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US 4,503,531 AGranted
Optical disc
AssigneePioneer Electronic Corporation
InventorHiroshi Kato
Life of this patent
Estimating the term…
Abstract
An optical disc includes a pair of substrates, at least one of which has predetermined information pits formed on one surface. The two substrates are bonded with a hot-melt adhesive having (1) a softening point of not more than 140.degree. C., (2) a dry tensile adhesive strength of not less than 1 kg/cm.sup.2 at 20.degree. C. and (3) a melt viscosity of not more than 1,000 P at 160.degree. C.
Claims7
An optical disc, comprising:
- a pair of substrates, at least one of which having predetermined information pits formed on one surface, said two substrates being bonded with a hot-melt adhesive having (1) a softening point of not more than 140.degree. C., (2) a dry tensile adhesive strength of not less than 1 kg/cm.sup.2 at 20.degree. C. and (3) a melt viscosity of not more than 1,000 P at 160.degree. C.
A laminated disc, comprising;
- at least a pair of substrates arranged in confronting relation, and an adhesive bonding said substrates, said adhesive being of a non-solvent type and including a base including at least one block thermoplastic elastomer and a tackifier.
Dependencies are inferred from the claim text.