A copolymer of ethylene and of isoprene, which comprises from 10 to 35 mol % of isoprene units, at least 70% of which are in the 3,4 configuration and a portion of which is in the 1,2 configuration is provided. A copolymer of this type with a reduced crystallinity is synthesized with a much higher productivity than its homologues of ethylene and of butadiene, and also confers improved curing properties on rubber compositions.

A copolymer of ethylene and of isoprene, which comprises from 10 to 35 mol % of isoprene units, at least 70% of which are in the 3,4 configuration and a portion of which is in the 1,2 configuration is provided. A copolymer of this type with a reduced crystallinity is synthesized with a much higher productivity than its homologues of ethylene and of butadiene, and also confers improved curing properties on rubber compositions.

Provided is a film, sheet, plate, or other such formed article having excellent transparency made of a copolymer obtained from a cyclic olefin monomer and an -olefin monomer. The present invention provides a formed article made from a copolymer having Tg of 170 C. or higher and an Al content of 50 ppm or less that is a copolymer including a structural unit of a cyclic olefin monomer (A) derived from norbornene and a structural unit of a monomer (B) derived from at least one C4-C12 -olefin.

Provided is a film, sheet, plate, or other such formed article having excellent transparency made of a copolymer obtained from a cyclic olefin monomer and an -olefin monomer. The present invention provides a formed article made from a copolymer having Tg of 170 C. or higher and an Al content of 50 ppm or less that is a copolymer including a structural unit of a cyclic olefin monomer (A) derived from norbornene and a structural unit of a monomer (B) derived from at least one C4-C12 -olefin.

A polar group-containing olefin copolymer comprising a structural unit (A) derived from at least one kind of monomer selected from the group consisting of ethylene and an olefin containing 3 to 20 carbon atoms, and at least one kind of structural unit (B) selected from the group consisting of a structural unit represented by the following general formula (I) and a structural unit selected from the following general formula (II):

##STR00001##

(reference numerals shown in the general formulae (I) and (II) are as described in the DESCRIPTION.)

Process for copolymerizing ethylene and esters of vinyl alcohol in the presence of free-radical polymerization initiators at pressures in the range of from 110 MPa to 500 MPa and temperatures in the range of from 100? C. to 350? C. in a continuously operated polymerization apparatus comprising a polymerization reactor and one or more compressors, which compress the monomer mixture fed to the polymerization reactor to the polymerization pressure, wherein the monomer mixture is compressed by a sequence of compression stages in which the compressed gas mixture is cooled after each compression stage and the fraction of the monomer mixture, which is liquid after this cooling, is separated off and returned to the polymerization apparatus in liquid form, and wherein at least a part of the liquid fractions obtained after compressing the monomer mixture in the respective compression stage to a pressure of from 0.2 MPa to 10 MPa is purified before being returned to the polymerization process.

Provided is a film, sheet, plate, or other such formed article having excellent transparency made of a copolymer obtained from a cyclic olefin monomer and an -olefin monomer. The present invention provides a formed article made from a copolymer having Tg of 170 C. or higher and an Al content of 50 ppm or less that is a copolymer including a structural unit of a cyclic olefin monomer (A) derived from norbornene and a structural unit of a monomer (B) derived from at least one C4-C12 -olefin.

Provided is a film, sheet, plate, or other such formed article having excellent transparency made of a copolymer obtained from a cyclic olefin monomer and an -olefin monomer. The present invention provides a formed article made from a copolymer having Tg of 170 C. or higher and an Al content of 50 ppm or less that is a copolymer including a structural unit of a cyclic olefin monomer (A) derived from norbornene and a structural unit of a monomer (B) derived from at least one C4-C12 -olefin.

-Olefin maleic acid copolymers and -olefin-co-maleimide copolymers have the CH.sub.2CH of the -olefin in the backbone of the copolymer with the maleic acid or maleimide and the remainder thereof extending from the backbone. The -olefin having the formula CH.sub.2 CH(CH.sub.2).sub.X-R.sup.1, and x being in the range of 1 to 19, y and z have a ratio in a range of 0.25: 1 to 8: 1, and n R.sup.1 yields a copolymer having an average molecular weight of less than 500 kg/mol. R.sup.1 (and R.sup.2 in the case of the -olefin-co-maleimide copolymers) is/are selected from a diverse group of moieties. The -olefin maleic acid copolymers and -olefin-co-maleimide copolymers each form lipid particles where the lipid can be from a galactolipid rich membrane of a cyanobacterium.

-Olefin maleic acid copolymers and -olefin-co-maleimide copolymers have the CH.sub.2CH of the -olefin in the backbone of the copolymer with the maleic acid or maleimide and the remainder thereof extending from the backbone. The -olefin having the formula CH.sub.2 CH(CH.sub.2).sub.X-R.sup.1, and x being in the range of 1 to 19, y and z have a ratio in a range of 0.25: 1 to 8: 1, and n R.sup.1 yields a copolymer having an average molecular weight of less than 500 kg/mol. R.sup.1 (and R.sup.2 in the case of the -olefin-co-maleimide copolymers) is/are selected from a diverse group of moieties. The -olefin maleic acid copolymers and -olefin-co-maleimide copolymers each form lipid particles where the lipid can be from a galactolipid rich membrane of a cyanobacterium.