Low-temperature and oil-resistant core-shell acrylic polymers

Abstract

Abstract ACRYLIC ELASTOMERS, PREPARED BY A POLY-STAGE POLYMERIZATION PROCEDURE IN WHICH A FIRST-STAGE POLYMER IS AT LEAST PARTIALLY ENCAPSULATED WITH SUBSEQUENT POLYMER, ARE PROVIDED. THE FIRST-STAGE POLYMER INCLUDES AT LEAST 50% BY WEIGHT MONOMERIC ACRYLATE WHICH WHEN HOMOPOLYMERIZED PRODUCES A POLYMER HAVING A GLASS TEMPERATURE BELOW ABOUT -35*C., SUCH AS BUTYL ACRYLATE, OPTIONALLY WITH MINOR PROPORTIONS OF OTHER ACRYLATES AND SUBSTITUTED ALKYL ACRYLATES SUCH AS ALKOXY- AND NITRILE-SUBSTITUTED ALKYL ARYLATES, AND GENERALLY ONE OR MORE CURING-SITE MONOMERS THAT CONTRIBUTE SITES FOR VULCANIZATION OF THE ELASTOMER. FOR RAPID CURE, IT IS PREFERRED TO USE A MONOMER WITH ACTIVE CHLORINE AS THE CURE-SITE. THE FINAL-STAGE POLYMER COMPRISES AT LEAST 60% BY WEIGHT ETHYL ACRYLATE AND/OR METHYL ACRYLATE, FROM 0 TO 40% OF AN ACRYLIC NITRILE, AND, PREFERABLY, A CURING-SITE MONOMER. OPTIONAL INTERMEDIATE POLYMERIZATION STAGES CAN BE INTERPOSED BETWEEN THE FIRST-STAGE POLYMERIZATION AND THE FINAL STAGE POLYMERIZATION. THE ELASTOMERS CAN BE COMPOUNDED AND VULCANIZED TO PRODUCE ELASTIC POLYMERS HAVING RUBBERY PHYSICAL CHARACTERISTICS HAVING A BALANCE OF DESIRABLE PROPERTIES WHICH PERMITS THEIR USE AS AUTOMOTIVE GASKETS, TRANSMISSION SEALS, AND THE LIKE IN DEMANDING AUTOMOTIVE ENVIRONMENTS. THE ELASTOMERS ARE ALSO USEFUL IN COATING COMPOSITIONS SUCH AS FOR PAPER AND IN CAULKS.

Inventors

• 👤 C Lane
• 👤 W Harrop
• 👤 R Graham

Bibliographic Details