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) REFLUXING AN AQUEOUS REACTION MIXTURE OF PHENOL, FORMALDEHYDE, AND SODIUM HYDROXIDE AT A TEMPERATURE RANGING FROM ABOUT 70*C. TO ABOUT 105*C. FOR A PERIOD OF TIME RANGING FROM ABOUT 30 MINUTES TO ABOUT 50 MINUTES, THE MOLAR RATIO OF FORMALDEHYDE TO PHENOL RANGING FROM ABOUT 1:1 TO ABOUT 3:1 AND THE MOLAR RATIO OF SODIUM HYDROXIDE TO PHENOL RANGING FROM ABOUT 0.01:1 TO ABOUT 050:1; (2) AFTER SAID PERIOD, MAINTAINING THE TEMPERATURE OF THE REACTION MIXTURE WITHIN THE RANGE OF FROM ABOUT 80*C. TO ABOUT 97*C., AND ADDING THERETO MALEIC ANHYDRIDE AND CITRIC ACID, THE MOLAR RATIO OF MALEIC ANHYDRIDE TO ORIGINAL PHENOL RANGING FROM ABOUT 0.005:1 TO ABOUT 0.15:1 AND THE MOLAR RATIO OF CITRIC ACID TO ORIGINAL PHENOL RANGING FROM ABOUT 0.05:1 TO ABOUT 0.2:1; (3) DEHYDRATING THE REACTION MIXTURE BY HEATING AT A TEMPERATURE OF FROM ABOUT 100*C. TO ABOUT 105*C.; (4) CURING THE DEHYDRATED MATERIAL BY PLACING IT IN BOILING WATER; (5) DRYING AND FURTHER CURING THE RESIN THUS OBTAINED AT A TEMPERATURE OF FROM ABOUT 70*C TO ABOUT 130* C. FOR A PERIOD OF TIME RANGING FROM ABOUT 1/2 HOUR TO ABOUT 18 HOURS; (6) REDUCING THE SIZE OF THE DRY RESIN TO A MEAN PARTICLE DIAMETER RANGING FROM ABOUT 5U TO ABOUT 40U; (7) ADDITIONALLY CURING THE PARTICULATE RESIN BY PLACING IT IN BOILING WATER; (8) DRYING THE PARTICULATE RESINOUS PRODUCT.