Olefin polymerization process using maintained phosphoric acid catalyst

Claim 1

A PROCESS FOR THE CATALYTIC POLYMERIZATION OF OLEFINS WHEREIN A GASEOUS MIXTURE CONTAINING SAID OLEFINS CONTACTS A PHOSPHORIC ACID FILM CATALYST, WHICH COMPRISES PREPARING SAID CATALYST BY SPREADING ON THE SURFACES OF NONPOROUS CARRIER PARTICLES A FILM OF FRESH PHOSPHORIC ACID OF NOT MORE THAN 85% H3PO4 CONCENTRATION, PASSING IN CONTACT WITH SAID CATALYS A PREHEATED STREAM OF SAID GASEOUS MIXTURE TOGETHER WITH A PROPORTION OF WATER VAPOR SUFFICIENT TO BE SUBSTANTIALLY IN EQUILIBRIUM WITH AN INITIAL OPERATING CONCENTRATION OF ACID OF ABOUT 85 TO 95% H3PO4 AT THE TEMPERATURE AND PRESSURE OF CONTACT UNTIL A PREDETERMINED OPERATING TEMPERATURE IN THE RANGE OF 250* TO 450* F. AND A PREDETERMINED OPERATING PRESSURE IN THE RANGE OF 200 TO 2000 P.S.I.G. ARE REACHED, CONTINUING THE PASSAGE OF SAID GASEOUS MIXTURE IN CONTACT WITH SAID CATALYST TO POLYMERIZC SAID OLEFINS WHILE MAINTAINING THE ACID FILM CONCENTRATION ON THE SURFACES OF SAID CARRIER PARTICLES AT NOT MORE THAN 104% H3PO4 BY THE CONTROLLED ADDITION OF WATER VAPOR TO SAID GASEOUS MIXTURE, INTERRUPTING THE POLYMERIZATION REACTION WHEN THE YIELD OF POLYMER FALLS OFF APPRECIABLY AT AN ACID FILM CONCENTRATION OF NOT MORE THAN 104% H3PO4, WASHING SAID CATALYST WITH WATER, AND REPEATING THE STEPS OF THE PROCESS AS AFORESAID.