Mitsubishi Chemical Corporation

Mitsubishi Kasei Corporation

Motonori Ueda

Masaaki Miyamoto

Kiyoji Kuma

Yoshitaka Shiraishi

Ryuji Uchimura

Masatoshi Kimura

Tomohiro Yamazaki

Masae Kubo

Michio Kawai

Yumito Uehara

Nobuo Enokido

Toshimitsu Inoue

Nobuyuki Shimizu

Kiyotoshi Fujioka

Shigenobu Harada

Polycarbonate resin, optical-information recording medium substrate made of the same, and optical-information recording medium

Polycarbonate resin, optical information recording medium substrate comprising the same, and optical information recording medium

A polycarbonate resin obtained by polymerizing an aromatic diol and a carbonate-forming compound using a monophenolic compound as a molecular weight modifier, wherein said polycarbonate resin contains from 0.2 to 2% by weight of a low-molecular weight compound represented by formula (I): ##STR1## wherein R.sup.1 represents an aromatic diol residue; and R.sup.2 represents a monophenolic compound residue, and wherein said polycarbonate resin provides less amount of low-molecular weight volatile matters even when heated or injection-molded. When heated at 350.degree. C. under reduced pressure of 1 mmHg for 20 minutes, the proportion of the low-molecular weight compound of formula (I) which volatilizes is not more than 0.2% by weight based on the weight of said low-molecular weight compound of formula (I) present in the polycarbonate resin. When heated at 400.degree. C. under reduced pressure of 1 mmHg for 30 minutes, the proportion of the low-molecular weight compound of formula (I) which volatilizes is not more than 2% by weight based on the low-molecular weight compound of formula (I) present in the polycarbonate resin.

Polycarbonate resin for substrate of optical recording medium

A large-capacity optical recording medium, comprises

Optical recording medium having zones wherein the number of sectors per

An ethylene homopolymer or copolymer comprising ethylene and not more than 10% by weight of an .alpha.-olefin having from 3 to 20 carbon atoms and a fuel tank obtained therefrom are disclosed, said ethylene homopolymer or copolymer having (1) an intrinsic viscosity [.eta.] of from 2 to 6 dl/g, (2) a density of from 0.945 to 0.970 g/cm.sup.3, (3) an R value of from 2.5 to 4, said R value being defined as a .sigma..sub.2 /.rho..sub.1 ratio, wherein .sigma..sub.1 and .sigma..sub.2 mean stress in elongation with a strain at 2 sec and 4 sec, respectively, under a flow at an elongational strain rate .epsilon. of 0.5 sec.sup.-1, and (4) a relationship between high-velocity impact strength (HRI-IZOD) measured at -30.degree. C. and a melt index under a load of 21.6 kg (HLMI) satisfying formula:

Ethylene polymer and fuel tank comprising the same

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Okayama, Japan

Motonori Ueda