摘要 |
Polycarbonate for production of disc substrates, a process for efficiently producing said polycarbonate, and a disc substrate made of said polycarbonate are disclosed. This polycarbonate has a low molecular weight polymer content of not more than 3% by weight, an unreacted bisphenol content of not more than 20 ppm, and a methylene chloride content of not more than 20 ppm, and can be obtained by extracting impurity-containing powdery polycarbonate with an organic solvent such as acetone and methyl ethyl ketone. This polycarbonate is particularly suitable for production of high quality disc substrates. |
申请人 |
IDEMITSU PETROCHEMICAL CO., LTD., TOKIO/TOKYO, JP |
发明人 |
KAZUNARI, OTSUBO, ICHIHARA-SHI CHIBA-KEN, JP;MOTONOBU, EZOE, ICHIHARA-SHI CHIBA-KEN, JP;HIDEO, AGO, ICHIHARA-SHI CHIBA-KEN, JP;KOJI, YAMAMOTO, ICHIHARA-SHI CHIBA-KEN, JP |