Polysulfide compositions and cure

Claim 1

IN A METHOD OF TREATING COMPOSITIONS CONTAINING MIXTURES OF LIQUID POLYALKYLENE POLYSULFIDE POLYMERS CURABLE TO A SYNTHETIC RUBBER AND VARYING IN MOLECULAR WEIGHT, AT LEAST 20% OF SAID MIXTURE BEING COMPOSED OF POLYMERS WHICH ARE LESS THAN 0.5 AND MORE THAN 1.5 THE AVERAGE MOLECULAR WEIGHT OF SUCH MIXTURE, TO IMPART ENHANCED HEAT RESISTANCE TO CURED BODIES MADE FROM SUCH COMPOSITIONS; INCORPORATING INTO SAID COMPOSITIONS A SOLUTION OF SOLUBLE SALT OF CHROMIC ACID IN A SOLVENT SELECTED FROM THE GROUP CONSISTING OF WATER AND ORGANIC SOLVENTS TO THEREBY CROSS-LINK POLYMERS OF HIGHER MOLECULAR WEIGHT DURIN CURING AND SIMULTANEOUSLY CROSS-LINK LOWE MOLECULAR WEIGHT POLYMERS AT A HIGHER RATE AND TO A GREATER EXTENT THAN SAID HIGHER MOLECULAR WEIGHT POLYMERS, TO OBTAIN A CURED ELASTOMER OF VITURALLY HOMOGENEOUS CHARACTER HAVING AN ENHANCED ABILITY TO WITHSTAND EXPOSURE TO HIGH TEMPERATURES AND MATERIALLY INCREASED RESISTNCE TO ATHE ACTION OF LIQUID HYDROCARBONS, SAID SOLUBLE SAIT OF CHROMIC ACID HAVING A SOLUBILITY IN WATER AT 20*C. AT LEAST AS GREAT AS THE SOLUBILITY OF POTASSIUM BICHROMATE IN WATER AT 20*C. AND BEING ADAPTED, UPON SOLUTION, TO LIBERATE ANIONS CONTAINING CHROMIUM.