US4248959A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of diazo printing plates using laser exposure
Assignee: CNA Holdings LLC
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Filing: 1978-12-07
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Granted: 1981-02-03
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Expires: 1998-12-07
Abstract
Abstract This invention relates to an improvement in a photochemical process for the preparation of printing plates wherein a printing plate comprising a photosensitive composition coated on a support is exposed to a pattern of laser light, the intensity of which light is modulated in accordance with an input source of information, and said printing plate is subsequently developed by removal from said support of that portion of the photosensitive coating composition which is not exposed to said pattern of laser light, the improvement comprising utilizing a pattern of laser light generated by a laser, and utilizing as a photosensitive composition a mixture consisting essentially of: (1) a negative-working condensate of a para-amino benzene diazonium compound present in an effective amount sufficient to sensitize said photosensitive composition to laser light, and (2) a colorant capable of absorbing light in the spectral range between about 450 -550 nm, said colorant selectively sensitizing the condensate to said laser light at a wavelength greater than about 450 nm, and being selected from the group consisting of azo, triarylmethane, xanthene and methine compounds.
Inventors
- 👤 William Jeffers
- 👤 Douglas Seeley
- 👤 Raimund J. Faust
- 👤 Shuchen Liu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 19:35
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/20; G03F7/2051; G03F7/2053; G03F7/2055; G03F7/004; G03F7/016; G03F7/0166; Y; Y10; Y10S; Y10S430/00; Y10S430/1053; Y10S430/1055; Y10S430/127; Y10S430/146; Y10S522/00; Y10S522/904
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
186 words
In a photochemical process for the preparation of printing plates wherein a printing plate comprising a photosensitive composition coated on a support is exposed to a pattern of laser light, the intensity of which light is modulated in accordance with an input source of information, and said printing plate is subsequently developed by removal from said support of that portion of the photosensitive coating composition which is not exposed to said pattern of laser light, the improvement comprising utilizing a pattern of laser light generated by a laser which has a significant emission of light at a wavelength greater than about 450 nm, and utilizing as a photosensitive composition a mixture consisting essentially of: (1) a negative-working condensate or a para-amino benzene diazonium compound present in an effective amount sufficient to sensitize said photosensitive composition to laser light, and (2) a colorant capable of absorbing light in the spectral range between about 450-550 nm, said colorant selectively sensitizing the condensate to said laser light at a wavelength greater than about 450 nm, and being selected from the group consisting of azo, triarylmethane, xanthene and methine compounds.
Claim 2
Dependent Claim
186 words
In a photochemical process for the preparation of printing plates wherein a printing plate comprising a photosensitive composition coated on a support is exposed to a pattern of laser light, the intensity of which light is modulated in accordance with an input source of information, and said printing plate is subsequently developed by removal from said support of that portion of the photosensitive coating composition which is not exposed to said pattern of laser light, the improvement comprising utilizing a pattern of laser light generated by a laser which has a significant emission of light at a wavelength greater than about 450 nm, and utilizing as a photosensitive composition a mixture consisting essentially of: (1) a negative-working condensate or a para-amino benzene diazonium compound present in an effective amount sufficient to sensitize said photosensitive composition to laser light, and (2) a colorant capable of absorbing light in the spectral range between about 450-550 nm, said colorant selectively sensitizing the condensate to said laser light at a wavelength greater than about 450 nm, and being selected from the group consisting of azo, triarylmethane, xanthene and methine compounds.
Claim 3
Dependent Claim
25 words
A process according to claim 1 wherein said condensate is a polymeric condensation product of a substituted p-aminobenzene diazonium salt of a dialkoxy aromatic compound.
Claim 4
Dependent Claim
43 words
A process according to claim 1 wherein said condensate is a polymeric condensation product selected from the group consisting of 3-methoxydiphenylamine-4-diazonium mesitylene sulfonate condensed with bis-(4-methoxymethylphenyl)ether, 3-methoxydiphenylamine-4-diazonium sulfate condensed with bis-(4-methoxymethylphenyl) ether, diphenylamine-4-diazonium chloride condensed with formaldehyde, and 3-methoxydiphenylamine-4-diazonium chloride condensed with formaldehyde.
Claim 5
Dependent Claim
57 words
A process according to claim 1 wherein said photosensitive composition is coated on said support such that the diazonium compound is present in a quantity within the range of about 0.01 to 0.8 gram per square meter, and said colorant is present in a quantity within the range of about 0.01 to 0.5 gram per square meter.
Claim 6
Dependent Claim
13 words
A process according to claim 4 wherein said support is a metal plate.
Claim 7
Dependent Claim
12 words
A process according to claim 4 wherein said support is a film.
Claim 8
Dependent Claim
15 words
A process according to claim 1 wherein said colorant is Rhodamine 6 GDN, C.I. 45,160.
Claim 9
Dependent Claim
15 words
A process according to claim 1 wherein said colorant is Neozapon Red BE, C.I. 12,716.
Claim 10
Dependent Claim
14 words
A process according to claim 1 wherein said colorant is Rhodamine FB, C.I. 45,170.
Claim 11
Dependent Claim
15 words
A process according to claim 1 wherein said colorant is Remacryl Magenta B, C.I. 42,520.
Claim 12
Dependent Claim
15 words
A process according to claim 1 wherein said colorant is Azo Eosin G, C.I. 14,710.
Claim 13
Dependent Claim
15 words
A process according to claim 1 wherein said colorant is Sandocryl Red B-6B, C.I. 48,013.
Claim 14
Dependent Claim
14 words
A process according to claim 1 wherein said colorant is Sudan Yellow, C.I. 12,055.
Claim 15
Dependent Claim
13 words
A process according to claim 1 wherein said colorant is Oracet Red B.
References Cited (Backward Citations)
US2702242A
Cited
US2871119A
Cited
US3260599A
Cited
US3567453A
Cited
US3615452A
Cited
US3679419A
Cited
US3628954A
Cited
US3778274A
Cited
US3637375A
Cited
US3664737A
Cited
US3850633A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-02-03 | 1984-08-04 | 1985-02-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-02-03 | 1988-08-04 | 1989-02-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-02-03 | 1992-08-04 | 1993-02-03 | $7700.00 | Window Closed / Lapsed |