Process of retaning mineral tanned leather with resorcinol-formaldehyde

Claim 1

A PROCESS FOR SIMULTANEOULY RETANNING AND INCREASING THE SHRINK TEMPERATURE OF MINERAL PRE-TANNED LEATHER COMPRISING THE STEPS OF WETTING SAID LEATHER WITH WATER IN EXCESS OF THE AMOUNT SAID LEATHER WILL ABSORB, DRAINING SAID LEATHER, INTIMATELY ADMIXING SAID LEATHER WITH RESORCINOL IN AN AMOUNT OF APPROXIMATELY 2 TO 5 PERCENT BASED ON THE WRUNG OUT LEVELED WEIGHT OF SAID PRE-TANNED LEATHER, THEREAFTER CONTACTING THE ADMIXTURE OF WET LEATHER AND RESORCINOL WITH FORMALDEHYDE IN AN AMOUNT OF FROM APPROXIMATELY 1.5 TO 3.0 MOLES PER MOLE OF SAID RESORCINOL, AND ESTABLISHING AND MAINTAINING THE PH OF SAID SYSTEM IN THE RANGE OF APPROXIMATELY 6.0-7.5 UNTIL THE SUPPLY OF RESORCINOL AND FORMALDEHYDE IN THE LIQUID PRESENT IN SAID SYSTEM IS EXHAUSTED, THE RESULTING RETANNED LEATHER BEING CAPABLE OF WITHSTANDING SHRINKAGE IN BOILING WATER.