Abstract 1. PROCESS FOR THE CONTINUOUS PREPARATION OF UREA FORMALDEHYDE RESINS CHARACTERISED: IN A FIRST STAGE OF REACTION, BY THE SUPPLY OF UREA AND FORMALDEHYDE IN MOLAR RATIO OF FORMALDEHYDE TO UREA OF 2:1 TO2.7:1 AND IN THAT STAGE WORKING AT TEMPERATURES OF 60 TO 95*C. WITH THE PH OF THE AQUEOUS REACTION MEDIUM RANGING FROM 8 TO 9.5, THE CONTACT TIME BEING FROM 15 TO 50 MINUTES; BY SUPPLYING THE PRODUCT FROM THE FIRST STAGE TO A SECOND STAGE OF REACTION TOGETHER WITH FORMIC ACID AND, IN THE SAID SECOND STAGE, WORKING AT TEMPERATURES OF 60 TO 95* C. WITH A PH IN THE AQUEOUS REACTION MEDIUM OF 4.0 TO 5.5, THE CONTACT TIME BEING FROM 4 TO 10 MINUTES; BY NEUTRALISING THE PRODUCT DISCHARGED FROM THE SECOND STAGE TO A PH OF 6.8 TO 7.5; BY SUPPLY THE SAID NEUTRALISED PRODUCT TO A THIRD STAGE OF REACTION TOGETHER WITH UREA AND WORKING IN THAT THIRD STAGE WITH MOLAR RATIOS OF FORMALDEHYDE TO UREA OF 1.40:1 TO 1.65:1, AT TEMPERATURES OF 60 TO 95*C. WITH A PH IN THE REACTION MEDIUM OF 5.7 TO 6.8 AND THE CONTACT TIME BEING BETWEEN 60 AND 240 MINUTES; BY COOLING THE UREA FORMALDEHYDE RESIN DISCHARGED FROM THE THIRD STAGE AND BRINGING ITS PH VALUE TO APPROXIMATELY 8.
PROCESS FOR THE CONTINUOUS PREPARATION OF UREA FORMALDEHYDE RESINS CHARACTERISED: IN A FIRST STAGE OF REACTION, BY THE SUPPLY OF UREA AND FORMALDEHYDE IN MOLAR RATIO OF FORMALDEHYDE TO UREA OF 2:1 TO2.7:1 AND IN THAT STAGE WORKING AT TEMPERATURES OF 60 TO 95*C. WITH THE PH OF THE AQUEOUS REACTION MEDIUM RANGING FROM 8 TO 9.5, THE CONTACT TIME BEING FROM 15 TO 50 MINUTES; BY SUPPLYING THE PRODUCT FROM THE FIRST STAGE TO A SECOND STAGE OF REACTION TOGETHER WITH FORMIC ACID AND, IN THE SAID SECOND STAGE, WORKING AT TEMPERATURES OF 60 TO 95* C. WITH A PH IN THE AQUEOUS REACTION MEDIUM OF 4.0 TO 5.5, THE CONTACT TIME BEING FROM 4 TO 10 MINUTES; BY NEUTRALISING THE PRODUCT DISCHARGED FROM THE SECOND STAGE TO A PH OF 6.8 TO 7.5; BY SUPPLY THE SAID NEUTRALISED PRODUCT TO A THIRD STAGE OF REACTION TOGETHER WITH UREA AND WORKING IN THAT THIRD STAGE WITH MOLAR RATIOS OF FORMALDEHYDE TO UREA OF 1.40:1 TO 1.65:1, AT TEMPERATURES OF 60 TO 95*C. WITH A PH IN THE REACTION MEDIUM OF 5.7 TO 6.8 AND THE CONTACT TIME BEING BETWEEN 60 AND 240 MINUTES; BY COOLING THE UREA FORMALDEHYDE RESIN DISCHARGED FROM THE THIRD STAGE AND BRINGING ITS PH VALUE TO APPROXIMATELY 8.
Claim 2
Dependent Claim
213 words
PROCESS FOR THE CONTINUOUS PREPARATION OF UREA FORMALDEHYDE RESINS CHARACTERISED: IN A FIRST STAGE OF REACTION, BY THE SUPPLY OF UREA AND FORMALDEHYDE IN MOLAR RATIO OF FORMALDEHYDE TO UREA OF 2:1 TO2.7:1 AND IN THAT STAGE WORKING AT TEMPERATURES OF 60 TO 95*C. WITH THE PH OF THE AQUEOUS REACTION MEDIUM RANGING FROM 8 TO 9.5, THE CONTACT TIME BEING FROM 15 TO 50 MINUTES; BY SUPPLYING THE PRODUCT FROM THE FIRST STAGE TO A SECOND STAGE OF REACTION TOGETHER WITH FORMIC ACID AND, IN THE SAID SECOND STAGE, WORKING AT TEMPERATURES OF 60 TO 95* C. WITH A PH IN THE AQUEOUS REACTION MEDIUM OF 4.0 TO 5.5, THE CONTACT TIME BEING FROM 4 TO 10 MINUTES; BY NEUTRALISING THE PRODUCT DISCHARGED FROM THE SECOND STAGE TO A PH OF 6.8 TO 7.5; BY SUPPLY THE SAID NEUTRALISED PRODUCT TO A THIRD STAGE OF REACTION TOGETHER WITH UREA AND WORKING IN THAT THIRD STAGE WITH MOLAR RATIOS OF FORMALDEHYDE TO UREA OF 1.40:1 TO 1.65:1, AT TEMPERATURES OF 60 TO 95*C. WITH A PH IN THE REACTION MEDIUM OF 5.7 TO 6.8 AND THE CONTACT TIME BEING BETWEEN 60 AND 240 MINUTES; BY COOLING THE UREA FORMALDEHYDE RESIN DISCHARGED FROM THE THIRD STAGE AND BRINGING ITS PH VALUE TO APPROXIMATELY 8.