Process of manufacture of temperaturesensitive recording paper

Claim 1

A PROCESS FOR MANUFACTURING TEMPERATURE-SENSITIVE RECORDING PAPER HAVING A LIGHT-COLORED COATING LAYER ON A DARK CARRIER PAPER BASE, COMPRISING ADMIXING WITH THE SOLUTION OF A POLYMERIZED ORGANIC SUBSTANCE HAVING A SINTERING POINT OF FROM ABOUT 80* TO 220*C. IN AN ORGANIC SOLVENT THEREFOR HAVING A BOILING POINT LOWER THAN THE SINTERING POINT OF SAID POLYMERIZED MATERIAL, AN ORGANIC LIQUID FREE FROM HYDROXYL GROUPS WHICH HAS A BOILING POINT ABOVE THE BOILING POINT OF SAID ORGANIC SOLVENT AND BELOW THE SINTERING POINT OF SAID POLYMERIC MATERIAL, WHICH IS INERT TOWARD SAID PAPER BASE, AND IN WHICH SAID POLYMERIZED MATERIAL IS INSOLUBLE, SAID LIQUID BEING ADDED IN SUCH AMOUNTS TO SAID SOLUTION THAT SAID POLYMERIZED MATERIAL IS NOT PRECIPITATED THEREFROM, AND THAT THE SOLIDS CONTENT OF THE RESULTING MIXTURE IS FROM ABOUT 6 TO 20% BY WEIGHT; APPLYING SAID RESULTING MIXTURE ON SAID PAPER BASE; HEATING THE RESULTING LAYER OF SAID MIXTURE ON SAID PAPER BASE TO EVAPORATE SUBSTANTIALLY EXCLUSIVELY SAID SOLVENT THEREFROM, THEREBY FORMING A FINELY DIVIDED GRAY TO WHITE PRECIPITATE OF SAID POLYMERIZED SUBSTANCE IN SAID INERT LIQUID ON SAID PAPER BASE; AND THEN HEATING FURTHER TO SUCH TEMPERATURE AS TO EVAPORATE SAID INERT LIQUID THEREFROM AND FORMING A GRAY TO WHITE COATING OF SAID POLYMERIZED SUBSTANCE ON SAID PAPER BASE.