Patent US4911966A successfully refreshed from Google Patents.
US4911966A
Expired / Lapsed
US
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Optical disk substrate
Assignee: Mitsubishi Chemical Corp
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Filing: 1988-12-02
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Granted: 1990-03-27
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Expires: 2008-12-02
Abstract
Abstract An optical disk substrate made of a non-crystalline thermoplastic resin comprising from to 80 to 100% by weight of a vinyl cyclohexane polymer (A) containing at least 80% by weight of a vinyl cyclohexane component in the molecular chain and from 0 to 20% by weight of a vinyl aromatic polymer (B) and having a light transmittance of at least 85%, a water absorbance of at most 0.1% by weight and a double refraction of at most 50 nm.
Inventors
- 👤 Masamitsu Murayama
- 👤 Kanji Kasahara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 11:03
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/24; G11B7/241; G11B7/252; G11B7/253; Y; Y10; Y10S; Y10S428/00; Y10S428/913; Y10S430/00; Y10S430/146; Y10T; Y10T428/00; Y10T428/31504
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
78 words
An optical disk substrate made of a non-crystalline thermoplastic resin comprising from 80 to 100% by weight of a vinyl cyclohexane polymer (A) containing at least 80% by weight of a vinyl cyclohexane component in the molecular chain and from 0 to 20% by weight of a vinyl aromatic polymer (B) and having a light transmittance of at least 85%, a water absorbance of at most 0.1% by weight and a double refraction of at most 50 nm.
Claim 2
Dependent Claim
78 words
An optical disk substrate made of a non-crystalline thermoplastic resin comprising from 80 to 100% by weight of a vinyl cyclohexane polymer (A) containing at least 80% by weight of a vinyl cyclohexane component in the molecular chain and from 0 to 20% by weight of a vinyl aromatic polymer (B) and having a light transmittance of at least 85%, a water absorbance of at most 0.1% by weight and a double refraction of at most 50 nm.
Claim 3
Dependent Claim
29 words
The optical disk substrate according to claim 1, wherein the vinyl cyclohexane polymer (A) is a polymer obtained by hydrogenating the aromatic ring of the vinyl aromatic polymer (B).
Claim 4
Dependent Claim
41 words
The optical disk substrate according to claim 1, wherein the vinyl aromatic polymer (B) is a noncrystalline polymer of a vinyl aromatic compound, or a copolymer of a vinyl aromatic compound with at most 20% by weight of other vinyl compound.
Claim 5
Dependent Claim
31 words
The optical disk substrate according to claim 3, wherein said vinyl aromatic compound is at least one member selected from the group consisting of styrene, α-methylstyrene, p-methylstyrene, t-butylstyrene and vinyl naphthalene.
Claim 6
Dependent Claim
38 words
The optical disk substrate according to claim 3, wherein said other vinyl compound is at least one member selected from the group consisting of a diene, a methacrylate, an acrylate, methacrylic acid, acrylic acid, itaconic acid and acrylonitrile.
References Cited (Backward Citations)
JPS6343910A
Cited
JPS641706A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-03-26 | 1993-09-25 | 1994-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-03-26 | 1997-09-25 | 1998-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-03-26 | 2001-09-25 | 2002-03-27 | $7700.00 | Window Closed / Lapsed |