Radiation imagery chemistry: process – composition – or product th – Radiation sensitive product – Silver compound sensitizer containing
Patent
1994-04-15
1996-03-19
Wright, Lee C.
Radiation imagery chemistry: process, composition, or product th
Radiation sensitive product
Silver compound sensitizer containing
430581, 430583, 430584, 430585, 430587, 430591, 430593, 430595, 546135, 548100, 548156, 548219, 5483057, G03C 112, G03C 114
Patent
active
055003370
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to polymethinic spectral sensitising dyes comprising at least one intracyclic thioether function macrocycle, and their use in silver halide photographic products. These spectral sensitising dyes improve the sensitivity of the photographic products whilst reducing the residual dye stain.
It is know that macrocyclic thioethers can be used at various stages in the manufacture of emulsions used in photography.
U.S. Pat. Nos. 3,021,215, 3,046,129, 3,046,132, and 3,046,133 describe the use of macrocyclic thioethers in the chemical sensitisation process.
U.S. Pat. Nos. 3,062,646 and 3,271,157 describe thioether macrocycles useful as chemical sensitisers and as solvents for silver halides.
European patent EP 295 190 describes photographic products using functionalised thioether macrocycles as anti-fogging agents.
In a publication Kexue Tongbao, Vol 28 No 6, June 1983, p.762-766, Chu Pufen et al describe carbocyanines comprising macrocycles with intracyclic oxygen atoms. These sensitising dyes comprising a macrocyclic ether improve the sensitometric properties when they are used on conventional emulsions. These documents do not mention the problem of residual dye stain.
Residual dye stain appears in a photographic product when the sensitising dye is not totally eliminated during the photographic processing.
The problem of residual dye stain in photographic products is related to the nature and quantity of spectral sensitising dyes used; it manifests particularly with emulsions requiring high quantities of sensitising dyes such as tabular grain emulsions, or with products requiring short processing times, such as products for radiography. The residual dye stain problem can be remedied by increasing the solubility of the sensitising dyes. U.S. Pat. No. 3,148,187 describes cyanine and merocyanine dyes carrying solubilising sulpho groups. The residual dye stain of the photographic products using these dyes decreases, but also a deterioration in the sensitometric characteristics is observed.
In fact the presence of the solubilising group which causes dissymmetry in the dye molecule is not favourable to the formation of J aggregates responsible for the spectral sensitivity given to the emulsion by the dye.
It was therefore necessary to find dyes which do not lose their spectral sensitising power whilst reducing the residual dye stain of the photographic products after processing.
The present invention relates to spectral sensitising dyes of the polymethine type comprising at least one macrocyclic thioether radical which comprises at least one sulphur atom and at least one oxygen atom, each sulphur or oxygen atom being separated from another sulphur or oxygen atom by an alkylene group comprising at least two carbon atoms.
The spectral sensitising dyes of the present invention are of a conventional polymethine type such as cyanines, merocyanines, complex cyanines or merocyanines, oxonols, hemioxonols, styryls, merostyryls, neocyanines and streptocyanines. These polymethine dyes generally consist of two heterocyclic rings connected by a methine chain with the formula --(C.dbd.C).sub.n --, n being an integer equal to or greater than 1.
The position of the macrocyclic thioether radical in the spectral sensitising dye is not decisive in the case of the present invention. The thioether macrocycle--sensitising dye bond may be produced in any position on the heterocyclic ring or rings.
The macrocyclic thioether radical may be condensed directly onto the polymethine dye or be a substituent on the polymethine dye.
When the macrocyclic thioether radical is condensed directly onto the polymethine dye, the sensitising dyes of the invention may be represented by the formula ##STR1## where
X represents a sulphur or oxygen atom, with the additional requirement that it represents at least one sulphur atom and at least one oxygen atom,
R.sup.1 and R.sup.2 are independently a hydrogen atom or an alkyl, aryl or alkenyl group, either substituted or not,
m is an integer equal to or greater than 1,
n is an integer
REFERENCES:
patent: 3021215 (1962-02-01), Williams et al.
patent: 3046129 (1962-07-01), Graham et al.
patent: 3046132 (1962-07-01), Minsk
patent: 3046133 (1962-07-01), Minsk
patent: 3062646 (1962-11-01), Dann et al.
patent: 3148187 (1964-09-01), Heseltine
patent: 3271157 (1966-09-01), McBride
patent: 4729946 (1988-03-01), Kasama et al.
patent: 4865965 (1989-09-01), Friour et al.
patent: 4987064 (1991-01-01), Saitou et al.
Chemical Abstracts, vol. 100, No. 4, 23 Jan. 1984 Columbus, OH, US; Abstract No. 28088s, P. Chu et al. "Spectral Sensitization by Cyanine Dyes Coupled with Crown Ethers" p. 337.
Kexue Tongbao, vol. 28, No. 6, Jun. 1983, pp. 762-766, Chu Pufen et al.
Benard Rejane
Friour Gerard A. D.
Martin Didier J.
Riveccie Marcel L. P.
Eastman Kodak Company
Rice Edith A.
Stewart Gordon M.
Wright Lee C.
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