Document 2jdLbvppwY60gD9XbxgmZmagp

Gyoss Reference: 94 Lin "Dulux" Resins, ion exchange CC; Mr. J. w. Hift} Lab. Dr. p. B, Evans, Lab. 10 MIL LABOBAIOBY LIBBABY 46I1NDEXED" tSr53 MEMORARDIM REPORT KQ,, M-318 Philadelphia Laboratory October 13, 1948 V f Ifti '(ffiCRAIIOil BLISTERING: AMBBRLJTE ION EXCHANGE RESINS BI "DULUXW Introduction: . This memo will record several experiments conducted with two ion exchange resins in 94 Line "Puluxw during the period of 6/28/43 to lO/H/480 Conclusions: The results of this preliminary study Indicate that the addition of small amounts of ion exchange resins will Improve the blister resistance of "Dalits". Additional work will be necessary to improve the dispersions and establish limits. Recommendation ffor ffuturo Program: .. ' The Amberlit resins used In these experiments were tough and resiliento We could not grind them fine enough for high gloss results. Therefore, an effort should be made to (1) procure more brittle, easier ground resins and/or (2) develop more efficient grinding techniques. Limits should then be established using the well dispersed material in-various formulations. Other test con ditions such as salt spray, humidity, and soap bath should be used. Effect in both primer and topcoat should be studied. Searching Action: Experiments with ion exchange rosins In anti-fouling primers for aircraft war conducted by E. R. Gilbert in the sum mon of 19420 This work was done in cooperation with the Naval Lab oratories, Anacostia Station,and was classified confidential. A search is being mads to locate any reports pertaining to this- work. Experimental Patella: - In starting .these experiments wo reasoned that osmotic pressure, a probable' cause of blistering, could be reduced by low ering the salt concentration of the water which permeate. the film. The two Amberlite ion exchange resins selected for the test were .3CE-59, anion exchanger, and SE-60, cation exchanger. They were supplied as 200 mash powder. ' . . i First attempts at gr lading these resins la a a tael ball mill. with .solvent filled .# The supplier, Resinous Products Co#, advised that the ye,sins contain 30-40$ moisture and that dehydra tion will improve grinding# We confirmed this with an eight day grind after dehydrating approx# $ hrs# at 225 F# The fineness was greatly improved# However, the addition in the typical 94 Lin gray enamel did cause lower gloss# Formulations containing 2, 4, 9,, and 15$ Amberlit on the enamel solids were prepared and placed in the water bath# In five days the controls were showing definite fine blisters# The 9 and 15% Amberlit a enamels Were showing loss of gloss only# After three weeks immersion the fail ures were only slightly, exaggerated and the test was discontinued# These results seems! conclusivei however. It would have been easier to grade the panels if they were all of the same initial gloss level# Another attempt to grind the Amberl.ite using a combina tion dry steel ball mill and 47 process grind gave only, slightly better dispersion# Results of this test in the blister bath con firmed the results if the first test# It is possible that the gloss failures of the Amberlite formulations were caused by the swelling of the dehydrated resin particles# Hydration after grinding would probably remedy this condition# PHILADELPHIA LABORATORY H# W# GODSHALK HWGspp f DUP030003093