phosphonic acid was employed instead of 14 5 grams the backside burn off was more than in example vi but not as much as in the untreated polyimide glass laminate and the backside temperature during exposure to a 2 000 u00b0 f flame was 650 u00b0 f the procedure of example i was repeated but 30 grams of the ammonium salt of methyl phosphonic acid was used instead of the ammonium salt of phenyl phosphinic acid the backside temperature during exposure to a 2 000 u00b0 f flame was 400 u00b0 f and there was essentially no resin burn off the procedure of example vii was used except that 15 grams of the diethylamine salt of phenyl phosphonic acid was used instead of 30 grams the procedure of example viii was used except that 15 grams of the n propylamine salt of phenyl phosphonic acid was used instead of 30 grams the backside temperature was 450 u00b0 f and the burn off was more than in example vii but not as bad as in the control the procedure of example xiv was used except that five grams of the n propylamine salt of phenyl phosphonic acid was used instead of 15 grams the procedure of example vii was used except that 30 grams of the dimethylamine salt of phenyl phosphonic acid was used instead of the diethylamine salt of phenyl phosphonic acid the backside temperature during exposure to a 2 000 u00b0 f flame was 400 u00b0 f with little burn off evidenced on the rear the procedure of example xvi was used except that 30 grams of the monomethylamine salt of phenyl phosphonic acid was used instead of the dimethylamine salt of phenyl phosphonic acid the.