Document 40Edv26OgwD6pv2d6Kog9rka

BA.- Ss 'v* >* 3 N 3521.01 I &M Promising new antifoulant ORGANOLEAD-ELASTOMERIC coatings have been found to offer extended protection against the growth offouling or ganisms because of their gradual release of toxicants over the life span of the paint film. Here are the results of exposure tests carried out in fouling waters of Connecticut and Maryland. *T OK. MAX KJtONSTEIN CHMl$T*t OCPAATMCMT. MANHATTAN COkLttC. ftftOtO, M.V. f\ saw form of anttfouling paint, is which m organolead chemical is used as the toxicant ta solvmt dispersions of synthetic rubber* compounded from elastomeric polymeric materials, has show* considerable prorrwx mi vtnom tc*wcr immersion too. The nr pufld. developed in research sponsored by International Lend Zinc Roordi O(|*ruuiion, Inc. (ILZROl. differ baakratty from pre viously developed or|okad<on* Uimn| Mifoulin| paints in ihai the earher coatings were based oa the principle that rf cuprous oxide (CUfO) ppnent were cortunuotaly exposed the p*mt turfsee. m*nrx pUnt and animal life would not be abk to attach Kcrmrht*. This type of resinous paint. with its high degree of pgmeo lation. has a limited surface stability under water, and this is manifested by "chalking." A* the surface layer chalks way on a continuous bam new layers of paint are exposed, and with them new quantities of cuprous oaidc as tox icant. The new elastomeric anlifouling paints do not develop surface chalking. Instead, they permit the organolead toxicant to be released gradually from the coating surface by diffusion. Such release continues to prevent the growth of plant and animat organisms on che coaled surface during the life of the COKMg. The amount of che kad-release. m terms of micropiM of kad per unit of area and time, n quite tmaR. Ex posure tots have shown, however, that it is effective in protecting costed panefc. boats, outboard crimes and other immersed surfaces to a high degree against fouling growth during exposure tot periods ranpng from 12 to 21 months. Laboratory tests have shewn that the rate of kad-release remains, for a certain paint material, nearly constant during test periods of one year or more. Previous research conducted by ILZRO established the effectiveness of organolead compounds in anlifouling paints ffj. The paint systems studied then were of the vinyl-rosin systems, such as US Navy Specification 121. of M1L-P-1593IA. and the vmyt-fegh rosin paints of U.S. Navy Specification 121/63 of MIL-P-I593l. In the first of these groups, the coating vetvck consists of PVCMC copolymer Vinyhle VYHH of Union Carbide Corp.. and WW gum rosin of Hercuka Incorporated in a ratio of 1:1. la the second pwp, the ratio is 1:4. In both lest formulations, inert*yl phos phate was used as che plasticiser. As anlifouling toxicant, both tpecifvcationa use cuprexa oxide m an amount about five times the total weight of vinyl resin and wood rosin in each paint. In die earlier work, the amount of cuprous oxide ia lest pamM waa reduced by 50 per cent and replaced by equal parts of m organolead com pound, such aa tnphayt lead ace tate (TPLA) or tributyl lead acetate fTBLA), and by pigments, such as red iron oxide and barytes. The antifoutag effect of the ocganotcad-containiag formulation proved superior to that obtained with formulations containing cuprous oxide alone. ClMtanarM VsNchl It must be noted that synthetic rubbers, or elastomers, represent polymer matenak which peas c m median icaJ properties similar to those of aatwral rubber: high deformability, rapid recovery of deformation and good mechanical strength. These materials may be described as "hetcrophaac** substances {2j. meaning that they con sist of more than one state, or "phase*" of their essentia! base material. The base material is contained in a high polymer, or (hme-dimcmkmal. phase which, alone, a not molocularly dispersible and not volatile (even under vacuum o when ripened lo elevated icmpcratu.'tk In this state the polymer is capable of increasing ha volume when it cornea u^o contact with suitable fluids, fusible matter or "sweHcrs" that penetrate the polymer i 'MSP jw'iiswjrii^iLpw -y- I t. ' t ! > : F I I- L IA 15 135 3 Fifurv 1 -- Cipomrt Mna mi cfw* flowing Into Severn River, Md. Top torn mows paroft after four mor<be of --poaum. hdy to November. 1971. Bottom row mow! tame ponot* aher 18 mo<tta. Pr>**a (from loft] am coated as folio** tR point Pb-1-39 **0>out tmwant, un point mXh ton g TFlAper 100 g navy entifouWng peart (MU.#*15931. f. 12LA31. The 1*o#cn" polymer has a h m* 50*C. (122 *Fk Thus treated, the creasing ratio of (hew tn-dmeouosai (erm apptartncc. The tolubk slate. or pamt can be applied to metal. plastics, phase matter, and since (he organdrad V'rx" of (hr bur maicnal reprr- concrete or polymer-treated fiber glass matures examined m this study have a will swrilcr subu*nce thi is. alone, surfaces. As (he volatile sweiler sol tendency to mcrease the volume of the volatile (at least under vacuum or at vents evaporate, the pigmented rubber- available rubbery pofymcrv the re elevated temperiureL and con. there based films dry into highly cohcwve sulting coatings have stronger mcchan- fore. form a rubber-Uke substance with and dense coating films that arc stable csl properties than had been the case the tri-dimcnwonaJ phase matter The under fresh or sea wa*er and under for the earlier mutiaes of elastomer*. orgxnolcad matter penetrates the varying temperature condition*. Furthermore, it is possible, daring swelling or ioUnt polymer materials, Conventional rubber dtspersions evaporation of the volatile sweiler sol or. tn particular, their solvent disper require for their "curing." or drying vents from the coating film, to apply sions, and influences the rubber4ke into dense coatings, the presence of two or more additional coats of the . ri materials, becoming a part of these sulfur or organosulfur compound or elastomeric paint, which swell together rubbers. accelerators. The application of Heal is into uniform, heavier coatings. These elastomeric solvent disper sho usually required to transform the Since the organolead compound has sions can be combined with ball-milled dispersions into stable rubber or "vul been incorporated into the coating ma dispersions of pigments in solvents. canized'' rubber layers. The new elas terial itself, it k to be found in each When mixtures of the elastomeric tomeric dtspersions, however, aa well layer of a muhi-coet dry film. The dispersions and the pigment dispersion as their pigmented forma, which con lead-release takes place uniformly and arc further ball-milled together, a uni tain organolesd compounds continuously throughout all layers of form dispersion is obtained. The or- throughout, do not require the pres die film, It k possible, therefore. In m ganotead component can be added to die vehicle, during pigment milling, or to the final ball-miiled paint. ence of sutfid or organosulfur com pounds, or the application of heat. They form highly coherent, dense remove by abrasives (such ns brush boats) any pan of the fiWa while re taining the lead release property In the In order to assure complete entry of coatings at room temperaU**. portion of the film that remains. die organolead component, the paint Since the properties of heterophase It k evident that such properties diooid be warmed during stirring to polymer substances vary with the in offer important posai bibties for tha i % f: 4- *<* ^ .( , V ' Vv ' j irigii^iTiitiriri-ii-iirVii.:>ifi(tfi Ttfix* 3 -- Outboard anginas ahor axposurs In Connecticut coat(at aatan from May to lata fati. 197? Only low** portion of angm* at Mt we* coated swth (sterner* antifoutmg pa>nt cor*a*n*og TPiA. Crittrs immersed portion of angina at n^K aaa coat ad with th# naw antrfoutant patnL h m one c4 Ae purpoiei of the Uhxikv) Inh lo observe the charic* MriKid at Ac mi panc-h under exvixJcd opmutr to fink aiicr or h i vynthet* cri*la Is changing Itv mi water* k ivmn tune initniK, a become* pi'swNf lo iru (he * aid at Ac precedmg period for it\ content of lead maticr. By cotnpain| nidi result* with akn at merd exposing prfioiK one may ciuMidt Ac cAbti at Ac fair at trad-release over a pven etpourr lime or tiudy eventual changes whctl might occur during extended pomfn It h iko puibh to compare Cocrrvpoodin| loh pttnh ccniurMf one imd of organolrad mailer, wch m mKifyl lead acetate. iA tCtief panti Containing under or|rH4cd com* TaW* I -- load laWou DrWeeancaa Ba+wwsn Qryowiliid CampaoawH in tlosiomarW NUH Ourlng lab a rart ary laiaumati TmN b 500 ad Water low pfe t ja N*r 100 4rt CikvtvHd. pm y> Caktivwd tr I . (THAI $ a TP\A prn> too a ||M - *> < *>< Mra> - 0 O' J "1'itiH >Wu - 3 J* rWn-VJ'J a - 0 0M -*+>"> I 100 nrrVk^00 l*a - 4 --of*-- <>tS*Y\ 4 W3 --<t%y IWtJ ' w# w*ac* pa raw (t *a V7f q ca| m* s.era ii - i io*gi 0 OOJCTf 9 Wokt * (t| tvAwyt Wa4 l* f% 1 Jf r*< 307 Car* H*i tOOdoya Ca*tuipA pm CafcvWwa W I pound, auch aa triphenyl lead acetate. THc determination of Ac lead matter m Ac immersion water was made in accordance with the dtChtaocw text method (6} as modification of ASTM Standard C-353-b4-T (a mcAod developed originally for the determination of lead release from glared ceramic surfaces). TebW I offers data on thia type of extended investiga tion on two corresponding test paints, one cf which contained triphcnyl lead acetate. Here the Wed-release hi rnktograms of lead per square embmeicr per day waa nearty the lame in Ac first ?7J daya of immeraioa as dunng Ac next 100 days (0.012 mtcrogram PtVcmVday and 0.011 microfram Pb/cm*/dayL Is Ac case of the paint containing mhueyf lead acetate, the lead-release waa conuktaMy higher in (he find >02 dayv showing a dccreaac m the sibw|ucnt 100 days- This phenomqi non rouhi from the fad that tnbufyl Wad acetate haa a greater leaching rale than the trtphcnyl lead acetate, which haa s contdcraNr degree of stability Aat n desirable for long-term at* pouifas. It n lo he acted that kakdrnr doe* not take place m the form of an inorganic Wad aah. The released matter can be extracted from the *mmersion water by Aakmg i( with ethyl ether. When Ac ether extract is applied to a micToacopc slide, and the ether a allowed to evaporate. Ac resi due. when viewed under Ae micro scope (450 XL has the appearance of typical polymeric materials. (The cWmeal constitution of auch waterreleased matter haa nor as yn been in vestigated.} i Lsod BHssss Dots Table I aho shows the total tendrelease per square centimeter of coated surface per year of immersion in varied 500-milliliter quantities of water, and it calculates the annual lead-fete*** from a square foot of sur face. For the Cnphenyt lead acetate paint, Ae lead-release imounh lo 4,000 marrograms, or 0.004 gram of Pb per year. If the paint were applied to a Atp. this total of Wad would be released per square foot cf ntrfacr throughout all the waters through which the Aip might travel during tha yarn. It n of interest, therefore, lo com pare these data with the known Wad content cf the water before the immer sion of the coatad surface. A recent aAeaa^alaWi i'y i. :K:'" .-.- ... o . 5 i I nuinkttiMt of "cW" turfaca Hi iropktl wtlcn where imHm fawHi| it prevalent. This cleaning action CM occur even after removal of the lop coaling layers, and while Ihe surface it under water, without requiring a dry dad. Ilntinin IHed The following clastomaric polymen have been uaed in the development of thb itudy (I) Solvent dnpcnioM of i commerdal potyssoprrnc. Goodyear** Natryn 400. a ftytet>e-buL*det>e-atyrene btock polymer. 9k K ChenwcaTs K/eion 1101; a chJoruaulfonatcd polyethylene, Du Pom's Hypalon )0, and a modifica tion of the coating by the additiao of an umaturated polyamide rcim. Gem cral Mi lb' Vcrsalon 1140. The organolcad chemical a in moil ---t. med as the only accelerator m (he drying of (he coning. (?) In another system, a fluid bwudiene-acrylonitnlc polymer, ft. F. Goodrich Chemical's Hycar 1312. was used jouifly with a Ou k J polyurethane. Ou Pom's Adiproe 1. 167. again using die organolead compound as the only accelerator component n ihe system. (3) Other elastomers have been in troduced m similar compositions, such as a poty<p*chlorohydrin. ft F. Goodrich ChermcaPs Hydr* ICO. OipnlMh Used Gaxrilty, organolead chemistry dcak with compoudi in which a carbon atom of at Wait one organic group m attached directly to a lead at<sn (J>. The materials that have primarily been used in the coalings of fhn study belong to the group of organotcad salts of the general type of ft* Pb X. in which ft represents a group attached to lead by carbon, and X aa amoruc group. The matenah used for (he mod pari can be further classified as triaryl or tnalkyl lead acyiates. such as tnphcnyl lead acetate, tnbutyl lead ace tate and others. These matcrisis were developed initially by the Institute for Organic Chemistry. TNO. in (Jtrecht. The Netherlands, and have since been produced industrially in the United States as well as m Europe. In one interesting farm, the orgsnolcad material is delivered after being wetted with a high-boiling aro matic fluid to avoid dust formation during handling and dispersion. This product is supplied by CtbaGeigy Marienbcrg GmbH in Germany under (he name Irgarol ftl 547. Fipjrn 2 -- Ship** rudder painted with txpmmafsl elastomer* antifouling coating after exposure in Connecticut coastal water* from An* to December. 1971. It has been pointed cul that the orgsnolcad matter n introduced tn the preparation of the new antifoulmg paints either to the elastomeric vehicle, during pigment dnperuon or into Ihe halt-milled paint The elastomeric polymer* are commercially widely available. In the yean between 1962 and 1972. the production of synthetic rubber* increased in the United State* from 1.574.000 long tons to 2.424.000 long tons, an increase of 54 per cent fdj. ftp-urn tbdii In order to follow the development of the elastomeric antifoulmg coaiinp in selected exposure tests, studies were made in laboratory water immersion tests as wdl as m ocean underwater a* posuret. For the laboratory tests, coldrolled steel paneh coated with two coats of wash primer (MIL-F-I332AB, formula 117) and two coats of the or* gsnolcad elastomeric antifouling pamts were used. In the outdoor seawater exposures, hot rolled, sandblasted sled paneb coaled with 0.7 to 0.8 mil of wash primer and 4.3 lo 4.75 mib of red lead vinyl primer (MIL-F-J5929B. formula 119) were utilized. On the early exposure lest paneb. these primer* were followed by about 13 mib of elastomeric paint with no orgsnolcad component but containing sulfur and a sulfur accelerator. These coalinp were topped with 3.0 to 3.5 mib of organolead elastomeric anti fouling paint (without sulfv* Compo nents). The tuttur-containing coatinp were developed in (he course of the work of thb research group (3) under the sponsorship of the Ui Naval Applied Science Laboratory. Brooklyn. N.Y^ which was later transferred to An napolis. Md. The organolead elas tomeric antifoulmg coatings without sulfur component* were developed by the same research group under the sponsorship of lLZftO. These paneb comprised Expostfe Grotp I. and were exposed in fouling water* of Che estuary of the Severn River la Maryland. In later teats, die organolead elas tomeric antifouling paints were ap plied directly over the primer coats in a thickness of sac lo lea mib. These paneb comprised Exposure Group U. The test paints of Group I were dark in color, since thetr pigmentalran con sisted of zinc oxide and channel-type carbon black; the paneb of Group II were light gray ta color, and vert coated with experimental test paiat referred to as G-4 paint. The same G-4 pa*n< formulation was used sa ocher exposure tests, such aa on a fiber glam motor boat where, over the wash primer, it was applied as the only addi tional coating material. After exposure for a season in bar nacle-rich coastal water* of Connecti cut. no trace of marine growth was ob served. and (he exposure test was repeated during the following season. In another test group, the G-4 paint was used as a protective coating on outboard ship engine* and exposed in Connecticut coastal waters. The result* of these exposure* are discussed later in thb article. Most recently, the paints have been to aluminum and to formed acrylic polymer objects- The paint was abo applied to hot-rolled steel test paneb over a commercial inorganic mac primer of the type of U S. Specifi cation MIL-F-38336. Here, the paints of Group I. as wxH as those of Group II, were applied successfully. It b abo worth mentioning that the vbcosity of the elastomeric paints can be modified for spray application in stead of brushing. oidnaestti&aMAHa , i t- i ; r v\ ,~X ............. . .. . - , _ mummm. LIA15138 u 3p!v a' ' 4 book (7) reports that lhe global nrM for lake or river water b one to left imcrogrwm of lead per titer. Higher values may eml in area* adjacent to lead ore deposits, heavily traveled highways, etc. What these data reveal a that the amount of tcad released from one square foot of painted suf- facc would not have significant influ ence on the mating tcad concentration in acawatcr. Control teat* were made on two water samples, one taken from the ca* tuary of the Severn River at An napolis. Md-, the other front the Harlem River adjacent lo the NYU Aerospace facility in the Brom, N.Y. The first test showed an average tcad content of 12.6 mkrograma per titer in dithizonc tests: the other showed 6-4 pigmented either with carbon bta* dir boat during the foflowi/^ uana microframs of Pb per liitf, i Brash Vatar Upesvra and zinc oxide or carbon black and one-half zinc oadc and one-half cuprous oaide. Neither type of this This time, however, a new form of triphcnyl lead acetate waa wed, con taining ten per cent of an aromatic The panels of Exposure Croup I were described earlier in this paper. paint showed fouling growth after II months of exposure. (They have been anti-dusting agent (Ciba-Gcigy Uanenberg GmbH'* Irgarol II 547). Their antifoulmg coatings comprised etaatomenc paints containing five to ten grams of triphcnyl lead acetate or tnbutyl lead acetate per 100 grama of test paint. These were exposed ade by side with a similar elastomeric paint based on a sulfur accelerator, but not Containing organotead toxicant They were exposed together with panels Coated with the same primer and r*w lomerk paints, but topcoaud w:th a Common type of antifouling pamt based oo cuprous oxide pigmentation with a vinyl-hgh rosin vehicle fNavy Specification MIL-F-1593IB, Type 121/63). This same paint was abo used containing cuprous oxide as well as some organotead component The exposure tests in the fouling waters of a creek flowing into the Severn River in Maryland showed that after four months, from July lo November. 1971. (he elastomeric paint without toxicant was covered with a beginning plant growih which, after It further inspected after 22 months of exposure and art still without any marine attachment or fouling growth). Some ex' the exposed panels arc dtow* in the photos of Figure I. In exposure tests of Group II. using organotead eiastomenc antifoulmg paints directly over (he primer system, the coatings were pigmented cither in the same manner as Group 1, or with the major portion of the carbon black replaced by a fine-particle-uzcd amor phous silica (hat r% produced by hydrolysis of silicon tetrachloride. This material is commerdaily avail able from Drgussa. |nc_ under the Aeroul-360 trade name, at a particle size of about five millimicron*. The pigment dispersion m the test paint consists, (hen. of zinc oxide, amor phous silica in some cases, and a slight Unting -- cither a small amount of carbon black, red lead oxide or other pigments. The paints were exposed in Mary fifftfi WaCar CigMM The organoicad antifoulmg eiaalomcric pamt G-4 waa applied to out board engines which were exposed M the Connecticut coastal waters. One of die engines was pamted only on (he lower pari; wNW the other engine was painted over the entire immersed arc*. The engines were exposed from May lo late fall. 1972. when they were pho tographed as shown an Figure 5. There is an abundance of marine growth on the unprotected part of one engine, while the test pamt shows high resistance to fouling wherever it sms applied Concerning the use of such casting on engines, it is of interest (hat the rlastomerk antifoulmg paints arc not affected by contact with mineral oiks, despite (heir being air-dried. The pasai was not dissolved after a 15-day im mersion in warm vacuum pump miner al oil at 100-F. 0**0. The release of month* of exposure, became the silt of land, on the same type of test panels a* lead matter into the oil was tested in a barnacle attachment. The same paint with organotead toxicant showed the were the coalings of Group I. as well as in the bamacW-nch coastal waters manner similar to that prcviomly described for lead content in immer- attachment of barnacles lo the sup of Connecticut; the tests are con tion water. porting exposure board, but none on the painted panel. The antifoulmg tinuing. Especially interesting w the application of (he experimental G-4 The lead-release after the 15day lest amounted to 2 *4 mkrogrsrm per paint. M(L-fMS93(B. showed the paint on a fiber glass motor boat di square inch, indicating that organoicad beginning of plant growth after four rectly over wash primer undercoat. elastomeric anttfouling paint can abo months of exposure, with progressive While the Connecticut coastal waters be employed under immersion condi fouling after J 9 months. in which the boat was operated are tions where contact between fouling Another organotead elastomeric paint was also exposed This paint was based on a butadiene-acrylonitrile heavily infested by barnacles, the painted rudder (Figure 2) showed high resistance to fouling after exposure water and oil h lo be expected, such as with offshore drilling rigs. Other exposure tests arc under way e polymer and a fluid polyurethane, but from June to December, 1971. in Australian waters, and in an area of was heat-reacted with a smaller The results were the same when sim Rhodesia where the antifoulmg paint amount of triphenyl lead acetate and ilar applications were carried out ox haa been applied to irrigation ditches ii. X # pypMpiW3IBp|8|WI^^ . '.- ' " , .' LI ^ 1513 q ' '- ' I : i ? [. j 4 .4 Science, New York University, Di versify Heights. Bronx. N.Y,, under the sponsorship of (he International Lead Zinc Research Organization. Inc. (Dr. S. F. Radtke. executive vicepresident and director of research}. The author was amkied by a number of students: Kevin A. Babiak, Anthony J. Chiaramida. Katherine M. Jaractcwtki, Tervxhy F Murphy. John G. Piuolo. James J. Webber and Rimes V. Vcbdiunaa. Since New York University discon tinued its School of Engineering and Science, in mid-197J, (he Coatings Research Laboratory has been trans ferred to the Chemistry Department, Manhattan College. Hayden Halt, Bronx. NY. 1047!. where these studies are continuing. The use of the exposure site ia the estuarial waters of (he So era River M Annapdn. Md- wan made possible tfirough the cooperation of Dr. Eugene C. Fischer and Mr. Efvvd Dyckman of the Oceanographic Laboratory. U-SNavai Skip Research and Develop ment Laboratory. The author ex presses his appreciation for this aseas- f/jCarr. Dodd S-. "Organolead Com pounds Protect Sup Bottoms." 5 -- spray *ppat*on Orw und tested ttcd. Panels * top row WOT Faint and VmrnlsM Production. f coated with four<omponOT rubber syKsm*, while (hot* in bottom row w o t coOTd with flu-d UAed**rw-ecTylQnitnle-pdy4'emarw system All syrtsnw cot* Vd. St, No. 2. pp 23-2*. Febru ary. 1964. tin orpno<M(j compound Pn^i A art bOT fleet. 6 wOT prwMt*d w*h Mill (2) Kronstem. Max. "The influence of t:;1-. pnmmr, C w o t pre-caeted with inorganic me primer. the Phases in Elastomeric b Coatings." Preprints of the Divi r sion of Organic Coatmp and fr Plastics Chemistry. American harbonrtg snails which tnmmil the \ tropical drtcwc, schistosomiasis (abo & known as mil fever). The prcitmiiury lidcrabie practical importance. In the case of surface cleaning cr partial paint-surface removal by mecharwcaJ Chemical Society, VoL 31. No. 2. pp 601-611. September. 1971. (J) Wi&cmsens. I_ C-. said van dcr i results in cncouri|iii| cleaning equipment at sea. it might be Kcrk, G. J. M.. Investigation* in Recent OOTtepmenti desirable to apply additional coe of paint over moest surfaces or when the the Field of Organdcsd Chemis try,** published by International In view of Che fact that the new elas moisture content of the air is high. Lead Zmc Research Organization. tomeric piinb are baaed on dnptniom la a ctrreal development, modifica !nc_. New York. N Y. (1965k of polymeric swelling material, the in* tion* of the viscosities of die eiaa* (4) Tacts and Figures: The US fluence on drying and adhewon of wet tomcric G-4 paints were made. These Chemical Industry." CVwiW and ajbatrates and low temperatures was modifications facilitate the formula- tyiwnaj New*, p, 13, June A studied. In these teats, the elastomeric boo of paint vehicles dial can be 1973. paints were applied to moistened ah- applied by spray or brush over ex <5j Kronstcin. Max, U-S. Pales* No. primed Med panels and. acme cases, tended areas. This developmental work J.531.547. issued January 24. at temperatures below normal for corn* k tuR in progress, but Figtrc S shows 1971. venUonal coatinp application. spray applications over bare sand (6) The Dithizone Method (diphenyf- Controlled conical mandrel tests, m blasted sicel (A), over waah-pnmad thiocarb.zone) issued by ASTM mown in Figure 4, were carried out on sand-blasted steel (Bk and over sand as `'Quantitative Method for the the panels. It was found that such blasted steel with inorganic bite Determination of Lead Extracted applications do not interfere with the primer fCk from Glazed Ceramic Surfaces." drying or adhesion of (He elastomeric f^c^tnosife^fgninitBs Standard C-555-64-T. antifouling paints. The work here reported was tatder- (7) Analysis for Trace Quantities of These application characteristics of taken in the Coating Research Labora Lead. Ethyl Corporation. Baton the new antifouling paints are of coo* tory el the School of Engineering and Rouge, La., September. 1972. I t. 'i :* i