Document M2RrZVVpRvKRX7RXwXVpordy

PAINT r e s e a r c h d e p a r t me n t Report cf Investigations Per.the Month cf July, 1956 VAN LOO G. G. SCHuER J. Wo Chapin J. M. DeVittoric R. L. Harper T. K, Hay L. E. Ludvig B. M. Morgan V, G, Nix H. J, Steiner R. K, Sutherland G. L, Nest COMPANY CONFIDENTIAL TO TECHNICAL INFORMATION MAILING LIST Project #12 - Exterior Primers Page 1 Exposure series 3347-c-3 at 70 months shows good per formance for emulsion primers with modifiers on pine and on weathered chalky and glossy surfaces. Similar primers with no modifier show loss of adhesion, par ticularly on chalky surfaces. No choice between tung, safflower oil or alkyd as modifiers. Monsanto experi mental primer based on 6SO-RJ 100 vehicle satisfactory; Dow experimental 2&C{ primer develops some checking and cissing. Project *$206 - Exterior Emulsion Paints Alkyd modification increases Erushomscer reading of latex paints. One coat extericr latex paints based on Rohm and Haas E-3S8 and latices show con siderable premise. Page 2 Project #177 - Pigment Studies Page 3 Nineteen pigments, including whites, extenders and colors were studied for 1JV absorption and reflection properties. The results show that at equal concentrations carbon black is more opaque than black Iren oxide. Of the extenders studied aluminum silicate has the lowest trans mission of ultraviolet. Exposure series 36442-36^9 F, examined after three years9 Florida south exposure, shows that Virflux PR-?, a buff colored natural TiO^, vhen used in an A-100 tint improves the tint retention of buffs and tans but reduces tint appearance in other tints. N14203 Paint Research July, 1966 Index - 2 Protect -177 - Cont, Exposure series 41547-41559 examined after a year's exposure in Chicago showed that barium carbonate used as the extender in house paint developed a severe chalk face. Exposure series 44195-44229 was prepared for exposure to study various titanium oxides (includ ing du Pont's R-96O, Cabot's RF-30 and American Potash's CR-800) in both oil type and alkyd type house paints. Exposure series 44468-44491 was prepared for exposure to evaluate titanium oxides from various suppliers in an acrylic house paint; also includes du Pont's potas sium titanate PKT. Project ?r97 - SWP Page 7 Exposure series 44513-44535 was prepared to study vari ous coatings over woods of varying paintability. The woods include Lauan, Ponderosa Pine and cedar. The paint systems include two coats self-primed and one coat of topcoat over the recommended primer. Previous series of similar nature had shown that Lauan (formerly called Philippine Mahogany) fell in the lower Group 5 or upper Group 4 of species of woods classified for paintability. Project ^86 - Leaded Zinc Pigments Page 8 Exposure~seri.es 44184-44192 was prepared to study the effect of leaded zinc oxide on the exterior performance of house paints. Of specific interest is the effect on film erosion and bulk film properties, 50 pounds of Vancide PA per 100 gallons of paint is included to inhibit mold growth as zinc oxide concentration goes down. Project #77 - Preservatives Dow NC-IOI3 mildewcide tends to shew reactivity with some types of latex. Package stability can be improved considerably by the use of Strodex PK-90. Page 9 0007-SWP-000018719 Paint Research July, 1966 Index - 3 Project 7t 201 - Exterior Clear Finishes and Pigmented Stains Page 10 Seven organic UV absorbers were analyzed with Cyasorb UV-24 proving to be the most efficient followed closely by Tinuvin 3-1^ The ether UV absorbers included Cyasorb UV-9, Uvinul N-539, Uvinul $*10, Tinuvin P and Bayer 318# Instron tests of Arcftint 565 indicate that the 55:45 blend of epoxidized oil and polyester is the best compro mise between elongation and tint retention when formu lating an exterior coating, Soce improvement in the bulk film properties cf linseed oil may be observed as the degree of polymerization is increased. In a study of linseed oils with increasing degree of polymerization the differences observed were not so marked as to pre dict great differences in relative changes of bulk film properties on exposure. Project #221 - Production Finishing of Forest Products page 12 Panels 3-095-3ollO L and 3^095-3-126 C show good mold resistance for medium oil alkyd primed cedar after 37 months in Louisiana and 44 months in Chicago. Busan 11-Ml and lS-M leaded zinc cxide improve the mold inhibition but low PVC emulsion Chek-Gard type primers are best for mold resistance, panels 37261-92 C show that immediate painting of wood substrates improved the performance over painting after the substrate has weathered. Cedar and Douglas Fir siding and Douglas Fir and medium density paper overlaid plywood all show poorer performance after as little as one mcnth*s wea thering before painting, after36 months* Chicago ex posure. Panels 42051-86 C and F show good perform ance for Check Retarders using either E-I72 cr a 4 blend of AC-34 and AC-201 after 9 months* exposure in Chicago and Florida, A-100 and production emulsion topcoats show better crack resistance than an alkyd topcoat. 0007-SWP-000018720 Paint Research July, 1966 Index - 4- Project #223 - Electrochemical Investigations Page 15 Work continued on the electrodeposition of polyolefins such as polypropylene, especially to improve flow and ' to eliminate craters and pinholes. Changes in cure schedule were not very helpful; a schedule of five minutes at if-OO0 F. was selected as optimum. The effects of "pack density" of the films were studied, using a considerably smaller particle size non commercial polypropylene. Smooth, continuous films were obtained on aluminum and steel. While TiC^ particles are small compared with the polyolefins, pigmentation with TiC^ offered no improvement. Attempts were made to reduce the particle size of polypropylene by dry grinding at very low tempera tures, e.g. -70 C., without much success. Deposition in a cell in which the particles had to pass through m a 25 micron mesh screen gave smoother films. Micro- thene FN-500 polyethylene with particles said to be below 20 microns gave no improvement. Work with alkali solubilized resin systems for electrodeposition looks m: promising at this time* A portable resistance bridge was designed and built for use in electrodeposition studies. Project #112 - Fire Retardant Faints Page 20 Ammelide, a product of the hydrolysis of me>:.ine is suspected as the cause of poor color acceptance of Phos-Chek p/30 based emulsion fire retardant paints. Evaluation of substitutes for melamine is in S;-f progress, \ ilrolect #103 - Metal Protective Paints Page 22 Panels 44416-35 C and F have been prepared for exposure in Chicago and Florida to test several emulsion primers for metal. 0007-SWP-000018721 PAINT RESEARCH DEPARTMENT Report of Investigations For the Month of July, 1966 Project #12 - Exterior Primers Series 323^7-63 was examined after TO months* exposure at Chicago. Emulsion primers were applied to pine siding, weathered chalty panels and to weathered glossy panels. Primers were based on Rhoplex AC~33 Flexbond 800 and Lytron 680 with alkyd, tung oil and safflower oil modifiers. One coat of A-100 A6 G 66 Seaway Green was used as the topcoat, performance on all substrates has been quite satisfactory. Adhesion to both the weathered chalky and glossy surfaces has been good. Similar primers with no modifier show loss of adhesion, particularly on the chalky surface. There is no choice between the three modifiers used in this series; all were instru mental in promoting good adhesion with no undesirable side effects. A Monsanto experimental primer, 30lh08-4 DD, based on a 68G-RJ-100 vehicle, gave satisfactory performance. A Dow experimental primer, P-688-H2-2, based on their 26^7 latex, shows some checking and has the appearance of cissing. A competitive alkyd emulsion primer, Fuller*s 7^79, gave satisfactory adhesion. Mildew has never presented a problem in this series. The results in general indicate satisfactory performance for emulsion primers, even on the pine panels which are normally considered a difficult surface to paint. N14203.01 c 0QQ7'SWP-0QG018722 Paint Research July, I966 -2- -ffc. Project $206 - Exterior Emulsion Paints Work has continued on self-priming and one coat exterior latex paints. With paints based on eight different latices, a com parison is being made to determine the effect of modifier on the per formance of these paints. Straight latex paints are compared with related paints containing a linseed alkyd modifier to the extent of 15$ and 25$ of the vehicle solids by volume. All paints are in the 81 - 86 KU range, Brushometer readings were determined. In general, alkyd modification tends to increase the Brushometer reading. A portion of our data is listed below to illustrate the magnitude of this change, Brushometer readings are given in poises. Paint 'M:. E-173 No Alkyd O.38 V% Alkyd 0.43 25# Alkyd 0.59 1.46 1.64 1.72 1.76 1.90 2.03 The Brushometer readings indicate that alkyd modification exerts a small but definite influence on the application properties of the paint. The E-388 and E-425 latices are the new Rohm and Haas experimentals which exhibit improved flow and have considerable brush drag, particularly the E-425 type* Readings indicate that E-425 paints can- be formulated with brush drag equal to that of an oil base house painty Actual application properties of the two types will difpfer due to the rapid drying rate of the latex paint and difference in 'Surface wetting characteristics. Brushometer readings for the E-173 paint are typical of the average latex paint with very little brush drag and illustrate why is so easy to apply such paints at an excessive spreading rate. :r.It is possible that the E-425 paint may have too much brush drag for <easy application to a chalky surface. E-388 paints may prove more .adaptable to a greater variety of surfaces and more exposure experi-ence is available with this latex. In general, it appears that the *'388 and E-425 latices represent a considerable step in the direc tion of a practical one coat latex paint. 0007-SWP-000018723 Paint Research July, 1966 -3- Project #177 - Pigment Studies Ve have recently completed a study of various pigments with regard to their ability to absorb and reflect ultraviolet radiation. The study includes white and colored pigments as well as extender pigments. Each pigment vas dispersed in an alkyd var nish at a concentration of 10 pounds per 100 gallons. A low con centration was chosen to allow some transmission by such pigments as rutile titanium dioxide. All data are reported for dry films having a corrected thickness of 2 mils. Also reported is the wave length at which transmission by the film becomes 0$. The results of this study are shown in Table I. The data are reported as percent transmission, the re mainder of the light being absorbed cr reflected by the film. It should be pointed out that the alkyd resin will absorb some of the radiation and therefore it cannot be assumed that all absorption is by the pigment only. 'However, the alkyd resin is constant throughout all samples and the transmission of one pigmented film relative to another should be quite meaningful. It is interesting to note that calcium carbonate transmits more ultraviolet radiation than magnesium silicate. We repeatedly observe that calcium carbonate extended paints exhibit better tint retention than magnesium silicate. This suggested that perhaps it absorbed and/or reflected more U7 energy than magnesium silicate, thereby protecting the binder. However, the results are contrary ,to this thought. It therefore appears that the oil demand of each pigment is of more importance. Calcium carbonate having less oil demand leaves mere free vehicle to function as pigment binder. It ^can also be assumed that because there is more total free vehicle _^the percentage of degraded binder would be les3 in a calcium carbon ate extended paint at any point in the exposure history, leaving nore vehicle to bind the pigment particles together into a continu ous film. 0007-SWP-000018724 Paint Research July, 1966 -4- Project #177 - Cont. t Table I \ ?. r'' & t- >s |- > g1 i< r-: i `.it :\Y * ' na&* sv ;? i* 1 >'*** ; r\ J. jI Transmission ox Ultraviolet by Pigments pigment S-W Code * Transmission 280 - kOO m/s 7----- Rutile titanium dicxide Anatase titanium dioxide 66 53 00 66 00 22 3.62* 2.88# Magnesium silicate Calcium carbonate 62 32 00 63 01 00 24.3 $ 29.2# Aluminum silicate 62 02 27 22.6# Barium sulfate 63 70 00 25-0^ Hepheline syenite Minex-4 26.05k Potassium titanate PKX 6.0# Zinc oxide 6? 21 00 21.2# Leaded zinc oxide 68 22 00 10.8# Basic lead silicate 68 01 00 24.1* Basic lead sulfate 68 10 00 19.0# Basic lead carbonate 68 05 00 18.25k Black iron oxide 71 50 00 9.255k Carbon black (10#) 70 50 00 0# Carbon black (1#) 70 50 00 17.8# Phthalocyanine Green Monastral Green B 0# - Dolamar Yellow 0# Quinacridone Red Monastral Red B 39* Wavelength of Zero Transmission 300 in/- 353 300 304 303 305 313 335 310 320 . 310 310 310 315 hoo 310 400 487 357 Exposure series 3&h^2"h9 was examined after 36 months of Florida south exposure. The series was prepared initially to study Virflux PR-5, a natural and lower cost TiC^in A-100. Virflux is an off-color pigment with a buff color. Therefore it was thought that in certain colors, such as tans and buffs, it would be practical to use Virflux and realise a saving on TiC^ cost. The tint appearance of paints containing Virflux is very good in tans and buffs because the chalk is a buff color. In a green tint the tint appearance is ouch poorer because the chalk color is much different than the ori ginal color of the paint. As reported earlier (Paint Research Monthly Report, Decem^>er 1965, page 7) Virflux is very low in light scattering efficiency. % On the basis of hiding power per dollar pigment cost, the standard J grades of TiCK are a better buy. However, in some specification formuiiv *at*ons where only Ti02 content is specified and the color can be toi leted Virflux could be used at a saving. 0Q07-SWP-0Q0018725 Project #177 ~ Conto Paint Research July, 1966 -5- Exposure series 4l547~4l559 was examined after 12 months* exposure at Chicago south. The series was prepared to study barium carbonate as an extender in house paint. The formulations studied are A2 W 4 SWP Gloss White, A2 W 8 SWP Trim and Tinting White and A2 W 8 tinted blue. In the test paints in which all the extender vas replaced by BaCC^ the general appearance was poor relative to the standard formula. In A2 W If type the standard was rated 7 for general appearance while the test paint was rated 4, The poor gen eral appearance results from an accumulation of chalk which cannot be removed easily. The chalk in turn collects air borne dirt, re sulting in a very dirty looking panel. Exposure series 44l93~^4229 was prepared to study various titanium dioxide pigments in A2 W 8 SWP Trim and Tinting White, B46 W Al6 P/C One Coat House Paint modified to contain only rutile Tips, and in A2 W 4 SWP Gloss White. The anatase pigments are studied in A2 W 4 and rutile pigments in A2 W 8 and B46 W Al6 modified. The latter two rexes are in white and a blue tint. The pigments studied are as follows: Pigment Supplier Ti-Pure R-900 Ti-Pure R-960 Ti-Pure IW du Pont du Pont du Pont Titanox AWD Titanox ACG Titanium Pigments Titanium Pigments Unitane 0R-600 Unitane 0-110 American Cyanamid American Cyanamid Troncx CR-800 American Potash RF-30 Cabot The paints are applied as two coat systems over A2 W 2 SWP tfudercoater on cedar siding and exposed in Chicago and Florida south vertical. 0007-SWP-000018726 Paint Research July, 1966 & 6- - Project #177 - Cont, Series M&68-91 was prepared for exposure at Chicago and Miami to evaluate several of the newer grades of titanium oxide. Exposures were made in white and blue in an acrylic latex paint, The test includes du Pont titanium oxides R-610, R-900, R-902 and 11-960, also the du Pont potassium titanate, "PKT." Due to the very high water demand of the PKT it is combined with R-610 in this initial exposure. Other titanium pigments appearing in this series are Titanium Pigment Corporation's RA-5O and RA-51, Amerliean jjyanamid's 0R-600 and 0R-640-A, and American Potash's CR-800. Two experimental grades identified as PRC-6 and PRC-7 are included. 0007-SWP-000018727 Project #97 - SWP Paint Research July, 1966 -7- Exposure series 44513-44535 was prepared to study most of our current exterior costings when exposed over wood substrates of varying paintability. The woods include Lauan, Ponderosa pine and cedar. The paints were applied as two coat systems over their recom mended undercoater on the left half of each board and two coats selfprimed on the right half of the board. The panels are exposed at Chicago south. t*f''.>.* % "f* Previous series similar in nature to 44513-44555 had shown that Lauan (formerly called Philippine Mahogany) fell into either the lower levels of Group 3 of species of wood classified by the Forest Products Laboratory for paintability, or into the upper levels of Group 4. W