Patent US1819655A successfully refreshed from Google Patents.
Patent US4481252A successfully refreshed from Google Patents.
US4481252A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sheet material
Assignee: Novartis AG
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Filing: 1982-11-19
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Granted: 1984-11-06
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Expires: 2002-11-19
Abstract
Abstract A transparent sheet material which is suitable for projection on overhead projectors comprises coated onto a support a binder layer containing discrete particles of an organic polymer which has substantially the same refractive index as the binder, the polymer comprising from 0.5 to 30% by weight of the binder. The coating gives a good key for typewritten characters produced by carbon ribbon or ink ribbon typewriters, for writing with e.g. ball-point pen, pencil, water or solvent based ink pens, Indian ink and inked rubber stamps.
Inventors
- 👤 Stephen R. Postle
- 👤 James Doyle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 06:06
CPC Classifications
B; B44; B44D; B44D3/00; B44D3/18; B41; B41M; B41M5/00; B41M5/50; B41M5/502; B41M5/508; B41M5/52; C; C08; C08J; C08J7/00; C08J7/04; C08J7/0427; C08J7/043; B41M5/5236; B41M5/5254; B41M5/5263; B41M5/5272; C08J2367/00; C08J2367/02; C08J2433/00; C08J2433/04; C08J2433/06; C08J2433/10; C08J2433/12; Y; Y10; Y10S; Y10S428/00; Y10S428/91; Y10T; Y10T428/00; Y10T428/25; Y10T428/254; Y10T428/31504; Y10T428/31507; Y10T428/31725; Y10T428/31768; Y10T428/31801
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
72 words
A transparent sheet material, which comprises coated onto a transparent support, a transparent binder layer having dispersed therein colourless organic polymer beads of from 0.5 μm to 40 μm in size and which have substantially the same refractive index as the binder, the organic polymer beads comprising from 0.5 to 30% by weight of the binder and the binder being gelatin, modified gelatin or a mixture of gelatin and a polymer latex.
Claim 2
Dependent Claim
72 words
A transparent sheet material, which comprises coated onto a transparent support, a transparent binder layer having dispersed therein colourless organic polymer beads of from 0.5 μm to 40 μm in size and which have substantially the same refractive index as the binder, the organic polymer beads comprising from 0.5 to 30% by weight of the binder and the binder being gelatin, modified gelatin or a mixture of gelatin and a polymer latex.
Claim 3
Dependent Claim
22 words
A material according to claim 1, wherein the particle size range of the polymer beads is from 1.5 μm to 5.0 μm.
Claim 4
Dependent Claim
21 words
A material according to claim 1, wherein the layer thickness of the binder layer is from 0.5 μm to 20 μm.
Claim 5
Dependent Claim
28 words
A material according to claim 3, wherein the layer thickness of the binder layer is just slightly less than the mean average particle size of the polymer beads.
Claim 6
Dependent Claim
20 words
A material according to claim 1, wherein the binder is gelatin and the organic polymer is polymethylmethacrylate in bead form.
Claim 7
Dependent Claim
25 words
A material according to claim 1, wherein the material of the support is cellulose triacetate, cellulose acetate-butyrate or subbed biaxially oriented polyester, polystyrene or polycarbonate.
Claim 8
Dependent Claim
35 words
A material according to claim 1 which has on at least one surface alphanumeric symbols which have been applied by typing using a carbon ribbon or which have been applied in a xeroxgraphic copying machine.
Claim 9
Dependent Claim
83 words
A process for the preparation of a transparent sheet material according to claim 1, which comprises coating onto a transparent sheet material a transparent binder layer having dispersed therein colourless organic polymer beads of from 0.5 μm to 40 μm in size and which have substantially the same refractive index as the binder, the organic polymer beads comprising from 0.5 to 30% by weight of the binder, and the binder being gelatin, modified gelatin or a mixture of gelatin with a polymer latex.
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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) | 1987-11-06 | 1988-05-07 | 1988-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-11-06 | 1992-05-07 | 1992-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-11-06 | 1996-05-07 | 1996-11-06 | $7700.00 | Window Closed / Lapsed |