Cross-linking of copolymers of ethylene and propylene

Abstract

Abstract Amorphous polypropylene or an amorphous copolymer of ethylene and propylene containing not more then 85% of ethylene are crosslinked by heating the polymer in the presence of sulphur and a di(aralkyl) peroxide of the formula: <FORM:0850455/IV(a)/1> in which R1 and R6 are aryl groups and R2, R3, R4 and R5 represent hydrogen or alkyl groups of less than 4 carbon atoms. The crosslinking may also be effected in the presence of red lead, a quinone oximino compound, and carbon black. The polymers may be made by either polymerizing the monomers in the presence of a catalyst formed by reacting a compound of Group IV-A, V-A, or VI-A, of the periodic table with an organometallic compound of Group I, II, or III, or by fluidized and/or supported metal oxide techniques. The Specification contains a long list of peroxides of which the following are exemplified i.e.bis (alpha, alpha dimethyl-benzyl) peroxide, bis (alpha, alpha dimethyl -p-t-butylbenzyl) peroxide, bis (alpha, alpha-dimethyl-p-isopropylbenzyl) peroxide, bis(alpha, alpha-dimethyl-p-methylbenzyl) peroxide, bis (alpha-isopropyl-benzyl) peroxide, benzyl (alpha alpha-dimethyl -p-isopropylbenzyl) peroxide, and benzyl (alpha, alpha-dimethyl-p-isopropyl benzyl) peroxide. Quinones mentioned are quinone mono- and dioxime, quinone dioxime dibenzoate, o-benzoquinone dioxime, 1,4-naphtho-quinone dioxime, o-benzoquinone dioxime dibenzoate, o-benzoquinone dioxime diacetate, and otoluquinone monoxime. In addition to the additives already mentioned other ingredients such as fillers, pigments, and plasticizers may also be admixed with the polymer. Specifications 748,583 and 804,641 are referred to.

Inventors

• 👤 Anderson E Robinson
• 👤 William D Willis

Bibliographic Details