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US5071906A
Expired / Lapsed
US
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Polarizing film and process for the production of the same
Assignee: Kuraray Co Ltd
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Filing: 1990-11-16
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Granted: 1991-12-10
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Expires: 2010-11-16
Abstract
Abstract A polarizing film comprising a uniaxially stretched film containing a polyvinyl alcohol having a degree of polymerization of at least about 2,500, and at least one polarizing agent selected from iodine and a dichroic dye, as well as a process for the production of the same. This polarizing film is superior in heat resistance and moist heat resistance to conventional films and has excellent optical properties, such as a high polarizing coefficient and transmittance.
Inventors
- 👤 Chikafumi Tanaka
- 👤 Masami Shiozawa
- 👤 Minoru Nishinohara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 23:06
CPC Classifications
C; C08; C08J; C08J7/00; C08J7/04; C08J7/06; G; G02; G02B; G02B5/00; G02B5/30; G02B5/3025; G02B5/3033; C08J2329/00; C08J2329/02; C08J2329/04
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
36 words
A polarizing film comprising a uniaxially stretched film containing a polyvinyl alcohol having a degree of polymerization of about 2,500 to about 10,000, and at least one polarizing agent selected from iodine and a dichroic dye.
Claim 2
Dependent Claim
36 words
A polarizing film comprising a uniaxially stretched film containing a polyvinyl alcohol having a degree of polymerization of about 2,500 to about 10,000, and at least one polarizing agent selected from iodine and a dichroic dye.
Claim 3
Dependent Claim
22 words
The polarizing film as claimed in claim 1, wherein said polyvinyl alcohol has a degree of polymerization of at least about 4,500.
Claim 4
Dependent Claim
22 words
The polarizing film as claimed in claim 1, wherein said polyvinyl alcohol has a degree of polymerization of about 6,000 to 10,000.
Claim 5
Dependent Claim
25 words
The polarizing film as claimed in claim 1, wherein said polarizing agent is dissolved in said polyvinyl alcohol solution before formation of the polarizing film.
Claim 6
Dependent Claim
50 words
The polarizing film as claimed in claim 1, wherein said polarizing film is polarized by forming a film with a mixture containing about 0.2 to 3% by weight of at least one polarizing agent selected from a group consisting of iodine and dichroic dye dissolved in a polyvinyl alcohol solution.
Claim 7
Dependent Claim
111 words
The polarizing film as claimed in claim 1, wherein said polyvinyl alcohol has a degree of polymerization of about 4,980 and a degree of hydrolysis of about 99.8%, and wherein said polarizing film is polarized by coating a film with a solution containing a polarizing agent selected from the group consisting of an aqueous solution containing 1% by weight of iodine and 5% by weight of potassium iodide; a dyeing liquor of 0.05% Congo Red (C.I. Direct Red 28); an aqueous solution containing 0.05% by weight of iodine and 0.25% by weight of potassium iodide; methanol containing 1% by weight of iodine; and methanol containing 0.5% by weight of methylene 4-aminoxanthopurpurin.
Claim 8
Dependent Claim
55 words
The polarizing film as claimed in claim 1, wherein said polyvinyl alcohol has a degree of polymerization of about 3,250 and a degree of hydrolysis of about 99.6% and wherein said polarizing film is polarized by coating a film with a solution containing 0.03% by weight of iodine and 0.20% by weight of potassium iodide.
Claim 9
Dependent Claim
48 words
The polarizing film as claimed in claim 1, wherein said polyvinyl alcohol has a degree of polymerization of about 6,740 and a degree of hydrolysis of about 99.2% and wherein said polarizing film is polarized by coating a film with methanol containing 0.5% by weight of methylene 4-aminoxanthopurpurin.
Claim 10
Dependent Claim
25 words
The polarizing film as claimed in claim 6, wherein said polarizing agent comprises methanol containing 1% by weight of Congo Red (C.I. Direct Red 28).
Claim 11
Dependent Claim
22 words
The polarizing film as claimed in claim 1, wherein said polyvinyl alcohol has a degree of hydrolysis of 95 to 100 mol%.
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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) | 1994-12-09 | 1995-06-10 | 1995-12-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-12-09 | 1999-06-10 | 1999-12-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-12-09 | 2003-06-10 | 2003-12-10 | $7700.00 | Window Closed / Lapsed |