Chemically reducing residual acrylonitrile monomer in nitrile polymers and shaped packaging materials formed therefrom
AssigneeMonsanto Company
InventorsI. Luis Gomez, Edward F. Tokas
Life of this patent
Estimating the term…
Abstract
A process for reducing free acrylonitrile monomer in nitrile polymers during melting which involves having an effective amount of an unsaturated fatty acid or a glyceride of oleic, linoleic and linolenic acid or compounds such as safflower and linseed oils as an acrylonitrile scavenger in admixture with the polymer during melting. Shaped products such as preforms, containers, film, sheet, etc., formed from such melt are well suited for packaging food, beverages, pharmaceuticals, cosmetics, etc., in that residual acrylonitrile monomer in the walls of such products is minimal.
Claims41
In the process of melting an acrylonitrile copolymer by physical working in the presence of free acrylonitrile monomer, the improvement which comprises having a scavenging amount of a C.sub.18 unsaturated fatty acid compound, which is an acid or a glyceride thereof in admixture with the copolymer during said melting to minimize free acrylonitrile monomer in the copolymer.
A method for reducing the content of free acrylonitrile monomer in shaped packaging materials formed of an acrylonitrile copolymer which comprises having a scavenging concentration of a C.sub.18 unsaturated fatty acid compound, which is an acid or a glyceride thereof in intimate contact with the polymer during at least one forming operation in which the polymer is heated to form a melt and shaped so that a packaging material is obtained with free acrylonitrile monomer content of less than about 7 ppm.
In the process for preparing shaped packaging materials from acrylonitrile copolymers, which process involves at least one forming operation comprising heating the polymer to form a melt containing free acrylonitrile monomer and shaping the polymer, the improvement which comprises having linseed oil or safflower oil in intimate contact with the acrylonitrile copolymer during at least one forming operation, said oil being employed in an amount sufficient to reduce the extractable free acrylonitrile monomer contents of the resulting packaging material.
A preform for conversion into a container for environmentally sensitive materials, said preform being formed of a thermoplastic material comprising at least about 10 weight percent of polymerized acrylonitrile monomer, the level of free acrylonitrile monomer in such preform being no greater than about 7 ppm based on the total weight of the polymer, the walls of such preform containing the reaction product of an unsaturated fatty acid and acrylonitrile monomer.
A shaped packaging material for environmentally sensitive products formed of a thermoplastic polymer comprising at least about 10 weight percent of polymerized acrylonitrile monomer, the level of free acrylonitrile monomer in said packaging material being no greater than about 7 ppm based on the total weight of the polymer, said packaging material containing the reaction product of an unsaturated fatty acid and acrylonitrile monomer.
Dependencies are inferred from the claim text.