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Patent US4992218A successfully refreshed from Google Patents.
US4992218A
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Process for producing a polarizing film
Assignee: Mitsubishi Gas Chemical Co Inc
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Filing: 1988-06-07
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Granted: 1991-02-12
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Expires: 2008-06-07
Abstract
Abstract A polarizing film comprising a polyvinyl alcohol-type film and a dichroic dye, a metallic ion and boric acid incorporated therein, and a process for producing the same, which comprises adsorbing a dichroic dye on a polyvinyl alcohol-type film, stretching the film substantially in one direction, immersing the stretched film in an aqueous solution containing a metallic ion and boric acid.
Inventors
- 👤 Akitoshi Sugio
- 👤 Ryozo Kawai
- 👤 Masaki Nagata
- 👤 Tamaki Kamimura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 15:51
CPC Classifications
B; B29; B29C; B29C55/00; B29C55/005; G; G02; G02B; G02B5/00; G02B5/30; G02B5/3025; G02B5/3033
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
50 words
A process for producing a polarizing film, which comprises adsorbing a dichroic dye on a polyvinyl alcohol-type film, subsequently stretching the film substantially in one direction, immersing the stretched film in an aqueous solution containing a metallic ion and boric acid, and subsequently heat treating the stretched film under tension.
Claim 2
Dependent Claim
50 words
A process for producing a polarizing film, which comprises adsorbing a dichroic dye on a polyvinyl alcohol-type film, subsequently stretching the film substantially in one direction, immersing the stretched film in an aqueous solution containing a metallic ion and boric acid, and subsequently heat treating the stretched film under tension.
Claim 3
Dependent Claim
38 words
The process of claim 1 wherein the metallic ion is on ion of at least one metal selected from the group consisting of magnesium, calcium, chromium, manganese, iron, cobalt, nickel, zirconium, copper, silver, tin, barium, aluminum and zinc.
Claim 4
Dependent Claim
30 words
The process of claim 1 wherein the amount of the metallic ion impregnated in the polarizing film is 0.2 to 20 mg as the metal per gram of the film.
Claim 5
Dependent Claim
28 words
The process of claim 1 wherein the amount of boric acid impregnated in the polarizing film is 0.3 to 30 mg as boron per gram of the film.
Claim 6
Dependent Claim
19 words
The process of claim 1 wherein the stretching is carried out at a stretch ratio of 2.5 to 8.
Claim 7
Dependent Claim
67 words
A process for producing a polarizing film, which comprises adsorbing a dichroic dye on a polyvinyl alcohol film, subsequently immersing the film in an aqueous solution containing a metallic ion and boric acid to impregnate the metallic ion and boric acid in the film, subsequently monoaxially stretching the film in the aqueous solution or in another liquid medium, and then subsequently heat-treating the stretched film under tension.
Claim 8
Dependent Claim
67 words
A process for producing a polarizing film, which comprises adsorbing a dichroic dye on a polyvinyl alcohol film, subsequently immersing the film in an aqueous solution containing a metallic ion and boric acid to impregnate the metallic ion and boric acid in the film, subsequently monoaxially stretching the film in the aqueous solution or in another liquid medium, and then subsequently heat-treating the stretched film under tension.
Claim 9
Dependent Claim
38 words
The process of claim 6 wherein the metallic ion is an ion of at least one metal selected from the group consisting of magnesium, calcium, chromium, manganese, iron, cobalt, nickel, zirconium, copper, silver, tin, barium, aluminum and zinc.
Claim 10
Dependent Claim
30 words
The process of claim 6 wherein the amount of the metallic ion impregnated in the polarizing film is 0.2 to 20 mg as the metal per gram of the film.
Claim 11
Dependent Claim
28 words
The process of claim 6 wherein the amount of boric acid impregnated in the polarizing film is 0.3 to 30 mg as boron per gram of the film.
Claim 12
Dependent Claim
19 words
The process of claim 6 wherein the stretching is carried out at a stretch ratio of 2.5 to 8.
References Cited (Backward Citations)
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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) | 1994-02-11 | 1994-08-13 | 1995-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-02-11 | 1998-08-13 | 1999-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-02-11 | 2002-08-13 | 2003-02-12 | $7700.00 | Window Closed / Lapsed |