Patent US5043405A successfully refreshed from Google Patents.
US5043405A
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US
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Methacrylic copolymer having low moisture absorption properties
Assignee: Asahi Kasei Corp
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Filing: 1990-07-02
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Granted: 1991-08-27
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Expires: 2010-07-02
Abstract
Abstract The methacrylic copolymer of the present invention is a novel copolymer having low moisture absorption properties which comprises specific proportions of methyl methacrylate units and tert-butylcyclohexyl methacrylate units, optionally with specific ethylenically unsaturated compound units copolymerizable with the above-mentioned monomer units. The copolymer of the present invention is excellent not only in colorlessness, transparency, moldability, low double refraction and heat stability but also in low moisture absorption properties and heat resistance and, therefore, is suitable for use as a material for shaped articles, such as an optical element substrate and a light transmissible extruded plate, and can particularly advantageously be used for applications, such as an optical disc substrate.
Inventors
- 👤 Toshinori Koseki
- 👤 Kimio Imaizumi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 21:21
CPC Classifications
C; C08; C08F; C08F220/00; C08F220/02; C08F220/10; C08F220/12; C08F220/14; G; G11; G11B; G11B7/00; G11B7/24; G11B7/241; G11B7/252; G11B7/253
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
122 words
A methacrylic copolymer having low moisture absorption properties, comprising (A) 2 to 30% by mole of tertbutylcyclohexyl methacrylate units, (B) 60 to 98% by mole of methyl methacrylate units and (C) 0 to 30% by mole of ethylenically unsaturated compound units represented by formula (1): ##STR5## wherein R 1 is a hydrogen atom or a methyl group and R 2 is a phenyl group, a methyl-substituted phenyl group or ##STR6## wherein Z is an alkyl group having 1 to 8 carbon atoms, which is unsubstituted or substituted with a fluorine atom, the total of (A), (B) and (C) being 100% by mole, and the copolymer having a weight average molecular weight in the range of from 10 4 to 10 7 .
Claim 2
Dependent Claim
122 words
A methacrylic copolymer having low moisture absorption properties, comprising (A) 2 to 30% by mole of tertbutylcyclohexyl methacrylate units, (B) 60 to 98% by mole of methyl methacrylate units and (C) 0 to 30% by mole of ethylenically unsaturated compound units represented by formula (1): ##STR5## wherein R 1 is a hydrogen atom or a methyl group and R 2 is a phenyl group, a methyl-substituted phenyl group or ##STR6## wherein Z is an alkyl group having 1 to 8 carbon atoms, which is unsubstituted or substituted with a fluorine atom, the total of (A), (B) and (C) being 100% by mole, and the copolymer having a weight average molecular weight in the range of from 10 4 to 10 7 .
Claim 3
Dependent Claim
56 words
The methacrylic copolymer having low moisture absorption properties according to claim 1, wherein the proportion of ethylenically unsaturated compound units (C) is 1 to 10% by mole and wherein R 1 in formula (1) is H and R 2 in formula (1) is ##STR7## wherein Z is an alkyl group having 1 to 8 carbon atoms.
Claim 4
Dependent Claim
43 words
The methacrylic copolymer having low moisture absorption properties according to claim 1, wherein the proportion of ethylenically unsaturated compound units (C) is 5 to 30% by mole and wherein R 2 in formula (1) is a phenyl group or a methyl-substituted phenyl group.
Claim 5
Dependent Claim
28 words
The methacrylic copolymer having low moisture absorption properties according to any one of claims 1 to 3, wherein said copolymer is in the form of a shaped article.
Claim 6
Dependent Claim
20 words
The methacrylic copolymer having low moisture absorption properties according to claim 4, wherein said shaped article is an injection-molded article.
Claim 7
Dependent Claim
21 words
The methacrylic copolymer having low moisture absorption properties according to claim 5, wherein said injection-molded article is an optical element substrate.
Claim 8
Dependent Claim
22 words
The methacrylic copolymer having low moisture absorption properties according to claim 6, wherein said optical element substrate is an optical disc substrate.
Claim 9
Dependent Claim
32 words
The methacrylic copolymer having low moisture absorption properties according to claim 5, wherein said copolymer has a weight average molecular weight in the range of from 10 4 to 2×10 5 .
Claim 10
Dependent Claim
32 words
The methacrylic copolymer having low moisture absorption properties according to claim 8, wherein said copolymer has a weight average molecular weight in the range of from 5×10 4 to 1.5×10 5 .
Claim 11
Dependent Claim
20 words
The methacrylic copolymer having low moisture absorption properties according to claim 4, wherein said shaped article is an extruded article.
Claim 12
Dependent Claim
22 words
The methacrylic copolymer having low moisture absorption properties according to claim 10, wherein said extruded article is a light transmissible extruded plate.
Claim 13
Dependent Claim
32 words
The methacrylic copolymer having low moisture absorption properties according to claim 10, wherein said copolymer has a weight average molecular weight in the range of from 10 5 to 3×10 5 .
Claim 14
Dependent Claim
32 words
The methacrylic copolymer having low moisture absorption properties according to claim 12, wherein said copolymer has a weight average molecular weight in the range of from 1.5×10 5 to 2.5×10 5 .
Claim 15
Dependent Claim
25 words
The methacrylic copolymer having low moisture absorption properties according to claim 4, wherein said shaped article is a light transmissible plate obtained by cast method.
Claim 16
Dependent Claim
32 words
The methacrylic copolymer having low moisture absorption properties according to claim 6, wherein said copolymer has a weight average molecular weight in the range of from 10 4 to 2×10 5 .
Claim 17
Dependent Claim
32 words
The methacrylic copolymer having low moisture absorption properties according to claim 7, wherein said copolymer has a weight average molecular weight in the range of from 10 4 to 2×10 5 .
Claim 18
Dependent Claim
32 words
The methacrylic copolymer having low moisture absorption properties according to claim 11, wherein said copolymer has a weight average molecular weight in the range of from 10 5 to 3×10 5 .
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-08-26 | 1995-02-25 | 1995-08-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-08-26 | 1999-02-25 | 1999-08-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-08-26 | 2003-02-25 | 2003-08-27 | $7700.00 | Window Closed / Lapsed |