Patent US280178A successfully refreshed from Google Patents.
Patent US4743409A successfully refreshed from Google Patents.
US4743409A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing a substrate for optical recording media
Assignee: Sekisui Chemical Co Ltd
•
Filing: 1986-06-10
•
Granted: 1988-05-10
•
Expires: 2006-06-10
Abstract
Abstract A process for preparing a substrate for optical recording media which comprises injection-molding a polyvinylacetal resin resulting from acetalization of polyvinylalcohol to a degree of at least 60 mole % with at least one acetalizing agent selected from the group consisting of aliphatic aldehydes, alicyclic aldehydes, aromatic aldehydes and heterocyclic aldehydes.
Inventors
- 👤 Shigeru Nomura
- 👤 Tetsuo Kadoya
- 👤 Takeo Kinoshita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 22:40
CPC Classifications
B; B29; B29C; B29C45/00; B29C45/0001; C; C08; C08F; C08F8/00; C08F8/48; C08J; C08J5/00; C08J5/18; G; G11; G11B; G11B7/00; G11B7/24; G11B7/241; G11B7/252; G11B7/253; G11B7/2533; C08F2810/00; C08F2810/20; G11B7/2534; G11B7/258; G11B7/2585
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
79 words
A process for preparing a substrate for optical recording media free from birefringence which comprises injection-molding a polyvinylacetal resin resulting from acetalization of polyvinylalcohol to a degree of at least 60 mole % with at least one alicyclic aldehyde wherein the polyvinyl acetal resin temperature in injection molding is 270° to 300° C., the polyvinylalcohol has a degree of polymerization of 100 to 2,500 and the polyvinyl alcohol has a degree of saponification of at least 95 mole %.
Claim 2
Dependent Claim
79 words
A process for preparing a substrate for optical recording media free from birefringence which comprises injection-molding a polyvinylacetal resin resulting from acetalization of polyvinylalcohol to a degree of at least 60 mole % with at least one alicyclic aldehyde wherein the polyvinyl acetal resin temperature in injection molding is 270° to 300° C., the polyvinylalcohol has a degree of polymerization of 100 to 2,500 and the polyvinyl alcohol has a degree of saponification of at least 95 mole %.
Claim 3
Dependent Claim
35 words
The process of claim 1 wherein the alicyclic aldehyde is selected from the group consisting of cyclohexanealdehyde, trimethylcyclohexanealdehyde, dimethylcyclohexanealdehyde, methylcyclohexanealdehyde, cyclopentanealdehyde, methylcyclopentanealdehyde, decahydro-beta-naphthaldehyde, cyclohexanecetaldehyde, alpha-camphorenealdehyde, phellandral, cyclocitral, trimethyltetrahydrobenzaldehyde, alpha-pyrronenealdehyde, myrtenal, dihydromyrtenal, camphenilanealdehyde, 4-methylcyclchexenealdehyde and 3-methylcyclohexenealdehyde.
References Cited (Backward Citations)
CA602855A
Cited
GB383045A
Cited
GB682194A
Cited
US3926918A
Cited
US3963618A
Cited
JPS54138091A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-05-10 | 1991-11-09 | 1992-05-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-05-10 | 1995-11-09 | 1996-05-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-05-10 | 1999-11-09 | 2000-05-10 | $7700.00 | Window Closed / Lapsed |