US4576892A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photosensitive materials
Assignee: Polychrome Corp
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Filing: 1985-03-12
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Granted: 1986-03-18
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Expires: 2005-03-12
Abstract
Abstract A presensitized plate adapted for use in lithography comprising a support member with a metal surface, e.g. aluminum metal, and overlying layer containing a diazo compound. In accordance with this invention, the relative exposure sensitivity of the diazo compound is improved by pretreatment to accelerate its reactivity in the presence of actinic light. One method of pretreatment involves preheating the diazo compound to a temperature above about 35° C. up to about 120° C. The improved lithographic plate and the process of preparing plate are claimed.
Inventors
- 👤 Eugene Golda
- 👤 Alan Wilkes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 12:28
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/20; G03F7/2022; Y; Y10; Y10S; Y10S430/00; Y10S430/143; Y10S430/146
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
139 words
In a presensitized plate, for use in lithography, having a support member with a metal surface and an overlying layer on said metal surface, said layer comprises a photosensitive composition further comprising a diazo compound relative to light, the improvement which comprises employing a diazo compound which has been subjected to treatment prior to preparation of the photosensitive composition, prior to being coated on said metal surface, and prior to imagewise exposure for a time period sufficient to accelerate its light reactivity characteristics thereby improving its relative exposure sensitivity, said treated diazo compound having an absorbance at 375 nm of 0.40-0.79 and at 650 nm of 0.90-2.0, and wherein said treatment comprises (a) heating said diazo compound to a temperature above about 35° C. up to about 120° C., (b) ultraviolet light, (c) laser beam, or (d) electron beam.
Claim 2
Dependent Claim
139 words
In a presensitized plate, for use in lithography, having a support member with a metal surface and an overlying layer on said metal surface, said layer comprises a photosensitive composition further comprising a diazo compound relative to light, the improvement which comprises employing a diazo compound which has been subjected to treatment prior to preparation of the photosensitive composition, prior to being coated on said metal surface, and prior to imagewise exposure for a time period sufficient to accelerate its light reactivity characteristics thereby improving its relative exposure sensitivity, said treated diazo compound having an absorbance at 375 nm of 0.40-0.79 and at 650 nm of 0.90-2.0, and wherein said treatment comprises (a) heating said diazo compound to a temperature above about 35° C. up to about 120° C., (b) ultraviolet light, (c) laser beam, or (d) electron beam.
Claim 3
Dependent Claim
38 words
In the lithographic plate of claim 1 wherein said treatment comprises heating said diazo compound to a temperature above about 35° C. up to about 120° C. for a time period sufficient to accelerate its light reactivity characteristics.
Claim 4
Dependent Claim
20 words
In the lithographic plate of claim 2 wherein the period of heating ranges from about 1 to about 150 hours.
Claim 5
Dependent Claim
19 words
In the lithographic plate of claim 1 wherein said treatment comprises treatment of the diazo compound with ultra-violet light.
Claim 6
Dependent Claim
20 words
In the lithographic plate of claim 1 wherein said treatment comprises treatment of the diazo compound with a laser beam.
Claim 7
Dependent Claim
20 words
In the lithographic plate of claim 1 wherein said treatment comprises treatment of the diazo compound with an electron beam.
Claim 8
Dependent Claim
129 words
In a presensitized plate for use in lithography, having a support member with an aluminum surface and an overlying layer on said aluminum surface, said layer comprising a photosensitive composition further comprising a diazo compound reactive to light to define printing and non-printing areas, the improvement which comprises heating said diazo compound, prior to preparation of the photosensitive composition, prior to being coated on said aluminum surface, and prior to imagewise exposure, to a temperature of from above about 35° C. up to about 120° C. for about 1 to about 150 hours whereby the light reactivity characteristic of the diazo compound has been accelerated thereby improving its relative exposure sensitivity, said treated diazo compound having an absorbance at 375 nm of 0.40-0.79 and at 650 nm of 0.90-2.0.
Claim 9
Dependent Claim
129 words
In a presensitized plate for use in lithography, having a support member with an aluminum surface and an overlying layer on said aluminum surface, said layer comprising a photosensitive composition further comprising a diazo compound reactive to light to define printing and non-printing areas, the improvement which comprises heating said diazo compound, prior to preparation of the photosensitive composition, prior to being coated on said aluminum surface, and prior to imagewise exposure, to a temperature of from above about 35° C. up to about 120° C. for about 1 to about 150 hours whereby the light reactivity characteristic of the diazo compound has been accelerated thereby improving its relative exposure sensitivity, said treated diazo compound having an absorbance at 375 nm of 0.40-0.79 and at 650 nm of 0.90-2.0.
Claim 10
Dependent Claim
22 words
In the lithographic plate of claim 7 wherein the diazo compound is a salt of the condensation product of formaldehyde with p-diazodiphenylamine.
Claim 11
Dependent Claim
22 words
In the lithographic plate of claim 7 wherein the diazo compound is a salt of the condensation product of formaldehyde with 4'-diazo-p-methoxydiphenylamine.
Claim 12
Dependent Claim
22 words
In the lithographic plate of claim 7 wherein the diazo compound is a salt of the condensation product of formaldehyde with 4-diazo-2,5-dimethoxy-4'-methyldiphenylsulfide.
Claim 13
Dependent Claim
137 words
In a process for preparing a presensitized plate, for use in lithography, by applying to a support member with a metal surface an overlying coating of a photosensitive composition comprising a diazo compound reactive to light to define printing and non-printing area, the improvement which comprises subjecting the diazo compound to treatment prior to preparation of the photosensitive composition, prior to being coated on said metal surface, and prior to imagewise exposure to accelerate its reactivity in the presence of light thereby improving its relative exposure sensitivity, said treated diazo compound having an absorbance at 375 nm of 0.40-0.79 and at 650 nm of 0.90-2.0, and wherein said treatment comprising (a) heating said diazo compound to a temperature above about 35° C. up to about 120° C., (b) ultraviolet light, (c) laser beam, or (d) electron beam.
Claim 14
Dependent Claim
137 words
In a process for preparing a presensitized plate, for use in lithography, by applying to a support member with a metal surface an overlying coating of a photosensitive composition comprising a diazo compound reactive to light to define printing and non-printing area, the improvement which comprises subjecting the diazo compound to treatment prior to preparation of the photosensitive composition, prior to being coated on said metal surface, and prior to imagewise exposure to accelerate its reactivity in the presence of light thereby improving its relative exposure sensitivity, said treated diazo compound having an absorbance at 375 nm of 0.40-0.79 and at 650 nm of 0.90-2.0, and wherein said treatment comprising (a) heating said diazo compound to a temperature above about 35° C. up to about 120° C., (b) ultraviolet light, (c) laser beam, or (d) electron beam.
Claim 15
Dependent Claim
13 words
In the process of claim 11 wherein said support metal surface is aluminum.
Claim 16
Dependent Claim
39 words
In the process of claim 11 wherein the treatment comprises heating the diazo compound to a temperature of above about 35° C. up to about 120° C., for a period of time sufficient to accelerate its light reactivity characteristics.
Claim 17
Dependent Claim
19 words
In the process of claim 13 wherein the period of heating ranges from about 1 to about 150 hours.
Claim 18
Independent Claim
92 words
A method of accelerating the reactivity of a photosensitive diazo compound and improving its relative exposure sensitivity to light which comprises heating said diazo compound to a temperature of from above about 35° C. to about 120° C., for about 1 to about 150 hours prior to exposing said diazo compoud to light, prior to formulating a photosensitive composition with said diazo compound, and prior to coating said diazo compound on a metal substrate, said heating diazo compound having an absorbance at 375 nm of 0.40-0.79 and at 650 nm of 0.90-2.0.
Claim 19
Independent Claim
92 words
A method of accelerating the reactivity of a photosensitive diazo compound and improving its relative exposure sensitivity to light which comprises heating said diazo compound to a temperature of from above about 35° C. to about 120° C., for about 1 to about 150 hours prior to exposing said diazo compoud to light, prior to formulating a photosensitive composition with said diazo compound, and prior to coating said diazo compound on a metal substrate, said heating diazo compound having an absorbance at 375 nm of 0.40-0.79 and at 650 nm of 0.90-2.0.
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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) | 1989-03-17 | 1989-09-16 | 1990-03-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-03-17 | 1993-09-16 | 1994-03-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-03-17 | 1997-09-16 | 1998-03-18 | $7700.00 | Window Closed / Lapsed |