US4720448A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of manufacturing photorelief printing plate using a liquid photopolymer
Assignee: Graham Packaging Plastic Products Inc
•
Filing: 1984-09-04
•
Granted: 1988-01-19
•
Expires: 2004-09-04
Abstract
Abstract In the process of making relief printing plates a liquid photopolymerizably layer having substantially identical negatives on each of its two sides and being in registration and also having a transparent substrate is exposed to an external light source so that both sides are exposed to the same image and after removal of the negatives the unexposed areas of the plate are removed.
Inventors
- 👤 Carlton R. Mousseau
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 13:48
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/20; G03F7/2022
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
157 words
The method of manufacturing a photorelief printing plate comprising the steps of: preparing a composite layer comprising a layer of a liquid photopolymer, a first printing negative on one side of the liquid photopolymer, a second printing negative on the other side of the liquid photopolymer, said second printing negative being substantially identical to said first printing negative and being in registration therewith, a transparent substrate between said liquid photopolymer and one of said printing negatives and in surface to surface contact with said liquid photopolymer and said one of said printing plates, said transparent substrate being bondable to said liquid photopolymer upon the curing of said liquid photopolymer; curing selected portions of said liquid photopolymer by exposing said composite layer to light sources external to said first and second printing negatives to permit light to pass through said negatives; removing said printing negatives from said composite layer; and removing the uncured portions of said liquid photopolymer.
Claim 2
Independent Claim
157 words
The method of manufacturing a photorelief printing plate comprising the steps of: preparing a composite layer comprising a layer of a liquid photopolymer, a first printing negative on one side of the liquid photopolymer, a second printing negative on the other side of the liquid photopolymer, said second printing negative being substantially identical to said first printing negative and being in registration therewith, a transparent substrate between said liquid photopolymer and one of said printing negatives and in surface to surface contact with said liquid photopolymer and said one of said printing plates, said transparent substrate being bondable to said liquid photopolymer upon the curing of said liquid photopolymer; curing selected portions of said liquid photopolymer by exposing said composite layer to light sources external to said first and second printing negatives to permit light to pass through said negatives; removing said printing negatives from said composite layer; and removing the uncured portions of said liquid photopolymer.
Claim 3
Dependent Claim
23 words
The method in accordance with claim 1 wherein the thickness of the liquid photopolymer in the composite layer is less than 50 mils.
Claim 4
Dependent Claim
32 words
The method in accordance with claim 1 and comprising the additional step of recycling at least a substantial portion of the removed uncured liquid photopolymer for use in manufacturing additional printing plates.
Claim 5
Independent Claim
85 words
The method in accordance with claims 1 or 2 in which the composite layer includes a layer of a strippable transparent film between said liquid photopolymer and the other of said printing negatives, and in surface to surface contact with said liquid photopolymer and said other of said printing plates, and in which the removal of the other of said printing negatives from said composite layer includes the separation of said film from the selectively cured photopolymer and from the other of said printing negatives.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-01-18 | 1991-07-20 | 1992-01-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-01-18 | 1995-07-20 | 1996-01-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-01-18 | 1999-07-20 | 2000-01-19 | $7700.00 | Window Closed / Lapsed |