Abstract: A copolymer of ethylene and an ethylenically .alpha.,.beta.-unsaturated acid halogenated phenyl ester represented by the formula (1): ##STR1## (wherein R is hydrogen or a methyl group, X is a halogen atom, Y is an alkyl group having 4 to 18 carbon atoms, n is 0 or 1, m is an integer of 1 to 5, and l is 0 or an integer of 1 to 4), wherein the halogenated phenyl ester group unit content is about 0.005 to about 10 mol %. This copolymer is excellent in dielectric breakdown characteristics and flexibility, and its excellent performance can be maintained over a long period of time. Thus, it is useful as a superhigh voltage electric wire cable insulative material.

Abstract: A stabilizer composition for synthetic resin is described comprising a piperazine derivative represented by the following formula (I): ##STR1## wherein R.sub.1 and R.sub.2 each represents an alkyl group having from 12 to 20 carbon atoms or a 2,2,6,6-tetramethyl-4-piperidyl group; R.sub.3 and R.sub.4 each represents a hydrogen atom or a methyl group; and n and m each represents 2 or 3.A synthetic resin composition is also described comprising polyolefin and the aforesaid piperazine derivative.

Abstract: An ethylene copolymer comprising an ethylene unit and an ester unit selected from ethylenically .alpha.,.beta.-unsaturated acid esters represented by the formula (I) or (II): ##STR1## wherein R.sup.1 represents a hydrogen atom or a methyl group; and R.sup.2 represents a halogenated alkyl group having from 1 to 15 carbon atoms; ##STR2## wherein R.sup.3 represents a hydrogen atom or a methyl group; and n represents 0 or 1,wherein said ester unit is present in a total amount of from 0.001 to 10 mol %. The copolymer has excellent dielectric breakdown characteristics, such as electricity treeing property, water treeing property, etc., and is useful as an insulating material for high-voltage cables.

Abstract: A phenol derivative represented by the formula ##STR1## wherein R.sup.1 is a secondary or tertiary hydrocarbon residue of having 3 to 8 carbon atoms, R.sup.2 is a hydrocarbon residue having 1 to 12 carbon atoms, X is ##STR2## wherein R.sup.3, R.sup.4 and R.sup.5 each is an alkylene group having 1 to 4 carbon atoms, Z is an n-valent group and n is an integer of 1 to 8.This compound is effective to prevent the oxidation of organic materials.

Abstract: A phenol derivative represented by the formula ##STR1## wherein R.sup.1 is a secondary or tertiary hydrocarbon residue of having 3 to 8 carbon atoms, R.sup.2 is a hydrocarbon residue having 1 to 12 carbon atoms, X is ##STR2## wherein R.sup.3, R.sup.4 and R.sup.5 each is an alkylene group having 1 to 4 carbon atoms, Z is an n-valent group and n is an integer of 1 to 8.This compound is effective to prevent the oxidation of organic materials.

Abstract: An ethylene copolymer comprising ethylene and a compound of formula (I) ##STR1## wherein R.sup.1 represents a hydrogen atom or a methyl group, and R.sup.2 represents a methyl group or an ethyl group, the content of the compound of formula (I) being from 0.005 to less than 10 mole %, and the copolymer being a random copolymer prepared by radical polymerization of ethylene and the compound of formula (I).