Document xJbL4aOxpavmYD0LaXERzKEg

CROSS fUEFSRSBCBt ' Emulsion Faints Protein Fro Emulsion Paints Speed Easy Explosives CIO 31 ffii 10 MMI511L UiOT LIBIM mmmm r epo r t b o , M-209 Philadelphia Laboratory July 27# 1948 ^biaiKw gff p| y'f IMPROVED WATER RESISTA1CE OF EMBLSIOB PAIR RUMS IBCOBPORATIBg CROSS LIEKIBQ AOBMTS AMP COLLOIDAL ALOMIBA Experiments have been completed evaluating (1) Aerotex 605 {American Cyan&mid) as a eroasllnfcing agent for CMC in a pro-, teln free emulsion paint and (2) colloidal alumina as an auxiliary film former in the present Wesce speed Easy formula. Conclusions; fh incorporation f Aerotex 605 produces no improvement in the wet erosion resistance of the protein free formula, The wet erosion resistance of the present Wasco Speed Easy formula can be improved by a factor of 5 times by incorporating colloidal alumina sol into the paste. Description and Evaluation of Aerotex 605 Two basic protein free formulas were mad up# one with methyl cellulose as the water phase colloid# the other with oarfeoxy methyl cellulose as the water phase colloid. The test paints were modifications of the above# wherein 5 and 10$ of the colloids were replaced by an equal weight of Aerotex .605 (solids basis). (Bet? Aerotex 605 is a water soluble melamine formaldehyde resin obtained from the American Cyanamid Company.) After 7 days air dry the paints were tested in the Gardner !~X05 Washability Machine with the following results? Code P -385^94196 P-385-P-94197 P-385-P-94198 P-385-P-94X99 P-385-R-26000 F-385-R-26001 Colloid a a CMC V ti $ Colloid Replaced 4 5 10 w 5 10 1 Strokes before failure .31 14 8 6 9 -2 All of these paints brushed, poorly du to rapid set up. There was some,evidence that Aerotex 605 in the MC formula does permit longer lapping time. Evaluation of Colloidal Aluminat Amounts of the colloidal alumina aqueous sol were Inoorprated into th Wesoo Speed Easy past as pr th table below* After seven days air dry the paints wer tested in the Gardner M-105 Wash* ability Machine with the following results * Code $> of Solid AlgOjC Present Based on Solid ~ 385-100 (B-30755) P-385-B-26002' P-385-E-26003 F-385-R-26004 w . foMm Strokes before failure a- 57 51 5* # Introduced as ,a 6*2^ AigOg solution. Small scale brushing, tests indicated that increasing amounts of AlgOg resulted in progressively poorer brushing character istics. It was noted that the colloidal alumina did not produce a bodying effect in the paint as was th ease with colloidal silica.; (See TO 1502 and 1502). Apparently the colloidal, alumina functions similarly to other inorganic film forming materials Which w have previously investigated such as colloidal silica and aluminum acstate. Beeemendations 1 (1) Aerotex 605 a It is doubtful if any improvement that weuld result in' a protein free formula from th us of a crosslinklag agent such as Aerotex 605 would warrant any further expenditure fsf research time. However, it should be classified with other mat erials such as ammonium alginate and earboxy methyl cellulose which we have used, to improve lapping time in emulsion paints. (2) Colloidal Alumina? If additional parts are approved for th fundamintir"6pedr Easy"project, colloidal alumina should be considered for further valuation on the basis of the improved wair resistance resulting from its Us. It would be preferable to colloidal silica in a protein containing paint because a bonding agent need not be present to prevent bodying. DUP030003087 -3 Raferp.cat Art2 605 - Letter - Dorman McBtirnoy to J. W. Iliff, dated XO/31/47 Colloidal Alumina - Letter - H. M,, Stark to Stuart Craves, dated 10/22/47 CWSibj PHILADELPHIA LABORATORY 0&U>4 C, SHAY DUP030003088