Preparation of sulfonated phenolic resins

Claim 1

A PROCESS FOR PREPARING A WATER SOLUBLE SYNTAN WHICH COMPRISES: (1) HEATING FORMALDEHYDE WITH A PHENOL SELECTED FROM THE GROUP CONSISTING OF (1) A MONOHYDRIC PHENOL WHICH IS UNSUBSTITUTED IN AT LEAST TWO OF THE ORTHO AND PARA POSITIONS AND WHICH MAY CONTAIN IN ADDITION TO THE HYDROXYL OXYGEN ONLY CARBON, HYDROGEN AND HALOGEN (2) A BIS PHENOL PRODUCED BY REACTING A MONOHYDRIC PHENOL WHICH IS UNSUBSTITUTED IN AT LEAST TWO OF THE ORTHO AND PARA POSITIONS AND WHICH MAY CONTAIN IN ADDITION TO THE HYDROXYL OXYGEN ONLY CARBON, HYDROGEN AND HALOGEN WITH AN ALDEHYDE UNDER ACID CONDITIONS AND (3) A BIS PHENOL PRODUCED BY REACTING A MONOHYDRIC PHENOL WHICH IS UNSUBSTITUTED IN AT LEAST TWO OF THE ORTHO AND PARA POSITIONS AND WHICH MAY CONTAIN IN ADDITION TO THE HYDROXYL OXYGEN ONLY CARBON, HYDROGEN AND HALOGEN WITH A KETONE UNDER ACID CONDITIONS AT ABOUT 50*-100* C. UNDER ALKALINE CONDITIONS, IN THE ABSENCE OF ANY SALT OF SULFUROUS ACID UNTIL SUBSTANTIALLY ALL THE FORMALDEHYDE IS COMBINED AND UNTIL THE REACTION HAS GONE BEYOND THE WATER SOLUBLE METHYLOL STAGE, THE RATIO OF PHENOL TO FORMALDEHYDE RANGING FROM ABOUT 1:1.5 TO 1:0.9; (2) HEATING THE CONDENSATION PRODUCT SO OBTAINED AT ABOUT 75*-100* C. AT A PH OF FROM ABOUT 4 TO 10 WITH A WATERSOLUBLE SALT OF SULFUROUS ACID UNTIL SUBSTANTIALLY ALL OF THE SULFITE IS COMBINED, THE RATIO OF PHENOL TO SO2 RANGING FROM ABOT 1:1 TO 1:0.15, THERE ALWAYS BEING SUFFICIENT FORMALDEHYDE SUPPLIED FOR REACTION WITH ALL OF THE SO2 AND FOR LINKING TOGETHER OF THE PHENOL GROUPS; (3) ADDING A STRONG ACID TO THE REACTION MIXTURE UNTIL ITS PH IS BELOW ABOUT 15; AND (4) HEATING THE STRONGLY ACID SOLUTION AT A TEMPERATURE OF FROM ABOUT 50* C. TO 100* C. WHICH IS SUFFICIENTLY HIGH TO CONVERT SUBSTANTIALLY ALL METHYLOL AND METHYLENE ETHER GROUPS PRESENT IN THE SULFONATED PHENOL-FORMALDEHYDE CONDENSATION PRODUCT TO METHYLENE GROUPS IN ABOUT ONE TO TWO HOURS WHEREIN THE MOL RATIO OF THE FORMALDEHYDE TO SO2 PRESENT IN THE REACTION PRODUCT VARIES DIRECTLY WITH ONE ANOTHER BETWEEN ABOUT 0.9:0.15 TO 1.5:1, RESPECTIVELY.