| 摘要 |
PURPOSE:To provide the title material low in birefringence and superior in transparency, heat resistance, and water absorption properties, which is suitable for a substrate of optical discs, and comprises as a main component a polymer produced from a compound having 2 or more vinylphenyl groups in the molecule and other vinyl monomer copolymerizable with the compound. CONSTITUTION:A composition obtained by mixing 5-50wt.% compound (A), as crosslinking agent, having 2 or more vinylphenyl groups in the molecule of formula I (wherein R is a substituent such as an aliphatic hydrocarbon group, halogenated alkyl, an aliphatic ring, an aromatic ring, a heterocyclic ring, or phenyl-substituted alkyl; and n is 2 or more, and a bond, for example, of O, S or formulae II-V may be included in the compound), for example, bisphenol A vinylbenzyl ether, 1,2-bis(p-vinylphenyl)ethan, or 1,6-bis(p-vinylbenzyl)hexyl ether, with 95-50wt.% other vinyl monomer (B) copolymerizable with component (A), for example, styrene (derivatives), is mixed with a radical initiator in a predetermined amount, and the mixture is poured into a mold for polymerization followed by degassing, and polymerized at a predetermined temperature for a predetermined time. |
