| 摘要 |
PURPOSE:To obtain a stable high speed rotation and an excellent recording and reproducing characteristics and durability by containing at least one kind of cyclic polyolefine obtained by copolymerizing ethylene and cyclick olefine in the resing forming a recording layer. CONSTITUTION:The optical recording disk uses the polymer of the cyclic polyolefine with the ethylene which has the structure shown in an expression I for its substrate and used glass for a protection substrate. The cyclic olefine may be synthsized by condensating cyclopentadiene genus and olefine corresponding to it by means of Diels-Alder reaction. It is desirable to construct a substrate 2 with tempered glass. It is desirable that the tempered glass uses chemically tempered glass and further desirably, chemically tempered alumina silicate glass because of its high mechanical strength. The thickness of the protection substrate 11 shall be in the range of 0.5 to 2.0 mm to ensure rigidity. The shape of the protection substrate 11 may correspond to that of the substrate 2. (where n is zero or positive integer, R<1>-R<12> is hydron, halogen atom or hydrocarbon residue respectively, and may be monocyclic or poly cyclic compound coupled each other; further monocyclic or polyclic group in the paewnthesis may be double bond, further R<3> and R<10>, R<11> may form alkyliden group.) |
