Process for making a resinous dentifrice cleaning agent

Claim 1

A PROCESS FOR PREPARING A LIGHT-COLORED PARTICULATE PHENOL-FORMALDEHYDE RESINOUS DENTIFRICE CLEANING AGENT, WHICH COMPRISES: (1) DISSOLVING PARAFORMALDEHYDE IN A REACTION MIXTURE OF MOLEN PHENOL AND CITRIC ACID AT A TEMPERATURE RANGING FROM ABOUT 75*C. TO ABOUT 130*C., THE MOLAR RATIO OF PARAFORMALDEHYDE TO PHENOL BEING FROM ABOUT 1:1 TO ABOUT 3:1, THE MOLAR RATIO OF CITRIC ACID TO PHENOL BEING FROM ABOUT 0.005:1 TO ABOUT 0.05:1; (2) SUBJECTING THE REACTION MIXTURE TO A TEMPERATURE RANGING FROM ABOUT 60*C. TO ABOUT 77*C. FOR ABOUT 50 MINUTES TO ABOUT 200 MINUTES, THEN RAISING THE TEMPERATURE TO A RANGE OF FROM ABOUT 80*C. TO ABOUT 104*C. FOR A PERIOD OF ABOUT 15 MINUTES TO ABOUT 60 MINUTES; (3) AFTER SAID PERIOD, MAINTAINING THE TEMPERATURE OF THE REACTION MIXTURE AT A LEVEL OF FROM ABOUT 75*C. TO ABOUT 108*C., AND ADDING THERETO ADDITIONAL CITRIC ACID IN AN AMOUNT OF FROM ABOUT 0.007 MOLE TO ABOUT 0.07 MOLE PER MOLE OF ORIGINAL PHENOL; (4) REFLUXING THE REACTION MIXTURE FOR ABOUT 1 HOUR TO ABOUT 3 HOURS AT A TEMPERATURE RANGING FROM ABOUT 103*C. TO ABOUT 115*C. TO POLYMERIZE THE MATERIAL; (5) DEHYDRATING THE POLMERIZED MATERIAL BY HEATING AT A TEMPERATURE OF FROM ABOUT 103*C. TO ABOUT 150*C.; (6) CURING THE DEHYDRATED POLYMER BY HEATING IN A VACUUM AT A TEMPERATURE RANGING FROM ABOUT 70* C. TO ABOUT 132*C.; (7) REDUCING THE SIZE OF THE RESIN THUS OBTAINED TO A MEAN PARTICLE DIAMETER RANGING FROM ABOUT 5U TO ABOUT 40U; (8) ADDITIONALLY CURING THE PARTICULATE RESIN BY HEATAT A TEMPERATURE RANGING FROM ABOUT 110*C. TO ABOUT 130*C.