Method of molding a polymer composition containing a tetraalkenyl orthosilicate
AssigneePhillips Petroleum Company
InventorLyle R. Kallenbach
Life of this patent
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Abstract
A method for producing molded articles by supplying to a mold a powdered thermoplastic material; heating the mold to fuse the material and cooling the mold to cause the fused thermoplastic material to solidify. The article is molded from a high density monoolefin thermoplastic polymer which contains a catalyst residue, a crosslinking amount of an acetylinic diperoxy compound and a tetraalkenyl orthosilicate compound. The molded article has at least one of increased crosslinking, lowered bubble formation and increased storage modulus.
Claims22
A method for producing molded articles which comprises:
- (a) supplying to a mold a measured amount of a powdered thermoplastic material comprising a high density solid mono-olefin polymer containing catalyst residue, a crosslinking amount of an acetylinic diperoxy compound, and an amount of at least one tetaalkenyl orthosilicate compound sufficient to accomplish at least one of increased crosslinking, lowered bubble formation and increased storage modulus;
- (b) heating the mold to fuse the powdered thermoplastic material;
- and
- (c) cooling the mold to cause the fused thermoplastic material to solidify resulting in a molded article of improved properties.
A method for producing molded articles which comprises:
- (a) supplying to a mold a measured amount of a powdered thermoplastic material comprising a high density solid mono-olefin polymer containing catalyst residue, at least one acetylenic diperoxy compound in the range of about 0.1 to about 10 weight percent based on the weight of the polymer, and at least one tetraalkenyl orthosilicate compound in the concentration of at least about 0.1 weight percent based on the weight of the polymer;
- (b) heating the mold to fuse the powdered thermoplastic material;
- and
- (c) cooling the mold to cause the fused thermoplastic material to solidify resulting in a molded article of improved properties.
A method for producing molded articles which comprises:
- (a) supplying to a mold a measured amount of a powdered thermoplastic material comprising a high density solid mono-olefin polymer retaining catalyst residue selected from the group consisting of ethylene homopolymers and copolymers of ethylene and at least one acyclic mono-1-olefin having 3-8 carbon atoms per molecule formed from at least 75 weight percent ethylene having a melt index of at least about 10, a crosslinking promoting amount of an acetylenic diperoxy compound, and at least one tetraalkenyl orthosilicate in an amount sufficient to accomplish at least one of increased crosslinking, reduced bubble formation, and improved storage modulus, and having the general formula:
- (R.sub.2 C.dbd.CR--CHR--O--).sub.4 Si
- wherein R is selected from hydrogen and alkyl radicals having from 1-4 carbon atoms per molecule and wherein each R can be the same or different;
- (b) heating the mold to fuse the powdered thermoplastic material;
- and
- (c) cooling the mold to cause the fused thermoplastic material to solidify resulting in a molded article having improved properties.
A method of reducing the formation of bubbles and increasing the crosslinking in hollow rotationally molded articles comprising;
- (a) supplying to a mold a measured amount of a powdered thermoplastic material comprising a high density solid mono-olefin polymer retaining catalyst residue, a crosslinking amount of an acetylinic diperoxy compound, and an amount of at least one tetraalkenyl orthosilicate compound sufficient to accomplish at least one of increased crosslinking, lowered bubble formation, and increased storage modulus;
- (b) rotating the mold while heating to fuse the powdered thermoplastic material against the walls of the mold thereby forming a fused hollow article;
- and,
- (c) cooling the mold to cause the hollow article to solidify resulting in a rotomolded article of improved properties.
Dependencies are inferred from the claim text.