DE1022090B - Process for generating a direct positive image in a halogen silver emulsion utilizing the clay desensitization effect - Google Patents

Description

The invention relates to an improved method for Production of direct positives in photographic silver halide emulsions which are used for clayden desensitization are receptive.

It is known that after a long period of training measured photosensitivity of certain photographic materials can be reduced, when the materials first undergo a relatively short exposure, for example with a duration of 0.001 seconds or less. This phenomenon is known as the »Clayden effect cc known. The peculiarity that characterizes the Clayden effect is that the preceding, Brief, intensive exposure desensitizes the emulsion to such an extent that a subsequent, weaker one Exposure has less of an effect on the photographic material than without pre-exposure. As what can generally be determined is the blackening resulting from the two superimposed exposures less than the blackening resulting from the weaker post-exposure alone. These as yQayden-Effektcc known phenomenon has a wide variety of practical uses. So is for example from U.S. Patent 2,691,586 the application of this phenomenon to the manufacture of a pre-masked photographic material became known, by means of its halftone negatives of a Halftone positive can be made without using the usual halftone mask. The usefulness such a pre-masked material in graphics, for example for letterpress printing, for lithographic printing Purpose and gravure printing depends on the degree of desensitization that can be achieved and, accordingly, on the degree of sensitivity of the material to the Clayden effect. . Often in a common, for the Clayden effect sensitive emulsion, the desensitization that can be achieved is insufficient for commercial purposes. The invention is therefore based on the object, the sensitivity of such an emulsion for a Increase Clayden desensitization.

This object is essentially achieved in that in a halogen silver emulsion, which is already at least shows some sensitivity to clay desensitization, a merocyanine or hemioxonol dye of the class specified below is stored.

To carry out the process according to the invention, emulsions can be used which, from the outset, d. H. So even without the addition of merocyanine or hemioxonol dyes, thanks to the clayden effect can be desensitized to a certain extent and that can then be achieved by the addition of these dyes stronger, up to a commercial exploitation method of production

of a direct positive image

in a halogen silver emulsion

taking advantage of the Clayden

Desensitization effect

Applicant:

Eastman Kodak Company,
Rochester, NY (V. St. A.)

Representative: Dr.-Ing. W. Wolff, patent attorney,
Stuttgart N, Lange Str. 51

Claimed priority:
V. St, v. America June 29, 1954

Edgar Alexander Mac William,

Rochester, NY (V. St. A.),
has been named as the inventor

can be desensitized to the extent possible by the Clayden effect. The phrase "desensitizable to a certain extent by the Clayden effect" is e.g. B. to understand a silver halide emulsion which, when exposed to a high-performance light bulb at a distance of 60.96 cm, has an output of about 18,000 lumen seconds in 0.0005 seconds with the interposition of a step wedge (of about 28 steps, starting with a blackening of about zero and a blackening increase of 0.3 per step) without intermediate treatment in a post-exposure with a 1000 watt tungsten filament lamp arranged at a distance of 60.96 cm from the emulsion of 2 minutes duration with the interposition of the same step wedge, but at least rotated by 90 ° shows a blackening shrinkage of 0.10 log E or ¹ Z ₃ density level between the areas exposed only to the weak exposure and the areas exposed to both the weak exposure and the strong pre-exposure when the material is 2% minutes at 20 ° with a developer of the following Composition is treated:

709 847/299

Hydroquinone 22.2 g

Anhydrous sodium sulfate ....-.- 30 g

Paraformaldehyde 7.5 g. "

Chewable tabsulnt 2.6 g

Boric acid, crystallized 7.5 g

Potassium bromide 1.6 g

Water to make up the solution ... 11

According to the invention, a suitable emulsion is now used, which in any stage of the manufacturing process, but before pouring them, a merocyanine or hemioxonol dye of the formula

= CH-CH:

CoH ₅

= C 'N-

! I.

N CS

CHoCOOH

C ₆ H ₅

CH-CR =

-CO -Carboxymethyl-5 - [(3-ethyl-2 (3 H) -benzothiazolylidene) ethylidene] -3-phenyl-2-thiohydantoin

or the formula

.CH ₂ - CH ₂ .

^ N-CH = CH-CH = C

CH ₂ - CH ₂ V. γ .-- ·

CO X = CH-CH = C

S-

^X N -CH ₂ COOH XS

3-carboxymethyl-5-ftS- (3-ethyl-2 (3H) -benzothiazolylidene) -

,. . , _ττ . ,. , j _{,, ν Ί} . _Tr äthylideni-rhodanine

has been admitted. Here, X denotes the small 25 5 _ O atoms required to complete one of the following nuclei: thiazole, thiazoline, benzothiazole, naphthothia- || zol, benzoxazole, naphthoxazole, quinoline, R is a _{hydrogen A 7} S C material atom or an alkyl, for example a methyl or ethyl group, Y to complete a
of the following nuclei required atoms: rhodanine, 30
Thiohydantoin, 2-thiooxazoldione, and R 'is an alkyl,
for example a methyl or ethyl group. ^ - ^ CH ₉

Examples of the dyes suitable according to the invention are:

35

C = CH-C = C

^N N - C ₂ H ₅

O CS

3-Ethyl-5- (3-ethyl-2 (3 H) -benzothiazolylidene-isopropylidene) -2-thio-2,4 (3,5) -oxazoldione

= CH-CH = C

NC ₆ H ₅ CS

Il χ

CH ₂ COOH

1-Carboxymethyl-5 - [(3-ethyl-2 (3H) -benzoxazolycene) -äthyKden] -3-phenyl-2-thiohydantoin

40

45 = CH-CH =

¹ N-CHXOOH

S- CS

C ₂ H ₅

3-Carboxymethyl-5 - [/ 3- (3-ethyl-2 (3 H) -benzoxazolylidene) ethylidene] rhodanine

X = CH-CH = C

[
S.

N-CH ₂ CH ₂ SO ₃ H -CS

55

C ₂ H ₅

5 - [(3-Ethyl-2 (3 H) -benzoxazolylidene) -ethylidene] -3-j3-sulfoethyl-rhodanine CH,

C = CH -

NC ₆ H ₅

N - CH, CHo N CS

CH ₂ COOH

1-Carboxymethyl-5 - [(3-methyl-2 (3H) -thiazoKnyKden) -isopropylidene] -3-phenyl-2-thiohydantoin

CH

JCXq V_ <

= CH-CH =

-NC ₂ H ₅

N-CH ₂ COOH
CS

3Xarboxymethyl-5 - [(3-ethyl-4-methyl-2 (3H) -thiazolylidene) -ethylidene] -rhodanine

-S.

= CH-C = C

CH ₂ N-CH ₃ CH ₃ S-

10.

N-CH ₂ COOH CS

L = CH - CH = C

V "

Il
, c

CH ₂ COOH

CS

3-carboxymethyl-5 - [(3-methyl-2 (3H) -thiazolylidene) - io 3-carboxymethyl-5 - [(1-ethyl-2 (1H) -quinolylidene) -isopropylidenj-rhodanine ethylidene] rhodanine

11.

Il

, CH ₂ - CH ₂ / C-.

HC ₂ ', N-CH = CH-CH = C ^Χ Ν-

^ ρ TT ρ ττ

VyXIo L / Χίο '

3-ethyl-5- [y- (l-piperidyl) allylidene] rhodanine

12th

, CH ₂ -HC ₂ ; ' ^ N-CH = CH-CH = C

C JnLo - C χίο

C _ß H _fl -NNC ₂ H ₅
-CS

3-Ethyl-1-phenyl-5- [y- (1-piperidyl) allylidene] -2-thiohydantoin

The following examples serve to further illustrate the invention.

example 1

Several parts of a halosilver gelatin emulsion which, when cast without a sensitizing dye, showed minimal Clayden effect, were given increasing amounts of 1-carboxymethyl-5 - [(3-ethyl-2 (3 H) -benzoxazolylidene) - ethylidene] -3-phenyl-2-thiohydantoin added. The various emulsions were each cast on a blank film, dried and briefly pre-exposed (0.0001 seconds) using a high-performance flash lamp with an output of around 18,000 lumen seconds and then by means of an exposure of 30 seconds with a duration of 60 seconds , 96 cm from the emulsion arranged 1000 watt tungsten filament lamp post-exposed. The test strips were treated with the developer solution specified above for ^{2 1} _{2 minutes at 20 °.} The sensitivity loss of each of the test strips was then determined, with the following results:

35 emulsion a very useful increase in the achievable degree of desensitization can be achieved.

Example 2

A photographic layer was produced and further processed as in Example 1, but as Sensitizing dye l-carboxymethyl-5 - [(3-methyl-2 (3 H) -thiazolinylidene) isopropylidene] -3-phenyl-2-thiohydantoin was used.

The following results were achieved:

45 mg of dye
per mole of halogen silver

55

100

150

Example 3

desensitization
(Δ log E)

0.32
0.19
0.53
1.60

mg of dye Desensitization per mole of halogen silver (Δ log E) A. 0 0.32 50 0.32 100 0.43 150 0.88 B. 0 0.14 100 0.69 133 1.22 166 > 1.60

The list shows / that by using the Sensitizing dyes according to the invention developed in 70:

A photographic layer was prepared as indicated in Example 1, containing 0.2 g of that indicated there It contained sensitizing dye per mole of silver (dissolved in methylamine and alcohol). The material was under contact through a slide by means of a spaced 60.96 cm from the emulsion Electronic high-performance flash lamp (USA. trade name. "Kodatron") with a flash duration pre-exposed for about 0.0001 seconds. The material was then removed by means of a 40 watt incandescent bulb arranged 152.4 cm exposed for 20 seconds. The film was in solution for 20 seconds the following composition to a positive copy

N-methyl-p-aminophenol sulfate 2.2 g

Hydroquinone 9 g

Anhydrous sodium sulfate 96 g

Sodium carbonate anhydrous 48 g

Potassium bromide 6 g

Water to top up on 11

Example 4

A series of photographic layers were prepared as indicated in Example 1, which are as follows indicated sensitizing dyes in the indicated amounts per mole of halosilver. If the materials are exposed and further treated as in Example 1, the following results can be obtained be achieved:

mg of dye Desensitization per mole tion log E, ge dye Halogen silver measure at a Blackening from i, o No dye 0.65 1-carboxymethyl 5 - [(3-ethyl-2 (3H) - benzoxazolylidene) - ethylidene] -3-phenyl- 75 2-thiohydantoin .... 150 0.75 the same 1.10 3-carboxymethyl 5 - [^ - (3-ethyl-2 (3H) - benzoxazolylidene) - 75 ethylidene] rhodanine. 150 0.55 the same > 2.30 3-carboxymethyl 5 - [(3-methyl-2 (3H) - thiazolylidene) -iso- 75 propylidenj-rhodanine 150 0.32 the same > 2.50

The emulsions which in and of themselves are used to produce a positive reproduction of an original using the Clayden effect, as described in the examples given above, can also be produced to create a negative image, either with the exposure with the illuminating or with exposure with the low-light source (but not both). the Emulsions can be developed in the usual way. The composition of the developer solution is not critical insofar as the emulsion has the required properties, i.e. the ability has to be desensitized by the Clayden effect. The stated advantages can also can be achieved with color developers which contain the usual couplers or dye formers.

On the basis of the detailed description, the person skilled in the art is in a position at any time to understand the concept of the invention to the present circumstances and conditions.

ao to adapt.

Claims (5)

Patent claims: 1. Process for producing a direct positive image in a halogen silver emulsion with use the clayden desensitization effect, characterized in that one of a clayden desensitization accessible halogen silver emulsion layer is used, which is a dye of the formula R'N -x - or the formula C = CH-CR = C CO , CH ₂ -CH _2x HC ₂ (^ ^) N-CH = CH-CH = C CO CH ₂ - CH ₂ ν. γ ..- ' Contains, where X to complete a nucleus of the thiazole, thiazoline, benzothiazole, Naphthothiazole, benzoxazole, naphthoxazole or quinoline series required atoms, R is a hydrogen atom or an alkyl group and R 'an alkyl group and Y those to complete a nucleus of the rhodanine, thiohydantoin or 2-thiooxazolidinedione series Required atoms means and that the layer with strong illuminance and an exposure time of less than 0.01 second is exposed imagewise and then with weak Illuminance and an exposure time of more than 0.01 seconds and then evenly post-exposed is being developed. 2. The method according to claim 1, characterized in that an emulsion layer is used, the l-carboxy-methyl-5 - [(3-ethyl-2 (3H) -benzoxazolylidene) - ethylidene] - 3 - phenyl - 2 - thiohydantoin. 3. The method according to claim 1, characterized in that an emulsion is used which contains 3-carboxy - methyl - 5 - [β - (3 - ethyl - 2 (3 H) - benzoxazolylidene) ethylidene] rhodanine. 4. The method according to claim 1, characterized in that an emulsion is used, the 1 - carboxy - methyl - 5 - [(3 - methyl - 2 (3H) - thiazolinylidene) - isopropylidene] - 3 - phenyl-2 - thiohydantoin. 5. The method according to claim 1, characterized in that an emulsion is used which 3-carboxymethyl-5 - [(3-methyl-2 (3 H) -thiazolylidene) isopropylidene] rhodanine. A priority document was displayed when the registration was announced.