Manufacture of polyvinyl chloride

Abstract

Abstract PRIOR PRACTICE OF MAKING HOMOGENEOUS RESINS OF VINYL CHLORIDE CONTAINING ADJUVANTS SUCH AS STABILIZERS, PLASTICIZERS, LUBRICANTS, FILLERS AND ANTIOXIDANTS HAS INVOLVED INTENSE MECHANICAL WORKING, FOR INSTANCE ON A ROLL MILL, AND HAS PROVED TO BE DIFFICULT OF SATISFACTORY EXECUTION. FREQUENTLY SUCH PROCESSES PRODUCED PRODUCTS POSSESSED OF POTENTIAL INSTABLILITY, INTRODUCED BY THE HEAT OF THE MIXING OPERATION, WHICH APPEARED DURING LATER OPERATIONS ON THE RESIN. LACK OF HOMOGENEITY WAS ALSO KNOWN, PRODUCING INFERIOR PRODUCTS. THE PRESENT PROCESS OF PREPARING FINELY DIVIDED POLYMERS IN POWDERS AND GRANULAR FORMS ACCOMPLISHES THE LOADING AND HOMOGENIZATION OF THE PARTICLES WITH THEIR WORKING ADJUVANTS BY BRINGING AN ORGANIC CARRIER LIQUID CONTAINING THE ADJUVANTS IN SOLUTION OR SUSPENSION INTO CONTACT WITH THE PULVERULENT, SOLID POLYMER TO BE LOADED, WITH AGITATION WHICH ACCOMPLISHES A THOROUGH MIXING OF THE TWO PHASES AND THE TRANSFER OF THE ADJUVANTS FROM THE LIQUID TO THE POLYMER. THE TRANSFER IS SEEMINGLY ACCOMPLISHED BY SORPTION, AND IS SUBSTANTIALLY COMPLETE, BUT THE APPLICANT IS NOT BOUND BY ANY THEORY OF TRANSFER. AFTER THE TRANSFER HAS BEEN ACCOMPLISHED THE CARRIER LIQUID IS EVAPORATED OFF AND REUSED.

Inventors

• 👤 Jean Claude Thomas

Bibliographic Details