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AssigneeSRI International
InventorsRobert Wilson, Sigridur Jonasdottir
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The invention is directed to olefin copolymers composed of nonhydrolyzable monomer units and hydrolyzable monomer units, the latter resulting from copolymerization of monomers containing a linkage that is hydrolytically cleavable in the presence of aqueous base or aqueous acid. Generally, the hydrolyzable monomer units represent a significant fraction of the copolymer, such that upon hydrolysis, a substantial portion of the copolymer is degraded into low molecular weight fragments. Also provided are degradable articles that are at least partially composed of a degradable copolymer in which hydrolyzable monomer units represent at least 20 mole % of the copolymer. These degradable articles include agricultural film products, adhesive tape substrates, bed linens, containers, disposable absorbent articles, packaging materials, bags, labels, pillow cases, protective clothing, surgical drapes, sponges, tampon applicators, disposable syringes, temporary enclosures and temporary siding, toys, wipes, foamed plastic products, and controlled release pellets, strips and tabs.
A degradable olefin copolymer prepared by addition polymerization, in the presence of a catalytically effective amount of a metallocene complex of a Group 4, 5, or 6 transition meta and a catalyst activator that renders the complex cationic or zwitterionic, of a monomer mixture containing at most 80 mole % of at least one nonhydrolyzable olefin monomer and at least 20 mole % of a diolefin monomer containing a hydrolytically cleavable linkage selected from a cyclic acetal linkage and an ester linkage.
A degradable article at least partially comprising a degradable copolymer composed of at most 80 mole % of nonhydrolyzable monomer units resulting from polymerization of nonhydrolyzable olefin monomers, and at least 20 mole % of hydrolyzable monomer units resulting from polymerization of hydrolyzable olefin monomers containing at least one linkage that is hydrolytically cleavable under acidic or basic conditions.
Dependencies are inferred from the claim text.