Radiation imagery chemistry: process – composition – or product th – Radiation sensitive product – Silver compound sensitizer containing
Reexamination Certificate
2000-10-12
2002-10-08
Schilling, Richard L. (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Radiation sensitive product
Silver compound sensitizer containing
C430S271100, C430S343000, C430S944000, C430S964000, C548S436000
Reexamination Certificate
active
06461804
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a new type of IR-sensitizing dyes and photographic materials containing these compounds.
BACKGROUND OF THE INVENTION
Light-absorbing dyes incorporated in photographic materials can accomplish a variety of goals, including their use as sensitizing dyes.
In silver halide photographic material these dyes are used as classical sensitizing dyes, preferably in the presence of a supersensitizer. In heat mode photographic materials these dyes are used as compounds capable of converting light into heat.
In recent years new techniques of image recording have emerged wherein the exposure source of the recording apparatus is a laser unit. For instance, one application of lasers as exposure unit is situated in the field of radiographic monitoring photography where a hard copy of radiographic information has to be produced. Other applications are situated in the field of phototype-setting and image-setting, where recorders are marketed which employ Ar ion lasers, He-Ne lasers or solid state semiconductor lasers, also called laserdiodes, as exposure source. The latter type of laser, the laserdiode, shows some advantages compared to other laser types such as low cost price, small size, long life time and no need for an acoustic-optical modulator. Generally the emission wavelength of these semiconductor laser beams is longer than 700 nm and mostly longer than 750 nm. Preferred are laser devices emitting at around 830 and 1060 nm. So, photographic materials appropriate for exposure by devices employing such laser diodes must be sensitized for the near infra-red region of the radiation spectrum.
An infra-red sensitized element must contain an infra-red spectral sensitizer. Compounds suitable as infra-red spectral sensitizer are disclosed in e.g. DE-A- 19 834 745, DE-A- 19 834 746, EP-A- 652 483, DE-A- 4 128 439 and EP-A- 444 786. The disclosed spectral sensitizers are however not optimal for spectral sensitization at 830 and 1060 nm for one or another reason such as no optimal spectral sensitization, a weak conversion of light into heat, rest absorbance, etc. So, there remains a need for better suitable spectral sensitizers.
OBJECTS OF THE INVENTION
It is an object of the present invention to provide spectral sensitizing compounds that are optimally suited for use in materials which would be irradiated with infra-red light emitting lasers.
SUMMARY OF THE INVENTION
According to the present invention there is provided a class of IR-sensitizing dyes, comprising two benzoindol rings and at least two sulphonic acid groups as defined in claim 1.
DETAILED DESCRIPTION OF THE INVENTION
Preferably said IR-sensitizing dyes, comprising two benzoindol rings and at least two sulphonic acid groups corresponding to the general formula I:
wherein
R
1
and R
4
each independently represent a hydrogen, an alkyl, an aryl or a sulphonic acid group
R
2
and R
3
each independently represent a hydrogen or an alkyl group,
R
5
and R
6
each independently represent a hydrogen, or sulphonic acid group
n and m each independently represents an integer from 1 to 6
wherein at least R
1
and R
4
or R
5
and R
6
represent a sulphonic acid group.
“More preferably, said IR-sensitizing dyes, comprising two benzoindol rings and at least two sulphonic acid groups, correspond to the general formula I wherein at least R
5
and R
6
are sulphonic acid groups.”
Examples of the IR-sensitizing dyes and their mode of preparation are listed below.
1 mole of product 1 and 1.2 mole of product 2 were dissolved in 300 ml of N-methyl-2-pyrrolidone and warmed till 50° C. 1.2 mol potassium hydroxide was added in 45 min at 50° C. The mixture was then stirred for 30 min at 50° C. and then was added 600 ml of methyl-t-butylether. The mixture was filtered and the filtrate evaporated till dry. The yield was 100%.
1 mole of intermediate product 1 is added to a mixture of 300 g sulfuric acid and 180 g fuming sulfuric acid. The mixture is let standing for 30 min and then is added concentrated ammonia till weak acid pH. This mixture is cooled to 20° C. and the product is filtered off. Yield 80%.
1 mole of intermediate product 2 and 1.5 mole of product 4 is added to 1000 ml i-propanol and warmed till boiling. The mixture is refluxed till almost a solution. The mixture is then cooled and filtered. To the filtrate is added 3000 ml ethylacetate, the mixture is filtered and the solid product is dried. Yield 45%.
1 mole intermediate product 3 is suspended in 1500 ml methylene chloride and 1500 ml tetrahydrofurane. 0.6 mole of product 5 is added and the mixture is let reacting for 5 h at 40° C. The methylene chloride is then distilled off and replaced by ethylacetate. The mixture is cooled and the precipitation is filtered and dried. Yield 67%.
1 mole of intermediate product 4 is dissolved in 1300 ml of methylene chloride. Thereto is added dropwise 1.2 mol of product 6. The mixture is stirred for 30 min. 1300 ml of ethylacetate is added. The solid is filtered off and dried. Yield 87%.
1 mole of intermediate product 5 and 1.5 of product 7 are dissolved in 1700 ml ethanol. 1.5 mole product 4 is added and the mixture is left standing for 2 h at 50° C. 1 mole potassium acetate is added and the mixture is stirred for 1 h at 20° C. The precipitate is filtered off and dried. Yield 40%.
1 mole of product 6 is dissolved in 2600 ml of acetic acid and sulfuric acid is added till the color changes. The mixture is filtered and there is added a mixture of 32000 ml of methyl-t-butylether/ethylacetate 1/1 to the filtrate. After stirring for 30 min the precipitate is filtered off and dried. Yield 36%.
1 mole of product 1 is dissolved in 300 ml N-methyl-2-pyrrolidone. Thereto is added 1.2 mole of product 9 and 1.1 mole of potassium hydroxide. The mixture is heated for 1 h at 80° C. Thereto is added 1000 ml of acetone and cooled. The solid is filtered off and dried. Yield 100%.
1 mole of intermediate product 8 and 1.05 mole of product 10 are dissolved in 500 ml of acetic acid. The solution is warmed up till 110° C. 1000 ml of ethylacetate is added. The mixture is cooled to 20° C., filtered and the filtrate is evaporated till an oil. To this oil was added 500 ml of toluene and this solution was evaporated till an oil. Yield 100%.
1 mole of intermediate product 9 is dissolved in 4000 ml of tetrahydrofurane and 1500 ml of product 8 (3 mole/l tetrahydrofurane) is added dropwise. The mixture is stirred for 1 h at 60° C. Afterwards the mixture is poured out into 1100 ml concentrated hydrochloric acid and 5000 ml of water. The mixture is concentrated to 1800 g and 2000 ethanol is added. The mixture is chilled for 50 h at 4° C. The precipitate is filtered off and dried. Yield 100%.
1 mole of intermediate product 8 is added to 320 g of sulfuric acid and 200 gr of fuming sulfuric acid. The mixture is left for 30 min at 60° C. Thereafter 2000 ml of acetic acid and 850 g of ammonium acetate is added and this mixture is warmed for 30 min at 100° C. The mixture is then cooled to 20° C. and filtered. The residue id boiled in acetic acid, filtered and evaporated to dry. 0.18 mole of product 8 is added ( 40% in water), the mixture is boiled for 30 min, filtered and the filtrate evaporated to dry. Toluene is added and the mixture evaporated to an oil. Yield: 6%
1 mole of intermediate product 11 is dissolved in 5000 ml of tetrahydrofurane and thereto is added 1000 ml of product 8 (3 mol/l in tetrahydrofurane). The mixture is stirred for 30 min at 600° C., poured in 5000 ml methanol with 6 mole of methane sulphonic acid and cooled to 20° C. The residue is filtered of and dried. Yield: 75%.
1 mole of product 12, 2 mole of product 13 and 0.02 mole of ammonium acetate are mixed in 350 ml of methanol and refluxed for 90 min. The mixture is cooled, 150 ml of methanol and 50 ml of water are added and the residue is filtered of and dried. Yield: 80%.
1 mole of intermediate product 13 is added to 1200 ml of toluene. 1 mole of acetic acid is added. 1.1 mole of product 14 is dropped into the mixture and said mixture is stirred for 150 mi
Agfa-Gevaert
Breiner & Breiner L.L.C.
Schilling Richard L.
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