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US 4,248,990 AGranted
Nonrandom copolymers of ethylene and unsaturated acid
AssigneeE. I. Du Pont de Nemours and Company
InventorsEdwin T. Pieski, Thomas F. Sashihara
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AssigneeE. I. Du Pont de Nemours and Company
InventorsEdwin T. Pieski, Thomas F. Sashihara
Estimating the term…
Compositionally uniform but nonrandom copolymers of ethylene and .alpha.,.beta.-ethylenically unsaturated carboxylic acids having from 3 to 8 carbon atoms are provided having an acid content of from about 6 to about 35 weight percent, a melt index of from about 0.1 to about 800, and a ratio of weight percent adjacent acid to weight percent total acid in the copolymer of from about 0.44 to about 1.0. These copolymers have improved physical properties such as hardness, stiffness, heat resistance and creep resistance. Further provided, is a process for preparing these copolymers in a constant environment stirred autoclave in a continuous manner wherein the reaction zone is maintained in a steady state at a pressure of from 0 to about 500 psi above, and at a temperature of from 0.degree. to about 15.degree. C. above that needed to maintain a single phase reaction mixture at a given concentration of copolymer and at the given acid comonomer content of the copolymer.
A compositionally uniform but nonrandom copolymer of ethylene and .alpha.,.beta.-ethylenically unsaturated carboxylic acid, said acid having from 3 to 8 carbon atoms and said copolymer containing on a weight basis from about 6 to about 35 percent acid, having a melt index of from about 0.1 to about 800, and having a ratio of weight percent adjacent acid to weight percent acid in the copolymer of from about 0.44 to about 1.0.
A compositionally uniform but nonrandom ionomer of ethylene and .alpha.,.beta.-ethylenically unsaturated carboxylic acid, said acid having from 3 to 8 carbon atoms, said copolymer containing, on a weight basis, from about 6 to about 35 percent acid, having from about 5 percent to about 90 percent of the carboxylic acid groups ionized by neutralization with metal cations having an ionized valence of from one to three inclusive, when the unsaturated acid is a monocarboxylic acid, and an ionized valence of one, when the unsaturated acid is a dicarboxylic acid and said metal cations being selected from the group consisting of uncomplexed and complexed metal ions, said ionomer having a melt index of from about 0.01 to about 100 and a ratio of weight percent adjacent acid to weight percent acid in the copolymer of from about 0.44 to about 1.0.
A process of preparing in a constant environment stirred autoclave a compositionally uniform but nonrandom copolymer of ethylene and an .alpha.,.beta.-ethylenically unsaturated carboxylic acid, said acid having from 3 to 8 carbon atoms and said copolymer containing, on a weight basis, from about 6 to about 35 percent acid, having a melt index of from about 0.1 to about 800, and having a ratio of weight percent adjacent acid to weight percent acid in the copolymer of from about 0.44 to about 1.0, said process comprising continuously charging ethylene, said acid and free radical initiator into a reaction zone maintained in a steady state at a pressure of from 0 to about 50 psi above, and at a temperature of from 0.degree. to about 15.degree. C. above that needed to maintain a single phase reaction mixture at the given concentration of copolymer in the reaction mixture and at the given acid comonomer concentration in the copolymer, the ethylene and acid being charged in a ratio of from about 15:1 to about 200:1, respectively, converting from about 5 to about 20 percent by weight of the monomers to copolymer, and continuously removing the copolymer and unreacted monomer from the reaction zone.
Dependencies are inferred from the claim text.