174 dry 400 " Leaded zinc oxide - 412 dry 120 D Chromic oxide - 478 dry 34-2 gal. Raw linseed oil - (2) 17.0 Bodied linseed oil -- (2538) 9.8 " 1.2 * .8 * 10.0 * Bodied linseed oil - (2538) Lead naphthenate -- (4230) Mn * - (4231) Mineral spirits - (348) Rheotol failed to show the expected performance in the first test ~t prepared from regular laboratory stocks of raw materials- e then "eated a part of the series using control paint prepared from the same terlals after dehydration for 18 hours at 200 F. Rheotol converted this Jjerial from one that brush marked badly to one of objectionably high flow, possible Sensitivity of Rheotol to small amounts of moisture makes it ir unsafe for general factory use. Its application apparently should ^limited to use in special cases requiring correction of such properties _g!o ss, flooding and flow. Rheotol is an efficient grind for oil type _etais but It might produce surprising side reactions because of its mois*8 sensitivity. It promoted fast settling to a hard cake in the green paint, hut has not exhibited this effect in SWP Rex 471. The original batch of green test paint showed a 1 H grind. To btain a paint with better dispersion, a second batch was prepared with rdrated pifjaents which had a 3 H grind. Improved dispersion produced .paint with lower consistency but with no apparent effect on flow pro xies. Paint Research April, 1953 -17- - Leaded Zinc Pigments Series 183BO - 7 F, C vere exposed during the month, testing tinted leaded zinc paints RB 4141 - 4144,. The special leaded zincs yolved are AUEL 2319 -- 2322, SWP Tint Base is shaded to match the special shades, as RB 4256 - 4259,, 0007-SWP-045598 0007-SWP-000114970 / ff'V Paint Research Msy, 1953 -24- - Leaded Zinc Plananta Exposures 18625-33 CS, CN, F, K were prepared during the month, nil Igdar bevel siding exposed vertical south at Florida, Coffeyville and Chicago also north at Chicago. These tests evaluate Ozlo 18 M leaded zinc in if 9 Painter Craft Exterior Semi-Paste Paint 684. The paints may be crlbed as follows: jo. Piament Cost Leaded Zinc Zinc Oxide Available L SR $111.00 L'k . e.R 112.70 f R 110.44 B R 110.25 1424 Dry Ozlo 18 M * nn 352 lb. 352 " 355 * 352 " 20.8 lb. 31. 23.4 . 24.6 A regular Rex 450 SKP Undercoater - Rex 471 SVP Gloss Vhite is used ^control. The paints are applied as 3-coat work with reductions as per the V 9 label, and also as 3-coat work starting with Rex 450 and following 1th two coats as per label. 0007-SWP-0455S9 0007-SWP-000114971 Paint Research June, 1955 "21- ijpB7 - Physical Properties of Pigments A number of model systems of pigment dispersions have been prepared to study further the relationships correlating the pigment pficmtratlon by volume in a paint with its viscosity at infinite shear ocity. The equation is closely related to the Vand derivation and is the form; log ft kC U-C jfcere-Woois the viscosity of the paint at infinite shear velocity., is ithe viscosity of the vehicle, C is the volume percentage of pigment in the t, and U and k are constants of the system. R is the ultimate pigment e concentration of the system, and k is a function of the shape factor the pigment. The high shear viscosities of the pigments anatase titanium ride 1405 dry, magnesium silicate 20 dry and a mixture of equal parts of ae pigments dispersed in raw linseed oil (2), bodied linseed oil (510), an SAE #10 motor oil, respectively, are being studied. After dispersion a 30% pigment concentration of each of these nine pastes on the three mill, the respective systems were diluted to 25, 20, 1.5, 10 and 5% gment volume content. Viscosity at infinite shear velocities of these stems is being obtained. The above systems are sufficiently diversified as to pigment p'arile shape and size distribution, end the vehicles induce such widely vaiy- structural effects that it is felt that these ^sterns are sufficiently rehensive to prove or disprove the relationships thus far established, {is hoped that the data obtained from the viscosity measurements may also aid interesting relationships of the structure effects induced -by various centrations of the same pigments in various vehicles. 0007-SWP- Paint Research July, 1955 -17= jh87 - Physical Properties of Pigments High shear viscosities of a number of pigment and. vehicle combiaa fctons have been determined at various concentrations of pigment. The pig"nent concen.tra.tion/viscosity vai.ues at infinite shear velocities check the `hyperbolic modification of the Vand viscosity equation well within experi-- Hartal error. This states that the logarithm of the specific viscosity of a pigment/binder system at infinitely high shear velocity is a iyperbolic function of the volumetric concentration of pigment present, Vs and two constants that characterise the system - U, the viscosimetric ultimate pigment volume concentration, and Ks the shape factor of the pigment, or: = log SV u-v O^o is the viscosity of the supernatant liquid of the system and leg, the viscosity of the system at infinite shear velocity. The systems studied so far include 0, 5, 10, 15, 20, 25, 30 and 55 per cent by volume of 1403 dry titanium dioxide, 20 dry magnesium Sili cate and a combination of a 1:1 ratio of 1405 and 20 diy in (510) bodied linseed oil, (2) raw linseed oil and SAE #10 mineral oil combinations dilu ted to about 0.45 poise viscosities with kerosene. The pigment dispersions, ^except those using the SAE #10 oil, were first made up at Z5% pigment volume concentration and diluted to the lower values to insure equal grind of all ;the pigment in each series. The SAE #10 oil dispersions at high values of pigaentation shoved such- extreme structure that concentrations of pigment lover than 55% were required. Since these model systems check the equation so well, several commercial multi-pigment, multi-vehicle paints will be tested to confirm completely the relationships for all viscosimetiic systems of the pigment In oleophilic vehicle systems. / The vehicles employed in the model qystans ware purposely chosen to give as high a divergence of structure in the dispersions as practicable. linseed oil is a vehicle of relatively high dispersive capacity, while raw linseed oil and mineral oils are rather poor in this respect. Vith these dispersions another empirical relationship has been established between struc- ; tare and conegatration of pigment. This is to the effect that the dynamic .dulu.s due to the structure of a pigment dispersion, , is a Iyperbolic function of the concentration of pigment, V, and two constants which differ r?Q the previous ones. These constants are C, a value which seems to be plated to, but not necessarily identical to the CPVC of the qystem, and k, "e Physical meaning of which is still questionable. The equation kV fits the data obtained on the viscosity C-V 0007-SWP-045601 0007-SWP-0001 Paint Research July, 1953 -18- - Cont, fiBasuraaents on the model systems surprisingly well, S in the equation |ls the slope of the viscosity curve in the shear velocity/viscosity Jrelation ships St)~& (L used to find the value of CO phe viscosity of a system at infinite shear velocity from measurements at [several shear velocities. Attempts to establish the physical meaning of U in the first [equation have led to a possible method for determining the ultimate fpignemt volume concentration of a pigment qrstem. This is the point at gvhlch a pigmait system is packed into its tightest configuration. It sis independent of the vehicle employed originally for the dispersion. Bhe method for obtaining this point may eveataaliy^Xead to. a gystam offobtaining the equivalent of the ideal" oil absorption of a gy stem inde- : [pendent of operator errors. More work is required before the'validity [of the endpoint obtained and its relationship to the viscosity of- the Cistern involved can be established definitely 0007-SWP-045602 0007-SWP-000114974 Paint Research August, 1953 -19r-- ^rifl7 - Physical Properties of Pigments The pigment concentration/visco sity characteristics of two ' commercial paints, Rex 471 SWP Gloss White and Rex 810 Flat-Tone White veTe determined to check the conformance of multL-oomponen't pigmenttinder systems with the -viscosity characteristics found for model dispersions. Vehicle was removed from a portion of each paint by ctii|u$e. The original paints were then diluted to 80, 60, 40, and i Zfl> of their original pigment content with the resulting supernatant vehicle. The high shear viscosities of these systons and the super natant vehicles were determined, and the viscosities extrapolated to .infinite shear velocities. The resulting values for viscosities at infinite shear velo. city fit well the logarithmic hyperbolic functions found for the model rstems. This indicates that mixtures of pigments and vehicles follow 3 the modified Vand and Bradley derivations. This was found to be true ^despite the fact that the Rex 810 vehicle showed considerable divergence ;.;.fTom Newtonian flow properties for measursnents at finite shear velo cities. The UPVC*factors for the Rex 471 md Rex 810 paints are 0.56 ; and 0.53, respectively, while the k factors are 0.88 and 0.89. Knowing ' these factors, the viscosity at infinite shear velocity of any concen tration of a specific pigment combination, V, in a specific combination of non-volatile and volatile vehicles can be calculated for that system ; ty the simple equation log ^5 = iog-|e, kV UPVC-V : The effect of Increasing or decreasing the PVC in a givm paint on the viscosity characteristics of that paint can thus be assessed readily. Folk on determining the effect of pigment ooncmtration on the structure of mnlti-component pigaent/binder systems is being continued. *UPVC denotes the "ultimate" pigment volume concentration, i.e., st closest packing. I 0007-SWP-045603 0007-SWP-000114975 Paint Research August, 1953 g'y: ^177 - Pigment Studies &; Panels 12349 - 12358 C were examined after 4-1/2 years'* exposure at 45 south in Chicago. This is a set of 6* x'12" cold rolled steel panels on which an evaluation of a stainless steel powder has been conducted. &. Other test conditions on this pigment have bem reported previously. In R?. gaieral, these earlier tests showed that stainless steel is not a good piggt mait in paints that are used in contact with inetal substrates. Under these Wlf conditions they tend to accelerate corrosion. These Chicago exposures |F- serve to confirm the earlier findings. The only advantage for stainless steel over aluminum in surface coatings was observed where severe chemical > fumes are prevalent. Even here a good chemically resistant vehicle such as gt vinyl copolymers and a primer are necessary to realize any benefit in appear|k . ance from the stainless steel pigment. Under normal atmospheric conditions K; aluminum pigmented top coats retain better appearance than stainless steel R.` pigmented top coats. 0007-SWP-045604 0007-SWP-000114976 Paint Research September., 1953 -iO'gifi? ~ Physical Properties of Pigments The evaluation of the high shear velocity viscosity data is being _____ o It has been found that vhen -the liquid phase involved in the "'suspension of a pignent/binder system is not strictly Newtonianj a cor rection factor accounting for this divergence from lineality is required,, [he vehicle system of Rex 810 Flat-Tcne has been found to be somewhat nonfevtonian, while most latex vehicles show wide departure from Newtonian jehavior due to the incorporation cf such materials as thickening agents nto the system. Although insufficient high shear viscosity data is presently for latex paint systems., the general, laws obtained for normal paint systems containing Newtonian binders are followed ty the Rex 810 system with non-Uevtonian binders vhen the appropriate corrections are 0007-SWP-045605 Paint Research September, 1953 -16- ijfi77 - Pigment Studies The color stability end flooding characteristics of a Beri.es of improved da Pont copper phthalocyanine blue pigments are being compared In a mineral spirits soluble alkyd enamel,, Each of the pigments under study *bs dispersed in the bodied linseed (310), ?onc resinate (3071) combination iiised in EL 44 Tint Base. Bases prepared in this manner were used to shade factoiy produced Rex 710 White Ehameloid to approximately equal color densities. Samples of each mamel tint are being stored at room tempera- Stare and at 135 F. to study color and flooding stability. Initial characteristics and ratings of the pignents under stucfc' follows Floodinfr Tint Factor CP 1037 BT 373-D BT 366-D BL 282-D CG 5960 125 S-V Toner du Pont xylene stable toner du Pont resin coated toner du Pont aluminum benzoate lake du Pont xylene stable toner du Pont xylene stable toner Very bad Very bad Moderate Very slight Very bad Very bad 97 98 93 126 94 105 Tint factors represent the grams of tint base used to shade i!0 ounces of Rex 710 enamel to the depth of color at which the serie3 is Jbeing evaluated* Flooding is rated by observing the extent to which a gdisturbed area of wet film contrasts with adjacent undisturbed film sur faces. The fresh film i3 disturbed at regilar intervals by wiping the finger tip gently across the surface during the setting up period. 0007-SWP-045606 0007-SWP-000114978 Paint Research October, 1.953 -ia- jpi7 - Physical Properties of Pigments From purely theoretical considerations, Vand was able to expand [|the derived equations of Einstein relating the pigment volume concentration ;0f paint-like suspensions of fine particles in liquids to include values &0f up to about 35% pignent. Somewhat later, Brailq t -, with the use of addit.tionel correction factors was able to extend these equations to include up ['to 45 - 50% of pigment. The Vand equation is of the gaieral form: log !o q - K log (1-c-qc2) Jhdiere -TOgpis the viscosity of the systan at infinite shear velocity, or where gpo structure remains in the system, <V70 is the viscosity of the supernatant Tvehicle, c is the volume percentage of pigment in the astern and K and q are ^constants of the system,, K represents the shape factor and q the "immobilizaEtion factor,1* or that quantity of vehicle immobilized when two particles of [the system collide.. One of the major difficulties in the use of the above equation with [given pigment concentration/viscosity data, is the fact that the constants K fold q are very difficult to evaluate., This can be done presently only by the gee of a series of tediously solved simultaneous equations, and thus far no isable graphical analysis has bear evolvedo Consequently the use of the Vand J&juation becomes very cumbersome for practical evaluation of paint systems. IHovever, the equation is very nearly proportional to a hyperbolic form of the log % - kc U-c lore , T)9 and c have the same significance as before and k is very nearly iproportional to K while U is very nearly a linear function of q U in this Ease represents the pignant concentration of a particular dispersion at which |tlie viscosity becomes infinitely great. The advantage of working with the hyperbolic equation is the fact $bt it can be solved very readily by the use of a simple nomograph on which ?tbe constants k and U can be evaluated easily. This takes the well known Z fora. One leg of the Z is a plot of log ^77bo ; the other k, and the diagonal. |is c. The plot takes on the following characteristics: 0007-SWP-045607 0007-SWP-000114979 m. - Cont= 20 10 9.0 3=0 7=0 6=0 5=0 4=0 3=0 ae rna> 2* 1.0 .9 .8 n&.. .7 =6 =5 =4 =3 Paint Research October, 1953 -n- 0007-SWP-045608 0007-SWP-000114980 vamm Paint Research October, 1953 -12- The above plot represents the'pigment conemtration/viscosity data obtained ty determining the viscosity at infinite shear velocity of 55, 30, 25 , 20, 15, 10, 5 and 0 per cent of titanium oxide, 1403 dry or 6600 dry, dispersed In rav linseed oil - thinner vehicle., By connecting the experimental values ' of log /n jo as the ordinate vith the pigment concartrations as the abscissa,, as in the above diagram, the lines all converge at one point. This point very simply designates the values of k and 0, the former being the linear distance below the abscissa expressed as a function of a logarithmic decade employed in the log ^oO plot, and U is the projection of the point parallel, to the ordinate and read off as a percentage of pigment on the c axis. Knowing k and TJ, thai for any combination of pigaent and hinder, the viscosity of any arbitrary percentage of pigment can be determined readily by the above ' Simple steps. Similarly the increase or decrease in viscosity by the addi ction or subtraction of any arbitrary quantity of the combination of pigments .used in the dispersion can be determined, as veLl as the effect of changing; .the viscosity of the vehicle on the viscosity of the pigmaited ^ystan. At this time no simple means of determining k or U has been worked out except ^through the viscosity measuranent of at least two concentrations of the given pigaents in the given vehicle. It is hoped, however, that at least 0 can be ; measured by other means in the ftitnre. One of the added advantages of the above ^stan of obtaining k and D 'is the fact that the nomograph can be constructed easily on the same semi- logarithmic paper on which the extrapolations for /flaare made in the plotting ` f <$&!$ ' log sq * ~ log oj+ s/VT for determining m from viscosity data at finite shear velocities. , v `0. 0007-SWP-045609 0007-SWP-000114981 Paint Research Decanber, 1953 -32- #187 - Physical Properties of Pigments The possibility of using a centrifuge for a rapid and simple pigment characterization test is being investigated. To date several pig ments have been studied by dispersing in raw linseed oil, bodied linseed oil, and an alkyd vehicle with the rapid ball milling technique and subsequently centrifuging a portion to observe the volume of the pigment cake. Compar able results have been found with the use of either the Sharpies supercentrifuge or the Size 1 lype 1 International cmtiifuge. The volume of piguent cake is reproducible with samples from the same batch while differ ent results are obtained with different batches. Also, the TOlumes check quite closely when the various vehicles are used for a givsr pigment, with raw linseed oil giving a slightly larger volume pigment cake. When a minute amount of water is added to the raw linseed oil dispersion of Ti02 to cause agglomeration, the resulting cake is noticeably larger and softer. However, when the pigment cakes are stirred and again caatiifuged, additional liquid can be drawn off and it is found that volumes are in closer agreement. While this endpoint has not the rheological significance of PPF, CPVC and UPVC, it is reproduced accurately, being entirely mechanical. It therefore may be as useful as present oil absorption tests. A preLimiuaty paper has been prepared for eventual publication. Paint Research Bulletin RC-93 "Prediction of Paint Viscosities in Relation to Ultimate Pigment Volume Conceitration" is being distributed with this report. 0007-SWF-045610 l 0007-SWP-000114982 0007-SWP-000114983 Paint research January, 1952 -15- |pfl7 - Fhysical Properties of Pigments One of the objections to determining the CFVC of some paint systems has teen the fact that on occasion excessively long filtration time3 are required. The majority of paint systems can he filtered, subsequent to vehicle substitution, in the relatively short periods of one to two hours. However, some systems con taining highly dispersed, very fine pigment particles may require five hours or 'more for the completion of the filtration step. Consequently, any technique vbich would shorten or eliminate the filtration step would be of considerable interest. A method has now been developed which dispenses with the filtration . step and substitutes a drying step at about 120 F., which need only be long enough : to eliminate volatiles. For the great majority of paints, this should require no more than 10 to 15 minutes for even those containing very fine and highly dispersed pigments. The general technique is very similar to the previous CFVC methods `employing the filtration cell. The paint is first put through the vehicle substiitution step. Whereas with the filter cell method, this was an optional step, it is ::,a necessary link in the new technique. This is because the dried cake subsequently < measured must have a composition above the CPVC. This is accomplished most easily ' ly a preliminary vehicle substitution. Only a single substitution is required for ;ithe new method, while several might be required for the filtration method for . paint samples which filtered with considerable difficulty. An exact small volume (.5 to 1.0 ml) of the substituted paint is placed 'upon a flat glass plate of about 4x4 inch size. After drying either at room tem perature or at slightly elevated temperatures long enough to remove volatile thinuers it is clamped into a special mercury dilatometer and the exact volume of the paint film is determined. From this volume and the volume of the total pigaent in `the wet film, the CFVC can be calculated in a manner similar to the original method. The whole determination, from the substituted paint forward, requires little more than 20 minutes, irrespective of the dispersion or fineness of the pigment involved. Considerable difficuHy was encountered in developing a method for deter mining the volume of the dried pigment cake. Because of the fact that the physical composition of this cake must be above the CFVC for the method to function, a con siderable amount of air is usually preseat within the cake. The original attempts w measure the. cake volume were made using water as the measuring liquid. The ^uter has a tendency to penetrate the cake to a slight degree and force out a "umber of air bubbles. To obtain the true volume of the cake, including voids, these air bubbles must also be measured as part of the cake volume. . A cell was designed where these free air bubbles could be measured simul"ueously with the remainder of the pignent cake. It was found, however, that, spending on the temperature of the water used for measurement, these bubbles would Partially dissolve in the water if this were too cold, or other bubbles plate out it were too warm, so that false results were obtained. An attsnpt was made to f^ait water penetration by use of a very thin silicone coating over the cake rface, but this too did not meet with success. 0007-SWP-045612 Paint Research January, 1952 -16f\R7 - Conte The method now employed, and which seems entirely satisfactory, utilizes i mercury cell with a very thin film of live rubber stretched across its face* :,jhe rubber conforms readily to the exact contour of the dried pigment cake, and when its glass substrate is pressed against the cell, the exact volume of the cake 1b measured. With this technique considerable time can be saved in future CPVC ''determinations. s 0007-SWP-045613 Paint Research Februi-i., s -952 -10- ;fl77 - Pigment Studies Accelerated chalking tests on various titanium dioxide pigaents ir. damar show the following results at-120 hours' Veather-Ometer exposures Code Descriotien Chalk Rate 1403 1901 R 2030 2173 2228 2174 1004 2132 Ti Pure R-110* Unitan OR 310 2140 66 A 1* Ti Cal R 27 Ti Pure FF Titanox 168 LO Titanex AA Ti Pure R 200 Ti Pure R 110 Ti Pure R 610 Titanox RA NC Titanox HC HT 60,000 series Chlorine Process Unitare OR 340 Titanox RC Ti Pure Rtf Ti Cal R 27 4 5 7 8 8 8 8 9 8 9 8 6 8 10 - Absent 0 = Vo V. free chalk particular interest due to supply situation. Phthalocyanine blue lake 24 R supplied ty the C. P Department retains , greater flood resistance than du Pont's BL 262 D and Hannon's Palomar #73 after two months' storage at normal and at elevated temperatures.. Reflectance Data . Pigment 24 R Age Fresh 1 Mo. 2 Mo. Blue_______ 75 F. '135 F. 58.2 '39.2 58.3 59.5 58.9 Green________ ________Amber 75* 135 F. 75 F. 155* F 24.9 24.6 23.9 24.2 24.3 16.6 16.2 15.8 ' _, 15.9 16.1 BL 282 D Palomar #73 Fresh 1 Mo. 2 Mo. Fresh 1 Mo. 2 Mo. 56.8 58.0 56.6 61.3 62.8 62.0 57.5 56.7 --, 62.8 62.0 25.0 25 ,,G 24.6 25.5 2o *6 25.1 24.8 24.9 25.2 25.0 16.8 16.7 16.4 16.8 16.8 16.3 16.5 16.7 10, 16.4 16.4 Films cast from enamels aged for two months show a greater change in the color values of the 24 R tinted specimens than those containing BL 282 D or Palomar #73 pigmentation. 0007-SWP-045614 0007-SWP-000114986 Paint 5 5- "rob February,, 1952 -11Crystal stability in strong solvents has been checked for two new jjjhtfaalocyanine blue toners, SK 61 A and SK 61 B, prepared ty the Chemical Products Laboratory. After one month storage at 130 F,, as dispersed in a vehicle, these two pigments show more fading than a competitive blue pigment. This fading presumably is the result of crystal growth resulting from a slight solubility of the pigment in the sol vents. The competitive pigment has the disadvantage of greater agglomeration the --W samples. A fourth phthalocyanine blue toner, 474 E-A, was also included in these tests as a controla Failures -due to cry stall! natron of E-A were not as severe in this latest test as they were in previous tests, the indications are that the tests should be repeated. 0007-SWP-045615 0007-SWP-000114987 Paint Research March, 1952 -9- jhfl7 - Physical Properties of Pigments Hork on the viscosity of paints at very high shear velocities was wntinued. A series of experiments was planned to prove or disprove the i^ilidity of the concept that at infinitely high shear velocities all structare in a paint has been effectively eliminated. Unfortunately, infinite rfiear velocity cannot be achieved by physical measurement, so that we must resort to a mathematical or graphical approach. By plotting the reciprocal of the shear velocity, D, against the viscosity, 71 , of the paint at a particular shear velocity, a graph is obtained which, when interpolated to l/D = 0 gives the value of the viscos"ty of that material at infinite shear velocity. A linear plot of these values results in a curve, which it is difficult to extrapolate. By plotting these values as the logarithm of the viscosity against the reciprocal square foot of the shear velocity, straight line relationships are observed for mo3t paints, provided the shear velocity does not go materially below about 200 reciprocal seconds. This is illustrated in the accompanying graph. If two paint tystems having exactly the same composition with the exception that one has a greater degree of structure than the other have their viscosities determined and the values plotted as outlined above, the intercept at infinite shear velocity should meet at the same point. Such systems can be prepared by employing the bodying effect of water on such pigment/binder com binations as Ti02 with raw linseed oil. If such a system is prepared ty first drying the Ti02 carefully, a paint of relatively low structure is obtained. adding 1$ of water to this systaa, it can be bodied up considerably. If the viscosities of these two systems, which differ only negligibly in composi,,tion bit materially in structure, are determined and platted in the manner sug gested above they will be found to have the same viscosity at Infinite shear Velocity. This is illustrated on the graph. A series of paints was run in this fashion with 5, 10, 15, 20, 25 and 30% pigment. AH of these materials were found to conform to the above, indi cating the original assumptions to be correct for this pigment/binder combina tion. Further tests will be carried out on other combinations as wall as on paints chosen arbitrarily. It is hoped that considerable information can be obtained by this *type of analysis about production batches of paints. 0007-SWP-045616 0007-SWP-000114988 Paint Research March, 1952 0007-SWP-000114989 Paint Research March, 1952 -11- fvH _ Plprment Studies Continued exposure of the Ti02 paints in the accelerated chalking 'tests show the following results at 375 hours in the Feather-Qmeter. Code Description CChalk Hate 1403 1901 R 2030 2173 2228 2174 1004 2132 Ti Pure R 110 Unitane OR 340 2140 66 A 1 Ti Cal R 27 10 - absent Ti Pure FF Titanox A 168 L0 Titanox AA Ti Pure R 200 Ti Pure R 110 Ti Pure R 610 Titanox RA NC Titanox RC HT 80,000 series Chlorine Process Unitane OR 540 Titanox RC Ti Pure LW Ti Cal R 27 - 2 2 2 4 2 3 2 2 2 2 2 1 2 0 - very, very free chalk These results would indicate that all Ti02 pigments eventually tend to arrive at the same constant chalk rate in this accelerated-test and that ttair differences lie in the length of period before chalking starts. It will P recalled that ratings at 120 hours reported in Februaiy listed the ,pigdkits la the expected order. Titanium Pigment Corporation has submitted a sample of Titano? t 50, 50 Ti02 qalcium base pigment. It was compared with Titanox RC HT, the 50% calcium base pigment, in Flat-Tone White, Semi-Lustre White and in SUP White on an equal Ti02 basis, balancing extender content. The teste _MOWed Titanox C 50 to have good grinding properties and to be useful where it pld be desirable to increase hiding within the same volume presently occupied \ the 30% TiOs pigment, or where more selectivity of inert content is pre- 5re<i- However, its hiding power per pound of Ti02 is somewhat lower. Data obtained in substitution in Plat-Tone White Rex 810 are as follovss 0007-SWP-045618 0007-SWP-000114990 Paint Research March, 1952 -12- OJ 645 Q 565# Titanox HC HT 20Q# 20 dry Magne sium Silicate 0J 655 Q 340# Titanox C 50 416# 20 dry OJ 656 Q 34Off Titanox C 50 200# 20 dry 200#' 2247 dry - Atomite 9.6 Sec. 11.4 18.3 sec. 26.1 * 8.4 sec. 9.6 " Good - Good + Slightly short Short Slightly short Very good Good Good - Good Slightly less uni form than 645 Q Good fondly of Tint 1(a) Over lap Good Good jj(b) O^jpr various surfaces Good Good enih resistance oYef glue s^e 1200 cycles 1158 cycles 1240 cycles ug - Contrast Ratio fit 400 sq.ft./gal. .975 .977 Substitution of Titanox C 50 in Semi-Lustre White Rex 210 for Titanox basis results in a reduction of opacity from 478 square feet |SfSfiHon to 452 square feet per gallon at 95% contrast ratio. Substitution uj;SWP Gloss Shite for the Titanox RC HT content on a TiOB basis shows only or loss of hiding. Panels 16874-89 were placed on exposure during the month 5* check the weathering properties of Titanox C 50 in SWP Gloss White and yellow Eft gray tints. Continued storage of two new phthalocyanine blue toners in -vinyl IJyicles SK 61 A and SK 61 B, prepared ty the Chemical Products Laboratory Fte+akTO 30116 Promise for these pigments. As reported last month these pigIthl S^QVB^ considerable fading during the first month of storage. However, fadlne ^0es uot appear to be due to crystal size growth as microscopic ^ta*iuation shovp no crys-fhls whereas the control, du Font's standard, shows 0007-SWP-045619 0007-SWP-000114991 Paint Research March, l;n -13- ciystalSo In addition, the 474 J5-A sample which was reported to hare shorn Cp performance than expected at one month has now failed very badly, re-iing confidence in the test procedure. The special phthalocyanine blue lake 24 R supplied ty the C. P. Departshovs acceptable color stability after a three month aging test in an eloid White Rex 710 paint system. Samples were stored at room temperature lat 1350 F. This material compared very favorably with control samples of "out's BL 282-D and Harmon's Palomar 73. It retains superior flood resisteturing the first hour of drying of the wet film, after which it takes an position with respect to the reference materials in this respect. Hunter Multipurpose reflectance values show a slight increase in gth of color for all samples through the over-all test period. Data for inspection follow. Refer to page 10 of the February report for previous Pigment Reflectance Data Blue Green Amber 24 R 24 R BL 282 D BL 282 D Palomar #73 Palomar #73 75 F. 135 F. 75 F. 135 F. 75 F. 135 F, 57.4 57.8 55.5 55.2 59.9 60.2 24.1 24.5 24.8 24.9 25.2 25.1 15.9 16.3 16.4 16.7 16.3 16.4 Exposures 15380-91 F were examined after 12 months' exposure at jlda vertical south. These panels, all cedar bevel siding primed with ;.450 Dndereoater, were retired because only fading developments were ested. The te3ts consisted of five phthalocyanine blue pigments sub$ted by the Organic Research Laboratory. They were made up into: -Hex 412 SVP Castilian Blue, full color depth, and (b) let-downs of same one part each to 7 parts of SUP Tint Base ty volume. The pigments are: #474E-A -- S-S, untreated. 474E-B -- S-W, treated. 474E-C -- General Dyestuff, Hellogen Blue, ENC. 474E-D -- du Pont Monastral Fast Blue, BNC, Lot 62 special. 474E-E -- ' * " Lot 50 regular. No film failure or gloss or dirt differences were noted. The routine rts shoved greater chalking on *C* and "D," but this was only barely notice- ai- 12 months. AH the full colors looked fairly good, allowing for some -masking. The let-downs were much poorer in appearance, due to excessive' asking and dirt. A few very minor differences in general fading were Jd, hit not enough to warrant rating any sample definitely better than the 0007-SWP-045620 0007-SWP-000114992 Paint Research April, 1952 A paper on the "How Properties of Pigmented. Systems11 is being prepared eseotation at the Gordon Research Conference on Organic Coatings on June 19. arch bulletin will be issued on this subject in the near future. 0007-SWP-045621 0007-SWP-000114993 I Paint Research May, 1952 Properties of Pigments _f The determination of the GPVC for a number of asphaltic materials coarse fillers was attempted. The filler particles were so er, that the usual CPVC technique was not applicable and modithe method must be employed in order to obtain checking results. ^Further wort on the "drying method" for CFVC, which eliminates tion step, has been carried out. A simple method for sealing been worked out so that the former difficulties with air -ears to have been eliminated. .A research bulletin, RC-91, wall be distributed. This covers it of "Flow Properties of Pigmented Systems" and is to be pre the Gordon Research Conference on Organic Coatings. 0007-SWP-045622 0007-SWP-0001 Paint Research Mgy, 1952 -11- -fndies in Flat Vail Paint Formulation At the Trade Sales Technical Board meeting held in Chicago on May 13 .ye were requested to evaluate the performance of the Lowe Brothers 59-A-14) and the S-W alkyd (4113) in several Mellotone and Flat-Tone $ions. The following rexes were checked; Mellotone Crown Blue 601, 'tn Brown 603, Persian Green 607; Flat-Tone Highland Green 841, *d Blue 842 and Winslow Brown 837. In general we found (39-A-14) to be superior to (4113) in uniformity over various surfaces and on our regular 15 minute lap test when used above rexes. The Mellotone formulas made with (4113) are thin in initial body e Flat-Tone colors made with (39-A-14) are abnormally high in consistThe tests indicate that a pigmentation based on part titanium calcium pare Ti02 is preferred to all titanium calcium for the hiding pigorder to obtain better washability and uniformity over tight and 'surfaces. Ve have found that a combination of pure Ti02 and added is preferred to titanium calcium for improving washability and uni,of tint over such surfaces. However, this type of pignentation would at higher in cost based on equal opacity. The improvsnents that can in washability and in uniformity of tint through pigmentation are |than can be obtained through the use of (39-A-14). Experimental Data on (59 A 14) and (4113) in Flat Wall Paints Wash- Uni- ability Uni formity over fo unity on glue over Vehicle Viscosity 15 min. size various Sex Tested Fresh O'Nite Brushing Flow lap (cycles) surfaces 603 ( 39 A 14) ll" Lowe Bros. .603 (4115) 5.4 15.8" 5.8 Good Good Good 552 Rather Good - Good - 920 thin Good Fair '607 (39 A 14) 15 'r Love Bros. 24.4 Good Good Good - 857 Good - 607 (4113) 6.6 l'' 601 (39 A 14) 18 Lowe Bros. 6.5 33.8 Too thin Good - Fair Slightly Good Good sticky 1205 351 Good Good (Cont.) 0007-SWP-045623 0007-SWP-0001 Paint Research May, 1952 -12- Experimental Data on (39 A 14) and (4113) in Flat Wall Paints (Cont.) Vehicle Bm Tested Viscosity :esh O'Nit Flow Wash- Uni- ability fonnity over on glue 15 min. si3e Ian (cycles) Unifoimiiy over various surfaces 5^601 (4113) 10.2* 15* Good - Good - mo Fair &41 (39 A 14) 20 Lowe Bros. 25 Good Fair - 412 sticky Good r841 (4113) -6.8 9.4 Good Fair Poor 601 Fair '842 (39 A 14) 20 Lowe Bros. 24 Slight! Good Good sticky 559 Good .842 (4115) 4 B ';-837 ( 39 A 14) 15 Lowe Bros. 8.2 17 Good Good Fair Poor Good Fair - 503 203 Fair Good 5 837 (4113) 6.6 7 Fair Poor 874 Fair , 841 (39 A 14) 17.2 18.6 Chicago Good Very good 1160 Good* 841 (4113) 7.0 8.5 Good Good 1280 Fair* ft 841 (4113) 5.7 5.8 Good Good 1940 Veiy good*-* .gmentation: 1403 titanium oxide, 2132 rutile titanium calcium, 586 calcium carbonate, 6300 Calwhite. He TiQ2 and. calcium carbonate pigmentation. Frederick A. Stresen-Reuter, Inc. has submitted a sample of No. 205 Pulp for our inspection. This material is a calcium pulp made from tty acids. The calcium soyate pulp was compared with calcium linoleate in BX 677. Experimental batches of Flat-Tone White were prepared with bases and the paints have been placed in storage to check suspension ^ies. The Oakland laboratory has submitted a sample of Hat-Tone White ith Lasher's L 238 0M low odor vehicle from Specialty Resins. The flat .^Paint sample is somewhat better than regular Flat-Tone White in odor but inferior in uniformity of tint over tight and porous surfaces. 0007-SWP-045624 0007-SWP-000114996 Paint Research Msy, 1952 -20- _7.tnc Pigments `.panels 13L46-9 F, C were examined after approximately 3 years' expoarida vertical south and at Chicago north and south, all cedar hevel ^___, with Rex 450 TJndercoater. (a) Regular SWP Tint Base of early Libs, of 412 dry co-fumed leaded zinc was compared with (b) our batch ' head Company's Dutch Boy Buff, a formula using a mechanical blend sine, with all lead as 18 dry basic carbonate white lead and a Viewer Inert content than our formula,, An added formula (c) was one J~the same as (a) tut a mechanical blend using 9 dry basic sulfate 'and 18 dry to match the composition of the 412 dry. The results on these tests had varied considerably in the past, ms failure had shown up. At present there is serious microscopic Florida on both mechanical-mix formulas, none cm (a). During most rjst year, Dutch Boy looked good due to superior color-retention; at ^looked poor due to chalk-masking and dirt (a3 did the (c) formula); ears it is back to a better appearance than the others due to more 4y elimination of chalk-mask and dirt.. The panels are being con test because of these past variations. 0007-SWP-045625 0007-SWP Paint Research December, 1952 -13- #86 - Leaded Zinc Pigments Laboratory produced, samples of yellow leaded zinc pigments have been placed on exposure at the Chicago fain as well as in Miami, Florida. For these exposures the pigments were dispersed in the SUP tint base vehicle substituting the yellow leaded zinc pigments for the entire pigaent volume normally contained in Rex 473 Tinting White. In comparison with this series of leaded zinc paints tvre control paints were used. Control paint A was standard Rex 473. Control paint B was made using 0 zlo 412 leaded zdnc oxide in the same manner as used on the experimental pigments; Portions of these control paints were shaded to match the lightest of the leaded zinc yellows while other portions were shaded to match the deepest of the leaded zinc yellows. Carbon arc exposures on this series of paints have completed 535 hours. At this stage chalking is just beginning on the control leaded zinc paints. This chalking is only sligit but there is evidence of some chalk face. The nixed pigment tint base is not chalking but it has flatted almost completely. The colored leaded zinc paints are quite'chalk resistant at this stage of exposure. This chalk resistance would be of considerable importance If it carries through on exterior exposure and in more practical formulating approaches. Panels 28148-59 C, F were prepared for exposure in Chicago and Florida south vertical of the initial experimaital paints. Work is under way on the more complete evaluation of pilot plant batches of similar pignents. 0007-SWP-045626 0007-SWP-000114999 Paint Research March, 1951 -12- L77 - Piement Studies The phthalocyanine blue color stability test that is being run on a series of five unidentified samples supplied by the Chemical Products Department continues. The sauries show excellent color stability for all samples in VLkyd and oil type vehicles as represented by Enameloid and SWP formulations, respectively. Samples of these rexes prepared from the separate pigment specimens have been observed after two months' aging at normal room and 135 F. temperatures. Similar tests in vinyl formula tions 6how weakness in certain samples after one month's storage. None of the full color dispersions in Enameloid Blue - Rex 70S show any color difference between the room and oven stored samples, A slight fading is apparent in all the oven stored let down tints of Enamel oid and SiJP. The full color SHP Rex 412 Castilian Blue samples show a slight deepening of color at the 155 F. storage level. It is now apparent that the poor wetting and severe agglomera tion and/or solubility reported for these pigments on page 12 of the February report is not a general characteristic, but it does apply to some of the samples in vinyl systems. Accumulated data will be released after the 3-month inspection. 0007-SWP-045628 0007-SWP-000115000 1 Paint Research March,-1951 -25- Exposures 12510-44 C, F were examined after two years' expo sure at Florida, vertical south and at' Chicago south and north. The panels are primed with regular Rex 450 Undercoater except for a few cases in which one of the test variations is made in the undercoater as well as in the top coat. The series was put out in cooperation with the National Lead Company, to the extent that they received samples of our paints and exposed them in their regular manner at Sayville, Long Island. We have received no recent information from them except as observed on our last annual inspection trip to their farm. The broad purpose was to evaluate various replacements of 45 X basic silicate white lead in Rex 471 SUP Gloss White and in SUP tint base. The substitution, less extensive in the tints then in the whites, involved three methods: A. Zinc oxide replacement by equal poundage, lead by equal volume. B. Maintain 35/65 lead/zinc ratio, replace on total volume. C. Same, but replace on total weight, adjust volume with extender. (In certain cases involving only Method A, (1) the zinc oxide level was lowered from the no-mal 32JJ to Z5% and 203, and (2) zinc oxide vaB introduced as Azo ZZZ-33 instead of leaded zinc.) A previous report at approximately one year showed no significant differences in performance, at least none which were confirmed at all loca tions. The present routine study Of Florida and Chicago tests indicates that no new differences of consequence have developed in the second year. The main tendency on dirt collection seems to he that the regular guides ' are cleaner than the specials', except that those the same as the regular hut lower in zinc oxide seem cleaner. The SUP tint base tests, huff and gray, aTe all well.within a satisfactory range of dirt collection and fading. The special formulas run about the same as the regulars in both respects. One sample carrying 414 dry and 45 X at a 253 ZnO level is definitely cleaner than the average, and one similar hut at 203 ZnO is somewhat cleaner and noticeably better in color. This is based on Florida results, which also show some incipient checking. Chicago tests show no noticeable differences. In general, the nse of 45 X and 414 dry Seems fully satisfactory through two years' expo sure, and essentially the same can be said of the reductions of zinc oxide level, which would have advantages from the standpoint of cost and supply. (The behavior at lower zinc oxide levels is rather unexpected and no ready explanation suggests itself.) 0007-SWP-0001 0007-SWP-045629 Paint Research April3 1951 -9- 4VH - Pigment Studies The phthalocyanine Hue1-color stability test has been carried through the 5-month aging pferiod in Enameloid Blue - Rex 708 and SVJP Castilian Blue - Rex 412. :A11 samples continue to show good stability at 135? F. storage temperature as veil as at 75 F. How ever, with vinyls marked failures are apparent after two months* storage. One pigment showed early failure in the form of agglomera tion but this failure has not progressed. Two of the pigments showed bad fading as a result of large crystal growth. The other two pig ments showed some agglomeration end some crystal growth but in gen eral gave the best performancei There are indications that the phth^locyanine blues in a urea-alkyd enamel are going to duplicate the perform ance in. vinyls. 0007-SWP-045630 Paint'Research Jun$, 1951 >11- fi 77 - Pigment Studies Phthalocyanine Blue Lakes The color stability of two phthalocyanine bine lake pigment camples is being determined in standard Enamsloid White - Rex 710 Shaded to the approximate depth of color of Enameloid Pastel Blue. The pigment specimens were selected for this study because of their superior performance in flooding characteristics tests run on 12 pre parations submitted by the C. F. Departmmt. du Pont's phthalocyenine blue lake BL 282 D is the control pigment in these tests. The pigment sample WSF 59 shows a alight weakness after aging one month at 135 F., while SF 70 appears to possess excellent stability. Additional inspections will be made after two end three month aging periods. - 0007-SWP-045631 It \ | ? v j 1 'i Paint Research July, 1951 jh77- Pigment studies The Ghanioal Products Department experimental phthalooyanine blue pigment saaple WSF 70 continues to show good color stability In the ilkyd type Enameloid formulation after two months aging. Samples of Enameloid TThite Rex 710 tinted with BL 44 type bases, containing WSF 59, jfSF 70, and du Font's BL 282 D laked phthalooyanine blue pigments, have been stored at room tenperature and at 135 P, The BL 282 D sample appears to have bleached veiry slightly during the 135 F storage, but the Hunter refleotanoe values of this film show excellent stability in comparison with the refleotanoe values of the original fresh film. A loss of color strsngth is readily apparent in the 135 F stored sample of. WSF 59 tinted enamel and is confirmed by the'increase in refleotanoe shown by this ohip. WSF 70 shows continued stability along with a dispersing aotion in the 135 F storage oondition which has developed an increase in the oolor strength at this inspection. W5F 59 :f 70 75 F 135 F 75 F 136 F 76 F 136 F Refleotanoe Values Fresh Enamel Film Green Blue Asher Green Blue ' Amber 28.8 62,0 20,2 26.6 61,4 30,0 26,8 61,6 20,2 29,4 63.8 20.7 29.0 63.1 20,6 30,8 63,0 22,6 28,6 61,2 20,3 28.4 60,7 20,0 27,5 60.5 19,6 0007-SWP-045632 Paint Research August, 1951 -9- jgfi.B7 - Physical Properties of Pigments The first phase of the work on correlating the bmshability of paints with their viscosities at high shear velocities has been completed. Very good check results are obtained when the values are compared at a shear velocity of about 15,000 reciprocal seconds, which corresponds to the shear velocities obtained in practical brushing. Because of the physical limits of the present viscometer, the vis cosities of the more viscous paints at the above mentioned shear velocities had to be obtained by extrapolation of a curve. To do this, a number of-readings for each paint are required. The methods and procedures for doing this are set forth in a research bulletin to be circulated in the near future. The project is to be continued with the construction of an apparatus on which the bmshability of a paint can be determined with a single reading. This should make the device very adaptable to routine testing of paints . Further work is also contemplated to establish the rela tionship between viscosity values obtained at high shear velocities and the flow characteristics of paints. It is hoped that a complete theological system can be established with which the viscosity be havior of given paints can be accurately predicted over relatively large ranges. Experimental work on establishing a gravimetric method for CPVC is being continued. The method shows promise of extending the scope of CPVC work, making the determination faster for some pigment/ binder systems than the present filter cell method. At the present time, however, the gravimetric method has not been perfected to the point where it can be employed with certainly* but some of the results obtained checked well with the present method. A paper on the "Electrokinetic Properties of Figaent Dis persions" will be presented at the Diamond Jubilee Meeting of the American Chemical Society at New York. 0007-SWP-045633 0007-SWP-000115005 Paint Research. August, 1951 -10- jjfl.77 - Pigment Studies ' The experimental phthalocyanine blue laked pipnent, USF 70, prepared by the C. P, Department, shows good color stability after 5 months at 75 and 135 F. in the form of Enameloid alkyd type ;pastel blue tints. This material has shown excellent stability under 75 F. storage and has increased slightly in color strength at 135 F. The moderate loss of reflectance across the board by the 155 F. 3-month aged sample confirms this gain in color strength. WSF 59, a second C. P. phthalocyanine blue lake, exhibits excellent stability at the 75 F. level bit' it faded observably in the 1350 p. test. This material shoved a slight weakness at 155 F. at the 2-month inspection. The extent of color change is indicated ty the variation of reflectance values with respect to those estab lished by films cast when the enamel was fresh. '* Both of these lakes retain their effective recovery of color .after their films are disturbed during the first 15 minutes of their ;setting up time'. They are equal to the control sample, du Pont'3 blue lake BL 282 D, at this point, but show increasing flooding character istics when disturbed after this time. Flooding is apparavb in the (BL 282 D tinted sample at this point elso, but it increases less vith time than in the WSF 59 and USF 70 tinted films. * Hunter Multipurpose Reflectometer test data follows: Reflectance Data Fresh Enamel Aged 2 Months Aged 5 Months Green Blue Amber Green Bib? Amber Green Blue Amber Control 75 F. 28.8 62.0 20.2 28.6 61.4 20.0 28.7 61.2 19.9 135 F. WSF 59 75 F. 29.4 63.8 '20,7 28.8 29.0 61.6 20.2 63.1 20.6 29.1 29.4 61.8 20.4 63.2 20.7 155 F. WSF 70 75 F. 28.6 135 F. 61.2 20.3 30.8 28.4 27.5 63.0 22.6 60.7 20.0 60.5 19.6 31.8 28.4 27.8 62.6 23.4 60.6 20.2 60.4 19.8 0007-SWP-045634 0007-SWP-000115006 Paint Research November, 1951 8- - 7 - Physical Properties of Pigments The paper on "Oil Absorption and Critical Pigment Volume Concentration" j been revised to include the latest concepts on the subject. It will be preb'ted at the Louisville Production Club meeting on December 12. 0007-SWP-045635 0007-SWP-000115007 Paint Research December, 1951 A new and improved phthalocyanine blue laked pigment 24-R supplied by P. Department has been placed under practical test for flooding char- and color stability ,, An Enameloid "Shite Rex 710 sample has been ^tinted to the approximate shade of Enameloid Pastel Blue with a HL 44 tTP base from 24-Ro This is being aged in package at room and at 135 F. tem peratures along with reference samples of Rex 710 that have been shaded to equal [depths of blue with du Font's HL 282-D and Hannon's Palomar Blue #73- Films tinted with 24-R exhibited superior flood resistance in comIpaiison with HL 282-D and #73 in draw-downs of the freshly prepared materials. ^Further examinations will be made after 2 weeks and 1, 2 and 5 month intervals- 0007-SWP-045636 0007-SWP-000115008