Compound for pinhole-free rotational casting
AssigneeUnion Carbide Corporation
InventorMichael W. Sowa
Life of this patent
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Abstract
Salts of fatty acids such as calcium stearate and lithium stearate are added to olefin polymer-based rotational molding compositions to provide rotational moldings with pinhole-free surfaces.
Claims12
A composition of matter formed by incorporating into a solid polymer selected from the group consisting of ethylene homopolymers, copolymers of ethylene and at least one acyclic mono-1 olefin hydrocarbon having 3 to 4 carbon atoms per molecule, and mixtures thereof, having a melt index of about 10 to 25 and a density in the range of 0.92 to 0.97,
- (a) a crosslinking amount of an acetylenic diperoxy compound which is hexyne having the formula ##STR2## wherein R is tertiary butyl, and (b) between 0.02 and 0.1 weight percent based on the weight of solid polymer, of at least one ester of thiodipropionic acid of the formula
- R.sub.1 --OOC--CH.sub.2 --CH.sub.2 --S--CH.sub.2 --CH.sub.2 --COO--R.sub.2
- wherein R.sub.1 and R.sub.2 are each lauryl hydrocarbon radicals having 12 carbon atoms, and wherein at least one R has at least 10 carbon atoms per molecule.
A method for producing hollow articles which comprises rotationally molding a composition of matter formed by incorporating into a solid polymer selected from the group consisting of ethylene homopolymers, copolymers of ethylene and at least one acyclic mono-1 olefin hydrocarbon having 3 to 4 carbon atoms per molecule, and mixtures thereof, having a melt index of about 10 to 25 and a density in the range of 0.92-0.97,
- (a) a crosslinking amount of an acetylenic diperoxy compound which is a hexyne having the formula ##STR3## wherein R is tertiary butyl, and (b) between 0.02 and 0.1 weight percent based on the weight of solid polymer, of at least one ester of thiodipropionic acid of the formula
- R.sub.1 --OOC--CH.sub.2 --CH.sub.2 --S--CH.sub.2 --CH.sub.2 --COO--R.sub.2
- wherein R.sub.1 and R.sub.2 are each lauryl hydrocarbon radicals having 12 carbon atoms, and wherein at least one R has at least 10 carbon atoms per molecule.
Dependencies are inferred from the claim text.