Document pm5XZ0RKrRXY8Oamy3a6y7gw

ALLIED RESEARCH BULLETIN Number RC 20 SUBJECT LEAD TITANATE EXPOSURE STUDIES S. F. Carlson -M. Van Loo December 3, 1936 ALLIED RESEARCH LABORATORIES Chicago, Illinois N14222 > + LEAD TITANATE EXPOSURE STUDIES funeral Statement Lead Titanate - a high temperature furnaced pigment, cream white in "'color, of high opacity - first became available for practical test purposes early 7 in 1954. Claims fcr great durability were made as a component of mixed paints. -- Exposure-Studies. 1954 . The pigment combinations shov.-n in Table I were put out for exposure 3 in 1934 on both Tfliite and Yellow Pine, using S?JP White as the guide coat on a por- r-tion of each panel to eliminate wood differences. These paints have gene through 'three summers' vertical exposure, . The oil used was half raw and half alkali refined Linseed. Because *io* f the high density of Lead Titanate, the poundage of pigments required to produce ready to use paints was considerably higher than normal, resulting in gallon ^weights up to 20 pounds for the 100$ Lead Titanate paint down to 17 pounds for the lower percentages containing inert pigments. Also, the Lead Titanate used had ?v . extremely high thixotropic properties, making it difficult to produce a satis- .factory ready to use consistency paint within the customary pigment-volume relation ships. These paints being between 24$ to 27$ pigment volume. .Panel No. 54 Sp 38 '54 Sp 39 ;54 Sp 56 54 Sp 41 ,54 Sp 59 ?54 Sp 40 54 Sp 42 34 Sp 57 54 Sp 58 .54 Sp 60 34 Sp 61 Lead Titanate 100$ 50$ 50$ 50$ 40$ 40$ 40$ 40$ 30$ 30$ 25$ Table I Plfgaent Compositions Titanox B White Lead Leaded Zinc 55/65 50$ - 40$ - -- 50$ - -- -- -- 40$ 50$' 15$ 10$ - - - 50$ 60$ - 40$ - 30$ 45$ 45$ Asbestine - 20$ 20$ 20$ 10$ 10$ 20$ 0007-SWP-000006808 2- - Exposure Results The high content Lend Titanate paints dried slower than normal paints, producing soft, tender films. This resulted in abnormal dirt collection and mildew formation} although the exposure location was such that the generally accepted types of paints exposed along with the Lead Titanate did not show mildew or abnormal dirt collection. After three summers' (-1/2 years) exposure the 100^ Lead Titanate paint has shown no tendency to "clean up" and remains almost black. Film is intact. The 50^ Lead Titanate, 50% Titonox B at the end of the third summer has begun to chalk heavily, although traces of the earlier excessive dirt collect ion remain. The film presents a strongly eroded appearance. ' The 4($ Lead Titanate-, 40^ Titancx B and 20% Asbestine shows bad cracking, generally following the volleys of the brush marks. Films chalking moderately but retaining appreciable dirt collection. This formulation with White Lead replacing Lead Titanate in other exposure tests has shown good dura bility with minimum tendency tow:.ru cracking. The panels similar to the two. preceding Lead Titsnates but with the Titanox B replaced with White Lead (BLC) both show excessive dirt collection, no chalking, film intact. The remaining exposure panels of this series contain Zinc Oxide in percentages varying from 20% to 40*. All are chalking moderately but still show considerable dirt collection. The Zinc Oxide apparently hardened the films in the earlier drying ana exposure stages so that a much milder form of dirt col lection resulted. Film 3tlll intact. - 0007-SWP-000006809 -5- , 'nse of Lead Titanate in Tints . . The performance of Lead Titanate as the component of the white base for light tints of house paints is indicated by exposure 34 Sp 61, which has the : following pigment composition; . 25$ Lead Titanate 6$ White Lead - 10$ BLC, 16$ BLS i 9$ Zinc Oxide , 0$ Asbestine V 100$ [ The degree of chalking at the end of the third summer is consider ably less than that of the 50 Lead, 40 Zinc, 10 inert base for tints used by S-W and several of the affiliated companies. The dirt collection is slightly greater. In locations where the dirt collection is at a minimum, tint reten tion of light colored paints containing 25$ Lead Titanate should be improved. In s' ' ' . ' .-locations - particularly- cities - where dirt collection is prevalent, the tint ',v retention as judged by general appearance, would not be as good as at present. ;-In this connection it should be noted that the low Zinc Oxide content in the fol lowing formula showed no improvement in reducing dirt collection over that of the i sabove formula or of the formula containing 40$ Zinc Oxide. 30$ Lead Titanate 50$ White Lead 20$ Zinc Oxide 10$ Asbestine 100$ rflse of Lead Titanate in Exterior Primers At the same time the above exposures were put out, a primer con- staining 77$ Lead Titanate and 23$ micaceous inert was applied over both White and SYellow Pine under SWP White-* To date the films remain intact, with no evidence .Of checking or cracking of the top coats. 0007-SWP-000006810 -4- Exuosure Studies, 1955 The 1955 series were devoted largely to a study of Lead Titanate as a major component in the pigmentation of exterior house paint primers. 29 such formulations were placed on exposure in two and three coat work on White Pine and Yellow Pine siding at Sarnia, Ontario. STOP Gloss White (Ti02 type) was used as the top coats. The formulations included Lead Titanate, approximately 7S%, with inerts such as Asbestine, Mica, and Sericite, with treated oil vehicles, in some instances with resins. The pigment-volume-concentrations varied from 31/5 to 35^. Lead Titanate was also used in proportions from 32i5 to 64^ with other opaque pig ments, including basic lead carbonate, and leaded zinc, some with inerts. In these formulations the pigr.ent-volume-concentratlons were held at 35. For details see "Outline of Exterior House Paint Primer Studies." These exposures have now been out slightly over one year and have not as yet reached a stage where they may be differentiated as to their merits as primer formulations. Studies which were initiated on the influence of Lead Titanate in | .Zinc Sulfide - Calcium Sulfate exterior paints vd.ll be dealt with in a separate report. l ' Exposure Studies. 1956. V . i The 1936 series includes a study of Lead Titanate as a component in the pigmentation of an oil paint for metal surfaces. The formulation is basically | a primer of vehicle construction such as was used for the wood primer tests of 1935. The finish coat is similar to SViP #363 Slate with a pigmentation of 2055 | Lead Titanate, 5355 Leaded Zinc 40/GO, 14/5 Basic Lead Carbonate, and 13}5 Asbestine. 0007-SWP-000006811 -5- ' As a control 7/e used tv/o coats of regular #363 Slate which has as its pigmentation 70$ Leaded. Zinc 40/60, 19$ Basic Lead Carbonate, and 11$ -Asbestine. At present, after 46 weeks of exposure at Chicago both panels have a fair general appearance with no film failures. The formula carrying 20$ Lead Titanate shows less chalking thon the regular, but contrary to our expectations, / shows a greater degree of fading. In the 1936 series, we have also extended the study of Lead Titanate -to improve tint retention in exterior house paints. Our tint base carried a pig- ,6. -'nentation of 10# Lead" Titanate, $0$ Leaded Zinc 50/50, 12$ Basic Lead Carbonate, i; and 12$ Asbestine. The paint v/eighed 17 pounds per gallon, and had a pigment- dvolume-concentration of 26.9$. , This base was tinted to match SWP #496 Ivory, #462 Cream, and #353 d Light Lead, respectively, and exposed against tile regular SWP tint as a control in .^each instance* The painting was done in three coat work on White Pine, and also I'as tv/o coat repaint work on previously painted and exposed White Pine panels* Since these exposures have only been out for a few months there is no distinct ^difference as yet in the tint retention of the Lead Titanate tints compared with the regulars. Howrever, where any differences do appear, they favor the Lead `Titanate. * There are 15 panels in the above series. This work will be further * '. extended to study formulations carrying a higher percentage of Lead Titanate. 'Three basic pigmentations will be used; (a) 70$ Leaded bine, 15$ Lead Titanate, )! 15$ Asbestine; (b) 65$ Leaded Zinc, 17-l/2 Lead Titanate, 17-1/2$ Asbestine; and (c) 60$ Leaded Zinc, 20$ Lead Titanate, 20$ Asbestine. 3 0007-SWP-000006812 6- | _' t>.onclusions to Date 1. In white paints. Lead Titanate in percentages sufficient to produce . definite results, produces a yellowish white sufficiently pronounced to be objectionable. 2. Films containing substantial percentages of Lead Titanate are subject to - excessive dirt collection and mildew formation. 3. Lead Titanate, Titanox B films - White Lead absent - tend to crack. 4. Improvement in tint retention of light colored paints is indicated but at the expense of heavier dirt collection. 5. Tfliile the primer tests over the resinous woods show excellent results to date - the slow, soft drying characteristics of Lead Titanate present definite difficulties as to fool-proof exterior primer formulations. i mv l s f c /ar 0007-SWP-000006813